***PAIN
Science Volume 302, Number 5643,
Does Rejection Hurt? An fMRI Study of Social Exclusion
Naomi I. Eisenberger,1* Matthew D. Lieberman,1 Kipling D.
Williams2
A neuroimaging
study examined the neural correlates of social exclusion and tested the
hypothesis that the brain bases of social pain are similar to those of physical
pain. Participants were scanned while playing a virtual ball-tossing game in
which they were ultimately excluded. Paralleling results from physical pain
studies, the anterior cingulate cortex (ACC) was more active during exclusion
than during inclusion and correlated positively with self-reported distress.
Right ventral prefrontal cortex (RVPFC) was active during exclusion and
correlated negatively with self-reported distress. ACC changes mediated the
RVPFC-distress correlation, suggesting that RVPFC regulates the distress of
social exclusion by disrupting ACC activity.
Psychosomatic Medicine 65:276-283 (2003)
Social Support and Experimental Pain
Jennifer L. Brown, MA, David Sheffield, PhD, Mark R.
Leary, PhD and Michael E. Robinson, OBJECTIVE:
The purpose of this experimental study was to supplement and expand on clinical
research demonstrating that the provision of social support is associated with
lower levels of acute pain. METHODS:
Undergraduates (52 men and 49 women) performed the cold pressor task either
alone or accompanied by a friend or stranger who provided active support,
passive support, or interaction. Pain perception was measured on a 10-point
scale.
RESULTS: Participants in the active support and passive
support conditions reported less pain than participants in the alone and
interaction conditions, regardless of whether they were paired with a friend or
stranger. CONCLUSIONS: These data
suggest that the presence of an individual who provides passive or active
support reduces experimental pain.
Journal of Rehabilitation
Research and Development Vol. 40, No. 5, Sept/Oct 2003 Pages 397–
An examination of the
relationship between chronic pain and post-traumatic stress disorder
John D. Otis, PhD; Terence
M. Keane, PhD; Robert D. Kerns, PhD
Abstract—Chronic
pain and post-traumatic stress disorder (PTSD) are frequently observed within
the Department of Veterans Affairs healthcare system and are often associated
with a significant level of affective distress and physical disability.
Clinical practice and research suggest that these two conditions co-occur at a
high rate and may interact in such a way as to negatively impact the course of
either disorder; however, relatively little research has been conducted in this
area. This review summarizes the current literature pertaining to the
prevalence and development of chronic pain and PTSD. Research describing the
comorbidity of both conditions is reviewed, and several theoretical models are
presented to explain the mechanisms by which these two disorders may be
maintained. Future directions for research and clinical implications are
discussed.
British Medical Bulletin 65:223-234 (2003)
Headache: lessons learned from functional imaging
Arne May
Department of Neurology,
Most
idiopathic headache syndromes are still recognized as vascular headaches
although the clinical picture points towards a central triggering cause. The
early functional imaging work using PET shed light on the genesis of some
syndromes, implying that the observed activation in migraine (brainstem) and in
cluster headache (hypothalamic grey) is involved in the pain process in a
permissive or triggering manner rather than simply as a response to first
division nociception per se. Using the advanced method of voxel-based
morphometry (VBM), it has been suggested that there is a correlation between
the brain area activated particularly in acute cluster headache, the posterior
hypothalamic grey matter, and some change in grey matter in the same region.
Moreover, also in a PET study in cluster headache and experimental headache, a
vasodilation of major basal vessels has been observed which is non-specific to
the cause and most likely the effect of a trigemino-parasympathetic reflex. Taken
together, functional neuroimaging in headache patients has revolutionised this
area of study and provided unique insights into some of the commonest maladies
in man, suggesting that migraine and cluster headache are primarily driven from
the brain.
NeuroImage
Volume 19, Issue 3 , July 2003, Pages 655-664
Pain modulates cerebral activity during cognitive
performance
a MR Technology, Institute for Biodiagnostics, National
Research Council,
Received
Journal of Clinical Psychology
Early View
(Articles online in advance of print)
Stressful events, appraisal, coping and recurrent
headache
Nicholas Marlowe *
Prince Henry
One
hundred fourteen headache sufferers recorded their headaches, stressful events,
appraisal processes, and coping responses over a 28 day period. Stressful
events were found to precede headache attacks more often than periods of
headache freedom. Primary appraisals (how much the event mattered), levels of
affective regulation coping and ratings of emotional upset were all higher for
stressful events that were not associated with subsequent headache. Stressful
events occurring during headache were followed by increases in the intensity of
the attack. In such instances, avoidance coping was associated with higher
ratings of headache intensity following the event and direct coping with lower
post-event ratings. It was concluded that stressful events may be causally
related to headache and that the ways in which headache sufferers respond to
these events may also have implications for the onset and intensity of attack
Cephalalgia. 2003;23 Suppl 1:1-4.
Peripheral and central activation of trigeminal pain
pathways in migraine: data from experimental animal models.
Buzzi MG, Tassorelli C, Nappi G.
IRCCS Neuromed,
EEG-studies
in migraine in the last decade has contributed modestly to the understanding of
headache pathogenesis. Headache patient groups seem to have increased EEG
responses to photic stimulation, but a useful biological marker for migraine in
single patients has not been found. In future EEG and QEEG studies we
recommend to use follow-up designs and record several EEGs across the migraine
cycle. It is also important to use a blinded study design in order to avoid
selection bias. A clinical EEG should be performed in patients with
acute headache attacks when either epilepsy, basilar migraine, migraine with
prolonged aura or alternating hemiplegia is suspected. Unequivocal
epileptiform abnormalities usually suggest a diagnosis of epilepsy. In children
with occipital spike-wave activity the probable diagnosis is childhood epilepsy
with occipital paroxysms (CEOP). The final diagnosis of either an epilepsy
syndrome or migraine must be mainly based on a clinical judgement.
Clinical Neurophysiology
Article in Press, Corrected Proof - Note to users
Short-term plastic changes of the human nociceptive
system following acute pain induced by capsaicin
Massimiliano Valeriani, , a, b, Lars Arendt-Nielsenc,
Domenica Le Peraa, d, Domenico Restucciaa, Tiziana Rossoe, Liala De Armasa, d,
Toni Maiesea, Antonio Fiaschie, Pietro Tonalia and Michele Tinazzie
Objective: To investigate possible neuroplastic changes
induced by pain in cerebral areas devoted to nociceptive input processing.
Methods: CO2 laser-evoked potentials (LEPs) were recorded
from 10 healthy subjects after stimulation of the right and left hand dorsum.
Acute pain was obtained by topical application of capsaicin on the skin of
right hand dorsum. LEPs were recorded after right and left hand stimulation
before capsaicin, at the peak pain and 10–20 min after capsaicin removal. Right
hand LEPs were evoked by laser stimuli delivered over the zone of secondary
hyperalgesia during capsaicin and on both the zones of primary and secondary
hyperalgesia after capsaicin removal.
Results: After right hand stimulation, the vertex LEPs,
which are generated in the cingulate cortex, were significantly decreased in
amplitude during capsaicin application and after capsaicin removal. Moreover,
the topography of these potentials was modified after capsaicin removal,
shifting from the central toward the parietal region. Dipolar modelling showed
that the dipolar source in the anterior cingulate cortex moved backward after
capsaicin removal. All these changes were not observed after stimulation of the
left hand, contralateral to the application of capsaicin, thus suggesting that
functional changes are selective for the painful skin and the adjacent
territories. Conclusions: Our results suggest that acute cutaneous pain may
inhibit the neural activity in regions of central nervous system processing
nociceptive inputs and cortical representation of these inputs can be rapidly
modified in presence of acute pain.
Clinical Neurophysiology
Volume 114, Issue 8 , August 2003, Pages 1497-1506
The disruptive effect of chronic pain on mismatch
negativity
B. D. Dick, , J. F. Connolly, P. J. McGrath, G. A. Finley,
G. Stroink, M. E. Houlihan and A. J. Clark
Objective:
To investigate the effect of chronic pain on processes that generate the
mismatch negativity (MMN).
Methods:Twelve participants with a diagnosis of chronic
intractable pain were tested before and after pain treatment. During testing,
event-related potentials were recorded while participants performed tasks of
varying difficulty.
Results: The amplitude of the MMN was found to be greater
following a nerve block procedure compared to MMN amplitude when participants
were experiencing chronic pain. This effect was found to occur in the MMN for
difficult-to-detect tones elicited while participants were performing a
simultaneous cognitively demanding visual task. MMN amplitude was found to be
greater with attention to difficult-to-detect deviants during pain but not in
no pain conditions.
Conclusions: These results provide an
electrophysiological correlate of previous findings that high levels of pain
disrupt cognition during the performance of demanding tasks.
Annual Review of Neuroscience
Mar 2003, Vol. 26, pp. 1-30
PAIN MECHANISMS: Labeled Lines Versus Convergence in
Central Processing
A.D. (Bud) Craig
Atkinson Pain Research Laboratory, Barrow Neurological
Institute,
The issue of whether pain is represented by specific
neural elements or by patterned activity within a convergent somatosensory
subsystem has been debated for over a century. The gate control theory
introduced in 1965 denied central specificity, and since then most authors have
endorsed convergent wide-dynamic-range neurons. Recent functional and
anatomical findings provide compelling support for a new perspective that views
pain in humans as a homeostatic emotion that integrates both specific labeled
lines and convergent somatic activity.
Pain Med. 2003 Jun;4(2):141-81.
A structured evidence-based review on the meaning of nonorganic
physical signs: Waddell signs.
Fishbain DA, Cole B, Cutler RB, Lewis J, Rosomoff HL,
Rosomoff RS.
Department of Psychiatry,
STUDY
DESIGN: This is a structured, evidence-based review of all available studies
addressing the concept of nonorganic findings: Waddell signs (WSs). OBJECTIVES:
To determine what evidence, if any, exists for the various interpretations for
the presence of WSs on physical examination. SUMMARY OF BACKGROUND DATA: WSs
are a group of eight physical findings divided into five categories, the
presence of which has been alleged at times to have the following
interpretations: Malingering/secondary gain, hysteria, psychological distress,
magnified presentation, abnormal illness behavior, abnormal pain behavior, and
somatic amplification. At the present time, there is, therefore, significant
confusion as to what these findings mean. METHODS: A computer and manual
literature search produced 61 studies and case series reports relating to WSs.
These references were reviewed in detail, sorted, and placed into tabular form
according to the following subject areas: 1) Reliability (test-retest); 2)
Reliability (inter-rater); 3) Reliability (factor analysis); 4) Validity,
psychological distress; 5) Validity, correlation Minnesota Multiphasic Pain
Inventory (MMPI); 6) Validity, correlation abnormal illness behavior; 7)
Validity, other behaviors; 8) Validity, as a nonorganic phenomenon; 9)
Validity, correlation pain drawing; 10) Validity, functional performance; 11)
Validity, treatment outcome; 12) Validity, predicting surgical treatment
outcome; 13) Validity, return to work outcome; 14) Validity, secondary gain
correlation; and 15) Validity, pain correlation. Each study in each topic area
was classified according to the type of study it represented according to the
type of evidence guidelines developed by the Agency for Health Care Policy and
Research (AHCPR). In addition, a list of 14 study quality criteria was used to
measure the quality of each study. Each study was categorized for each
criterion as positive, (criterion filled), negative (criterion not filled), or
not applicable independently by two of the authors. A percent quality score was
obtained for each study by counting the total number of positives obtained,
dividing by 14 minus the total number of not applicables, and multiplying by
100. Only studies having a quality score of 75% or greater were used to
formulate the conclusions of this review. The strength and consistency of the
evidence represented by the remaining studies in each topic area (above) was
then categorized according to the strength and consistency AHCPR guidelines.
Conclusions of this review for each topic area are based on these results. RESULTS
OF DATA SYNTHESIS: Of the 61 studies, four had quality scores below 75% and
were not used to generate the results of this review. According to the AHCPR
guidelines for strength and consistency of the reviewed data, the following
results were obtained: 1) There was consistent evidence for WSs being
associated with decreased functional performance, poor nonsurgical treatment
outcome, and greater levels of pain; 2) There was generally consistent evidence
for WSs not being associated with psychological distress, abnormal illness
behavior, or secondary gain; 3) There was also generally consistent evidence
that WSs are an organic phenomenon and that they cannot be used to discriminate
organic from nonorganic problems; 4) There was inconsistent evidence that WSs
do demonstrate inter-rater reliability, do not correlate with the neurotic
triad of the MMPI, are associated with poorer surgical treatment outcome, and
are associated with nonreturn to work; 5) There was little or no evidence that
WSs demonstrate test-retest reliability, or reliable factors, and are
associated with self-esteem problems, catastrophizing, or the nonorganic pain
drawing. CONCLUSIONS: Based on the above results, the following conclusions
were made: 1) WSs do not correlate with psychological distress; 2) WSs do
not discriminate organic from nonorganic problems; 3) WSs may represent an
organic phenomenon; 4) WSs are associated with poorer treatment outcome; 5) WSs
are associated with greater pain levels; 6) WSs are not associated with secondary
gain; and 7) As a group, WS studies demonstrate some methodological problems.
Journal of Pain and Symptom Management
Volume 26, Issue 2 , August 2003, Pages 769-775
Hyperalgesia: An Emerging Iatrogenic Syndrome
Sebastiano Mercadante MD, Patrizia Ferrera MD, Patrizia
Villari MD and Edoardo Arcuri MD
Clinical reports suggest that opioids, intended to abolish
pain, can unexpectedly produce hyperalgesia. This paradoxical effect may be
mechanistically related to tolerance induced by increasing doses of opioids.
Two case reports illustrate a syndrome characterized by increasing pain pursued
by escalating opioid doses, which results in a worsening of the clinical
picture. Several experimental data may help explain the course of this
challenging clinical condition. In escalating opioid doses rapidly, a risk
of opioid-induced hyperalgesia should be recognized, as higher doses of opioids
may stimulate rather than inhibit the central nervous system by different
mechanisms. Alternative procedures should be taken into consideration to break
this cycle, should it occur. More data are needed to detect this condition,
as currently no diagnostic information on specific markers, clinical or
biochemical, exists.
Pain
Article in Press, Corrected Proof - Note to users
Preoperative prediction of severe postoperative pain
C. J. Kalkman, , a, K. Visserb, J. Moena, G. J. Bonselc,
D. E. Grobbeed and K. G. M. Moonsa, d
We
developed and validated a prediction rule for the occurrence of early
postoperative severe pain in surgical inpatients, using predictors that can be
easily documented in a preoperative setting. A cohort of surgical inpatients
(n=1416) undergoing various procedures except cardiac surgery and intracranial
neurosurgery in a
Pain
Volume 104, Issue 3 , August 2003, Pages 509-517
Sensory hypersensitivity occurs soon after whiplash
injury and is associated with poor recovery
Michele Sterling, , a, Gwendolen Julla, Bill Vicenzinoa
and Justin Kenardyb
Hypersensitivity
to a variety of sensory stimuli is a feature of persistent whiplash associated
disorders (WAD). However, little is known about sensory disturbances from the
time of injury until transition to either recovery or symptom persistence.
Quantitative sensory testing (pressure and thermal pain thresholds, the
brachial plexus provocation test), the sympathetic vasoconstrictor reflex and
psychological distress (GHQ-28) were prospectively measured in 76 whiplash subjects
within 1 month of injury and then 2, 3 and 6 months post-injury. Subjects were
classified at 6 months post-injury using scores on the Neck Disability Index:
recovered (<8), mild pain and disability (10–28) or moderate/severe pain and
disability (>30). Sensory and sympathetic nervous system tests were also
measured in 20 control subjects. All whiplash groups demonstrated local
mechanical hyperalgesia in the cervical spine at 1 month post-injury. This
hyperalgesia persisted in those with moderate/severe symptoms at 6 months but
resolved by 2 months in those who had recovered or reported persistent mild
symptoms. Only those with persistent moderate/severe symptoms at 6 months
demonstrated generalised hypersensitivity to all sensory tests. These changes
occurred within 1 month of injury and remained unchanged throughout the study
period. Whilst no significant group differences were evident for the
sympathetic vasoconstrictor response, the moderate/severe group showed a
tendency for diminished sympathetic reactivity. GHQ-28 scores of the
moderate/severe group were higher than those of the other two groups. The
differences in GHQ-28 did not impact on any of the sensory measures. These
findings suggest that those with persistent moderate/severe symptoms at 6 months
display, soon after injury, generalised hypersensitivity suggestive of changes
in central pain processing mechanisms. This phenomenon did not occur in those
who recover or those with persistent mild symptoms.
PAIN. In Press
Hyperalgesia
versus response bias in fibromyalgia
Roger B. Fillingim*
Excerpt...
The findings of Petzke et al. (2003) further indicate that
individuals with FM process nociceptive information differently than controls.
There are inevitably multiple biopsychosocial factors that interact in complex
ways to produce these alterations in pain sensitivity. The results of their
research suggest that measures of pain sensitivity that are freer of response
bias still demonstrate enhanced pain responses in FM. The mechanisms underlying
the enhanced pain responses of FM patients remain to be determined, but the
careful and systematic research described by Petzke et
al.(2003) informs us that the enhanced pain sensitivity in FM is not an
artifact of response bias. A more thorough understanding of the hyperalgesia
observed in FM will help elucidate its pathophysiology, ultimately leading to
more effective diagnosis and treatment of this complex and disabling syndrome.
Curr Pain Headache Rep. 2003 Oct;7(5):362-8.
Related Articles, Links
Epidemiology of fibromyalgia.
Neumann L, Buskila D.
Department of Epidemiology, Faculty of Health Sciences,
Ben-Gurion University of the Negev, Beer Sheva, Israel. lily@bgumail.bgu.ac.il
Chronic
widespread pain, the cardinal symptom of fibromyalgia (FM), is common in the
general population, with comparable prevalence rates of 7.3% to 12.9% across
different countries. The prevalence of FM in the general population was
reported to range from 0.5% to 5% and up to 15.7% in the clinic. The common
association of FM with other rheumatic disorders, chronic viral infections, and
systemic illnesses has been well documented in several studies. Up to 65% of
patients with systemic lupus erythematosus meet the criteria for FM. FM is
considered a member of the family of functional somatic syndromes. These
syndromes are very common and share a similar phenomenology, epidemiologic
characteristics, high rates of occurrence, a common pathogenesis, and similar
management strategies. A high prevalence of FM was demonstrated among
relatives of patients with FM and it may be attributed to genetic and
environmental factors.
Pain. 2003 Aug;104(3):665-72.
The effect of combined therapy (ultrasound and
interferential current) on pain and sleep in fibromyalgia.
Almeida TF, Roizenblatt S, Benedito-Silva AA, Tufik S.
Multidisciplinary
treatment has proven to be the best therapeutic option to fibromyalgia (FM) and
physiotherapy has an important role in this approach. Considering the
controversial results of electrotherapy in this condition, the aim of this
study was to assess the effects of combined therapy with pulsed ultrasound and
interferential current (CTPI) on pain and sleep in FM. Seventeen patients
fulfilling FM criteria were divided into two groups, CTPI and SHAM, and
submitted to pain and sleep evaluations. Pain was evaluated by body map (BM) of
the painful areas; quantification of pain intensity by visual analog scale
(VAS); tender point (TP) count and tenderness threshold (TT). Sleep was
assessed by inventory and polysomnography (PSG). After 12 sessions of CTPI or
SHAM procedure, patients were evaluated by the same initial protocol. After
treatment, CTPI group showed, before and after sleep, subjective improvement of
pain in terms of number (BM) and intensity (VAS) of painful areas (P<0.001,
both); as well as objective improvement, with decrease in TP count and increase
in TT (P<0.001, both). Subjective sleep improvements observed after CTPI
treatment included decrease in morning fatigue and in non-refreshing sleep complaint
(P<0.001, both). Objectively, PSG in this group showed decrease in sleep
latency (P<0.001) and in the percentage of stage 1 (P<0.001), increase in
the percentage of slow wave sleep (P<0.001) and in sleep cycle count
(P<0.001). Decrease in arousal index (P<0.001), number of sleep stage
changes (P<0.05) and wake time after sleep onset (P<0.05), were also
observed and no difference regarding pain or sleep parameters were verified
after SHAM procedure. This study shows that CTPI can be an effective therapeutic
approach for pain and sleep manifestations in FM.
NeuroImage
Volume 19, Issue 4 , August 2003, Pages 1738-1747
Functional activity mapping of the mesial hemispheric
wall during anticipation of pain
Carlo A. Porro, , a, Valentina Cettoloa, Maria Pia
Francescatoa and Patrizia Baraldib
The
relative contributions of autonomic arousal and of cognitive processing to
cortical activity during anticipation of pain, and the role of changes in
thalamic outflow, are still largely unknown. To address these issues, we
investigated with functional magnetic resonance imaging (fMRI) the activity of
the contralateral mesial hemispheric wall in 56 healthy volunteers while they
expected the stimulation of one foot, which could be either painful or
innocuous. The waiting period was characterized by emotional arousal, a
moderate rise in heart rate, and by increases in mean fMRI signals in the
medial thalamus, mid- and posterior cingulate cortex, and in the putative foot
area of the primary somatosensory and motor cortex. The same brain regions,
excepting posterior cingulate, were also activated by somatosensory
stimulation. We identified by cross-correlation analysis a cluster population
whose fMRI signal time course was related to the mean heart rate (HR) profile,
showing selective changes of activity during the waiting period. Positively
correlated clusters were found mainly in sensorimotor areas, mid- and posterior
cingulate, and dorsomedial prefrontal cortex. Negatively correlated clusters
predominated in the perigenual anterior cingulate and ventromedial prefrontal
cortex. HR clusters had different characteristics from, and showed limited
spatial overlap with, clusters whose fMRI signals were related to the
psychophysical pain intensity profile; however, both cluster populations were
affected by anticipation. These findings unravel a complex pattern of brain
activity during uncertain anticipation of noxious input, likely related both to
changes in the level of arousal and to cognitive modulation of the pain system.
Rheumatology 2003; 42: 959-968
Risk factors for new-onset low back pain amongst
cohorts of newly employed workers
E. F. Harkness1,, G. J. Macfarlane1,2, E. S. Nahit1,2, A.
J. Silman1 and J. McBeth1
Objectives.
To test the hypothesis that work-related mechanical, psychosocial and physical
environment factors would predict new-onset low back pain (LBP) in newly
employed workers. Methods. A total of
1186 newly employed workers were recruited from a variety of occupational
settings. Those who were free from LBP at baseline were identified. Subjects
were followed up at 12 and 24 months. Work-related mechanical, psychosocial and
physical environment exposures were measured. Generalized estimating equations
were used to assess predictors of new-onset LBP. Results. New-onset LBP was reported by 119
(19%) and 81 (19%) subjects at 12 and 24 months, respectively. Several
work-related mechanical exposures predicted new-onset LBP including lifting
heavy weights with one or two hands, lifting heavy weights at or above shoulder
level, pulling heavy weights, kneeling or squatting for 15 min or longer. Of
the psychosocial factors examined, stressful and monotonous work significantly
predicted symptom onset. In addition, hot working conditions and pain at other
sites also predicted new-onset LBP. On multivariate analysis these risks were
only moderately attenuated but the 95% confidence intervals excluded unity only
for the latter, non-mechanical, exposures.
Conclusion. In this cohort of newly employed workers, from a range of
occupations, several aspects of the work-place environment, other than
mechanical factors, were important in predicting new-onset LBP. These results
emphasize that interventions aimed at reducing the occurrence of LBP are likely
to be most successful if they intervene across these domains.
Central Sensitization in Fibromyalgia and Other
Musculoskeletal Disorders
Lars Arendt-Nielsen PhD and Thomas Graven-Nielsen PhD
Laboratory for Human Experimental Pain Research, Fredrik
Bajers Vej 7 Building D3, Center for -Sensory-Motor Interaction Aalborg
University, Aalborg, DK-9220, Denmark
Current Pain and Headache Reports 2003 7:355-361
(published 1 October 2003)
Muscle
hyperalgesia and referred pain play an important role in chronic
musculoskeletal pain. New knowledge on the involved basic mechanisms and better
methods to assess muscle pain in the clinic are needed to revise and optimize
treatment regimens. Increased muscle sensitivity is manifested as pain
evoked by a normally non-nociceptive stimulus (allodynia), increased pain
intensity evoked by nociceptive stimuli (hyperalgesia), or increased referred
pain areas with associated somatosensory changes. Some manifestations of
sensitization, such as expanded referred muscle pain areas in patients with chronic
musculoskeletal pain, can be explained from animal experiments showing
extrasegmental spread of sensitization. An important part of the pain
manifestations (eg, tenderness and referred pain) related to chronic
musculoskeletal disorders may result from peripheral and central sensitization,
which may play a role in the transition from acute to chronic pain.
Fibromyalgia, Hepatitis C Infection, and the Cytokine
Connection
Mollie E Thompson MD and André Barkhuizen MD
Division of Arthritis and Rheumatic Diseases, 3181 Sam
Jackson Park Road OP-09, Oregon Health Science University, Portland, OR, 97239,
USA
Current Pain and Headache Reports 2003 7:342-347
(published 1 October 2003)
Fibromyalgia
and chronic hepatitis C infection share many clinical features including
prominent somatic complaints such as musculoskeletal pain and fatigue. There is
a growing body of evidence supporting a link between cytokines and somatic
complaints. This review discusses alterations of cytokines in fibromyalgia,
including increased serum levels of interleukin (IL)-2, IL-2 receptor, IL-8,
IL-1 receptor antagonist; increased IL-1 and IL-6 produced by stimulated
peripheral blood mononuclear cell in patients with FM for longer than 2 years;
increased gp130, which is a neutrophil cytokine transducing protein; increased
soluble IL-6 receptor and soluble IL-1 receptor antagonist only in patients
with fibromyalgia who are depressed; and IL-1 ß, IL-6, and TNF-a by reverse
transcriptase-polymerase chain reaction in skin biopsies of some patients with
fibromyalgia. In addition, this review describes the mechanism by which
alterations in cytokines in fibromyalgia and chronic hepatitis C infection can
produce hyperalgesia and other neurally mediated symptoms through the presence
of cytokine receptors on glial cells and opiate receptors on lymphocytes and
theinfluence of cytokines on the hypothalamus-pituitary-adrenal axis such as
IL-1, IL-6, and TNF-a activating and IL-2 and IFN-a down-regulating the HPA axis,
respectively. The association between chronic hepatitis C infection and
fibromyalgia is discussed, including a description of key cytokine changes in
chronic hepatitis C infection. Future studies are encouraged to further
characterize these immunologic alterations with potential pathophysiologic and
therapeutic implications.
J Negat Results Biomed. 2003 Aug 23;2(1):4.
Prospective Epidemiological Observations on the Course
of the Disease in Fibromyalgia Patients.
Noller V, Sprott H.
Department of Rheumatology and Institute of Physical
Medicine, University Hospital Zurich, Switzerland. haiko.sprott@usz.ch
OBJECTIVES:
The aim of the study was to carry out a survey in patients with fibromyalgia
(FM), to examine their general health status and work incapacity
(disability-pension status), and their views on the effectiveness of therapy
received, over a two-year observation period. METHODS: 48 patients diagnosed
with FM, according to the American College of Rheumatology (ACR) criteria, took
part in the study. At baseline, and on average two years later, the patients
underwent clinical investigation (dolorimetry, laboratory diagnostics, medical
history taking) and completed the Fibromyalgia questionnaire (Dettmer and
Chrostek 1). RESULTS: 27/48 (56%) patients participated in the two-year
follow-up. In general, the patients showed no improvement in their symptoms
over the observation period, regardless of the type of therapy they had
received. General satisfaction with quality of life improved, as did satisfaction
regarding health status and the family situation, although the degree of pain
experienced remain unchanged. In comparison with the initial examination, there
was no change in either work-capacity or disability-pension status.
CONCLUSIONS: The FM patients showed no improvement in pain, despite the many
various treatments received over the two-year period. The increase in general
satisfaction over the observation period was believed to be the result of
patient instruction and education about the disease. To what extent a
population of patients with FM would show similar outcomes if they did not
receive any instruction/education about their disorder, cannot be ascertained
from the present study; and, indeed, the undertaking of a study to investigate
this would be ethically questionable. As present, no conclusions can be made
regarding the influence of therapy on the primary and secondary costs
associated with FM.
Nordic Journal of Psychiatry
Volume 57, Number 1 / 2003, 61 - 66
Chronic pain disorder associated with psychogenic
versus somatic factors: A comparative study. Michael Binzer, Michael
Binzer, Michael Binzer
Fifty-one
consecutive non-depressed patients with chronic pain referred to a
multidisciplinary pain clinic were assessed. In 32 patients, pain was judged
to be associated with psychogenic factors only, while pain in 19 patients could
be attributed solely to a general medical condition. The methods of
investigation comprised visual analogue scales (VAS) and pain drawings, the
Dysfunctional Attitude Scale (DAS), the Karolinska Scales of Personality (KSP),
locus of control (LOC) and EMBU (for assessing perceived parental rearing
practices). Mean age, gender distribution, analgesic consumption, pain
duration, percentage of body area pain as well as body localization of pain
were comparable in both groups. Patients with psychogenic pain reported higher
levels of general bodily discomfort but less concentration difficulties and
memory disturbances compared with the somatic pain patients. There were no
significant intergroup differences on any of the LOC, DAS, KSP or EMBU items.
LOC turned out to be extremely external, whereas DAS, KSP and EMBU scores were
comparable to normal controls in earlier work. The paucity of differences
between the two patient groups and the unremarkable personality structure of
patients led to somewhat conflicting conclusions, and the results of the study
pose one more piece of evidence for the futility of the dichotomous organic vs.
psychogenic distinction of chronic pain disorders.
Psychological Bulletin
Volume 129(4) July 2003 p 495–521
Hypnosis and Clinical Pain
Patterson, David R; Jensen, Mark P.
Hypnosis
has been demonstrated to reduce analogue pain, and studies on the mechanisms of
laboratory pain reduction have provided useful applications to clinical
populations. Studies showing central nervous system activity during hypnotic
procedures offer preliminary information concerning possible physiological
mechanisms of hypnotic analgesia. Randomized controlled studies with
clinical populations indicate that hypnosis has a reliable and significant
impact on acute procedural pain and chronic pain conditions. Methodological
issues of this body of research are discussed, as are methods to better
integrate hypnosis into comprehensive pain treatment.
Annual Review of Neuroscience, Jul 2003, Vol. 26, pp. 1-30
PAIN MECHANISMS: Labeled Lines Versus Convergence in
Central Processing
A.D. (Bud) Craig; bcraig@chw.edu
The issue
of whether pain is represented by specific neural elements or by patterned
activity within a convergent somatosensory subsystem has been debated for over
a century. The gate control theory introduced in 1965 denied central
specificity, and since then most authors have endorsed convergent
wide-dynamic-range neurons. Recent functional and anatomical findings provide
compelling support for a new perspective that views pain in humans as a
homeostatic emotion that integrates both specific labeled lines and convergent
somatic activity.
Annual Review of Pharmacology and Toxicology, In Press
Voltage-Gated Sodium Channels and Hyperalgesia
Josephine Lai, Frank Porreca, John C. Hunter, Michael S.
Gold
Abstract Physiological and pharmacological evidence have demonstrated
a critical role for voltage-gated sodium channels (VGSCs) in many types of
chronic pain syndromes because these channels play a fundamental role in the
excitability of neurons in the central and peripheral nervous systems.
Alterations in function of these channels appear to be intimately linked to
hyperexcitability of neurons. Many types of pain appear to reflect neuronal
hyperexcitability, and importantly, use-dependent sodium channel blockers are
effective in the treatment of many types of chronic pain. This review focuses
on the role of VGSCs in the hyperexcitability of sensory primary afferent
neurons and their contribution to the inflammatory or neuropathic pain states.
The discrete localization of the tetrodotoxin (TTX)-resistant channels, in
particular NaV1.8, in the peripheral nerves may provide a novel opportunity for
the development of a drug targeted at these channels to achieve efficacious
pain relief with an acceptable safety profile.
Rheumatology, In Press
The role of workplace low-level mechanical trauma,
posture and environment in the onset of chronic widespread pain
J. McBeth*, E. F. Harkness, A. J. Silman, and G. J.
Macfarlane; john.mcbeth@man.ac.uk.
Background.
We have recently demonstrated that individual psychosocial factors are
important predictors of the onset of chronic widespread pain. It has been
hypothesized that excessive mechanical exposure may also be associated with
symptom onset, although this has not been formally examined. We therefore
determined the relative contributions of individual psychosocial and
work-related mechanical, posture and environment factors in symptom onset.
Methods. We conducted a population-based prospective
survey and identified 1658 adults aged 18-65 yr who were symptom-free. At
baseline, detailed information was obtained on work-related mechanical and
environment factors using validated instruments. Individual psychosocial
features were also measured. Subjects free of chronic widespread pain at
baseline were followed up at 12 and 36 months to identify those reporting the
onset of new symptoms.
Results. In all, 1445 (91%) returned the questionnaire at
12 months and 978 (89%) at 36 months. Of these, 81 and 92 respectively reported
new chronic widespread pain. Symptom onset was predicted by workplace factors
{pushing/pulling heavy weights [relative risk (RR) = 1.8, 95% confidence
interval (CI) 1.1, 3.0]; repetitive movements of the wrists (RR = 1.8, 95% CI
1.2, 2.7); kneeling (RR = 2.2, 95% CI 1.2, 4.1)} and individual factors
[aspects of illness behaviour (RR = 2.9, 95% CI 1.6, 5.3); somatic symptoms (RR
= 1.9 95% CI 1.1, 3.3); fatigue (RR = 1.9, 95% CI 1.2, 3.1); baseline pain
symptoms (RR = 2.5, 95% CI 1.6, 3.9)]. In multivariate analysis,
pushing/pulling heavy weights, repetitive wrist movements, kneeling and other
pain at baseline were associated with new-onset chronic widespread pain.
However, the strongest predictor was a high score on the illness behaviour
scale. Conclusion. This study provides only limited support for the
hypothesis that low-level mechanical injury may be a risk factor for developing
chronic widespread pain. The onset of chronic widespread pain appears to be
multifactorial and is strongly predicted by individual psychosocial factors
Rheumatology, In Press
Does psychological vulnerability determine health-care
utilization in fibromyalgia?
P. L. Dobkin, M. De Civita, S. Bernatsky, H. Kang, and M.
Baron; patricia.dobkin@mcgill.ca.
Objectives.
Patients with fibromyalgia (FM) undergo multiple testing and referral to specialists,
and often use complementary/alternative medicine (CAM) services. The objectives
of the study were: (i) to document health service utilization, and (ii) to
examine whether psychological vulnerability was associated with visits to
physicians and CAM providers. Methods. Women (N = 178) with a diagnosis of
primary FM completed a psychosocial test measuring pain, perceived stress,
global psychological distress, sexual abuse history, co-morbidity and
disability due to FM. Subjects also completed a health services questionnaire,
documenting visits to physicians and CAM providers during the previous 6
months. Psychological vulnerability was operationalized as obtaining high
scores on psychological distress, perceived stress and reporting at least one
abusive event. Results. The average number of visits was 7.2 to physicians
and 11.3 to CAM providers. Conclusions. The number of physician visits was
significantly associated with more co-morbidity. Psychologically vulnerable
subjects were more likely to use CAM services than those not so classified.
Rheumatology, In Press
A biopsychosocial model of pain and depression in
rheumatoid arthritis: a 12-month longitudinal study
T. Covic, B. Adamson, D. Spencer, and G. Howe:
tcovic@csu.edu.au.
Objective.
To cross-validate a biopsychosocial model using physical disability,
helplessness and passive coping to predict depression and pain in rheumatoid
arthritis (RA). Methods. Clinical and psychological measures were collected
from 157 RA patients at three time points over a period of 12 months. Path
analysis was used for cross-sectional and longitudinal prediction of depression
and pain. Results. Helplessness and passive coping were found to be
significant mediators of the relationship between the physical disability and
future depression and pain. Cross-sectionally, the predictive model could
account for 52-94% of the variance of pain and 37-71% of the variance of
depression. Longitudinally, the predictive model could explain 29-43% of the
variance of pain and 21-33% of the variance of depression. Conclusions. These
results suggest that physical disability, helplessness and passive coping have
a significant impact on the levels of pain and depression experienced by RA
patients.
Pain, Article in Press
Blood pressure but not cortisol mediates stress effects
on subsequent pain perception in healthy men and women
Mustafa al'Absi, and Karen L. Petersen
Research
has demonstrated that exposure to acute stress may attenuate pain perception.
Mechanisms of this effect in humans have not been determined. This study was
conducted to determine the extent to which psychophysiological and
adrenocortical responses to acute stress predict subsequent pain perception.
One hundred and fifty-two healthy participants (80 women) were assigned to one
of two conditions: rest followed by the cold pressor test (CPT; N=76) or stress
followed by CPT (N=76). The stress protocol consisted of a public-speaking
challenge. Participants rated their pain every 15 s during a 90-s hand CPT (0–4
°C), and they completed the short form of the McGill Pain Questionnaire.
Salivary cortisol, mood, blood pressure (BP), and impedance cardiography
measures were collected in both conditions. Women had lower BP and reported
greater pain than men in both conditions (ps<0.01). Participants in the
stress condition reported less pain during CPT than those in the rest condition
(p=0.02). Regression analyses demonstrated that the stress effect on pain
ratings was mediated by systolic BP level during stress; however, cortisol
responses did not affect this relationship. Mood changes were independent
predictors of pain. The study demonstrates that BP changes in response to
stress mediate the stress-induced attenuation of pain perception.
Experimental Neurology
Volume 184, Supplement 1 , November 2003, Pages 80-88
Insights into the pathophysiology of neuropathic pain
through functional brain imaging
Kenneth L. Casey, , a, Jürgen Lorenzb and Satoshi
Minoshimac
We
present here an example case of neuropathic pain with heat allodynia as a major
symptom to illustrate how the functional imaging of pain may provide new
insights into the pathophysiology of painful sensory disorders. Tissue injury
of almost any kind, but especially peripheral or central neural tissue injury,
can lead to long-lasting spinal and supraspinal re-organization that includes
the forebrain. These forebrain changes may be adaptive and facilitate
functional recovery, or they may be maladaptive, preventing or prolonging the
painful condition, and interfering with treatment. In an experimental model of
heat allodynia, we used functional brain imaging to show that: (1) the
forebrain activity during heat allodynia is different from that during normal
heat pain, and (2) during heat allodynia, specific cortical areas, specifically
the dorsolateral prefrontal cortex, can attenuate specific components of the
pain experience, such as affect, by reducing the functional connectivity of
subcortical pathways. The forebrain of patients with chronic neuropathic pain
may undergo pathologically induced changes that can impair the clinical
response to all forms of treatment. Functional imaging, including PET, fMRI,
and neurophysiological techniques, should help identify brain mechanisms that
are critical targets for more effective and more specific treatments for
chronic, neuropathic pain.
Pain
Volume 105, Issue 3 , October 2003, Pages 481-488
Analgesic and placebo effects of thalamic stimulation
Serge Marchand, Ron C. Kupers, M. Catherine Bushnell, and
Gary H. Duncan
Numerous
clinical studies have reported successful relief of chronic pain with sensory
thalamic stimulation. However, even with the extensive use of sensory thalamic
stimulation as a clinical tool in the relief of chronic pain, the results are
still inconsistent. This discrepancy could probably be explained by the fact
that the majority of these studies are case reports or retrospective analyses,
which have often used imprecise pain measurements that do not allow a rigorous
statistical evaluation of pain relief. None of these studies measured the
effect of stimulation on clinical pain for longer than a few hours per day,
which is an important aspect considering that clinical pain can vary over time.
Moreover, placebo controls are seldom included. In the current study, we
measured patients' pain perception at home over a 2-week period, both during
days of normal stimulation of the sensory thalamus and during days without
stimulation. Patients also came to the laboratory to assess the effects of thalamic
and placebo stimulation on clinical pain, experimental heat pain, innocuous air
puff and visual stimulation. A potential relation between the perceived
paresthesia and analgesic efficacy during thalamic and placebo stimulation was
also explored. We found that thalamic stimulation significantly affected
clinical and experimental pain perception, but that an important placebo
component also exists. On the other hand, neither thalamic nor placebo
stimulation affected air puff and visual ratings, suggesting that the effect
applies specifically to pain and hence is not caused by a general change in
attention. The level of paresthesia elicited during the placebo manipulation
was also directly correlated with the degree of placebo pain relief. These
results suggest that thalamic stimulation produces a small but significant
reduction in pain perception, but that a significant placebo effect also
exists.
Jensen, Mark P. PhD
Questionnaire Validation: A Brief Guide for Readers of
the Research Literature.[Editorial]
Clinical Journal of Pain. 19(6):345-352, November/December
2003.
Because
of the importance of pain assessment to understanding the nature and scope of
pain problems, and for testing the efficacy of pain treatments, new pain
measures are frequently developed. Research that describes the development and
evaluation of pain measures should include detailed information concerning the
validity and reliability of the measures. However, for the findings from this
research to be most useful, the consumers of this research (clinicians and
researchers who use pain measures) should understand the concepts of validity
and reliability, and the procedures used for evaluating these in pain
assessment research. The purpose of this commentary is to provide a summary of
these psychometric issues, using the study and findings of Krause and Backonja
as an illustrative example of the concepts.
Kerr, Daniel P. DPhil; Walsh, Deirdre M. DPhil; Baxter,
David DPhil
Acupuncture in the Management of Chronic Low Back Pain:
A Blinded Randomized Controlled Trial.[Article]
Clinical Journal of Pain. 19(6):364-370, November/December
2003.
Objective:
To assess the efficacy of acupuncture in the treatment of chronic low back
pain. Methods: Patients (n = 60) with chronic low back pain were recruited and
randomly allocated to either Acupuncture therapy or Placebo transcutaneous
electrical nerve stimulation (TENS) groups. Patients were treated weekly for 6
weeks, and blinded assessments were carried out pre- and post-treatment using the
McGill Pain Questionnaire (MPQ) and visual analog scales (VAS) for pain, the
Short-form 36 quality-of-life questionnaire, and a simple range of motion
measurement. A total of 46 patients completed the trial and were followed up at
6 months. Results: Analysis of results using t tests showed that in both groups
there were significant pre-post improvements for all scores, except for MPQ
scores in the Placebo-TENS group. There was no significant difference between
the 2 groups for any of the outcome measures at the end of treatment. Results
from the 6-month follow-up would suggest that the response was better in the
acupuncture group. Discussion: Further research is necessary to fully assess
the efficacy of this treatment in combating chronic low back pain using larger
sample sizes or alternative control groups.
Grabow, Theodore S. MD; Tella, Prabhav K. MBBS, MPH; Raja,
Srinivasa N. MD
Spinal Cord Stimulation for Complex Regional Pain
Syndrome: An Evidence-Based Medicine Review of the Literature.[Article]
Clinical Journal of Pain. 19(6):371-383, November/December
2003.
Objectives:
The purpose of this investigation is to assess the evidence for efficacy of SCS
in the management of pain in patients with CRPS. Methods: Search strategy:
Electronic databases such as Medline and Cochrane Library were queried using
key words such as "spinal cord stimulation," "reflex sympathetic
dystrophy (RSD)," and "complex regional pain syndrome (CRPS)."
Selection criteria: Relevant published randomized controlled trials (RCT),
cohort studies, case-control studies, case series, and case reports that
described SCS as the primary treatment modality for patients with CRPS were
eligible for inclusion. Data collection and analysis: Data extracted from
qualified studies were summarized in sections of methodology, demographics, SCS
equipment, primary and secondary outcomes, and complications. Results: Thirteen
studies using the primary search strategy and 7 studies from their reference
lists were considered. Five of these 20 studies were discarded. One RCT, 2
prospective observational, and 12 retrospective observational studies were
eventually considered. The methodological quality of all studies was poor
except for the single RCT study. Discussion: Although limited in quality and
quantity, available evidence from the examined literature suggests that SCS is
effective in the management of pain in patients with CRPS (grade B/C).
Clinically useful information extracted from the available studies is very
limited in guiding clinicians in the rational use of SCS for pain management in
CRPS patients. Future attempts to investigate the efficacy of SCS in CRPS
patients should involve methodologically robust designs such as randomized
studies that have sufficient power.
J Trauma Stress. 2003 Oct;16(5):451-7.
A preliminary examination of treatment for
posttraumatic stress disorder in chronic pain patients: a case study.
Shipherd JC, Beck JG, Hamblen JL, Lackner JM, Freeman JB.
Manualized
treatments have become popular, despite concern about their use when comorbid
diagnoses are present. In this report, the efficacy of manualized posttraumatic
stress disorder (PTSD) treatment was examined in the presence of chronic pain.
Additionally, the effect of PTSD treatment on chronic pain and additional psychiatric
diagnoses was explored. Six female patients with both PTSD and chronic pain
following motor vehicle accidents were treated for PTSD using a multiple
baseline design. The results indicate that manualized treatment for PTSD was
effective in reducing PTSD symptoms in these patients. Although there
were no changes in subjective pain, there were pain-related functional
improvements and reductions in other psychiatric diagnoses for the majority of
patients.
J Head Trauma Rehabil, Vol. 19, No. 1, pp. 2–X,
2004 (In Press).
The Problem of Pain
Keith Nicholson, PhD; Michael F. Martelli, PhD
Pain
problems, especially posttraumatic headache, are very common following head
trauma. Pain may be the most significant problem, more disabling than any brain
or other injuries, and interfering with aspects of cognition or other function.
However, posttraumatic headache and most other chronic posttraumatic pain
problems remain poorly understood. This article reviews fundamental issues that
should be considered in understanding the nature of chronic pain including the
distinction between acute and chronic pain; neurobiological distinctions between
the lateral and medial pain system; nociceptive versus neuropathic or other
central pain; sensitization effects; the widely accepted view of chronic pain
as a multidimensional subjective experience involving sensory,
motivational-affective and cognitive-behavioral components; the problem of
mind-body dualism; the role of psychosocial factors in the onset, maintenance,
exacerbation or severity of pain; plus issues of response bias and malingering.
J Head Trauma Rehabil, Vol. 19, No. 1, pp. 10–X,
2004
Psychological, Neuropsychological, and Medical
Considerations in Assessment and Management of Pain
Michael F. Martelli, PhD; Nathan D. Zasler, MD; Mark C.
Bender, PhD; Keith Nicholson, PhD
Pain is a
common yet challenging problem, particularly following traumatic injuries to
the head or neck. It is a complex, multidimensional subjective experience with
no clear or objective measures; yet it can have a significantly disabling
effect across a wide range of functions. Persisting misconceptions owing to
mind-body dualism have hampered advances in its understanding and treatment. In
this article, a conceptualization of pain informed by recent research and
derived from a more useful biopsychosocial model guides discussion of relevant
medical, psychological, and neuropsychological considerations. This pain
process model explains chronicity in terms of hyperresponsiveness and
dysregulation of inhibitory or excitatory pain modulation mechanisms. Related
neurocognitive effects of chronic pain are examined and recommendations for
minimizing its confounding effects in neuropsyhological evaluations are
offered. A biopsychosocial assessment model is presented to guide understanding
of the myriad of factors that contribute to chronicity. A brief survey of
general classes and samples of the more useful pain assessment instruments is
included. Finally, this model offers a rational means of organizing and
planning individually tailored pain interventions, and some of the most useful
pharmacologic, physical, and behavioral strategies are reviewed.
Health Psychol. 2003 Nov;22(6):592-7.
Biological and psychological factors associated with
memory function in fibromyalgia syndrome.
Sephton SE, Studts JL, Hoover K, Weissbecker I, Lynch G,
Ho I, McGuffin S, Salmon P.
Department of Psychiatry and Behavioral Sciences,
University of Louisville School of Medicine, Louisville, KY, US.
sephton@louisville.edu
Fibromyalgia
is a stress-related disorder characterized by chronic pain, memory impairment,
and neuroendocrine aberrations. With the hypothesis that biological and
psychological symptoms may underlie the cognitive problems, the relative
influences of neuroendocrine function and psychological factors on declarative
memory were examined among 50 women with fibromyalgia. This within-group
analysis controlled for age, education, pain, and relevant medications.
Neuroendocrine function and depression had significant independent associations
with memory function. Higher log-transformed mean salivary cortisol levels were
associated with better performance on both immediate and delayed visual recall
and with delayed verbal recall. Depressive symptoms were negatively associated
with verbal recall. These findings suggest that a basic disorder of endocrine
stress responses may contribute to the cognitive symptoms experienced by
fibromyalgia patients. ((c) 2003 APA, all rights reserved)
OLD
Shock-induced
hyperalgesia: IV. Generality. .
Journal of Experimental Psychology:
Animal Behavior Processes. 2001 Jul Vol 27(3) 219-238
Meagher, Mary W.; Ferguson, Adam R.; Crown, Eric D.; McLemore, Sherilyn; King,
Tamara E.; Sieve, Amy N.; Grau, James W.
Brief-moderate shock (3, 0.75
s, 1.0 mA) has opposite effects on different measures of pain, inducing
antinociception on the tail-flick test while lowering vocalization thresholds
to shock and heat (hyperalgesia) and enhancing fear conditioned by a gridshock
unconditioned stimulus (US). This study examined the generality of
shock-induced hyperalgesia under a range of conditions and explored parallels
to sensitized startle. Reduced vocalization thresholds to shock and
antinociception emerged at a similar shock intensity. Severe shocks (3, 25 s,
1.0 mA or 3, 2 s, 3.0 mA) lowered vocalization threshold to shock but increased
vocalization and motor thresholds to heat and undermined fear conditioned by a
gridshock or a startling tone US. All shock schedules facilitated startle, but
only brief-moderate shock inflated fear conditioning. The findings suggest that
brief-moderate shock enhances the affective impact of aversive stimuli, whereas
severe shocks attenuate pain.
Shock-induced hyperalgesia: III. Role of the bed
nucleus of the stria terminalis and amygdaloid nuclei.
Behavioral Neuroscience. 2000 Jun Vol
114(3) 561-573
Crown, Eric D.; King, Tamara E.; Meagher, Mary W.;
Grau, James W.
Rats
exposed to a few moderately intense (1 mA) shocks subsequently exhibit lower
vocalization thresholds to shock and thermal stimuli. They also exhibit
facilitated learning in a Pavlovian conditioning paradigm. Together, these results
suggest that shock exposure can enhance pain (hyperalgesia). The present study
examined the role of the amygdala and bed nucleus of the stria terminalis
(BNST), 2 systems that have been implicated in the induction and maintenance of
negative affective states. Experiment 1 showed that lesions of the central, but
not the basolateral, amygdala eliminate shock-induced hyperalgesia as measured
by a decrease in vocalization thresholds to shock. Experiment 2 revealed that
central nucleus lesions also prevent shock-induced sensitization of the
vocalization response to heat. Anterior, but not posterior, BNST lesions had a
similar effect.
Neuroscience & Biobehavioral Reviews
Article in Press, Corrected Proof
Descending modulation of pain
G. F. Gebhart,
Although
interest in descending modulation of spinal cord function dates back to the
time of Sherrington, the modern era began in the late 1960s when it was shown
that focal electrical stimulation in the midbrain of the rat produced analgesia
sufficient to permit surgery. From this report evolved the concept of
endogenous systems of pain modulation. Initial interest focused on descending
inhibition of spinal nociceptive processing, but we now know that descending
modulation of spinal nociceptive processing can be either inhibitory or
facilitatory. As our understanding of descending facilitatory, or
pro-nociceptive influences grows, so too has our appreciation of its potential
importance. Accumulating evidence suggests that descending facilitatory
influences may contribute to the development and maintenance of hyperalgesia
and thus contribute to chronic pain states.
Neuroscience & Biobehavioral Reviews
Article in Press, Corrected Proof
Adaptations or pathologies? Long-term changes in brain
and behavior after a single exposure to severe threat
Christoph P. Wiedenmayer, , a, b
a Department of Psychiatry, Columbia University College of
Physicians and Surgeons, 1051 Riverside Drive, Unit 40, New York, NY 10032, USA
b Division of Developmental Psychobiology, NY State
Psychiatric Institute, New York, NY 10032, USA
The
experience of a single threatening situation may alter the behavior of an
animal in a long-lasting way. Long-lasting changes in behavior have been
induced in laboratory animals to model and investigate the development and
neural substrate of human psychopathologies. Under natural conditions, however,
changes in behavior after an aversive experience may be adaptive because
behavioral modifications allow animals to adjust to a threat for extended periods
of time. In the laboratory setting, properties of the aversive situation and
the potential of the animal to respond to the threat may be altered and lead to
extensive, prolonged changes, indicating a failure in behavioral regulation. Such
long-term changes seem to be mediated by neuronal alterations in components of
the fear pathway. To understand psychopathologies, determinants of
exaggerated responsivity and the underlying molecular and neural processes have
to be analyzed in a comparative way under conditions that produce normal and
abnormal fear and anxiety.
*** PAIN®, Vol. 107 (1-2) (2004) pp. 7-15
Evidence for spinal cord hypersensitivity in chronic
pain after whiplash injury and in fibromyalgia
Borut Banic, Steen Petersen-Felix, Ole K. Andersen, Bogdan
P. Radanov, P.M. Villiger, Lars Arendt-Nielsen and Michele Curatolo:
michele.curatolo@insel.ch
Patients
with chronic pain after whiplash injury and fibromyalgia patients display
exaggerated pain after sensory stimulation. Because evident tissue damage is
usually lacking, this exaggerated pain perception could be explained by
hyperexcitability of the central nervous system. The nociceptive withdrawal
reflex (a spinal reflex) may be used to study the excitability state of spinal
cord neurons. We tested the hypothesis that patients with chronic whiplash pain
and fibromyalgia display facilitated withdrawal reflex and therefore spinal
cord hypersensitivity. Three groups were studied: whiplash (n=27), fibromyalgia
(n=22) and healthy controls (n=29). Two types of transcutaneous electrical
stimulation of the sural nerve were applied: single stimulus and five repeated
stimuli at 2 Hz. Electromyography was recorded from the biceps femoris muscle.
The main outcome measurement was the minimum current intensity eliciting a
spinal reflex (reflex threshold). Reflex thresholds were significantly lower in
the whiplash compared with the control group, after both single (P=0.024) and
repeated (P=0.035) stimulation. The same was observed for the fibromyalgia
group, after both stimulation modalities (P=0.001 and 0.046, respectively). We
provide evidence for spinal cord hyperexcitability in patients with chronic
pain after whiplash injury and in fibromyalgia patients. This can cause
exaggerated pain following low intensity nociceptive or innocuous peripheral
stimulation. Spinal hypersensitivity may explain, at least in part, pain in the
absence of detectable tissue damage.
Prolotherapy Injections, Saline Injections, and
Exercises for Chronic Low-Back Pain: A Randomized Trial
Michael J. Yelland, FRACGP, FAFMM, Paul P. Glasziou, PhD,
FRACGP, Nikolai Bogduk, MD, DSc, Philip J. Schluter, BSc(Hons), PhD, and Mary
McKernon, RN,
SPINE Volume 29, Number 1, pp 9–
Objectives.
To assess the efficacy of a prolotherapy injection and exercise protocol in
the treatment of chronic nonspecific low back pain. Design. Randomized
controlled trial with two-by-two factorial design, triple-blinded for injection
status, and single-blinded for exercise status. Setting. General practice.
Participants. One hundred ten participants with nonspecific
low-back pain of average 14 years duration were randomized
to have repeated prolotherapy (20% glucose/ 0.2% lignocaine) or normal saline
injections into tender lumbo-pelvic ligaments and randomized to perform either
flexion/extension exercises or normal activity over 6 months. Main outcome
measures: Pain intensity (VAS) and disability scores (Roland-Morris) at
2.5, 4, 6, 12, and 24 Months. Results. Follow-up was achieved in 96% at
12 months and 80% at 2 years. Ligament injections, with exercises and with
normal activity, resulted in significant and sustained reductions in pain and
disability throughout the trial, but no attributable effect was found for
prolotherapy injections over saline injections or for exercises over normal
activity. At 12 months, the proportions achieving more than 50% reduction in
pain from baseline by injection group were glucose-lignocaine: 0.46 versus
saline: 0.36. By activity group these proportions were exercise: 0.41 versus
normal activity: 0.39. Corresponding proportions for 50% reduction in
disability were glucose-lignocaine: 0.42 versus saline 0.36 and exercise: 0.36
versus normal activity: 0.38. There were no between group differences in any of
the above measures. Conclusions. In chronic nonspecific low-back pain,
significant and sustained reductions in pain and disability occur with ligament
injections, irrespective of the solution injected or the concurrent use of
exercises.
Chronic back pain and major depression in the general
Canadian population
Shawn R. Currie and JianLi Wang
Pain, Volume 107, Issues 1-2 , January 2004, Pages 54-60
Chronic
pain and depression are two of the most common health problems that health
professionals encounter, yet only a handful of epidemiological studies have
investigated the relationship between these conditions in the general
population. In the present study we examined the prevalence and correlates of
major depression in persons with chronic back pain using data from the first
cycle of Canadian Community Health Survey in a sample of 118,533 household
residents. The prevalence of chronic back pain was estimated at 9% of persons
12 years and older. Rates of major depression, determined by the short-form of
the Composite International Diagnostic Interview, were estimated at 5.9% for
pain-free individuals and 19.8% for persons with chronic back pain. The
rate of major depression increased in a linear fashion with greater pain
severity. In logistic regression models, back pain emerged as the
strongest predictor of major depression after adjusting for possible
confounding factors such as demographics and medical co-morbidity. The
combination of chronic back pain and major depression was associated with
greater disability than either condition alone, although pain severity was
found to be the strongest overall predictor of disability.
Pain, In Press, Corrected Proof
Safety and efficacy of intranasal ketamine for the
treatment of breakthrough pain in patients with chronic pain: a randomized,
double-blind, placebo-controlled, crossover study,
Daniel B. Carr, Leonidas C. Goudas, William T. Denman,
Daniel Brookoff, Peter S. Staats, Loralie Brennen, Geoff Green, Randi Albin,
Douglas Hamilton, Mark C. Rogers et al.
Few
placebo-controlled trials have investigated the treatment of breakthrough pain
(BTP) in patients with chronic pain. We evaluated the efficacy and safety of
intranasal ketamine for BTP in a randomized, double-blind, placebo-controlled,
crossover trial. Twenty patients with chronic pain and at least two spontaneous
BTP episodes daily self-administered up to five doses of intranasal ketamine or
placebo at the onset of a spontaneous BTP episode (pain intensity 5 on a 0–10
scale). Two BTP episodes at least 48 h apart were treated with either ketamine
or placebo. Patients reported significantly lower BTP intensity following
intranasal ketamine than after placebo (P<0.0001), with pain relief within
10 min of dosing and lasting for up to 60 min. No patient in the ketamine group
required his/her usual rescue medication to treat the BTP episode, while seven
out of 20 (35%) patients in placebo group did (P=0.0135). Intranasal ketamine
was well tolerated with no serious adverse events. After ketamine
administration, four patients reported a transient change in taste, one patient
reported rhinorrhea, one patient reported nasal passage irritation, and two
patients experienced transient elevation in blood pressure. A side effect
questionnaire administered 60 min and 24 h after drug or placebo administration
elicited no reports of auditory or visual hallucinations. These data suggest
that intranasal administration of ketamine provides rapid, safe and effective
relief for BTP.
Br J Anaesth. 2004 Feb; 92(2): 235-7.
Pain on medical wards in a district general hospital.
Dix P, Sandhar B, Murdoch J, MacIntyre PA.
BACKGROUND:
Little attention has been paid to pain on medical wards, with publications
limited to the management of surgical patients. We wanted to establish the
prevalence and severity of pain in the general medical setting, and how this
compared with other clinical specialties. METHODS: All consenting adult
in-patients were assessed daily for 5 days. Patients recorded the occurrence
and severity of pain, and whether their pain was bearable. The pain team
reviewed patients with unbearable pain. RESULTS: 1594 questionnaires were
completed, representing 54% of the target population. 887 patients reported
pain, 17% with pain scores over 6, and 10% with unbearable pain. The
distribution of pain was similar for all ward types with 52% of patients on
medical wards reporting pain. Of these, 20% reported severe pain and 12%
unbearable pain. When patients with pain scores over 6 were analysed by
consultant specialty, elderly care, general medicine, and general surgery
scored highest. In each specialty 20-25% of patients with pain reported a pain
score over 6. In patients reviewed by the pain team, reasons for poor analgesia
included inadequate information, pain assessment, analgesic prescribing, and administration
and patient reporting. CONCLUSION: Patients in all hospital specialities
experience pain. Until the issue of pain management in medical patients is
fully addressed the situation will not improve. Br J Anaesth 2004; 92: 235-7
Pain, In Press, Corrected Proof, Editorial
Is intranasal ketamine an appropriate treatment for
chronic non-cancer breakthrough pain?
Rae F. Bell, and
Eija Kalso
In
conclusion, ketamine may be a potentially useful adjuvant to opioids for the
treatment of refractory cancer pain. In this context it is usually given in low
dose and as a continuous infusion. We would suggest that, until the results of
long-term data are available, intranasal ketamine should be used with caution
and confined to the treatment of problematic cancer-related breakthrough pain.
We would contend that the use of a drug of addiction (ketamine) by a
rapid-acting (intranasal) route for the treatment of chronic non-cancer pain is
inappropriate and should, at least in the light of current knowledge, be avoided.
Central pain: distributed effects of focal lesions
Kenneth L. Casey
Pain, In Press, Corrected Proof, Editorial
For now,
it seems clear that we must consider the possibility that CP is caused by the
combination of a focal lesion and a distributed deficit in one or more
neurotransmitter or neuromodulator mechanisms. If true, this observation would
put us a giant step toward an understanding of the pathophysiology of CP. We
could then address the genetic, developmental, and acquired factors, including
mediators of maladaptive plasticity and functional reorganization, that may put
patients at risk for the development of CP and other forms of neuropathic pain.
Adolescent chronic pain: patterns and predictors of
emotional distress in adolescents with chronic pain and their parents
Christopher Eccleston, Geert Crombez, Anna Scotford,
Jacqui Clinch and Hannah Connell
Pain, In Press, Corrected Proof
Adolescents
with chronic pain also report severe disability and emotional distress. A
clinical sample of 80 adolescents and accompanying parents were investigated to
first measure the extent of distress, and second to investigate the
relationships between adolescent distress, parental distress and adolescent
coping. Measures of pain intensity, anxiety, depression, disability and coping
were obtained from adolescents. Parents completed measures including their own
anxiety, depression and parenting stress. Overall, adolescents reported high levels
of disability, depression and anxiety, and parents reported high levels of
depression, anxiety and parenting stress. Multiple regression analyses revealed
that the best predictors of adolescent emotional distress were the extent to
which the adolescents catastrophize and seek social support to cope with the
pain. There were no clear predictors of parental anxiety or depression but the
specific pattern of parenting stress was best predicted by the younger age of
the adolescent, the greater the chronicity of the problem, and the greater the
extent of adolescent depression. These findings suggest that emotional coping
is a critical variable in the distress associated with adolescent chronic pain.
It is argued that adolescent emotional coping may best be understood within a
relational context of seeking emotional support.
Pain, Volume 107, Issue 3, Pages 199-290 (February 2004),
Editorial
Biomarkers for pain
Eija Kalso
Various
proteins can be measured in the CSF and other body fluids. They will increase our
understanding of the mechanisms that underlie inflammation, nerve injury and
tissue damage. These proteins can also be tested as new targets for therapeutic
approaches. The pain experience, however, will remain subjective and outside
the reach of a biochemistry lab. Even substance P(ain) turned out to be more
complicated than what we expected. Antagonists for the receptor of substance
P(ain) turned out to be potential drugs for depression, not pain!
The effects of failing to control pain: an experimental
investigation
Sabine A. Janssen, Philip Spinhoven and Arnoud Arntz
Pain,Volume 107, Issue 3 (February 2004), Pages 227-233
Chronic
pain patients are often confronted with repeated failure to achieve pain
relief. The aim of this study was to experimentally investigate the effects of
repeated failing attempts to control pain on pain impact (pain intensity,
emotional and physiological responses). Perceived control over an
electrocutaneous pain stimulus was manipulated between subjects by success or
failure feedback on a task by which control over pain could be acquired. In
addition, success or failure at the task was manipulated without suggesting a
possibility to control pain. It was hypothesized that successful control would
lead to lowest pain impact, whereas failure to control pain would lead to even
higher pain impact than absent control. Furthermore, it was hypothesized that
failure feedback would increase pain impact when compared to success feedback.
Results indicated that repeated failure to control pain increased anger and
heart rate responses compared to the other conditions, but not pain intensity. It
is concluded that persistent efforts to control pain in the face of failure may
lead to the maintenance or exacerbation of physiological and emotional
responses.
Pain. 2004 Jan; 107(1-2): 99-106.
Marital functioning, chronic pain, and psychological
distress.
Cano A, Gillis M, Heinz W, Geisser M, Foran H.
This
study examined whether marital functioning variables related uniquely to
psychological distress and diagnoses of depressive disorder independent of pain
severity and physical disability. Participants were 110 chronic musculoskeletal
pain patients. Hierarchical regression results showed that marital variables
(i.e. marital satisfaction, negative spouse responses to pain) contributed
significantly to depressive and anxiety symptoms over and above the effects of
pain severity and physical disability. In contrast, marital variables were not
significantly related to diagnoses of depressive disorder (i.e. major
depression, dysthymia, or both) after controlling for pain variables. In
multivariate analyses, physical disability and marital satisfaction were
uniquely related to depressive symptoms whereas physical disability, pain
severity, and negative spouse responses to pain were uniquely related to
anxiety symptoms. Only physical disability was uniquely related to major
depression. The results suggest that models of psychological distress in
chronic pain patients might be enhanced by attributing greater importance to
interpersonal functioning and increasing attention to anxiety.
The role of neuroticism, pain catastrophizing and
pain-related fear in vigilance to pain: a structural equations approach
Liesbet Goubert, Geert Crombez and Stefaan Van Damme
Pain,Volume 107, Issue 3 (February 2004) , Pages 234-241
The
present study aimed at clarifying the precise role of pain catastrophizing,
pain-related fear and personality dimensions in vigilance to pain and pain
severity by means of structural equation modelling. A questionnaire survey was
conducted in 122 patients with chronic or recurrent low back pain. Results
revealed that pain catastrophizing and pain-related fear mediated the
relationship between neuroticism and vigilance to pain. Furthermore, vigilance
to pain was found to be associated with heightened pain severity. Finally, we
found that neuroticism moderated the relationship between pain severity and
catastrophic thinking about pain. The results strongly support the idea that
vigilance to pain is dependent upon catastrophic thinking and pain-related
fear. Neuroticism is best conceived of as a vulnerability factor; it lowers
the threshold at which pain is perceived as threatening, and at which
catastrophic thoughts about pain emerge.
Disengagement from pain: the role of catastrophic
thinking about pain.
Van Damme S, Crombez G, Eccleston C.
Pain. 2004 Jan; 107(1-2): 70-6.
This
paper reports an experimental investigation of attentional engagement to and
disengagement from pain. Thirty-seven pain-free volunteers performed a cueing
task in which they were instructed to respond to visual target stimuli, i.e.
the words 'pain' and 'tone'. Targets were preceded by pain stimuli or tone
stimuli as cues. Participants were characterized as high or low pain
catastrophizers, using self-reports. We found that the effect of cueing upon
target detection was differential for high and low pain catastrophizers.
Analyses revealed a similar amount of attentional engagement to pain in both
groups. However, we also found that participants high in pain catastrophizing
had difficulty disengaging from pain, whereas participants low in pain
catastrophizing showed no retarded disengagement from pain. Our results provide
further evidence that catastrophic thinking enhances the attentional demand
of pain, particularly resulting in difficulty disengaging from pain. The
clinical implications of these findings are discussed.
Pain. 2004 Jan; 107(1-2): 176-90.
Exercise and chronic low back pain: what works?
Liddle SD, Baxter GD, Gracey JH.
The aim
of this review was to investigate current evidence for the type and quality of
exercise being offered to chronic low back pain (CLBP) patients, within
randomised controlled trials (RCTs), and to assess how treatment outcomes are
being measured. A two-fold methodological approach was adopted: a
methodological assessment identified RCTs of 'medium' or 'high' methodological
quality. Exercise quality was subsequently assessed according to the
predominant exercise used. Outcome measures were analysed based on current
recommendations. Fifty-four relevant RCTs were identified, of which 51 were
scored for methodological quality. Sixteen RCTs involving 1730 patients
qualified for inclusion in this review based upon their methodological quality,
and chronicity of symptoms; exercise had a positive effect in all 16 trials.
Twelve out of 16 programmes incorporated strengthening exercise, of which 10
maintained their positive results at follow-up. Supervision and adequate
compliance were common aspects of trials. A wide variety of outcome measures
were used. Outcome measures did not adequately represent the guidelines for
impairment, activity and participation, and impairment measures were
over-represented at the expense of others. Despite the variety offered,
exercise has a positive effect on CLBP patients, and results are largely
maintained at follow-up. Strengthening is a common component of exercise
programmes, however, the role of exercise co-interventions must not be
overlooked. More high quality trials are needed to accurately assess the role
of supervision and follow-up, together with the use of more appropriate outcome
measures
Correlation between pain, disability, and quality of
life in patients with common low back pain.
Kovacs FM, Abraira V, Zamora J, Teresa Gil del Real M,
Llobera J, Fernandez C, Bauza JR, Bauza K, Coll J, Cuadri M, Duro E, Gili J,
Gestoso M, Gomez M, Gonzalez J, Ibanez P, Jover A, Lazaro P, Llinas M, Mateu C,
Mufraggi N, Muriel A, Nicolau C, Olivera MA, Pascual P, Perello L, Pozo F,
Revuelta T, Reyes V, Ribot S, Ripoll J, Ripoll J, Rodriguez E; kovacs@kovacs.org
Spine. 2004 Jan 15; 29(2): 206-10.
STUDY
DESIGN: Correlation among previously validated questionnaires. OBJECTIVES: To
determine the correlation between pain, disability, and quality of life in
patients with low back pain. SUMMARY OF BACKGROUND DATA: The Visual Analogue
Scale (VAS), and the Roland-Morris (RMQ), Oswestry (OQ), and EuroQol (EQ)
Questionnaires are validated instruments to assess pain, low back pain-related
disability, and quality of life. METHODS: The study was done in the primary
care setting, in Mallorca, with 195 patients who visited their physician for
LBP. Individuals were given the VAS, RMQ, OQ, and EQ on their first visit and
14 days later. RESULTS: Median duration of pain when entering the study was 10
days (P25,P75: 3, 40). On day 1, simple correlation was r = 0.347 between VAS
and RMQ, r = -0.422 between VAS and EQ, and r = -0.442 between RMQ and EQ. On
day 15, simple correlation was r = 0.570 between VAS and RMQ, r = -0.672
between VAS and EQ, and r = -0.637 between RMQ and EQ. Multiple linear
regression models showed that, on day 1, the VAS score explains 12% of the RMQ
score and the VAS and RMQ scores explain 27% of the EQ score. On day 15, the
VAS score explains 33% of the RMQ score, and the VAS and RMQ scores explain 58%
of the EQ score. On day 1, a 10% increase in VAS worsens disability by 3.3% and
quality of life by 2.65%. On day 15, a 10% increase in VAS worsens disability
by 4.99% and quality of life by 3.80%. Prestudy duration of pain had no
influence on any model. All these correlation coefficients and models are
significant at the P < 0.001 level. The OQ had lower correlation values with
the other three scales, and only two of them were significant. CONCLUSION: Clinically
relevant improvements in pain may lead to almost unnoticeable changes in
disability and quality of life. Therefore, these variables should be assessed
separately when evaluating the effect of any form of treatment for low back
pain. The influence of pain and disability on quality of life progresses
while they last, and doubles in 14 days. In acute and subacute patients, this
increase is not dependent on the previous duration of pain.
Graded activity for low back pain in occupational
health care: a randomized, controlled trial.
Staal JB, Hlobil H, Twisk JW, Smid T, Koke AJ, van
Mechelen W.
Ann Intern Med. 2004 Jan 20; 140(2): 77-84.
BACKGROUND:
Low back pain is a common medical and social problem frequently associated with
disability and absence from work. However, data on effective return to work
after interventions for low back pain are scarce. OBJECTIVE: To determine the
effectiveness of a behavior-oriented graded activity program compared with
usual care. DESIGN: Randomized, controlled trial. SETTING: Occupational health
services department of an airline company in the Netherlands. PATIENTS: 134
workers who were absent from work because of low back pain were randomly
assigned to either graded activity (n = 67) or usual care (n = 67).
INTERVENTION: Graded activity, a physical exercise program based on
operant-conditioning behavioral principles, to stimulate a rapid return to
work. MEASUREMENTS: Outcomes were the number of days of absence from work
because of low back pain, functional status (Roland Disability Questionnaire),
and severity of pain (11-point numerical scale). RESULTS: The median number of
days of absence from work over 6 months of follow-up was 58 days in the graded
activity group and 87 days in the usual care group. From randomization onward,
graded activity was effective after 50 days of absence from work (hazard ratio,
1.9 [95% CI, 1.2 to 3.2]; P = 0.009). The graded activity group was more
effective in improving functional status and pain than the usual care group.
The effects, however, were small and not statistically significant.
CONCLUSIONS: Graded activity was more effective than usual care in reducing
the
number of days of absence from work because of low back
pain.
Dose-dependent Effects of Propofol on the Central
Processing of Thermal Pain.
Hofbauer RK, Fiset P, Plourde G, Backman SB, Bushnell MC.
Anesthesiology. 2004 Feb; 100(2): 386-394.
SUMMARY:
BACKGROUND Anatomic and physiologic data show that multiple regions of the
forebrain are activated by pain. However, the effect of anesthetic level on
nociceptive input to these regions is not well understood.METHODS The authors
used positron emission tomography to measure the effect of various
concentrations of propofol on pain-evoked changes in regional cerebral blood
flow. Fifteen volunteers were scanned while warm and painful heat stimuli were
presented to the volar forearm using a contact thermode during administration
of target propofol concentrations of 0.0 microg/ml (alert control), 0.5
microg/ml (mild sedation), 1.5 microg/ml (moderate sedation), and 3.5 microg/ml
(unconsciousness).RESULTS During the 0.5-microg/ml target propofol
concentration (mild sedation), the subjects' pain ratings increased relative to
the alert control condition; correspondingly, pain-evoked regional cerebral
blood flow increased in the thalamus and the anterior cingulate cortex. In
contrast, when subjects lost consciousness (3.5 microg/ml), pain-evoked
responses in the thalamus and the anterior cingulate cortex were no longer
observed, whereas significant pain-evoked activation remained in the insular
cortex.CONCLUSION These data show that propofol has a dose-dependent effect
on thalamocortical transfer of nociceptive information but that some
pain-evoked cortical activity remains after loss of consciousness.
Communicative dimensions of pain catastrophizing:
social cueing effects on pain behaviour and coping.
Sullivan MJ, Adams H, Sullivan ME.
Pain. 2004 Feb; 107(3): 220-6.
The study
was designed to assess whether the social context of a pain experience impacted
on the relation between catastrophizing and duration of pain behaviour. Based
on a communal coping model, the prediction was that the presence of an observer
during a pain procedure would differentially influence the display of pain
behaviour in high and low catastrophizers. University undergraduates taking
part in a cold pressor procedure were randomly assigned to one of two
conditions: (1) participant alone (n=30), or (2) observer present (n=34).
Analysis of video records revealed that high pain catastrophizers displayed
communicative pain behaviours (e.g. facial displays, vocalizations) for a
longer duration when an observer was present compared to high pain
catastrophizers who were alone during the pain procedure. The duration of pain
management behaviours (e.g. holding, rubbing) did not vary significantly as a
function of catastrophizing. When the observer was present, high
catastrophizers also reported using fewer cognitive coping strategies than low
catastrophizers. The pattern of findings suggests that in the presence of an
observer, high pain catastrophizers show a propensity to engage in strategies
that more effectively communicate their pain, and are less likely to engage in
strategies that might minimize pain. Theoretical implications of the findings
are discussed.
Placebo-Induced Changes in fMRI in the Anticipation and
Experience of Pain
Tor D. Wager, James K. Rilling, Edward E. Smith, Alex
Sokolik, Kenneth L. Casey, Richard J. Davidson, Stephen M. Kosslyn, Robert M.
Rose, and Jonathan D. Cohen
Science 2004 303: 1162-1167
The
experience of pain arises from both physiological and psychological factors,
including one's beliefs and expectations. Thus, placebo treatments that have no
intrinsic pharmacological effects may produce analgesia by altering
expectations. However, controversy exists regarding whether placebos alter
sensory pain transmission, pain affect, or simply produce compliance with the
suggestions of investigators. In two functional magnetic resonance imaging
(fMRI) experiments, we found that placebo analgesia was related to decreased
brain activity in pain-sensitive brain regions, including the thalamus, insula,
and anterior cingulate cortex, and was associated with increased activity
during anticipation of pain in the prefrontal cortex, providing evidence that
placebos alter the experience of pain.
Empathy for Pain Involves the Affective but not Sensory
Components of Pain
Tania Singer, Ben Seymour, John O'Doherty, Holger Kaube,
Raymond J. Dolan, and Chris D. Frith
Science 2004 303: 1157-1162
Our
ability to have an experience of another's pain is characteristic of empathy.
Using functional imaging, we assessed brain activity while volunteers
experienced a painful stimulus and compared it to that elicited when they
observed a signal indicating that their loved one—present in the same room—was
receiving a similar pain stimulus. Bilateral anterior insula (AI), rostral
anterior cingulate cortex (ACC), brainstem, and cerebellum were activated when
subjects received pain and also by a signal that a loved one experienced pain.
AIand ACC activation correlated with individual empathy scores. Activity in the
posterior insula/secondary somatosensory cortex, the sensorimotor cortex
(SI/MI), and the caudal ACC was specific to receiving pain. Thus, a neural
response in AIand rostral ACC, activated in common for "self" and
"other" conditions, suggests that the neural substrate for
empathic experience does not involve the entire "pain matrix." We
conclude that only that part of the pain network associated with its affective
qualities, but not its sensory qualities, mediates empathy.
Journal of Behavioral Medicine
27 (1): 91-100, February 2004
Parafunctional Clenching, Pain, and Effort in
Temporomandibular Disorders
Alan G. Glaros , Eric Burton
This
study tested the hypotheses that (1) parafunctional clenching increases pain
and can lead to a diagnosis of temporomandibular disorder (TMD) pain and (2)
electromyographic (EMG) activity during parafunctional clenching is
significantly and positively correlated with reports of pain. Fourteen
individuals without TMD participated in 5 consecutive days of 20-min long EMG
biofeedback training sessions of the left and right temporalis and masseter
muscles. Subjects were randomly assigned to either a Decrease or
Increase group and were instructed to maintain EMG activity below 2 µV or
above 10 µV during training, respectively. Two Increase subjects and no
Decrease subjects were diagnosed, by a blinded examiner, with TMD pain
following training. Self-reported pain posttraining was significantly higher
for the Increase group. Masseter EMG activity was strongly correlated with
pain. Parafunctional clenching increases pain and can lead to a diagnosis of
TMD in otherwise pain-free individuals. Pain reports are positively correlated
with the activity of the masseter muscle.
Journal of Behavioral Medicine
27 (1): 77-89, February 2004
Pain-Related Anxiety in the Prediction of Chronic
Low-Back Pain Distress
Kevin E. Vowles, Michael J. Zvolensky, Richard T. Gross,
Jeannie A. Sperry; kvowles@mix.wvu.edu
This
study evaluated the relation of particular aspects of pain-related anxiety to
characteristics of chronic pain distress in a sample of 76 individuals with
low-back pain. Consistent with contemporary cognitive–behavioral models of
chronic pain, the cognitive dimension of the Pain Anxiety Symptoms Scale (PASS;
McCracken, Zayfert, and Gross, 1992, Pain 50: 67–73) was uniquely predictive
of cognitive-affective aspects of chronic pain, including affective distress,
perceived lack of control, and pain severity. In contrast, the escape
and avoidance dimension of the PASS was more predictive of behavioral
interference in life activities. Overall, the findings are discussed within
the context of identifying particular pain-related anxiety mechanisms
contributing to differential aspects of pain-related distress and clinical
impairment.
Occupational Medicine 2004;54:3-13
Low back pain interventions at the workplace: a
systematic literature review
Torill H. Tveito, Mari Hysing and Hege R. Eriksen
Objective
To assess the effect of controlled workplace interventions on low back pain
(LBP) through a review of controlled studies. The rising costs of employees
with LBP have resulted in an abundance of offers to society and organizations
of interventions to prevent and/or treat the problem. Little is known of the
effect of the different interventions.
Methods A systematic literature search based on the inclusion criteria:
controlled trial, work setting and assessment of at least one of the four main outcome
measures: sick leave; costs; new episodes of LBP; and pain. Effect of
the interventions was reported for the four main outcome measures. Results Thirty-one publications from 28
interventions were found to comply with the inclusion criteria. Exercise
interventions to prevent LBP among employees and interventions to treat
employees with LBP have documented an effect on sick leave, costs and new
episodes of LBP. Multidisciplinary interventions have documented an effect on
the level of pain. Conclusions The
results show that there is good reason to be careful when considering
interventions aiming to prevent LBP among employees. Of all the workplace
interventions only exercise and the comprehensive multidisciplinary and
treatment interventions have a documented effect on LBP. There is a need for
studies employing good methodology.
The Spine Journal, Article in Press
Efficacy of spinal manipulation and mobilization for
low back pain and neck pain: a systematic review and best evidence synthesis
Gert Bronfort PhD, DC, Mitchell Haas DC, MA, Roni L. Evans
DC, MS and Lex M. Bouter PhD Background
context: Despite the many published randomized clinical trials (RCTs), a
substantial number of reviews and several national clinical guidelines, much
controversy still remains regarding the evidence for or against efficacy of
spinal manipulation for low back pain and neck pain.
Purpose: To reassess the efficacy of spinal manipulative
therapy (SMT) and mobilization (MOB) for the management of low back pain (LBP)
and neck pain (NP), with special attention to applying more stringent criteria
for study admissibility into evidence and for isolating the effect of SMT
and/or MOB.
Study design: RCTs including 10 or more subjects per group
receiving SMT or MOB and using patient-oriented primary outcome measures (eg,
patient-rated pain, disability, global improvement and recovery time).
Methods: Articles in English, Danish, Swedish, Norwegian
and Dutch reporting on randomized trials were identified by a comprehensive
search of computerized and bibliographic literature databases up to the middle
of 2002. Two reviewers independently abstracted data and assessed study quality
according to eight explicit criteria. A best evidence synthesis incorporating
explicit, detailed information about outcome measures and interventions was
used to evaluate treatment efficacy. The strength of evidence was assessed by a
classification system that incorporated study validity and statistical
significance of study results. Sixty-nine RCTs met the study selection criteria
and were reviewed and assigned validity scores varying from 6 to 81 on a scale
of 0 to 100. Forty-three RCTs met the admissibility criteria for evidence.
Results
Acute LBP: There is moderate evidence that SMT provides
more short-term pain relief than MOB and detuned diathermy, and limited
evidence of faster recovery than a commonly used physical therapy treatment
strategy.
Chronic LBP: There is moderate evidence that SMT has an
effect similar to an efficacious prescription nonsteroidal anti-inflammatory
drug and that SMT/MOB is effective at least in the short term when compared
with placebo and general practitioner care. There is limited to moderate
evidence that SMT is better than physical therapy and home back exercise in
both the short and long term. There is limited evidence that SMT is as good or
better than chemonucleolysis for disc herniation in the short and long term.
However, there is also limited evidence that MOB is inferior to back exercise
after disc herniation surgery.
Mix of acute and chronic LBP:/MOB provides either similar
or better pain outcomes in the short and long term when compared with placebo
and with other treatments, such as McKenzie therapy, medical care, management
by physical therapists, soft tissue treatment and back school.
Acute NP: There are few studies, and the evidence is
currently inconclusive.
Chronic NP: There is moderate evidence that SMT/MOB is
superior to general practitioner management for short-term pain reduction but
that SMT offers less pain relief in the long term than high-technology
rehabilitative exercise. There is limited evidence that SMT, in both the short
and long term, has a similar effect to low technology exercise and to physical
therapy.
Mix of acute and chronic NP. The overall evidence is not
clear. There is moderate evidence that MOB is superior to physical therapy and
family physician care, and similar to SMT in both the short and long term.
There is limited evidence that SMT, in both the short and long term, is
inferior to physical therapy.
Conclusions: Our data synthesis suggests that
recommendations can be made with some confidence regarding the use of SMT
and/or MOB as a viable option for the treatment of both low back pain and NP.
There have been few high-quality trials distinguishing between acute and
chronic patients, and most are limited to shorter-term follow-up. Future trials
should examine well-defined subgroups of patients, further address the value of
SMT and MOB for acute patients, establish optimal number of treatment visits
and consider the cost-effectiveness of care.
The Spine Journal, Article in Press
The influence of intense exercise-based physical
therapy program on back pain anticipated before and induced by physical
activities
James Rainville MD, Carol Hartigan MD, Cristin Jouve MD
and Eugenio Martinez MD
Background
context: Pain anticipated before and induced by physical activities has been
shown to influence the physical performance of patients with chronic back pain.
Limited data exist as to the influence of treatment on this component of pain.
Purpose: This study attempted to determine if pain anticipated before and
induced by physical activities was altered during an exercise-oriented physical
therapy program for chronic back pain. bStudy design/setting: Subjects were
recruited from three physical therapy sites with similar spine rehabilitation
programs that used intense exercise delivered in a group format. During the
recruitment period, 70 subjects with chronic low back pain and disability
agreed to participate and complied with recommended treatments. The primary
outcome measures were anticipated and induced pain as assessed by visual analog
scales (VAS) during six tests of back flexibility and strength. Additional
outcome measures included the performance levels of these six tests (trunk
flexion, extension, straight leg raising, back strength, lifting from floor to
waist and waist to shoulder height), global back and leg VAS and Oswestry Low
Back Pain Disability Questionnaire scores. Methods: At evaluation for the spine
rehabilitation programs, we recorded the anticipated and induced pain levels
associated with the six tests of back function, the performance levels on each
test and global pain and disability scores. Subjects then participated in the
spine rehabilitation program that consisted of intense exercise delivered up to
three times per week, for 2 hours over a period of 6 weeks. All outcome
measures were reassessed at discharge. Pre- and posttreatment outcome scores
were statistically compared using paired sample t tests and chi-squared test.
Spearman correlation coefficients were used to compare anticipated and induced
pain results with global back and leg pain VAS scores, Oswestry scores and
physical performance levels for each physical test. Results: Most measures of
anticipated and induced pain improved between evaluation and discharge.
Improvements were noted for global back pain (p<.001), leg pain (p=.001),
disability (p<.001) and performance on each physical testing (p<.001) after
treatment. Performances on all physical testing correlated with anticipated and
induced pain for all tests at evaluation but only for measures of flexibility
at discharge. Improvements in global pain and disability correlated with
improvements in anticipated and induced pain with physical testing.
Conclusion: Anticipated and induced pain with physical
activities was lessened after physical therapy using exercise. Anticipated and
induced pain with physical activities related to physical performance levels,
global pain and disability ratings. These findings may help explain how
exercise exerts a positive influence on chronic back pain and disability.
The Spine Journal
Volume 4, Issue 1 , 2 January 2004, Pages 106-115
Exercise as a treatment for chronic low back pain
James Rainville MD, Carol Hartigan MD, Eugenio Martinez
MD, Janet Limke MD, Cristin Jouve MD and Mark Finno MD
Background
context: Exercise is a widely prescribed treatment for chronic low back pain,
with demonstrated effectiveness for improving function and work. Purpose: The
goal of this article is to review several key aspects about the safety and
efficacy of exercise that may help clinicians understand its utility in
treating chronic back pain. Study design/setting: A computerized literature search
of MEDLINE was conducted using "exercise," "fitness,"
"back pain," "backache" and "rehabilitation" as
search words. Identified abstracts were scanned, and useful articles were
acquired for further review. Additional references were acquired through the personal
collections of research papers possessed by the authors and by reviewing prior
review articles on this subject. These final papers were scrutinized for data
relevant to the key aspects about exercise covered in this article. Results:
For people with acute, subacute or chronic low back pain, there is no evidence
that exercise increases the risk of additional back problems or work
disability. To the contrary, current medical literature suggests that exercise
has either a neutral effect or may slightly reduce risk of future back
injuries. Exercise can be prescribed for patients with chronic low back pain
with three distinct goals. The first and most obvious goal is to improve or
eliminate impairments in back flexibility and strength, and improve performance
of endurance activities. There is a large body of evidence confirming that this
goal can be accomplished for a majority of patients with chronic low back pain.
The second goal of exercise is to reduce the intensity of back pain. Most
studies of exercise have noted overall reduction in back pain intensity that
ranges from 10% to 50% after exercise treatment. The third goal of exercise is
to reduce back pain–related disability through a process of desensitization of
fears and concerns, altering pain attitudes and beliefs and improving affect.
The mechanisms through which exercise can accomplish this goal have been the
subject of substantial research. Conclusions: Exercise is safe for individuals
with back pain, because it does not increase the risk of future back injuries
or work absence. Substantial evidence exists supporting the use of exercise as
a therapeutic tool to improve impairments in back flexibility and strength.
Most studies have observed improvements in global pain ratings after exercise
programs, and many have observed that exercise can lessen the behavioral,
cognitive, affect and disability aspects of back pain syndromes.
The Spine Journal
Volume 3, Issue 6 , November-December 2003, Pages 435-441
Neck and shoulder pain in 70- to 79-year-old men and
women: findings from the Health, Aging and Body Composition Study
Molly T. Vogt PhD,, Eleanor M. Simonsick PhD, Tamara B.
Harris MD, Michael C. Nevitt PhD, James D. Kang MD, Susan M. Rubin MPH, Stephen
B. Kritchevsky PhD and Anne B. Newman MD, MPH
Background
context: Musculoskeletal pain in the cervicobrachial region is considered a
major health problem among adults of working age, but little is known about the
impact of this pain in the elderly.
Purpose: Determine the prevalence of neck and shoulder
pain in a well-functioning cohort, identify factors associated with this pain,
assess the pattern of coexisting joint pain and evaluate the impact of this
pain on physical functioning. Study design: Cross-sectional study. Patient
sample: Black and white men and women, aged 70 to 79 years, participating in
the Health, Aging and Body Composition (Health ABC) study. Methods: Between
April 1997 and June 1998, 3,075 men and women participating in Health ABC study
completed the initial home interview and clinical examination. Information was
collected on musculoskeletal pain, medical history, depressive symptomatology
and physical function. Physical performance measures were obtained. Results: A
total of 11.9% of participants reported neck pain of one month or more in
duration and 18.9% reported shoulder pain. White women had the highest
prevalence of neck pain (15.4%) and black women the highest prevalence of
shoulder pain (24.3%). The correlates of both neck and shoulder pain were
female gender, no education beyond high school, poorer self-rated health,
depressive symptomatology and a medical history of arthritis, heart attack,
angina. Increasing severity of both neck and shoulder pain was associated with
an increased prevalence of joint pain at other body sites and with poor
functional capacity. Measures of physical performance involving the upper
extremity were also decreased. Conclusions: Neck and shoulder pain, either
alone or in conjunction with pain in other joints, has a substantial impact on
the function and well-being of the older adults in this cohort.
Back and Neck Pain Exhibit Many Common Features in Old
Age: A Population-Based Study of 4,486 Danish Twins 70-102 Years of Age.
Spine. 29(5):576-580, March 1, 2004.
Hartvigsen, Jan DC, PhD *; Christensen, Kaare MD, PhD +;
Frederiksen, Henrik MD, PhD +
Study Design. Cross-sectional and longitudinal analysis of
data comprising 4486 Danish twins 70-102 years of age. Objectives. To describe
the 1-month prevalence of back pain, neck pain, and concurrent back and neck
pain and the development of these over time, associations with other health
problems, education, smoking, and physical, and mental functioning. Summary of
Background Data. Back pain and neck pain are prevalent symptoms in the
population; however, there is little research addressing these conditions in
older age groups. Methods. Extensive interview data on health, lifestyle,
social, and educational factors were collected in a nationwide cohort-sequential
study of 70+-year-old Danish twins. Data for back pain, neck pain, lifetime
prevalence of a comprehensive list of diseases, education, and self-rated
health were based on self-report. Physical and mental functioning were measured
using validated performance tests. Data including associated factors were
analyzed in a cross-sectional analysis for answers given at entry into the
study, and longitudinal analysis was performed for participants in all four
surveys. Results. The overall 1-month prevalence for back pain only was 15%,
for neck pain only 11%, and for concurrent back and neck pain 11%. The
prevalence varied negligibly over time and between the age groups, and 63% of
participants in all surveys had no episodes or only one episode of back or neck
pain. Back pain and neck pain were associated with a number of other diseases
and with poorer self-rated health. Back and neck pain sufferers had
significantly lower scores on physical but not cognitive functioning. Conclusions. Back pain and neck pain are common,
intermittent symptoms in old age. Back pain and neck pain are associated with
general poor physical health in old age.
The Spine Journal
Volume 3, Issue 6 , November-December 2003, Pages 460-465
Correlation of clinical examination characteristics with
three sources of chronic low back pain
Sharon Young PT, Cert. MDT, Charles Aprill MD and Mark
Laslett PT, Dip. MT, Dip. MDT
Background
context:Research has demonstrated some progress in using a clinical examination
to predict discogenic or sacroiliac (SI) joint sources of pain. No clear
predictors of symptomatic lumbar zygapophysial joints have yet been
demonstrated. Purpose: To identify significant components of a clinical
examination that are associated with symptomatic lumbar discs, zygapophysial joints
and SI joints. Study design: A prospective, criterion-related concurrent
validity study performed at a private radiology practice specializing in spinal
diagnostics. Patient sample:The sample consisted of 81 patients with chronic
lumbopelvic pain referred for diagnostic injections. Outcome measures:
Contingency tables were constructed for nine features of the clinical
evaluation compared with the results of diagnostic injections. Statistical
analysis included chi-squared test for independence, phi and odds ratios with
confidence intervals. Method: Patients received blinded clinical examinations
by physical therapists, and diagnostic injections were used as the criterion
standard. Results: Significant relationships were found between discogenic pain
and centralization of pain during repeated movement testing, and pain when
rising from sitting. Lumbar zygapophysial joint pain was associated with
absence of pain when rising from sitting. Sacroiliac joint pain was related to
three or more positive pain provocation tests, pain when rising from sitting,
unilateral pain and absence of lumbar pain. Conclusions: Significant
correlations exist between clinical examination findings and symptomatic lumbar
discs, zygapophysial and SI joints. The strongest relationships were seen
between SI joint pain and three or more positive pain provocation tests,
centralization of pain for symptomatic discs and absence of pain when rising
from sitting for symptomatic lumbar zygapophysial joints.
The Spine Journal
Volume 3, Issue 5 , September-October 2003, Pages 400-403
Failed back surgery: etiology and diagnostic evaluation
Jerome Schofferman MD, James Reynolds MD, Richard Herzog
MD, Edward Covington MD, Paul Dreyfuss MD and Conor O'Neill MD
BACKGROUND
CONTEXT: This is a synopsis of a symposium presented to the North American
Spine Society Annual Meeting in Montreal, Canada, 2002. PURPOSE: To provide the
reader with a distillation of the material presented regarding the diagnosis of
failed back surgery syndrome (FBSS). METHODS: Panel presentation. RESULTS: The
proper treatment of patients with FBSS depends on a precise and accurate
diagnosis. With a careful history, examination, imaging studies, psychological
evaluation and diagnostic injections, a diagnosis can be reached in over 90% of
patients. The most common diagnoses are foraminal stenosis (25% to 29%),
painful disc (20% to 22%), pseudarthrosis (14%), neuropathic pain (10%),
recurrent disc herniation (7% to 12%), facet joint pain (3%) and sacroiliac
joint (SIJ) pain (2%). Psychological factors are always present and may help or
hinder. Common psychological diagnoses include depression, anxiety disorder and
substance abuse disorder. Diagnostic injections are very useful for facet joint
pain, SIJ pain and discogenic pain; they may also be used to confirm a putative
neural compression as a cause of pain. CONCLUSIONS: Spine surgeons must be
aware of the common causes of FBSS in order to be able to thoroughly evaluate
their patients and to minimize the occurrence of this problem.
Pain Med. 2003 Jun;4(2):141-81.
A structured evidence-based review on the meaning of
nonorganic physical signs: Waddell signs.
Fishbain DA, Cole B, Cutler RB, Lewis J, Rosomoff HL,
Rosomoff RS.
Department of Psychiatry, University of Miami School
of Medicine, Miami, Florida, USA. d.fishbain@miami.edu.
STUDY
DESIGN: This is a structured, evidence-based review of all available studies
addressing the concept of nonorganic findings: Waddell signs (WSs). OBJECTIVES:
To determine what evidence, if any, exists for the various interpretations for
the presence of WSs on physical examination. SUMMARY OF BACKGROUND DATA: WSs
are a group of eight physical findings divided into five categories, the
presence of which has been alleged at times to have the following
interpretations: Malingering/secondary gain, hysteria, psychological distress,
magnified presentation, abnormal illness behavior, abnormal pain behavior, and
somatic amplification. At the present time, there is, therefore, significant
confusion as to what these findings mean. METHODS: A computer and manual
literature search produced 61 studies and case series reports relating to WSs.
These references were reviewed in detail, sorted, and placed into tabular form
according to the following subject areas: 1) Reliability (test-retest); 2)
Reliability (inter-rater); 3) Reliability (factor analysis); 4) Validity,
psychological distress; 5) Validity, correlation Minnesota Multiphasic Pain
Inventory (MMPI); 6) Validity, correlation abnormal illness behavior; 7)
Validity, other behaviors; 8) Validity, as a nonorganic phenomenon; 9)
Validity, correlation pain drawing; 10) Validity, functional performance; 11)
Validity, treatment outcome; 12) Validity, predicting surgical treatment
outcome; 13) Validity, return to work outcome; 14) Validity, secondary gain
correlation; and 15) Validity, pain correlation. Each study in each topic area
was classified according to the type of study it represented according to the
type of evidence guidelines developed by the Agency for Health Care Policy and
Research (AHCPR). In addition, a list of 14 study quality criteria was used to
measure the quality of each study. Each study was categorized for each
criterion as positive, (criterion filled), negative (criterion not filled), or
not applicable independently by two of the authors. A percent quality score was
obtained for each study by counting the total number of positives obtained,
dividing by 14 minus the total number of not applicables, and multiplying by
100. Only studies having a quality score of 75% or greater were used to
formulate the conclusions of this review. The strength and consistency of the
evidence represented by the remaining studies in each topic area (above) was
then categorized according to the strength and consistency AHCPR guidelines.
Conclusions of this review for each topic area are based on these results.
RESULTS OF DATA SYNTHESIS: Of the 61 studies, four had quality scores below 75%
and were not used to generate the results of this review. According to the
AHCPR guidelines for strength and consistency of the reviewed data, the
following results were obtained: 1) There was consistent evidence for WSs being
associated with decreased functional performance, poor nonsurgical treatment
outcome, and greater levels of pain; 2) There was generally consistent evidence
for WSs not being associated with psychological distress, abnormal illness
behavior, or secondary gain; 3) There was also generally consistent evidence
that WSs are an organic phenomenon and that they cannot be used to discriminate
organic from nonorganic problems; 4) There was inconsistent evidence that WSs
do demonstrate inter-rater reliability, do not correlate with the neurotic
triad of the MMPI, are associated with poorer surgical treatment outcome, and
are associated with nonreturn to work; 5) There was little or no evidence that
WSs demonstrate test-retest reliability, or reliable factors, and are
associated with self-esteem problems, catastrophizing, or the nonorganic pain
drawing. CONCLUSIONS: Based on the above results, the following conclusions
were made: 1) WSs do not correlate with psychological distress; 2) WSs
do not discriminate organic from nonorganic problems; 3) WSs may represent an
organic phenomenon; 4) WSs are associated with poorer treatment outcome; 5) WSs
are associated with greater pain levels; 6) WSs are not associated with
secondary gain; and 7) As a group, WS studies demonstrate some methodological
problems.
Facet Joint Kinematics and Injury Mechanisms During
Simulated Whiplash.
Pearson, Adam M. BA; Ivancic, Paul C. MPhil; Ito, Shigeki
MD; Panjabi, Manohar M. PhD
Spine. 29(4):390-397, February 15, 2004.
Study
Design. Facet joint kinematics and capsular ligament strains were evaluated
during simulated whiplash of whole cervical spine specimens with muscle force
replication. Objectives. To describe facet joint kinematics, including facet
joint compression and facet joint sliding, and quantify peak capsular ligament
strain during simulated whiplash. Summary of Background Data. Clinical studies
have implicated the facet joint as a source of chronic neck pain in whiplash
patients. Prior in vivo and in vitro biomechanical studies have evaluated facet
joint compression and excessive capsular ligament strain as potential injury
mechanisms. No study has comprehensively evaluated facet joint compression,
facet joint sliding, and capsular ligament strain at all cervical levels during
multiple whiplash simulation accelerations. Methods. The whole cervical spine
specimens with muscle force replication model and a bench-top trauma sled were
used in an incremental trauma protocol to simulate whiplash of increasing
severity. Peak facet joint compression (displacement of the upper facet surface
towards the lower facet surface), facet joint sliding (displacement of the
upper facet surface along the lower facet surface), and capsular ligament
strains were calculated and compared to the physiologic limits determined
during intact flexibility testing. Results. Peak facet joint compression was
greatest at C4-C5, reaching a maximum of 2.6 mm during the 5 g simulation.
Increases over physiologic limits (P < 0.05) were initially observed during
the 3.5 g simulation. In general, peak facet joint sliding and capsular
ligament strains were largest in the lower cervical spine and increased with
impact acceleration. Capsular ligament strain reached a maximum of 39.9% at
C6-C7 during the 8 g simulation. Conclusions. Facet joint components may be
at risk for injury due to facet joint compression during rear-impact
accelerations of 3.5 g and above. Capsular ligaments are at risk for injury at
higher accelerations.
Sterling, Michele PhD; Jull, Gwendolen PhD; Vicenzino,
Bill PhD; Kenardy, Justin PhD
Characterization of Acute Whiplash-Associated
Disorders.
Spine. 29(2):182-188, January 15, 2004.
Study
Design. An experimental study of motor and sensory function and
psychological distress in subjects with acute whiplash injury. Objectives.
To characterize acute whiplash injury in terms of motor and sensory systems
dysfunction and psychological distress and to compare subjects with higher and
lesser levels of pain and disability. Summary of Background Data. Motor system
dysfunction, sensory hypersensitivity, and psychological distress are present
in chronic whiplash associated disorders (WAD), but little is known of such
factors in the acute stage of injury. As higher levels of pain and disability
in acute WAD are accepted as signs of poor outcome, further characterization of
this group from those with lesser symptoms is important. Materials and Methods.
Motor function (cervical range of movement [ROM], joint position error [JPE];
activity of the superficial neck flexors [EMG] during a test of cranio-cervical
flexion), quantitative sensory testing (pressure, thermal pain thresholds, and
responses to the brachial plexus provocation test), and psychological distress
(GHQ-28, TAMPA, IES) were measured in 80 whiplash subjects (WAD II or III)
within 1 month of injury, as were 20 control subjects. Results. Three subgroups
were identified in the cohort using cluster analysis based on the Neck
Disability Index: those with mild, moderate, or severe pain and disability. All
whiplash groups demonstrated decreased ROM and increased EMG compared with the
controls (all P < 0.01). Only the moderate and severe groups demonstrated
greater JPE and generalized hypersensitivity to all sensory tests (all P <
0.01). The three whiplash subgroups demonstrated evidence of psychological
distress, although this was greater in the moderate and severe groups. Measures
of psychological distress did not impact on between group differences in motor
or sensory tests. Conclusions. Acute whiplash subjects with higher levels of
pain and disability were distinguished by sensory hypersensitivity to a variety
of stimuli, suggestive of central nervous system sensitization occurring soon
after injury. These responses occurred independently of psychological distress.
These findings may be important for the differential diagnosis of acute
whiplash injury and could be one reason why those with higher initial pain and
disability demonstrate a poorer outcome.
Correlation Between Pain, Disability, and Quality of
Life in Patients With Common Low Back Pain.
Spine. 29(2):206-210, January 15, 2004.
Kovacs, Francisco M. MD, PhD; Abraira, Victor PhD; Zamora,
Javier PhD; Teresa Gil del Real, Maria MPH; Llobera, Joan MD, MPH; Fernandez,
Carmen MD [S];
Study Design.
Correlation among previously validated questionnaires. Objectives. To determine
the correlation between pain, disability, and quality of life in patients with
low back pain. Summary of Background Data. The Visual Analogue Scale (VAS), and
the Roland-Morris (RMQ), Oswestry (OQ), and EuroQol (EQ) Questionnaires are
validated instruments to assess pain, low back pain-related disability, and
quality of life. Methods. The study was done in the primary care setting, in
Mallorca, with 195 patients who visited their physician for LBP. Individuals
were given the VAS, RMQ, OQ, and EQ on their first visit and 14 days later.
Results. Median duration of pain when entering the study was 10 days (P25,P75:
3, 40). On day 1, simple correlation was r = 0.347 between VAS and RMQ, r =
-0.422 between VAS and EQ, and r = -0.442 between RMQ and EQ. On day 15, simple
correlation was r = 0.570 between VAS and RMQ, r = -0.672 between VAS and EQ,
and r = -0.637 between RMQ and EQ. Multiple linear regression models showed
that, on day 1, the VAS score explains 12% of the RMQ score and the VAS and RMQ
scores explain 27% of the EQ score. On day 15, the VAS score explains 33% of
the RMQ score, and the VAS and RMQ scores explain 58% of the EQ score. On day
1, a 10% increase in VAS worsens disability by 3.3% and quality of life by
2.65%. On day 15, a 10% increase in VAS worsens disability by 4.99% and quality
of life by 3.80%. Prestudy duration of pain had no influence on any model. All
these correlation coefficients and models are significant at the P < 0.001
level. The OQ had lower correlation values with the other three scales, and
only two of them were significant. Conclusion. Clinically relevant improvements
in pain may lead to almost unnoticeable changes in disability and quality of
life. Therefore, these variables should be assessed separately when evaluating
the effect of any form of treatment for low back pain. The influence of pain
and disability on quality of life progresses while they last, and doubles in 14
days. In acute and subacute patients, this increase is not dependent on the
previous duration of pain.
Pain, In Press
Development and validation of the Neuropathic Pain
Symptom Inventory
Didier Bouhassira, Nadine Attal, Jacques Fermanian, Haiel
Alchaar, Michèle Gautron, Etienne Masquelier, Sylvie Rostaing, Michel
Lanteri-Minet, Elisabeth Collin, Jacques Grisart and François Boureau
This
study describes the development and validation of the Neuropathic Pain Symptom
Inventory (NPSI), a new self-questionnaire specifically designed to evaluate
the different symptoms of neuropathic pain. Following a development phase and a
pilot study, we generated a list of descriptors reflecting spontaneous ongoing
or paroxysmal pain, evoked pain (i.e. mechanical and thermal allodynia/hyperalgesia)
and dysesthesia/paresthesia. Each of these items was quantified on a (0–10)
numerical scale. The validation procedure was performed in 176 consecutive
patients with neuropathic pain of peripheral (n=120) or central (n=56) origin,
recruited in five pain centers in France and Belgium. It included: (i)
assessment of the test–retest reliability of each item, (ii) determination of
the factorial structure of the questionnaire and analysis of convergent and
divergent validities (i.e. construct validity), and (iii) evaluation of the
ability of the NPSI to detect the effects of treatment (i.e. sensitivity to
change). The final version of the NPSI includes 10 descriptors (plus two
temporal items) that allow discrimination and quantification of five distinct clinically
relevant dimensions of neuropathic pain syndromes and that are sensitive to
treatment. The psychometric properties of the NPSI suggest that it might be
used to characterize subgroups of neuropathic pain patients and verify whether
they respond differentially to various pharmacological agents or other
therapeutic interventions.
WOW!!!!
Pain, In Press
Graded motor imagery is effective for long-standing
complex regional pain syndrome: a randomised controlled trial
G. L. Moseley
Complex
regional pain syndrome type 1 (CRPS1) involves cortical abnormalities similar
to those observed in phantom pain and after stroke. In those groups, treatment
is aimed at activation of cortical networks that subserve the affected limb,
for example mirror therapy. However, mirror therapy is not effective for
chronic CRPS1, possibly because movement of the limb evokes intolerable pain.
It was hypothesised that preceding mirror therapy with activation of cortical
networks without limb movement would reduce pain and swelling in patients with
chronic CRPS1. Thirteen chronic CRPS1 patients were randomly allocated to a
motor imagery program (MIP) or to ongoing management. The MIP consisted of two
weeks each of a hand laterality recognition task, imagined hand movements and mirror
therapy. After 12 weeks, the control group was crossed-over to MIP. There was a
main effect of treatment group (F(1,11)=57, P<0.01) and an effect size of
~25 points on the Neuropathic pain scale. The number needed to treat for a 50%
reduction in NPS score was ~2. The effect of treatment was replicated in the
crossed-over control subjects. The results uphold the hypothesis that a MIP
initially not involving limb movement is effective for CRPS1 and support the
involvement of cortical abnormalities in the development of this disorder.
Although the mechanisms of effect of the MIP are not clear, possible
explanations are sequential activation of cortical pre-motor and motor
networks, or sustained and focussed attention on the affected limb, or both.
Pain, Article in Press
Lowering fear-avoidance and enhancing function through
exposure in vivo:
A multiple baseline study across six patients with back
pain
Katja Boersma, Steven Lintona, Thomas Overmeer, Markus
Jansson, Johan Vlaeyen and Jeroen de Jong
This
study investigated the effects of an exposure in vivo treatment for chronic
pain patients with high levels of fear and avoidance. The fear-avoidance model
offers an enticing explanation of why some back pain patients develop
persistent disability, stressing the role of catastrophic interpretations;
largely fueled by beliefs and expectations that activity will cause injury and
will worsen the pain problem. Recently, an exposure in vivo treatment was
developed that aims to enhance function by directly addressing these fears and
expectations.
The
purpose of this study was to describe the short-term, consequent effect of an
exposure in vivo treatment. The study employed a multiple baseline design with
six patients who were selected based on their high levels of fear and
avoidance.
The
results demonstrated clear decreases in rated fear and avoidance beliefs while
function increased substantially. These improvements were observed even though
rated pain intensity actually decreased somewhat. Thus, the results replicate
and extend the findings of previous studies to a new setting, with other
therapists and a new research design. These results, together with the initial
studies, provide a basis for pursuing and further developing the exposure
technique and to test it in group designs with larger samples.
Pain, Article in Press
Possible association of interleukin 1 gene locus
polymorphisms with low back pain
S. Solovieva, P. Leino-Arjasa, J. Saarelab, K. Luomaa, R.
Raininkod and H. Riihimäki
Based on
a hypothesis that interleukin 1 (IL-1) activity is associated with low back
pain (LBP), we investigated relationships between previously described
functional IL-1 gene polymorphisms and LBP. The subjects were a subgroup of a
Finnish study cohort. The IL-1(C889–T), IL-1(C3954–T) and IL-1 receptor
antagonist (IL-1RN)(G1812–A, G1887–C and T11100–C) polymorphisms were genotyped
in 131 middle-aged men from three occupational groups (machine drivers,
carpenters and office workers). A questionnaire inquired about individual and
lifestyle characteristics and the occurrence of LBP, the number of days with
pain and days with limitation of daily activities because of pain, and pain
intensity, during the past 12 months. Lumbar disc degeneration was determined
with magnetic resonance imaging. Carriers of the IL-1RNA1812 allele had an
increased risk of LBP (OR 2.5, 95% CI 1.0–6.0) and carriers of this allele in
combination with the IL-1T889 or IL-1T3954 allele had a higher risk of and more
days with LBP than non-carriers. Pain intensity was associated with the
simultaneous carriage of the IL-1T889 and IL-1RNA1812 alleles (OR 3.7, 95%
CI 1.2–11.9). Multiple regression analyses allowing for occupation and disc
degeneration showed that carriage of the IL-1RNA1812 allele was associated with
the occurrence of pain, the number of days with pain and days with limitations
of daily activities. Carriage of the IL-1T3954 allele was associated with the
number of days with pain. The results suggest a possible contribution of
the IL-1 gene locus polymorphisms to the pathogenesis of LBP. The
possibility of chance findings cannot be excluded due to the small sample size.
Pain, Article in Press
Evidence for heritability of pain in patients with
traumatic neuropathy
Marshall Devor
...convincing
data in animals for heritable pre-disposition to developing chronic pain after
nerve injury...humans, however, it is inherently difficult to document a
genetic contribution....
Tentative evidence of heritability can come from observing
whether multiple nerve injures in individual patients are consistently
associated with chronic pain, or the absence of pain...a recent report on
traumatic double amputees in Sierra Leone showed a very high bilateral
concordance for stump and phantom limb pain...in only a fraction of patients.
But when they occurred in one arm, they almost always occurred also in the
other...another example...published recently in Pain, support an inference of
intrinsic individual predisposition to neuropathic pain....prevalence of
neuropathic pain lasting at least 6 months in patients who underwent coronary
artery bypass graft (CABG) surgery...cause some nerve
trauma...sternotomy...saphenectomy, etc. ...authors reported chronic pain
secondary to the chest surgery in 12% of 1080 patients, chronic leg pain
secondary to the saphenectomy in 9.3%, and chronic pain at both locations in
18% for a grand total of chronic pain in 39.3%. The use of pain descriptors
(words) associated with neuropathy was frequent, and pain had a considerable impact
on quality-of-life measures...reemphasize the risk of chronic pain due to
iatrogenic nerve injury during surgery...frequently missed...results also
deliver a second message not noted by the authors. If the chances of developing
pain at each site were independent, and related only to the vagarities of the
surgical procedure itself, and these chances are 0.12 for chest pain and 0.09
for leg pain, then the odds of getting pain at both sites would be only
0.12×0.09=0.01 (1.1%). In fact...pain at both sites occurred much more often,
in 18% of patients (P<0.001, 2)...more conservative calculation =8.1%
(P<0.001, 2). ...data herefore constitute evidence that certain patients are
pre-disposed to developing chronic pain after nerve injury....The individual
pre-disposition to chronic neuropathic pain suggested by these data may well
reflect genetic control of the processes that underlie the pain. As noted
above, recent animal studies have provided strong evidence of a considerable
degree of heritability in neuropathic pain phenotype. Nonetheless, certain
caveats... in addition to genes, individual pre-dispositions may also have
roots in socialization and other environmental factors. For example, pain at
one site may induce in the individual global `hypervigilance' to similar
symptoms elsewhere. Likewise, it is possible that despite attention to uniform
technique, that subtle differences among surgical teams contributed to the high
concordance of pain at the two sites.
Pain, Article in Press
Development of and recovery from long-term pain. A
6-year follow-up study of a cross-section of the adult Danish population
Jørgen Eriksen, Ola Ekholm, Per Sjøgren and Niels K.
Rasmussen
A 6-year
follow-up study of a cross-section of the adult Danish population, based on data
from the Danish Health and Morbidity Surveys in 1994 and 2000 is presented. The
pain populations were identified through the pain intensity verbal rating scale
(VRS) included in the Short Form 36. The 2000 survey also included a question
on duration of pain (>6 months). Using this as the `gold standard', a
validation study was performed, which identified the highest accuracy (85%) at
the VRS cut-off level: no pain, very mild, or mild pain (control group) versus
moderate, severe, or very severe pain (pain group). The cohort comprised 2649
individuals, representative of the Danish population. Prevalence rates of pain
in 1994 and 2000 were 13.5 and 15.7%, respectively. The cumulated 6-year
incidence of pain development was 10.7%, and the cumulated incidence of pain
recovery was 52.1%. During the investigated period, 9.2% of individuals moved
from a `no pain status' to a `pain status', 7% moved from a `pain status' to a
`no pain status', and 6.5% maintained their `pain status'. Significant risk
factors for pain development were female gender [odds ratio (OR) 1.5, 95%
confidence interval (CI) 1.2–2.0], short education (OR 1.5, CI 1.0–2.2), poor
self-rated health (OR 3.3, CI 2.4–4.7), and having at least one long-standing
disease (OR 2.6, CI 2.0–3.4). Significant predictors for pain recovery were
male gender, younger age, cohabitation status, good self-rated health, good
mental health, having no long-standing disease, and having an annual income
above US$ 15400.
Pain, Article in Press
Chronic pain patients are impaired on an emotional
decision-making task
A. Vania Apkarian, Yamaya Sosa, Beth R. Krauss, P.
Sebastian Thomas, Bruce E. Fredrickson, Robert E. Levy, R. Norman Harden and
Dante R. Chialvo
Chronic
pain can result in anxiety, depression and reduced quality of life. However,
its effects on cognitive abilities have remained unclear although many studies
attempted to psychologically profile chronic pain. We hypothesized that
performance on an emotional decision-making task may be impaired in chronic
pain since human brain imaging studies show that brain regions critical for
this ability are also involved in chronic pain. Chronic back pain (CBP)
patients, chronic complex regional pain syndrome (CRPS) patients, and normal
volunteers (matched for age, sex, and education) were studied on the Iowa
Gambling Task, a card game developed to study emotional decision-making.
Outcomes on the gambling task were contrasted to performance on other cognitive
tasks. The net number of choices made from advantageous decks after subtracting
choices made from disadvantageous decks on average was 22.6 in normal subjects
(n=26), 13.4 in CBP patients (n=26), and -9.5 in CRPS patients (n=12), indicating
poor performance in the patient groups as compared to the normal controls
(P<0.004). Only pain intensity assessed during the gambling task was
correlated with task outcome and only in CBP patients (r=-0.75, P<0.003).
Other cognitive abilities, such as attention, short-term memory, and general
intelligence tested normal in the chronic pain patients. Our evidence indicates
that chronic pain is associated with a specific cognitive deficit, which may
impact everyday behavior especially in risky, emotionally laden, situations.
Pain, Article in Press
Central representation of muscle pain and mechanical
hyperesthesia in the orofacial region: a positron emission tomography study
Ron C. Kupers, Peter Svensson and Troels S. Jensen
Functional
neuroimaging studies of the human brain have revealed a network of brain
regions involved in the processing of nociceptive information. However,
little is known of the cerebral processing of pain originating from muscles.
The aim of this study was to investigate the cerebral activation pattern evoked
by experimental jaw-muscle pain and its interference by simultaneous mechanical
stimuli, which has been shown to evoke hyperesthesia. Ten healthy subjects
participated in a PET study and jaw-muscle pain was induced by bolus injections
of 5% hypertonic saline into the right masseter muscle. Repeated von Frey hair
stimulation (0.5 Hz) of the skin above the masseter muscle was used as the
mechanical stimulus. Hypertonic saline injections caused strong muscle pain
spreading to adjacent areas. von Frey stimulation was rated as non-painful but
produced hyperesthesia during jaw-muscle pain. Jaw-muscle pain was
associated with significant increases in regional cerebral blood flow (rCBF) in
the dorsal-posterior insula (bilaterally), anterior cingulate and prefrontal
cortices, right posterior parietal cortex, brainstem, cavernous sinus and
cerebellum. No rCBF changes occurred in primary or secondary somatosensory
cortices. In contrast, von Frey stimulation produced a significant rCBF
increase in the contralateral SI face representation. Mechanical
hyperesthesia was associated with significant rCBF increases in the subgenual
cingulate and the ventroposteromedial and dorsomedial thalamus. These
results suggest that the cerebral processing of jaw-muscle pain may differ from
the processing of cutaneous pain and that mechanical hyperesthesia, which often
is encountered in clinical cases, has a unique representation in the brain.
Salomons, Timothy V. ; Osterman, Janet E.; Gagliese,
Lucia; Katz, Joel
Pain Flashbacks in Posttraumatic Stress Disorder.
Clinical Journal of Pain. 20(2):83-87, March/April 2004.
Objectives:
Surgical patients who regain consciousness while under general anesthesia may
develop symptoms of Posttraumatic Stress Disorder (PTSD). One common PTSD
symptom is the experiencing of abnormal perceptions during which the patient
feels as if the trauma is recurring. The objective of this report is to
document the re-occurrence of pain as part of the PTSD sequelae. Results: We
present two patients who developed PTSD following an episode of awareness under
anesthesia. In both cases, posttraumatic sequelae persisted for years and
included pain symptoms that resembled, in quality and location, pain
experienced during surgery. In addition to their similarity to the original
pain, these pain symptoms were triggered by stimuli associated with the
traumatic situation, suggesting that they were flashbacks to the episode of
awareness under anesthesia. Discussion: The similarity between the patients'
pain symptoms and pain experienced during trauma, the triggering by traumatic
cues, and the associated emotional arousal and avoidance suggest the
involvement of a somatosensory memory mechanism.
Pain, Article in Press
Spinal cord stimulation for patients with failed back
surgery syndrome or complex regional pain syndrome: a systematic review of
effectiveness and complications
Judith A. Turner, John D. Loeser, Richard A. Deyo and
Stacy B. Sanders
We
conducted a systematic review of the literature on the effectiveness of spinal
cord stimulation (SCS) in relieving pain and improving functioning for patients
with failed back surgery syndrome and complex regional pain syndrome (CRPS). We
also reviewed SCS complications. Literature searches yielded 583 articles, of
which seven met the inclusion criteria for the review of SCS effectiveness, and
15 others met the criteria only for the review of SCS complications. Two
authors independently extracted data from each article, and then resolved
discrepancies by discussion. We identified only one randomized trial, which
found that physical therapy (PT) plus SCS, compared with PT alone, had a
statistically significant but clinically modest effect at 6 and 12 months in
relieving pain among patients with CRPS. Similarly, six other studies of much
lower methodological quality suggest mild to moderate improvement in pain with
SCS. Pain relief with SCS appears to decrease over time. The one randomized
trial suggested no benefits of SCS in improving patient functioning. Although
life-threatening complications with SCS are rare, other adverse events are
frequent. On average, 34% of patients who received a stimulator had an adverse
occurrence. We conclude with suggestions for methodologically stronger studies
to provide more definitive data regarding the effectiveness of SCS in relieving
pain and improving functioning, short- and long-term, among patients with
chronic pain syndromes.
Hypervigilance to Pain in Fibromyalgia: The Mediating
Role of Pain Intensity and Catastrophic Thinking About Pain
Crombez, Geert PhD, Eccleston, Chris, Van den Broeck,
Annelies, Goubert, Liesbet, Van Houdenhove, Boudewijn
Clinical Journal of Pain. 20(2):98-102, March/April 2004
Objective:
To investigate the mediating role of pain intensity, catastrophic thinking
about pain, and negative affectivity in explaining enhanced attention for pain
in patients with fibromyalgia. Methods: Sixty-four patients with fibromyalgia
and 46 patients with chronic low back pain completed self-report instruments of
vigilance to pain, negative affectivity, and catastrophic thinking about pain.
These measures, along with diagnostic group and pain intensity, were entered
into a partial correlational analysis to investigate which variables mediate
the relationship between diagnostic group (fibromyalgia vs. chronic low back
pain) and vigilance to pain. Results: Fibromyalgia patients reported
significantly greater vigilance to pain than patients with chronic low back
pain. They also reported higher pain intensity, more negative affectivity, and
more catastrophic thinking about pain than patients with chronic low back pain.
Vigilance to pain was correlated significantly with pain intensity, negative
affectivity, and catastrophic thinking about pain. Further analyses revealed
that pain intensity and catastrophic thinking about pain, but not negative
affectivity, mediated the relationship between diagnostic group and vigilance
to pain. Conclusion: Fibromyalgia patients report a heightened vigilance to
pain. This vigilance is not a unique characteristic of fibromyalgia but is related
to the intensity of pain and catastrophic thinking about pain.
Confirmatory Factor Analysis of the Tampa Scale for
Kinesiophobia: Invariant Two-Factor Model Across Low Back Pain Patients and
Fibromyalgia Patients.
Goubert, Liesbet; Crombez, Geert; Van Damme, Stefaan;
Vlaeyen, Johan W. S.; Bijttebier, Patricia; Roelofs, Jeffrey
Clinical Journal of Pain. 20(2):103-110, March/April 2004.
Objectives:
(1) To investigate the factor structure of the Tampa Scale for Kinesiophobia
(TSK) in a Dutch-speaking sample of chronic low back pain (CLBP) patients using
confirmatory factor analysis, (2) to examine whether the internal structure of
the TSK extends to another group of fibromyalgia (FM) patients, and (3) to
investigate the stability of the factor structure in both patient groups using
multi-sample analysis. Patients and Methods: TSK-data from 8 studies collected
in Dutch and Flemish chronic pain patients were pooled. For 188 CLBP patients
and 89 FM patients, complete data were available. Confirmatory factor analyses
were performed to assess 4 models of kinesiophobia, and to examine which factor
model provided the best fit. Furthermore, a multi-sample analysis was performed
to investigate the stability of the factor structure in both patient groups.
Results: For both CLBP and FM patients, the 2-factor model containing the
factors "activity avoidance" and "pathologic somatic focus"
was superior as compared with the 4-factor model containing the factors
"harm," "fear of (re)injury." "importance of
exercise," and "avoidance of activity". Moreover, the 2-factor
model was found to be invariant across CLBP and FM patients, indicating that
this model is robust in both pain samples. Discussion: As the 2-factor
structure provided the best fit of the data in both patient samples, we
recommend to use this version of the TSK and its 2 subscales in both clinical
practice and research. Based on the content of the items, the subscales were
labeled "Harm" and "Fear-avoidance."
Smith, Michael T.; Perlis, Michael L.; Haythornthwaite,
Jennifer A.
Suicidal Ideation in Outpatients With Chronic
Musculoskeletal Pain: An Exploratory Study of the Role of Sleep Onset Insomnia
and Pain Intensity.
Clinical Journal of Pain. 20(2):111-118, March/April 2004.
Objectives:
Sleep disturbance, depression, and heightened risk of suicide are among the
most clinically significant sequelae of chronic pain. While sleep disturbance
is associated with suicidality in patients with major depression and is a
significant independent predictor of completed suicide in psychiatric patients,
it is not known whether sleep disturbance is associated with suicidal behavior
in chronic pain. This exploratory study evaluates the importance of insomnia in
discriminating suicidal ideation in chronic pain relative to depression
severity and other pain-related factors. Methods: Fifty-one outpatients with
non-cancer chronic pain were recruited. Subjects completed a pain and sleep
survey, the Pittsburgh Sleep Quality Index, the Beck Depression Inventory, and
the Multidimensional Pain Inventory. Subjects were classified as "suicidal
ideators" or "non-ideators" based on their responses to BDI-Item
9 (Suicide). Bivariate analyses and multivariate discriminant function analyses
were conducted. Results: Twenty-four percent reported suicidal ideation
(without intent). Suicidal ideators endorsed higher levels of: sleep onset
insomnia, pain intensity, medication usage, pain-related interference,
affective distress, and depressive symptoms (P < 0.03). These 6 variables
were entered into stepwise discriminant function analyses. Two variables
predicted group membership: Sleep Onset Insomnia Severity and Pain Intensity,
respectively. The discriminant function correctly classified 84.3% of the cases
(P < 0.0001). Discussion: Chronic pain patients who self-reported severe
and frequent initial insomnia with concomitant daytime dysfunction and high
pain intensity were more likely to report passive suicidal ideation,
independent from the effects of depression severity. Future research aimed
at determining whether sleep disturbance is a modifiable risk factor for
suicidal ideation in chronic pain is warranted.
(JUST) HEADACHE
Headache: The Journal of Head and Face Pain
Volume 43 Issue 10 Page 1042 - November 2003
Exploring the Relationship Between Maternal Migraine
and Child Functioning
Maria A. Fagan, MSc
Objective.To
investigate the relationship between mothers' migraines and the roles and
expectations of their children. Methods.Twenty-five mothers diagnosed with
migraine completed questionnaires concerning their levels of migraine-related
disability and their parenting and child-rearing attitudes. Migraine-related
disability was assessed using the Migraine-Specific Quality of Life
Questionnaire (version 2.1). Parenting and child-rearing attitudes were
assessed using the Adult-Adolescent Parenting Inventory. Results.Significant
positive relationships were found between the mothers' migraine-related
disability and both inappropriate expectations of their children and
parent-child role reversal; ie, the more migraine-related disability reported
by the mothers, the more they reported having inappropriate expectations of
their children and favoring parent-child role reversal. Conclusions.This study
suggests that migraine may be associated with dysfunctional parenting
patterns. More specifically, it suggests that in families wherein the
mother has migraine, children may be at risk of inappropriately or
prematurely assuming roles for which they are developmentally unready. Clinical
implications are that mothers with migraine may benefit from some type of
family-focused intervention, in addition to headache treatment.
Headache: The Journal of Head and Face Pain
Volume 43 Issue 10 Page 1097 - November 2003
Work Attendance Despite Headache and Its Economic
Impact: A Comparison Between Two Workplaces
Ragnhild Raak, RN, PhD; Anders Raak, MD
Objective.To
study work attendance despite headache in 2 different workplaces and its
economic impact. Background.Literature on the economic impact of headache
traditionally has focused on direct costs. Little is known concerning headache
experienced at work and its costs due to loss of effectiveness and
productivity. Method.We sent a questionnaire to 800 employees in Sweden400 at a
technology company (private employee population) and 400 at a university
hospital (public employee population). We attempted to assess the prevalence of
headache, work attendance despite the presence of acute headache, and the
impact of acute headache upon work effectiveness. Subjects self-scored
decreased work effectiveness resulting from headache during the previous 3
months and recorded the number of days at work despite headache. From these
data, we estimated the economic loss resulting from headache. Results.The
survey response rate was 71.5%. The prevalence of headache was 64% in the
private employee population and 78% in the public employee population.
Thirty-nine percent of the private employees and 57% of the public employees
reported experiencing headache as a result of stress. Fifty percent reported
that they went to work despite headache, and the mean number of days at work
despite headache, during the previous 3 months, was 6.6 days in the private
employee group and 6.1 days in the public employee group. A 25% decrease in
work effectiveness was estimated, and, extrapolating from our data, we
calculated the cost of lost effectiveness due to headache among employers in
Sweden to be approximately 1.4 billion euros a year. Conclusion.The economic
burden of headache experienced at work is substantial, suggesting that
workplace-based treatment and prevention programs emphasizing stress management
may be financially, as well as clinically, advantageous.
Headache: The Journal of Head and Face Pain
Volume 43 Issue 10 Page 1049 - November 2003
Migraine Frequency and Intensity: Relationship With
Disability and Psychological Factors
Jane E. Magnusson, PhD; Werner J. Becker, MD
Background.Migraine
can be disabling, but it varies greatly in frequency and intensity between
individuals. It is not clear which clinical features have the greatest impact
on a migraineur's quality of life. Objective.To determine the influence of
headache intensity and frequency on headache-related disability. Methods.Patients
who were referred to a headache clinic and given a diagnosis of migraine with
or without aura or transformed migraine (n = 115) were divided into different
groups based on headache frequency and mean headache intensity. Headache
frequency was determined from patient diaries. Headache intensity also was
assessed from patient diaries and from scores on the pain severity scale of the
Multidimensional Pain Inventory (MPI). Headache-related disability was assessed
with the Headache Disability Inventory and by scores on the activity
interference scale of the MPI. The degree of depression present was assessed
with the Beck Depression Inventory, and emotional distress was measured by
scores on the affective distress scale of the MPI. Results.In our patient
population, higher mean headache intensity levels were associated with higher
levels of headache-related disability. Our results also suggested that
increased headache intensity is associated with higher levels of depression and
emotional distress, although this correlation was statistically significant in
only 1 of 4 comparisons. Headache frequency did not correlate with disability,
depression, or emotional distress. Conclusions.For a headache referral
population, headache intensity appears to be a major determinant of
headache-related disability, and it also correlates, to some extent, with the
degree of depression and emotional distress present. Headache frequency was not
clearly related to disability or psychological factors.
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