Cardiac-Gated Neuromodulation Increased Baroreflex Sensitivity and Reduced Pain Sensitivity in Female Fibromyalgia Patients.

The study presents a novel approach of programing pain inhibition in chronic pain patients based on the hypothesis that pain perception is modulated by dysfunctional dorsal medial nucleus tractus solitarii (dmNTS) reflex arcs that produce diminished baroreflex sensitivity (BRS) resulting from a conditioned response. This study tested whether administration of noxious and non-noxious electrical stimuli synchronized with the cardiac cycle resets BRS, reestablishing pain inhibition. A total of 30 pain-free normotensives controls (NC) and 32 normotensives fibromyalgia (FM) patients received two, ≈8 min-epochs of cardiac-gated, peripheral electrical stimuli. Non-painful and painful electrical stimuli were synchronized to the cardiac cycle as the neuromodulation experimental protocol (EP) with two control conditions (CC1, CC2). BRS, heart-rate-variability (HRV), pain threshold and tolerance, and clinical pain intensity were assessed. Reduced BRS in FM at baseline increased by 41% during two, ≈8 min-epochs of stimulation. Thresholds in FM increased significantly during the experimental protocol (all Ps < 0.001) as did HRV. FM levels of clinical pain significantly decreased by 35.52% during the experimental protocol but not during control stimulations (p < 0.001). Baroreceptor training may reduce FM pain by BRS-mediated effects on intrinsic pain regulatory systems and autonomic responses.

Efficacy of Systolic Extinction Training in Fibromyalgia Patients With Elevated Blood Pressure Response to Stress: A Tailored Randomized Controlled Trial.

OBJECTIVE: An intrinsic pain regulatory system is modulated by both cardiovascular dynamics that influence baroreflex sensitivity (BRS) and is diminished in fibromyalgia (FM). Baroreceptors relay cardiovascular output to the dorsal medial nucleus tractus solitarius reflex arcs that regulate pain, sleep, anxiety, and blood pressure. The aim of this study was to evaluate the effects of systolic extinction training (SET), which combines operant treatment (OT) with baroreflex training (BRT). BRT delivers peripheral electrical stimulation within a few milliseconds of the systolic or diastolic peak in the cardiac cycle. In addition, we compared SET to OT-transcutaneous electrical stimulation (TENS) independent of the cardiac cycle and aerobic exercise (AE)-BRT in FM patients with elevated blood pressure responses to stress. METHODS: Sixty-two female patients with FM were randomized to receive either SET (n = 21), OT-TENS (n = 20), or AE-BRT (n = 21). Outcome assessments were performed before treatment (T1), after 5 weeks of treatment (T2), and after the 12-month follow-up (T3). RESULTS: In contrast to patients receiving OT-TENS or AE-BRT, those receiving SET reported a significantly greater reduction in pain and pain interference (all P < 0.01) that was maintained at the 12-month follow-up. Clinically meaningful pain reduction at T3 was achieved in 82% of patients in the SET group, 39% of those in the OT-TENS group, and only 14% of those in the AE-BRT group. Patients in the SET group showed a significant increase (57%) in BRS following treatment, while neither the AE-BRT group or the OT-TENS group showed significant changes over time. CONCLUSION: SET resulted in statistically significant, clinically meaningful, and long-lasting pain remission and interference compared to OT-TENS and AE-BRT. These results suggest that BRS modification is the primary mechanism of improvement. Replication of our results using larger samples and extension to other chronic pain conditions appear to be warranted.

Evidenced-Based Guidelines on the Treatment of Fibromyalgia Patients: Are They Consistent and If Not, Why Not? Have Effective Psychological Treatments Been Overlooked?

We compared the recommendations and methodology of several recent evidence-based guidelines for the management of patients with fibromyalgia published by professional organizations: 1) American Pain Society (APS; 2005), 2) Association of the Scientific Medical Societies in Germany (AWMF; 2012), 3) Canadian Pain Society (CPS; 2013; also used in the United Kingdom), and 4) European League Against Rheumatism (EULAR; 2016). Each guideline used systematic reviews and meta-analyses as highest level of evidence; APS, CPS, and AWMF also included individual randomized clinical trials. The APS, CPS, and AWMF assigned the highest ranking of recommendation to aerobic exercise, cognitive-behavioral therapy, amitriptyline, and multicomponent treatment. In contrast, the most recent EULAR guidelines assign the highest level of recommendation to exercise, contrary to the 2008 EULAR guidelines, which recommended pharmacotherapy. Although there was some consistency for pharmacological treatment recommendations among the 4 guidelines, APS, CPS, and AWMF guidelines gave the higher ranking to cognitive-behavioral therapy and multicomponent treatments. The inconsistencies across guidelines can be attributed to the criteria used for study inclusion, outcome measures used, weighting systems, and composition of the review panels. A guideline consensus is needed to harmonize the discrepancies. PERSPECTIVE: This article presents an overview and highlights the inconsistencies of 4 recent clinical practice guidelines for treatment of fibromyalgia patients related to study inclusion criteria, outcome measures used, ranking system used, and composition of the review panels. The discrepancies suggest a need to create a guideline consensus to synthesize guidelines.

Fibromyalgia syndrome: metabolic and autophagic processes in intermittent cold stress mice.

Fibromyalgia is characterized by widespread musculoskeletal pain, fatigue, and depression. The aim was to analyze potential mitochondrial dysfunction or autophagy in mice after exposure to intermittent cold stress (ICS). Muscle and liver specimens were obtained from 36 mice. Lactate dehydrogenase (LDH) activity was measured. Microtubule-associated protein light chain 3 (MAP1LC3B) and glycogen content were determined histologically; muscle ultrastructure by electron microscopy. Mitochondrial- and autophagy-related markers were analyzed by RT-qPCR and Western blotting. ATP level, cytotoxicity, and caspase 3 activity were measured in murine C2C12 myoblasts after ICS exposure. Coenzyme Q10B (COQ10B) transcript was up-regulated in limb muscle of ICS mice, whereas its protein content was stable. Cytochrome C oxidase 4 (COX4I1) and LDH activity increased in limb muscle of male ICS mice. Glycogen content was lower in muscle and liver tissue of male ICS mice. Electron micrographs of ICS mice specimens showed mitochondrial damage and autophagic vesicles. A significant up-regulation of autophagic transcripts of MAP1LC3B and BECLIN 1 (BECN1) was observed. Map1lc3b protein showed an aggregated distribution in ICS mice and SqSTM1/p62 (p62) protein level was stable. Furthermore, ATP level and caspase activity, detected as apoptotic marker, were significantly lowered after ICS exposure in differentiated C2C12 myoblasts. The present study shows that ICS mice are characterized by mitochondrial dysfunction, autophagic processes, and metabolic alterations. Further investigations could dissect autophagy process in the proposed model and link these mechanisms to potential therapeutic options for fibromyalgia.

Morphological Alterations in Gastrocnemius and Soleus Muscles in Male and Female Mice in a Fibromyalgia Model.

BACKGROUND: Fibromyalgia (FM) is a chronic musculoskeletal pain disorder, characterized by chronic widespread pain and bodily tenderness and is often accompanied by affective disturbances, however often with unknown etiology. According to recent reports, physical and psychological stress trigger FM. To develop new treatments for FM, experimental animal models for FM are needed to be development and characterized. Using a mouse model for FM including intermittent cold stress (ICS), we hypothesized that ICS leads to morphological alterations in skeletal muscles in mice. METHODS: Male and female ICS mice were kept under alternating temperature (4 °C/room temperature [22 °C]); mice constantly kept at room temperature served as control. After scarification, gastrocnemius and soleus muscles were removed and snap-frozen in liquid nitrogen-cooled isopentane or fixed for electron microscopy. RESULTS: In gastrocnemius/soleus muscles of male ICS mice, we found a 21.6% and 33.2% decrease of fiber cross sectional area (FCSA), which in soleus muscle concerns the loss of type IIa and IIx FCSA. This phenomenon was not seen in muscles of female ICS mice. However, this loss in male ICS mice was associated with an increase in gastrocnemius of the density of MIF+ (8.6%)-, MuRF+ (14.7%)-, Fbxo32+ (17.8%)-cells, a 12.1% loss of capillary contacts/muscle fiber as well as a 30.7% increase of damaged mitochondria in comparison with male control mice. Moreover, significant positive correlations exist among densities (n/mm(2)) of MIF+, MuRF+, Fbxo32+-cells in gastrocnemius/ soleus muscles of male ICS mice; these cell densities inversely correlate with FCSA especially in gastrocnemius muscle of male ICS mice. CONCLUSION: The ICS-induced decrease of FCSA mainly concerns gastrocnemius muscle of male mice due to an increase of inflammatory and atrogenic cells. In soleus muscle of male ICS and soleus/gastrocnemius muscles of female ICS mice morphological alterations seem to occur not at all or delayed. The sex-specificity of findings, which is not easily reconciled with the epidemiology of FM (female predominance), implicate that gastrocnemius muscle of male ICS mice should preferentially be used for future investigations with FM. Moreover, we suggest to investigate morphological and/or molecular alterations at different time-points (up to two weeks) after ICS.

Stress exacerbates pain in the everyday lives of women with fibromyalgia syndrome--The role of cortisol and alpha-amylase.

OBJECTIVE: Although fibromyalgia syndrome (FMS) is a chronic condition, its cardinal symptom pain is known to fluctuate over the day. Stress has often been claimed to exacerbate pain; however, there is barely any evidence on whether or not this is true on a day-to-day basis (and, alternatively, on whether pain leads to increased stress levels). Using an ecologically valid measurement design, we tested whether and how stress and pain are intertwined in participants with FMS. We additionally examined the role of the two major stress-responsive systems, the hypothalamic-pituitary-adrenal axis and the autonomic nervous system, as potential mediators of this relationship. METHODS: An ambulatory assessment study was conducted over the course of 14 days. On each day, 32 females with FMS provided six diary entries on momentary stress and pain levels. Saliva samples were collected at the same time points to determine cortisol and alpha-amylase as indicators of stress-responsive systems. RESULTS: Higher stress at a given measurement time point was associated with higher reported pain levels at the subsequent time point (UC=1.47, p<0.001), but not vice versa (UC<0.01, p=0.179). The stress-pain relationship was neither mediated by momentary cortisol nor by alpha-amylase; however, momentary cortisol was independently associated with momentary pain (UC=0.27, p=0.009). CONCLUSION: Stress seems to be a powerful exacerbating factor for pain as experienced by patients with FMS in their everyday lives. Cortisol may be involved in the diurnal fluctuation of pain levels in patients with FMS. Future studies should identify relevant daily stressors in persons with FMS and scrutinize the mechanisms underlying the cortisol-pain relationship.

The relationship among psychological and psychophysiological characteristics of fibromyalgia patients.

UNLABELLED: This study examined the relationship of psychophysiological response patterns in fibromyalgia with psychological characteristics and comorbid mental disorders. Surface electromyographic data, systolic and diastolic blood pressure, heart rate (HR), and skin conductance levels were recorded continuously during baseline, stress, and relaxation tasks. Cluster analysis revealed 4 subgroups of patients who differed on pain characteristics and cognitive, affective, and behavioral responses to pain and stress. The largest group (46.7%) was characterized by elevated blood pressure levels and stress reactivity (a disposition assumed to be a vulnerability factor for the development of diseases) associated with pain, anxiety, physical interference, low activity, and pain behaviors. A second group (41.6%) showed low baseline blood pressure and reactivity, and high activity and stress. A third group (9.2%) displayed high baseline skin conductance level, reactivity, and depression, and a fourth small group (2.5%) displayed elevated baseline electromyographic response and reactivity with high levels of anxiety and depression. These data suggest that unique psychophysiological response patterns are associated with psychological coping and mental disorders in fibromyalgia patients. The identification of the mechanisms that contribute to these group differences will further our understanding of the mechanisms involved in the development and maintenance of fibromyalgia and suggest differential treatment strategies. PERSPECTIVE: This article presents psychological characteristics and comorbidity with mental disorders of psychophysiological subgroups of fibromyalgia patients. This mechanistic analysis will assist scientific identification of systems-based pathways that contribute to autonomic and stress mechanisms that mediate chronic pain. Demonstration of distinct, homogeneous subgroups is an important step towards personalized, mechanism-oriented treatments.

Treatment-related changes in brain activation in patients with fibromyalgia syndrome.

Little is known about the effects of successful treatment on brain function in chronic pain. This study examined changes in pain-evoked brain activation following behavioral extinction training in fibromyalgia patients. Using functional magnetic resonance imaging, brain activation to painful mechanical stimuli applied to the 2nd phalanx of the left 2nd digit (m. flexor digitorum) was assessed in 10 patients with fibromyalgia syndrome (FM) before and after behavioral extinction training. The behavioral treatment significantly reduced interference from pain in the FM patients. Mechanical pain threshold and pain tolerance increased significantly after treatment. Activation in the insula shifted bilaterally from a more anterior site before treatment to a more posterior location after treatment. The pre- to post-treatment reduction in both interference related to pain and pain severity were significantly associated with bilateral activation in pain-evoked activity in the posterior insula, the ipsilateral caudate nucleus/striatum, the contralateral lenticular nucleus, the left thalamus and the primary somatosensory cortex contralateral to the stimulated side. These data show a relation between successful behavioral treatment and higher activation bilaterally in the posterior insula and in the contralateral primary somatosensory cortex. Future studies should compare responders and non-responders for differential treatment effects and examine in more detail the mechanisms underlying these changes.

Stress and resilience in rheumatic diseases: a review and glimpse into the future.

Stress resilience factors, and interventions to ease stress and enhance resilience, are gaining increasing attention for the treatment of rheumatic conditions. This Review presents a digest of empirical work on the factors that determine the risk of adapting poorly to a rheumatic condition, and on the resilience factors that counteract such risks. We consider the types of stress-management and resilience treatments that are most effective in promoting the physical and psychological functioning of patients at risk of long-term adjustment problems. Prospective research shows that cognitive-behavioral and social risk and resilience factors predict the long-term physical and psychological functioning of patients with rheumatic conditions. Furthermore, validated screening instruments are becoming increasingly useful in clinical practice to identify and select patients at risk. Stress-management and resilience interventions offer promising ways to improve the long-term functioning of patients. These treatment methods might be especially useful when they are tailored to the specific risk and resilience factors of patients, and when they incorporate innovative approaches to the delivery of services, including internet applications such as eHealth, to increase efficiency and availability of treatments, and to optimize patient empowerment in rheumatic conditions.

Guidelines on the management of fibromyalgia syndrome - a systematic review.

We compared the methodology and the recommendations of evidence-based guidelines for the management of fibromyalgia syndrome (FMS) to give an orientation within the continuously growing number of reviews on the therapy of FMS. Systematic searches up to April 2008 of the US-American National Guideline Clearing House, the Scottish Intercollegiate Guidelines Network, the Association of the Scientific Medical Societies in Germany (AWMF) and Medline were conducted. Three evidence-based guidelines for the management of FMS published by professional organizations were identified: The American Pain Society (APS) (2005), the European League Against Rheumatism (EULAR) (2007), and the AWMF (2008). The steering committees and panels of APS and AWMF were comprised of multiple disciplines engaged in the management of FMS and included patients, whereas the task force of EULAR only consisted of physicians, predominantly rheumatologists. APS and AWMF ascribed the highest level of evidence to systematic reviews and meta-analyses, whereas EULAR credited the highest level of evidence to randomised controlled studies. Both APS and AWMF assigned the highest level of recommendation to aerobic exercise, cognitive-behavioral therapy, amitriptyline, and multicomponent treatment. In contrast, EULAR assigned the highest level of recommendation to a set of to pharmacological treatment. Although there was some consistency in the recommendations regarding pharmacological treatments among the three guidelines, the APS and AWMF guidelines assigned higher ratings to CBT and multicomponent treatments. The inconsistencies across guidelines are likely attributable to the criteria used for study inclusion, weighting systems, and composition of the panels.

Are psychological treatments effective for fibromyalgia pain?

This article considers four broad classes of psychological techniques and their effects on fibromyalgia (FM) pain. A literature search identified 14 randomized controlled trials (RCTs) of cognitive-behavioral therapy (CBT) and operant-behavioral therapy (OBT), five relaxation RCTs, five biofeedback RCTs, five hypnotherapy RCTs, and two writing intervention RCTs. For psychoanalytic therapy in FM, no RCTs have been published. The highest effect sizes (r = 0.53-2.14) for pain reduction are found after CBT and OBT group treatments. Relaxation as a single treatment has not been proven useful. Hypnotherapy and writing intervention have demonstrated mild treatment effects, whereas psychological treatment is effective in FM pain. Considering the heterogeneity of FM, the promising effects of matched interventions such as CBT and OBT with pharmacotherapy, exercise, and other treatment domains require further research.

Pain ratings and somatosensory evoked responses to repetitive intramuscular and intracutaneous stimulation in fibromyalgia syndrome.

To determine the presence of perceptual sensitization and related brain responses we examined 15 patients with fibromyalgia syndrome and 15 healthy controls comparable in age and sex. Multichannel EEG recordings and pain ratings were obtained during the presentation of 800 painful electrical intramuscular and intracutaneous stimuli to the left m. erector spinae and the left m. extensor digitorum. The stimulus intensity was adjusted to 50% between pain threshold and tolerance. Detection and pain thresholds were significantly lower in the fibromyalgia syndrome group. Sensitization occurred for both groups during intramuscular stimulation. In the EEG data the fibromyalgia syndrome patients showed higher N80 amplitudes compared with the healthy controls. Arm stimulation and intramuscular stimulation yielded higher N80 and N150 amplitudes compared with intracutaneous stimulation or stimulation of the back. These results indicate lower pain thresholds in the fibromyalgia syndrome patients after electrical stimulation and a higher N80 amplitude both indicative of enhanced sensory processing in this group.

Management of fibromyalgia syndrome--an interdisciplinary evidence-based guideline.

The prevalence of fibromyalgia syndrome (FMS) of 1-2% in the general population associated with high disease-related costs and the conflicting data on treatment effectiveness had led to the development of evidence-based guidelines designed to provide patients and physicians guidance in selecting among the alternatives. Until now no evidence-based interdisciplinary (including patients) guideline for the management of FMS was available in Europe. Therefore a guideline for the management of fibromyalgia syndrome (FMS) was developed by 13 German medical and psychological associations and two patient self-help organisations. The task was coordinated by two German scientific umbrella organisations, the Association of the Scientific Medical Societies in Germany AWMF and the German Interdisciplinary Association of Pain Therapy DIVS. A systematic search of the literature including all controlled studies, systematic reviews and meta-analyses of pharmacological and non-pharmacological treatments of FMS was performed in the Cochrane Library (1993-12/2006), Medline (1980-12/2006), PsychInfo (1966-12/2006) and Scopus (1980-12/ 2006). Levels of evidence were assigned according to the classification system of the Oxford-Centre for Evidence Based Medicine. Grading of the strengths of recommendations was done according to the German program for disease management guidelines. Standardized procedures were used to reach a consensus on recommendations. The guideline was reviewed and finally approved by the boards of the societies involved and published online by the AWMF on april 25, 2008: http://www.uni-duesseldorf.de/AWMF/ll/041-004.htm. A short version of the guideline for patients is available as well: http://www.uni-duesseldorf.de/AWMF/ll/041-004p.htm. The following procedures in the management of fms were strongly recommended: information on diagnosis and therapeutic options and patient-centered communication, aerobic exercise, cognitive and operant behavioural therapy, multicomponent treatment and amitriptyline. Based on expert opinion, a stepwise FMS-management was proposed. Step 1 comprises confirming the diagnosis and patient education and treatment of physical or mental comorbidities or aerobic exercise or cognitive behavioural therapy or amitriptyline. Step 2 includes multicomponent treatment. Step 3 comprises no further treatment or self-management (aerobic exercise, stress management) and/or booster multicomponent therapy and/or pharmacological therapy (duloxetine or fluoxetine or paroxetine or pregabalin or tramadol/aminoacetophen) and/or psychotherapy (hypnotherapy or written emotional disclosure) and/or physical therapy (balneotherapy or whole body heat therapy) and/or complementary therapies (homeopathy or vegetarian diet). The choice of treatment options should be based on informed decision-making and respect of the patients' preferences.

Responder criteria for operant and cognitive-behavioral treatment of fibromyalgia syndrome.

OBJECTIVE: To predict the effects of cognitive-behavioral therapy (CBT) and operant-behavioral therapy (OBT) in fibromyalgia syndrome (FMS). METHODS: A total of 125 patients who fulfilled the American College of Rheumatology FMS criteria were randomly assigned to CBT (n = 42), OBT (n = 43), or attention placebo (AP; n = 40). The pretreatment to 12-month followup reliability change index was used to determine clinically meaningful changes in pain intensity and physical impairment. Multinominal logistic regression analyses were used to determine the predictors of improvement in pain intensity and physical impairment for the entire sample. Analyses of variance were computed to compare the characteristics of responders and nonresponders in each of the 3 interventions. RESULTS: At the 12-month followup, 53.5%, 45.2%, and 5% of patients in the OBT, CBT, and AP groups, respectively, reported clinically meaningful improvements in pain intensity. Similarly, 58.1%, 38.1%, and 7.5% of patients treated with OBT, CBT, and AP, respectively, reported clinically significant improvements in physical impairment. Prior to treatment, the OBT physical impairment responders displayed significantly more pain behaviors, physical impairment, physician visits, solicitous spouse behaviors, and level of catastrophizing compared with nonresponders. The CBT physical impairment responders, compared with nonresponders, reported higher levels of affective distress, lower coping, less solicitous spouse behavior, and lower pain behaviors. CONCLUSION: The results of this study suggest that pretreatment patient characteristics are important predictors of treatment response and may serve as a basis for matching treatments to patient characteristics. Prospective outcome studies are needed to confirm whether the tailoring of treatment actually leads to better outcomes for patients with FMS.

Psychophysiological responses in patients with fibromyalgia syndrome.

Physical and emotional stress and altered reactivity of the autonomic nervous system have been implicated in the development and maintenance of fibromyalgia syndrome (FMS). This study investigated blood pressure, heart rate (HR), skin conductance levels (SCL), and surface electromyograms (EMG) from the trapezius muscle in 30 FMS patients and 30 age- and sex-matched healthy controls (HCs). All measures were continuously recorded during baseline (BL), social conflict, mental arithmetic, and relaxation tasks. The FMS patients showed significantly higher stress ratings and self-reported stress responses. Baseline EMG levels were significantly lower, and BL HR was significantly elevated. During both stress tasks, HR reactivity was significantly lower, and SCL reactivity was significantly higher in the FMS group. This pattern of low BL muscle tension and high BL HR, along with low HR and high SCL reactivity to stress, is discrepant to other chronic pain syndromes and suggests unique psychophysiological features associated with FMS. Several potential mechanisms for these psychophysiological responses are discussed.

Psychological pain treatment in fibromyalgia syndrome: efficacy of operant behavioural and cognitive behavioural treatments.

The present study focused on the evaluation of the effects of operant behavioural (OBT) and cognitive behavioural (CBT) treatments for fibromyalgia syndrome (FMS). One hundred and twenty-five patients who fulfilled the American College of Rheumatology criteria for FMS were randomly assigned to OBT (n = 43), CBT (n = 42), or an attention-placebo (AP) treatment (n = 40) that consisted of discussions of FMS-related problems. Assessments of physical functioning, pain, affective distress, and cognitive and behavioural variables were performed pre-treatment and post-treatment as well as 6 and 12 months post-treatment. Patients receiving the OBT or CBT reported a significant reduction in pain intensity post-treatment (all Fs > 3.89, all Ps < 0.01). In addition, the CBT group reported statistically significant improvements in cognitive (all Fs > 7.95, all P < 0.01) and affective variables (all Fs > 2.99, all Ps < 0.02), and the OBT group demonstrated statistically significant improvements in physical functioning and behavioural variables (all Fs > 5.99, all Ps < 0.001) compared with AP. The AP group reported no significant improvement but actually deterioration in the outcome variables. The post-treatment effects for the OBT and CBT groups were maintained at both the 6- and 12-month follow-ups. These results suggest that both OBT and CBT are effective in treating patients with FMS with some differences in the outcome measures specifically targeted by the individual treatments compared with an unstructured discussion group. The AP group showed that unstructured discussion of FMS-related problems may be detrimental.

Heterogeneity of psychophysiological stress responses in fibromyalgia syndrome patients.

Dysregulated psychophysiological responses have been observed in patients with fibromyalgia syndrome (FMS), although the results are inconsistent. Surface electromyographic (EMG), systolic and diastolic blood pressure, heart rate (HR), and skin conductance levels (SCLs) were continuously recorded at baseline, and during a series of stress and relaxation tasks in 90 FMS patients and 30 age and sex matched healthy controls (HCs). The patient sample demonstrated lower baseline EMG levels compared to the HCs on all tasks. In contrast, the patients displayed elevated HR and SCL (sympathetic vasomotor and sudomotor indices, respectively) during both stress tasks. A cluster analysis identified four psychophysiological response patterns: 63.3% of HCs showed increased muscle tension and stable cardiovascular responses; 34.8% of FMS patients showed a pattern of increased sympathetic vasomotor reactivity with stable sudomotor and reduced muscular response; 12.2% of FMS patients showed a pattern of increased sympathetic sudomotor reactivity connected with increased sympathetic vasomotor response and reduced muscular response; and, in contrast, 46.7% of FMS patients showed a pattern of parasympathetic vasomotor reactivity and reduced sudomotor as well as muscular response. The identification of low baseline muscle tension in FMS is discrepant with other chronic pain syndromes and suggests that unique psychophysiological features may be associated with FMS. The different psychophysiological response patterns within the patient sample support the heterogeneity of FMS.

Predictors of pain behaviors in fibromyalgia syndrome.

OBJECTIVE: To evaluate the contributions of physical, pain-related, cognitive, stress-related, affective, and spouse-related variables to differences in pain behaviors in subgroups of patients with fibromyalgia syndrome (FMS). METHODS: One hundred forty FMS patients underwent medical, physical, and psychological evaluation. Patients and 30 pain-free controls performed a routine physical activity (window-washing task) to elicit pain behaviors with or without the presence of their spouses. The behaviors and spouses' responses during this task were videotaped and subsequently rated. Patients were classified as dysfunctional (DYS), interpersonally distressed (ID), or adaptive copers (AC) based on responses to the Multidimensional Pain Inventory. Hierarchical regression analyses were used to identify predictors of pain behaviors for the total group and subgroups of patients. RESULTS: Patients classified as DYS demonstrated the highest number of pain behaviors compared with those classified as ID or AC. This difference was observable when the spouse was present. Spouse responses and physical variables were significantly related to pain behaviors in the DYS and ID groups with the model accounting for 77.1% and 41.9% of the variance, respectively. In contrast, for the AC group, stress factors were the most significant predictor of pain behaviors, accounting for 22.8% of the variance. CONCLUSION: The results indicate that different variables account for the presence of pain behaviors in different subgroups of patients. The data provide support for the heterogeneity of the diagnosis of FMS and have implications for treatment of subgroups of patients.

Comorbid depression and anxiety in fibromyalgia syndrome: relationship to somatic and psychosocial variables.

OBJECTIVE: The prevalence as well as predictors of psychiatric disorders (Diagnostic and Statistical Manual of Mental Disorders, 4th edition [DSM-IV] axis I and II) in patients with fibromyalgia syndrome (FMS) was evaluated. METHOD: One-hundred fifteen patients with FMS participated in the Structured Clinical Interview for DSM-IV to assess current mental disorders. In addition, patients completed standardized questionnaires regarding pain, pain impact, anxiety, depression, posttraumatic stress disorder-like symptoms, and sexual and physical abuse. RESULTS: Patients were grouped into one of three psychosocial subgroups based on responses to the Multidimensional Pain Inventory (MPI)-Dysfunctional (DYS), Interpersonally Distressed (ID), and Adaptive Copers (AC). Axis I diagnoses were present in 74.8% of the participants overall with the DYS subgroup mainly reporting anxiety and the ID group mood disorders. The AC group showed little comorbidity. Axis II diagnoses were present in only 8.7% of the FMS sample. CONCLUSION: These results suggest that FMS is not a homogeneous diagnosis, but shows varying proportions of comorbid anxiety and depression dependent on psychosocial characteristics of the patients. The results demonstrate the importance of not treating patients with FMS as a homogeneous group. Assessment should not only examine the presence of widespread pain and the number of tender points, but also the presence of affective distress. Treatment should focus both on physical and emotional dysfunction.

Operant behavioral treatment of fibromyalgia: a controlled study.

OBJECTIVE: To evaluate the efficacy of operant pain treatment for fibromyalgia syndrome (FMS) in an inpatient setting. METHODS: Sixty-one patients who fulfilled the American College of Rheumatology criteria for FMS were randomly assigned to the operant pain treatment group (OTG; n = 40) or a standardized medical program with an emphasis on physical therapy (PTG; n = 21). Pain assessments were performed before, immediately after, 6 months after, and 15 months after treatment. RESULTS: The OTG patients reported a significant and stable reduction in pain intensity, interference, solicitous behavior of the spouse, medication, pain behaviors, number of doctor visits, and days at a hospital as well as an increase in sleeping time. Sixty-five percent of the OTG compared with none of the patients in the PTG showed clinically significant improvement. CONCLUSION: These results suggest that operant pain treatment provided in an inpatient setting is an effective treatment for FMS, whereas a purely somatically oriented program may lead to a deterioration of the pain problem.