The association between experimental and clinical pain measures among persons with fibromyalgia and chronic fatigue syndrome.

Evoked or experimental pain is often used as a model for the study of clinical pain, yet there are little data regarding the relationship between the two. In addition, there are few data regarding the types of stimuli and stimulus intensities that are most closely related to clinical pain. In this study, 36 subjects with fibromyalgia (FM), chronic fatigue syndrome (CFS), or both syndromes were administered measures of clinical pain and underwent a dolorimetry evaluation. Subjects also underwent experimental pain testing utilizing heat and pressure stimulation. Stimulation levels evoking low, moderate and high sensory intensity, and comparable levels of unpleasantness, were determined for both types of stimuli using random staircase methods. Clinical pain was assessed using visual analogue ratings and the short form of the McGill Pain Questionnaire (MPQ). Ratings of heat pain sensation were not significantly associated with clinical pain ratings, with the exception of unpleasantness ratings at high stimulus intensities. Pain threshold and tolerance as assessed by dolorimetry were significantly associated with average measures of clinical pain. Both intensity and unpleasantness ratings of pressure delivered using random staircase methods were significantly associated with clinical pain at low, moderate and high levels, and the strength of the association was greater at increasingly noxious stimulus intensities. These findings suggest that random pressure stimulation as an experimental pain model in these populations more closely reflects the clinical pain for these conditions. These findings merit consideration when designing experimental studies of clinical pain associated with FM and CFS.     

Psychological treatments for fibromyalgia: A meta-analysis

The aims of the present analysis were to investigate the short- and long-term efficacies and treatment moderators of psychological interventions for fibromyalgia. A literature search using PubMed, PsychINFO, the Cochrane Library, and manual searches identified 23 eligible studies including 30 psychological treatment conditions and 1396 patients. Meta-analytic integration resulted in a significant but small effect size for short-term pain reduction (Hedges’s g = 0.37, 95% confidence interval (CI): 0.27-0.48) and a small-to-medium effect size for long-term pain reduction over an average follow-up phase of 7.4 months (Hedges’s g = 0.47, 95% CI: 0.3-0.65) for any psychological intervention. Psychological treatments also proved effective in reducing sleep problems (Hedges’s g = 0.46, 95% CI: 0.28-0.64), depression (Hedges’s g = 0.33, 95% CI: 0.20-0.45), functional status (Hedges’s g = 0.42, 95% CI: 0.25-0.58), and catastrophizing (Hedges’s g = 0.33, 95% CI: 0.17-0.49). These effects remained stable at follow-up. Moderator analyses revealed cognitive-behavioral treatment to be significantly better than other psychological treatments in short-term pain reduction (Hedges’s g = 0.60, 95% CI: 0.46-0.76). Higher treatment dose was associated with better outcome. Publication-bias analyses demonstrated that the effect sizes were robust. The results suggest that the effects of psychological treatments for fibromyalgia are relatively small but robust and comparable to those reported for other pain and drug treatments used for this disorder. Cognitive-behavioral therapy was associated with the greatest effect sizes.     

Self-reported somatosensory symptoms of neuropathic pain in fibromyalgia and chronic widespread pain correlate with tender point count and pressure-pain thresholds

Widespread pain and pain hypersensitivity are the hallmark of fibromyalgia, a complex pain condition linked to central sensitization. In this study the painDETECT questionnaire (PDQ), validated to identify neuropathic pain and based on pain quality items, was applied in a cross-sectional sample of patients with chronic widespread pain (CWP). The aims of the study were to assess the patient-reported sensory neuropathic symptoms by PDQ and to correlate these with tender point (TP) count and pressure-pain thresholds. Eighty-one patients (75 F, 6 M) with CWP (ACR-criteria) filled in the PDQ. Manual TP examination was conducted according to ACR guidelines. Computerized cuff pressure algometry was used for the assessment of pressure-pain detection thresholds (PDT, unit: kPa) and pressure-pain tolerance thresholds (PTT, unit: kPa). Mean TP count was 14.32 (range: 2-18), mean PDQ score 22.75 (range: 5-37). Mean PDT was 8.8 kPa (range: 2-36) and mean PTT 30.9 kPa (range: 4-85). Deep-tissue hyperalgesia was the predominant somatosensory symptom reported in 83%, but other neuropathic symptoms were also frequent, e.g. burning 51% and prickling 47%. Statistically significant correlations were found between PDQ score and TP count: r = 0.35 (p < 0.01), and PDQ score and PDT: r = 0.45 (p < 0.01), and PTT: r = 0.43 (p < 0.01). The study indicates that pain in CWP has neuropathic features, and that the presence and number of tender points are associated with neuropathic pain symptoms. A high mean PDQ score was found to correlate with TP count and pressure-pain thresholds. The PDQ may become a useful tool assisting in the identification of central sensitization in patients with CWP and in the future diagnostic assessment fibromyalgia.     

The role of cannabis in treatment-resistant fibromyalgia women

Background

Fibromyalgia is a complex pain-focused syndrome. Previous studies showed that Cannabis is efficacious in promoting sleep, deepening and lengthening the sleep cycle, and good pain relief (compared with the SSRIs and SNRIs).

Purpose

This study aimed to use the World Health Organization Quality of Life Bref questionnaire (WhoQoL-bref) to characterize the impact of Cannabis Treatment initiation on the quality of life in women suffering from treatment-resistant fibromyalgia.

Methods

A prospective cohort study involving 30 women aged 18–70 years old diagnosed with fibromyalgia, exhausted pharmacological fibromyalgia treatment, and started Cannabis treatment. Pregnant women were excluded. WhoQoL-bref was filled before Cannabis treatment initiation and 1 month following treatment.

Results

Women's average age was 46 years (±5), with a poor general quality of life (1.47 ± 0.63), poor general health (1.47 ± 0.78), pain and discomfort, and dependence on medication (3.77 ± 1.3 and 3.07 ± 1.74, respectively) prior to Cannabis intervention. Cannabis treatment for 30 days showed a marked improvement in general quality of life (1.97 scores, p < 0.01), general health (1.83, p < 0.01), physical health (1.5, p < 0.01), and psychological domain (1.3, p < 0.01). Financial resources and home environment were not influenced by cannabis treatment (p = 0.07, p = 0.31, respectively).

Conclusion

Results suggest a potentially significant role of Cannabis in treatment-resistant Fibromyalgia women. Early Cannabis treatment may result in a beneficial short-term effect on the quality of life through its influence on pain, sleep, and physical and psychological domains. Further studies are still indicated to understand this potential and its long-term beneficial impact.     

常见慢性咳嗽病因及其诊断探讨

目的 探讨常见慢性咳嗽的病因及疾病表现的临床意义,为经验性治疗提供依据.方法 按慢性咳嗽的病因诊断流程对160例患者的病因构成进行分析,比较常见病因慢性咳嗽患者的咳嗽时相、性质、诱发因素及相关伴随症状,统计方法采用U检验,计算P值.结果 共入选160例2009年1月至12月宜昌市中心人民医院呼吸科门诊慢性咳嗽患者,其中常见病因分布依次为咳嗽变异性哮喘(CVA) 72例占45.00％、上气道咳嗽综合征(UACS) 54例占33.75％、嗜酸性粒细胞性支气管炎(EB) 14例占8.75％、胃食管反流性咳嗽(GERC)9例占5.63％,其他病因共11例、占6.87％.不同病因组临床表现有差异.CVA患者夜间咳嗽构成比为52.8(38/72),明显高于其他病因;UACS患者以白天咳嗽为主,70.2％伴有鼻后滴流症状,且绝大部分伴有鼻炎相关症状或有鼻炎病史,高于其他各组;GERC患者饮食相关咳嗽占66.7％,77.8％伴有反流症状明显高于其他病因组;上述症状差异均有统计学意义.但EB患者临床症状无特异性.结论 各种病因的慢性咳嗽具有一定的临床特征,慢性咳嗽病因构成及咳嗽时相、部分伴随症状对病因诊断具有一定的参考价值.     

Cigarette smoking and pain: depressive symptoms mediate smoking-related pain symptoms

Numerous studies have shown an association between smoking and pain, with smokers reporting more pain and worse functioning. However, little is known about factors that impact this complex relationship. This study investigated the association between smoking, pain, and depressive symptoms. Participants were new patients seen at a multidisciplinary pain clinic. All patients were mailed an intake packet of validated questionnaires as part of an ongoing research and clinical care initiative. Of the 497 patients evaluated, 426 had valid smoking data. Among these patients, 32.6% (n = 139) reported being current smokers, 31.7% (n = 135) were classified as former smokers, and 35.7% (n = 152) were never smokers. A multivariate analysis of covariance (smoking status, age, gender, education) revealed a main effect for pain severity (F = 7.36, P<0.001), pain interference (F = 4.03, P = 0.001), and depressive symptoms (F = 7.87, P<0.001). Current smokers demonstrated higher pain severity, pain interference, and depressive symptoms compared with former smokers and never smokers (P<0.01 for all analyses), while there were no differences between the former-smoker and never-smoker groups. However, the effect of smoking on pain severity (P = 0.06) and pain interference (P = 0.22) was no longer significant after controlling for depressive symptoms in a mediation model. Additionally, among former smokers, longer quit duration was associated with less pain severity. In conclusion, smoking rates were high and smoking was associated with a worse chronic pain phenotype. Importantly, depressive symptoms emerged as a critical mediating factor in helping to explain the relationship between smoking and pain.     

Determination of fibromyalgia syndrome after whiplash injuries: methodologic issues

Problems in diagnosing fibromyalgia syndrome (FM) among motor vehicle collision (MVC) patients with whiplash (WL) include the following: the predominance of tender points (TPs) in the neck/shoulder girdle region; the 3-month duration of widespread pain criterion; and, the stability of diagnosis. The present study examined the prevalence of FM in a cohort (N = 326) patients with persistent neck pain 3 months after WL injury who were enrolled in a treatment program. Physical examinations were performed at baseline and at the end of treatment. Results indicated that WL patients had a greater proportion of neck/shoulder girdle TPs, relative to distal TPs. Compared with a matched cohort of treatment-seeking FM patients, WL patients indicated less distal TPs (mean = 7.3 TPs vs mean = 5.6 TPs, P < .001), but were equivalent on neck/shoulder girdle TPs (mean = 9.0 TPs vs 9.2 TPs, NS). Baseline prevalence of FM for the WL cohort based on ACR criteria was 14% (95% CI = 10%-18%), adjusted TP criterion discounting for neck/shoulder tenderness indicated a prevalence of FM of 8% (95% CI = 5%-11%). Finally, 63% of patients meeting American College of Rheumatology FM criteria at baseline did not meet this criterion at post-treatment (∼6-months after an MVC). In conclusion, present criteria used in determining FM may result in spuriously inflated rates of diagnosis among WL patients because of persistent localized tenderness after an MVC. Furthermore, the transient nature of FM “symptoms” among WL patients should be taken into account before making a final diagnosis.     

Long-term maintenance of the analgesic effects of transcranial magnetic stimulation in fibromyalgia

We assessed for the first time the long-term maintenance of repetitive transcranial magnetic stimulation (rTMS)-induced analgesia in patients with chronic widespread pain due to fibromyalgia. Forty consecutive patients were randomly assigned, in a double-blind fashion, to 2 groups: one receiving active rTMS (n = 20) and the other, sham stimulation (n = 20), applied to the left primary motor cortex. The stimulation protocol consisted of 14 sessions: an “induction phase” of 5 daily sessions followed by a “maintenance phase” of 3 sessions a week apart, 3 sessions a fortnight apart, and 3 sessions a month apart. The primary outcome was average pain intensity over the last 24 hours, measured before each stimulation from day 1 to week 21 and at week 25 (1 month after the last stimulation). Other outcomes measured included quality of life, mood and anxiety, and several parameters of motor cortical excitability. Thirty patients completed the study (14 in the sham stimulation group and 16 in the active stimulation group). Active rTMS significantly reduced pain intensity from day 5 to week 25. These analgesic effects were associated with a long-term improvement in items related to quality of life (including fatigue, morning tiredness, general activity, walking, and sleep) and were directly correlated with changes in intracortical inhibition. In conclusion, these results suggest that TMS may be a valuable and safe new therapeutic option in patients with fibromyalgia.     

Emotional modulation of pain and spinal nociception in fibromyalgia

Fibromyalgia (FM) is characterized by widespread pain, as well as affective disturbance (eg, depression). Given that emotional processes are known to modulate pain, a disruption of emotion and emotional modulation of pain and nociception may contribute to FM. The present study used a well-validated affective picture-viewing paradigm to study emotional processing and emotional modulation of pain and spinal nociception. Participants were 18 individuals with FM, 18 individuals with rheumatoid arthritis (RA), and 19 healthy pain-free controls (HC). Mutilation, neutral, and erotic pictures were presented in 4 blocks; 2 blocks assessed only physiological-emotional reactions (ie, pleasure/arousal ratings, corrugator electromyography, startle modulation, skin conductance) in the absence of pain, and 2 blocks assessed emotional reactivity and emotional modulation of pain and the nociceptive flexion reflex (NFR, a physiological measure of spinal nociception) evoked by suprathreshold electric stimulations over the sural nerve. In general, mutilation pictures elicited displeasure, corrugator activity, subjective arousal, and sympathetic activation, whereas erotic pictures elicited pleasure, subjective arousal, and sympathetic activation. However, FM was associated with deficits in appetitive activation (eg, reduced pleasure/arousal to erotica). Moreover, emotional modulation of pain was observed in HC and RA, but not FM, even though all 3 groups evidenced modulation of NFR. Additionally, NFR thresholds were not lower in the FM group, indicating a lack of spinal sensitization. Together, these results suggest that FM is associated with a disruption of supraspinal processes associated with positive affect and emotional modulation of pain, but not brain-to-spinal cord circuitry that modulates spinal nociceptive processes.     

The potential benefits of applying a narrative analytic approach for understanding the experience of fibromyalgia: a review

Purpose: People with fibromyalgia (FM), a medically unexplained illness, habitually experience widespread pain and fatigue. While some qualitative research has aimed to understand the experiences of people with FM, studies from a specific narrative perspective are particularly lacking. This review argues that future research could be significantly enhanced by studies which analyse the narratives of people with FM. Method: This argument is made through reference to an examination of the extant qualitative literature on the experience of FM and theories and narrative studies on chronic illnesses and identity. Results: The empirical literature is reviewed from a narrative perspective; this assumes that the stories people tell reveal much about their identities and social worlds. As such, it is proposed that narrative analysis is particularly well suited for exploring issues of self and culture and for appreciating how meanings evolve over time. Further, it is also argued that consideration of these issues is particularly relevant for understanding the experience of FM given the enigmatic nature of the syndrome and its chronic course. Conclusions: The review concludes by emphasizing that narrative analysis is a valuable method which offers the potential for uncovering novel insights about the illness experience for these individuals.

Implications for Rehabilitation

• Fibromyalgia is a chronic syndrome characterised by pain and fatigue.

• Previous research has neglected the social context within which experience of fibromyalgia develops.

• Narrative studies have the potential to reveal how people make sense of illness.

• It is important for health professionals to acknowledge and validate the uncertainly of the illness experience in fibromyalgia.

     

Effects of a six-week mobile app versus paper book intervention on quality of life,symptoms, and self-care in patients with fibromyalgia: a randomized parallel trial

BackgroundThe ProFibro application (app) was developed as a Mobile Health resource to promote self-care in fibromyalgia management.ObjectiveThis study aimed to assess the effects of the use of the ProFibro app for six weeks compared to the use of a traditional paper book of similar content to improve health-related quality of life, symptoms, and self-care agency in individuals with fibromyalgia.MethodsForty individuals with fibromyalgia were included in this randomized, single-blind, parallel trial. One group received intervention content using the ProFibro app on a smartphone while the other received similar information using a paper book. Participants were assessed at baseline and after six weeks. The primary outcome was the Revised Fibromyalgia Impact Questionnaire. Secondary outcomes were Widespread Pain Index, Pain Visual Analog Scale, Symptom Severity Scale, and Appraisal of Self-Care Agency Scale – Revised.ResultsNo differences in changes were found between groups at the end of the treatment for any outcome. Both groups showed improvements in symptom severity.ConclusionsThe use of the ProFibro app for six weeks was not more effective than the use of a traditional paper book with similar content for health-related quality of life, symptoms, or self-care agency in individuals with fibromyalgia. Both groups showed improvements from baseline on severity of symptoms, suggesting that the self-care program using a mobile app or a paper book may be beneficial for individuals with fibromyalgia.     

Clustering of symptoms associated with fibromyalgia in a Finnish Twin Cohort

The objective was to assess the prevalence and heritability of symptoms associated with fibromyalgia in a population‐based working‐age twin sample. The study was based on the 12,502 like‐sexed twins of the Finnish Twin Cohort and 49 diagnosed fibromyalgia patients who answered the same questionnaire in 1990–1992. Questions that were considered to best match symptoms of fibromyalgia were validated between the twins and the fibromyalgia patients. Latent class analysis was used to classify the subjects into more homogeneous groups with respect to the symptom items. The pairwise distribution of symptom classes in relation to zygosity and gender was modelled using quantitative genetic models to estimate heritability. Responses to all fibromyalgia‐related items were obtained from 10,608 twins. A similar proportion of men (12%) and women (13%) was placed in the third latent class, which best represented possible fibromyalgia patients. Subjects in this class had a similar symptom profile as the diagnosed fibromyalgia patient group, but they were less severely affected. The two other latent classes represented subjects that were virtually symptom free and subjects with some symptoms. The heritability of liability to symptom class membership was estimated to be 51% (95% CI 45–56%). The prevalence of symptoms associated with fibromyalgia in our population‐based sample unselected for disease status was comparable to the prevalence of widespread pain reported in population based studies. The symptoms known to be associated with fibromyalgia seem to have a strong genetic background.     

Parent perceptions of adolescent pain expression: the adolescent pain behavior questionnaire

Pain behaviors provide meaningful information about adolescents in chronic pain, enhancing their verbal report of pain intensity with information about the global pain experience. Caregivers likely consider these expressions when making judgments about their adolescents’ medical or emotional needs. Current validated measures of pain behavior target acute or procedural pain and young or non-verbal children, while observation systems may be too cumbersome for clinical practice. The objective of this research was to design and evaluate the Adolescent Pain Behavior Questionnaire (APBQ), a parent-report measure of adolescent (11-19 years) pain expressions. This paper provides preliminary results on reliability and validity of the APBQ. Parent-adolescent dyads (N = 138) seen in a multidisciplinary pain management clinic completed the APBQ and questionnaires assessing pain characteristics, quality of life, functional disability, depressive symptoms, and pain catastrophizing. Principal components analysis of the APBQ supported a single component structure. The final APBQ scale contained 23 items with high internal consistency (α = 0.93). No relationship was found between parent-reported pain behaviors and adolescent-reported pain intensity. However, significant correlations were found between parent-reported pain behaviors and parent- and adolescent-reported functional disability, pain catastrophizing, depressive symptoms, and poorer quality of life. The assessment of pain behaviors provides qualitatively different information than solely recording pain intensity and disability. It has clinical utility for use in behavioral treatments seeking to reduce disability, poor coping, and distress.     

Disruption of cognitive function in fibromyalgia syndrome

Accumulating evidence points to significant cognitive disruption in individuals with Fibromyalgia Syndrome (FMS). This study was carried out in order to examine specific cognitive mechanisms involved in this disruption. Standardized experimental paradigms were used to examine attentional function and working memory capacity in 30 women with FMS and 30 matched controls. Cognitive function was examined using performance on these tests and between group results were analysed in the context of important psychological and behavioural measures. Performance of standardized everyday attentional tasks was impaired in the FMS group compared to controls. Working memory was also found to be impaired in this group. Stimulus interference was found to be significantly worse in the FMS group as the demands of the tasks increased. These effects were found to exist independent of the measures of mood and sleep disruption. However, when pain levels were accounted for statistically, no differences existed between groups on cognitive measures. These findings point to disrupted working memory as a specific mechanism that is disrupted in this population. The results of this study suggest that pain in FMS may play an important role in cognitive disruption. It is likely that many factors, including disrupted cognition, play a role in the reduced quality of life reported by individuals with FMS.     

The relationship between work engagement and psychological distress of hospital nurses and the perceived communication behaviors of their nurse managers: A cross-sectional survey

BackgroundCommunication between nurse managers and nurses is important for mental health of hospital nurses.ObjectiveThe aim of the present study was to investigate the relationship between managers’ communication behaviors toward nurses, and work engagement and psychological distress among hospital nurses using a multilevel model.DesignThe present study was a cross-sectional questionnaire survey.SettingsThe participants were nurses working at three hospitals in Japan.ParticipantsA total of 906 nurses from 38 units participated in the present study. The units with small staff sizes and participants with missing entries in the questionnaire were excluded. The data for 789 nurses from 36 questionnaire survey units were analyzed.MethodA survey using a self-administered questionnaire was conducted. The questionnaire asked staff nurses about communication behaviors of their immediate manager and their own levels of work engagement, psychological distress, and other covariates. Three types of manager communication behaviors (i.e., direction-giving, empathetic, and meaning-making language) were assessed using the Motivating Language scale; and the scores of the respondents were averaged for each unit to calculate unit-level scores. Work engagement and psychological distress were measured using the Utrecht Work Engagement Scale and the K6 scale, respectively. The association of communication behaviors by unit-level managers with work engagement and psychological distress among nurses was analyzed using two-level hierarchical linear modeling.ResultsThe unit-level scores for all three of the manager communication behaviors were significantly and positively associated with work engagement among nurses (p < 0.05). This association was smaller and non-significant after adjusting for the psychosocial work environment. The individual levels of all three of the manager communication behaviors were also significantly and positively associated with work engagement (p < 0.05). None of the three manager communication behaviors was significantly associated with psychological distress (p > 0.05).ConclusionMotivating language by unit-level managers might be positively associated with work engagement among hospital nurses, which is mediated through the better psychosocial work environment of the unit.     

The role of cardiovascular activity in fibromyalgia and conditioned pain modulation

Fibromyalgia (FM) is a chronic widespread pain condition of unknown origin. Reduced endogenous pain inhibition could be related to high pain sensitivity in FM. Associations between conditioned pain modulation (CPM) and cardiovascular responses to pain have been observed in healthy subjects (HS). Because reduced cardiovascular reactivity to various stressors has been reported in FM patients, we investigated relationships between CPM and cardiovascular response to the cold pressor test (CPT) in 22 FM patients and 25 HS. CPM was evaluated by comparing pain intensity produced by a 120-second heat test stimulus (HTS) before and after a CPT (2 minutes, 12°C). The CPT, used to activate CPM, produced greater pain intensity in FM patients. Patients with FM had higher heart rates than HS at baseline and during CPT. Higher heart rate was related with higher pain intensity during the CPT. Blood pressure increments during CPT were weaker in the FM group. CPM was less effective in FM patients than in HS. Importantly, systolic blood pressure responses during CPT were positively related to CPM effectiveness, suggesting that reduced blood pressure response during the conditioning stimulus could be involved in CPM dysfunction in the FM group. Higher heart rate could be implicated in the greater sensitivity to cold pain in FM. Patients with FM have reduced blood pressure response to a painful CPT. Reduced cardiovascular reactivity to pain could have important involvement in diminished endogenous pain inhibition efficacy and FM pathophysiology.     

Maintenance of windup of second pain requires less frequent stimulation in fibromyalgia patients compared to normal controls

Many chronic pain syndromes, including fibromyalgia (FM), show evidence of central nervous system hyperexcitability related to central sensitization. Windup (WU) of second pain reflects increased excitability of spinal cord neurons that is related to central sensitization. Psychophysical testing can help characterize this important central nervous system phenomenon because of the parallels between electrophysiological WU and WU of second pain. Animal experiments have shown that once WU has been established, only low frequency tonic nociceptive input is required to maintain the sensitized state of dorsal horn neurons (WU-maintenance or WU-M). The stimulus frequency necessary to maintain the hyperexcitability of spinal cord neurons can provide a measure of central sensitization. Because central sensitization plays an important role in many chronic pain syndromes including FM, we compared WU-M in 72 normal controls (NC) and 104 FM subjects. WU of second pain was produced by a train of 0.7 s duration thermal pulses applied to the glabrous surface of the hands at a frequency of 0.3 Hz. Enhanced second pain associated with WU could, thereafter, be maintained in FM but not NC subjects for up to 120 s by stimuli delivered at 0.16 and 0.08 Hz (WU-M stimuli). These two frequencies of stimulation do not produce WU when delivered alone. Thus, unlike NC subjects, FM subjects showed enhanced second pain during WU-M stimuli at very low stimulus frequencies, indicating central sensitization. Increased WU sensitivity, enhanced WU-M, and increased WU-related aftersensations help account for persistent pain conditions in FM subjects. In addition to WU, WU-M appears to be a useful tool to study mechanisms of pain in patients with characteristics of central sensitization.     

The relationship between PTSD and chronic pain: Mediating role of coping strategies and depression

People with chronic pain and comorbid posttraumatic stress disorder (PTSD) report more severe pain and poorer quality of life than those with chronic pain alone. This study evaluated the extent to which associations between PTSD and chronic pain interference and severity are mediated by pain-related coping strategies and depressive symptoms. Veterans with chronic pain were divided into 2 groups, those with (n = 65) and those without (n = 136) concurrent PTSD. All participants completed measures of pain severity, interference, emotional functioning, and coping strategies. Those with current PTSD reported significantly greater pain severity and pain interference, had more symptoms of depression, and were more likely to meet diagnostic criteria for a current alcohol or substance use disorder (all p-values <.01). Participants with PTSD reported more use of several coping strategies, including guarding, resting, relaxation, exercise/stretching, and coping self-statements. Illness-focused pain coping (i.e., guarding, resting, and asking for assistance) and depressive symptoms jointly mediated the relationship between PTSD and both pain interference (total indirect effect = 0.194, p < .001) and pain severity (total indirect effect = 0.153, p = .004). Illness-focused pain coping also evidenced specific mediating effects, independent of depression. In summary, specific pain coping strategies and depressive symptoms partially mediated the relationship between PTSD and both pain interference and severity. Future research should examine whether changes in types of coping strategies after targeted treatments predict improvements in pain-related function for chronic pain patients with concurrent PTSD.     

COMT moderates the relation of daily maladaptive coping and pain in fibromyalgia

Forty-five women with fibromyalgia (FM) engaged in a 30-day electronic diary assessment, recording daily ratings of pain and 2 forms of maladaptive coping: pain catastrophizing and pain attention. Participants were genotyped for the val¹⁵⁸met single nucleotide polymorphism (rs4680) in the catechol-O-methyltransferase (COMT) gene. COMT genotype moderated the daily relations of both maladaptive coping processes and pain. FM women with the homozygous met/met genotype evidenced more pain on days when pain catastrophizing was elevated relative to heterozygous and homozygous val¹⁵⁸ carriers. FM women with the homozygous met/met genotype evidenced more pain on days when pain attention was elevated relative to those with the homozygous val/val genotype. Evidence is presented to suggest that these are independent effects. The findings provide multimeasure and multimethod support for genetic moderation of a maladaptive coping and pain process, which has been previously characterized in a sample of postoperative shoulder pain patients. Further, the findings advance our understanding of the role of COMT in FM, suggesting that genetic variation in the val¹⁵⁸met polymorphism may affect FM pain through pathways of pain-related cognition.     

Efficacy of memantine in the treatment of fibromyalgia: A double-blind,randomised, controlled trial with 6-month follow-up

Fibromyalgia (FM) is a prevalent and disabling chronic disease. Recent studies have found elevated levels of glutamate in several brain regions, leading to hypotheses about the usefulness of glutamate-blocking drugs such as memantine in the treatment of FM. The aim of this study was to evaluate the efficacy of memantine in the treatment of pain and other clinical variables (global function, clinical impression, depression, anxiety, quality of life) in FM patients. A double-blind, parallel randomised controlled trial was developed. A total of 63 patients diagnosed with FM were recruited from primary health care centres in Zaragoza, Spain. Memantine was administered at doses of 20 mg/d after 1 month of titration. Assessments were carried out at baseline, posttreatment, and 3- and 6-month follow-up. Compared with a placebo group, memantine significantly decreased ratings on a pain visual analogue scale (Cohen’s d = 1.43 at 6 months) and pain measured with a sphygmomanometer (d = 1.05). All other secondary outcomes except anxiety also improved, with moderate-to-large effect sizes at 6 months. Compared with placebo, the absolute risk reduction obtained with memantine was 16.13% (95% confidence interval = 2.0% to 32.6%), and the number needed to treat was 6.2 (95% confidence interval = 3 to 47). Tolerance was good, with dizziness (8 patients) and headache (4 patients) being the most frequent side effects of memantine. Although additional studies with larger sample sizes and longer follow-up times are needed, this study provides preliminary evidence of the utility of memantine for the treatment of FM.