Fibromyalgia Group Research Articles

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.

Painful effects of auditory startle, forehead cooling and psychological stress in patients with fibromyalgia or rheumatoid arthritis

ObjectiveThe aim of this study was to determine whether the clinical pain associated with rheumatoid arthritis or fibromyalgia would increase during standard laboratory tasks and, if so, whether these increases were linked with individual differences in psychological distress. MethodsTwenty-three patients with fibromyalgia and 16 patients with rheumatoid arthritis rated changes in clinical pain after an acoustic startle stimulus, during painful forehead cooling, and during stressful mental arithmetic. In addition, pain tolerance was assessed during a submaximal effort tourniquet test, and patients provided ratings of distress on a standard Depression, Anxiety and Stress Inventory. ResultsPain at rest was associated with depression scores in patients with rheumatoid arthritis, and was associated with stress scores in the fibromyalgia group. However, pain tolerance was unrelated to individual differences in psychological distress in either group. In patients with fibromyalgia, clinical pain increased after the acoustic startle stimulus and painful forehead cooling, and increased during stressful mental arithmetic. Arthritic pain also increased during forehead cooling and mental arithmetic in association with indices of psychological distress. ConclusionsThese findings suggest that processes linked with individual differences in distress aggravate pain in rheumatoid arthritis, whereas some other mechanism (e.g., failure of stress-related pain modulation processes or an aberrant interaction between nociceptive afferent and sympathetic efferent fibers) triggers stress-induced pain in fibromyalgia.

Kinematics gait disorder in men with fibromyalgia

The aim of this study was to assess the kinematics disorder of gait in men with fibromyalgia. We studied 12 male with fibromyalgia and 14 healthy men. Each participant of the study walked five trials along a 18.6-m walkway. Fibromyalgia patients completed a Spanish version of Fibromyalgia Impact Questionnaire. Significant differences between fibromyalgia and control groups were found in velocity, stride length, and cadence. Gait parameters of men affected by fibromyalgia were impaired when compared to those of healthy group due to bradykinesia. According to previous studies to assess gait variables in female patients, the male with fibromyalgia also showed lower values of velocity, cadence, and stride length than healthy group but not reported significant differences in swing, stance, single, or double support phase.

Vulnerability to traumatic stress in fibromyalgia patients: 19 month follow-up after the great East Japan disaster

IntroductionThe aim of this study was to investigate vulnerability and long-term influence of traumatic stress caused by the Great East Japan Disaster which occurred on March 11, 2011, in patients with fibromyalgia, which is a chronic pain syndrome probably involving central sensitization.MethodsA total of 60 female patients with fibromyalgia were compared with female patients with rheumatoid arthritis (RA, n = 23) as another chronic pain disease, and with female healthy controls (HC, n = 26) in the observational study. To evaluate responses to traumatic stress, the scores of Impact of Event Scale-Revised (IES-R) were assessed one month after the disaster and every six months until 19 months after the disaster. We also evaluated levels of depression during the study period. To know the score of IES-R of patients with fibromyalgia during usual living, we assessed IES-R in another population of fibromyalgia patients without exposure to a great disaster.ResultsThe mean score of IES-R one month after the disaster in the fibromyalgia group (24.6 [SD 18.9]) was significantly higher than that of RA group (13.4 [SD 14.5]) or HC group (9.1 [9.2]) (F = 9.96, p < 0.0001). However, the mean score of IES-R in fibromyalgia patients without exposure to a great disaster was (20.3 [SD 18.7]), which was almost the same value as the fibromyalgia group seven months after the disaster (20.2 [SD 19.5]). Repeated measures analysis of variance showed significant effect of time course in the depression-related symptoms (F = 6.68, P = 0.001), and a post-hoc test revealed that the number of depression-related symptoms one month before the disaster was significantly different from other time points until 19 months after the disaster, respectively.ConclusionsAlthough response to acute stress induced by the great earthquake was likely to be settled within seven months after the disaster, depression-related symptoms have been increasing for more than one year after the disaster, despite exclusion of patients with major depression at baseline. This long-lasting worsening of depression-related symptoms may have been in response to chronic stress induced by the fear of radiation due to the nuclear power disaster. These findings suggest that patients with fibromyalgia are vulnerable to chronic stress rather than acute stress.

Effect of fibromyalgia on bone mineral density in patients with fibromylagia and rheumatoid arthritis

Fibromyalgia (FM) may t cause a decrease in bone mineral density (BMD) because of decreased mobility. The condition is relatively frequent in rheumatoid arthritis (RA) and RA patients with FM have more disability than those without FM. We evaluated the effect of FM on BMD and investigated the effect of FM on BMD in RA patients. We included age-matched 56 FM, 52 RA patients, and 37 healthy females as controls. Twenty three of all RA subjects met 1990 ACR FM criteria. Patients using the antiresorptive drugs, those on hormone replacement therapy, patients with thyroid or parathyroid dysfunction were excluded. Self-reported pain and fatigue severity, functional items of FM impact questionnaire were questioned in FM and RA patients. In all subjects, BMD of the lumbar spine and femur neck were determined by dual X-ray absorptiometry, and T-scores were recorded. Self-reported pain and fatigue scores in FM subjects were significantly higher than in RA patients (P<0.001). The mean lumbar spine and femur neck BMD and their T-scores in RA patients were significantly lower than in FM and control groups (P values<0.01). There was no difference in BMD between FM subjects and the control group. BMD in RA patients with and without FM were similar (P>0.05). There was a significant negative correlation between self-reported pain score and lumbar spine BMD in FM subjects (r=-0.41, P=0.006). In spite of functional disability, FM does not cause a decrease in BMD. The presence of FM in RA patients does not result in a change in BMD.

Features of Temporomandibular Disorders in Fibromyalgia Syndrome

This study aimed to investigate the prevalence of clinical features of temporomandibular disorders (TMD) in patients with fibromyalgia. The test group (FMG) consisted of 40 women with fibromyalgia (FM) compared to the control group of 40 healthy subjects using the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). The variables were compared using Fisher’s exact test and a Mann-Whitney test. Facial pain was reported by 85% of the FM group, and 77.5% were diagnosed with myofascial TMD. Muscle pain during jaw movements, daytime bruxism/clenching, and limited mouth opening were significantly higher in the test group. There was no difference between groups in: 1. joint noises; 2. sleep bruxism/clenching; and 3. excursive or non-excursive movements. Classic signs of TMD, such as joint noise and self-reporting of clenching at night, are not associated with fibromyalgia syndrome as demonstrated in the current study. However, the self-reported daytime parafunctions, muscle pain in jaw movements, and limited mouth opening are features of the patients in the current study. This study revealed specific muscle involvement of TMD is also presence in FM.

Assessment of the relationship between postural stability and sleep quality in patients with fibromyalgia

The aim of this study is to investigate the relationship of postural stability and sleep disorders in patients with fibromyalgia syndrome. Frequency of falls in the last 6 months in 48 fibromyalgia and 32 control subjects were recorded. Postural stability was assessed by static posturography device (Tetrax, Sunlight Medical Ltd., Israel). Functional assessment consisted of lower-body strength; one-leg stance test were applied to all subjects. Fibromyalgia impact questionnaire (FIQ), sleep quality numeric rating scale (NRS), and Pittsburgh Sleep Quality Index were inquired. The number of falls in the last 6 months was significantly higher in the fibromyalgia group. Mean total value of stability indexes was 201.7 ± 70.9 vs. 162.6 ± 29.6 in fibromyalgia and control subjects (p < 0.05). NRS and Pittsburgh Sleep Quality Index were significantly higher in fibromyalgia patients. It was detected that there were significant relationships between fall risk and NRS scores (r = 0.565), and FIQ fatigue subscores (r = 0.560) (both p < 0.05). Worse postural performance and fall risk found in the fibromyalgia patients compared to controls were related with the sleep quality in the last 24 h and level of fatigue.

Self-reported physical health, mental health, and comorbid diseases among women with irritable bowel syndrome, fibromyalgia, or both compared with healthy control respondents.

Physicians often encounter patients with functional pain disorders such as irritable bowel syndrome (IBS), fibromyalgia (FM), and their co-occurrence. Although these diseases are diagnosed exclusively by patients' report of symptoms, there are few comparative studies about patients' perceptions of these diseases. To compare perceptions of these conditions among 4 groups-3 clinical groups of older women with IBS, FM, or both disorders (IBS plus FM) and 1 similarly aged control group of women with no IBS or FM-using their responses to survey questions about stressful life events, general physical and mental health, and general medical, pain, and psychiatric comorbidities. Using data from the Biopsychosocial Religion and Health Study survey, responses from women were compared regarding a number of variables. To compare stress-related and physical-mental health profiles across the 4 groups, 1-way analyses of variance and χ(2) tests (with Tukey-Kramer and Tukey post hoc tests, respectively) were used, with α set to .05. The present study comprised 3811 women. Participants in the control group, the IBS group, the FM group, and the IBS plus FM group numbered 3213 (84.3%), 366 (9.6%), 161 (4.2%), and 71 (1.9%), respectively, with a mean (standard deviation) age of 62.4 (13.6), 64.9 (13.7), 63.2 (10.8), and 61.1 (10.9) years, respectively. In general, participants in the control group reported fewer lifetime traumatic and major life stressors, better physical and mental health, and fewer comorbidities than respondents in the 3 clinical groups, and these differences were both statistically significant and substantial. Respondents with IBS reported fewer traumatic and major life stressors and better health (ratings and comorbidity data) than respondents with FM or respondents with IBS plus FM. Overall, respondents with both diseases reported the worst stressors and physical-mental health profiles and reported more diagnosed medical, pain, and psychiatric comorbidities. The results revealed statistically significant, relatively large differences in perceptions of quality of life measures and health profiles among the respondents in the control group and the 3 clinical groups.

Self‐reported sensory descriptors are associated with quantitative sensory testing parameters in patients with cervical radiculopathy, but not in patients with fibromyalgia

The painDETECT questionnaire (PD-Q) has been used as a tool to characterize sensory abnormalities in patients with persistent pain. This study investigated whether the self-reported sensory descriptors of patients with painful cervical radiculopathy (CxRAD) and patients with fibromyalgia (FM), as characterized by responses to verbal sensory descriptors from PD-Q (sensitivity to light touch, cold, heat, slight pressure, feeling of numbness in the main area of pain), were associated with the corresponding sensory parameters as demonstrated by quantitative sensory testing (QST). Twenty-three patients with CxRAD (eight women, 46.3 ± 9.6 years) and 22 patients with FM (20 women, 46.1 ± 11.5 years) completed the PD-Q. Standardized QST of dynamic mechanical allodynia, cold and heat pain thresholds, pressure pain thresholds, mechanical and vibration detection thresholds, was recorded from the maximal pain area. Comparative QST data from 31 age-matched healthy controls (HCs; 15 women) were obtained. Patients with CxRAD demonstrated a match between their self-reported descriptors and QST parameters for all sensory parameters except for sensitivity to light touch, and these matches were statistically significant compared with HC data (p ≤ 0.006). The FM group demonstrated discrepancies between the PD-Q and QST sensory phenotypes for all sensory descriptors, indicating that the self-reported sensory descriptors did not consistently match the QST parameters (p = ≤0.017). Clinicians and researchers should be cautious about relying on PD-Q as a stand-alone screening tool to determine sensory abnormalities in patients with FM.

Muscle fiber velocity and electromyographic signs of fatigue in fibromyalgia

Fibromyalgia (FM) is a disorder of widespread muscular pain. We investigated possible differences in surface electromyography (sEMG) in clinically unaffected muscle between patients with FM and controls. sEMG was performed on the biceps brachii muscle of 13 women with FM and 14 matched healthy controls during prolonged dynamic exercises, unloaded, and loaded up to 20% of maximum voluntary contraction. The sEMG parameters were: muscle fiber conduction velocity (CV); skewness of motor unit potential (peak) velocities; peak frequency (PF) (number of peaks per second); and average rectified voltage (ARV). There was significantly higher CV in the FM group. Although the FM group performed the tests equally well, their electromyographic fatigue was significantly less expressed compared with controls (in CV, PF, and ARV). In the patients with FM, we clearly showed functional abnormalities of the muscle membrane, which led to high conduction velocity and resistance to fatigue in electromyography.

The Japanese version of the modified ACR Preliminary Diagnostic Criteria for Fibromyalgia and the Fibromyalgia Symptom Scale: reliability and validity

The aim of this study is to investigate the reliability and validity of the Japanese version of the modified American College of Rheumatology (ACR) Preliminary Diagnostic Criteria for Fibromyalgia (mACR 2010-J) and the Fibromyalgia Symptom Scale (mFS-J). According to the ACR 1990 classification criteria, patients with chronic pain were divided into the fibromyalgia group and nonfibromyalgia group (rheumatoid arthritis and osteoarthritis). Patients in both groups were assessed using mACR 2010-J and mFS-J. 294 of 462 (64%) patients in the fibromyalgia group met mACR 2010-J, whereas 4% (9/231) of the nonfibromyalgia group did, with sensitivity of 64%, specificity of 96%, positive predictive value of 97%, negative predictive value of 56%, and positive likelihood ratio of 16.3. Mean total scores on mFS-J significantly differentiated the fibromyalgia from the nonfibromyalgia group. According to the value of the Youden index, the best cutoff score for the mFS-J was 9/10. Our findings indicate that mACR 2010-J as a positive test and mFS-J as a quantification scale might be suitable for assessing fibromyalgia among Japanese chronic pain populations.

Inflammatory/Stress Feedback Dysregulation in Women with Fibromyalgia

Objective: Although one of the current hypotheses of the aetiology of fibromyalgia (FM) syndrome involves inflammatory and neuroendocrine disorders, its biophysiology still remains unclear. The purpose of the present investigation was to study the systemic inflammatory and stress responses, as well as the innate response mediated by monocytes and neutrophils in FM patients. Methods: Twenty-five women diagnosed with primary FM and 20 age-matched healthy women (control group) were enrolled in the study. Circulating ‘neuroendocrine-stress’ biomarkers (CRH, ACTH, cortisol, NA, eHsp72, serotonin and IGF-1) were evaluated by ELISA. Serum IL-8 and CRP concentrations were also determined by ELISA, and inflammatory cytokine release by monocytes [IL-1β, TNFα, IL-6, IL-10, IL-18, monocyte chemotactic protein-1 (MCP-1) and RANTES] was evaluated by the Luminex BioPlex system. The phagocytic process of neutrophils (chemotaxis, phagocytosis and microbicide capacity) was also evaluated. Results: FM patients showed an inflammatory state accompanied by an altered stress response. This is mainly manifested by high circulating levels of IL-8 and CRP (in 100% of the FM group), high circulating levels of cortisol, and increased systemic levels of NA and eHsp72. There is also increased release of inflammatory cytokines (IL-1β, TNFα, IL-6, IL-10, IL-18 and MCP-1) by monocytes, and enhanced activation of the functional capacity of neutrophils (chemotactic, phagocytic and fungicidal activities). Conclusion: An inflammatory/stress feedback dysregulation underlies FM. Whether dysregulation of the stress response is the cause of the inflammatory dysregulation or vice versa is also discussed.

Screening for the presence of FMR1 premutation alleles in a Spanish population with fibromyalgia

Fragile X mental retardation 1 (FMR1) premutation carriers, who are at risk of having children with fragile X Syndrome, were initially considered as clinically unaffected. However, recent clinical and molecular studies have shifted this point of view. The incidence of premutation in the general population is substantial. Apart from the well-documented fragile X-associated tremor-ataxia and fragile X premature ovarian insufficiency, there is a broad constellation of symptoms including depression, anxiety, muscle pain, autoimmune and thyroid disease, chronic fatigue, and fibromyalgia that has been described, particularly in females with the premutation (55-200 repeats). Fibromyalgia (FM) is the most common cause of widespread pain and comprises a heterogeneous group of patients, affecting 2-3 % of the general population. We analyzed the FMR1 gene in a cohort of females diagnosed with fibromyalgia in order to assess the incidence of premutated alleles. CGG repeat size was determined in 353 females suffering from FM and results were compared with a control group. Four premutated carriers in the FM group were detected. The observed incidence is higher than that described for a normal female population (1/88 vs 1/250). The early detection of premutation carriers for the FMR1 gene among individuals diagnosed with fibromyalgia is important and would be helpful in correct genetic counseling of patients and their families, who may be at risk of having children with fragile X syndrome, the most common known cause of inherited intellectual disability and autism. Our data should be cautiously interpreted based on just this study; nevertheless, screening for the FMR1 gene in FM patients at least with presentations suggestive of FMR1 gene-related disease seems recommendable.

Association of herbal cannabis use with negative psychosocial parameters in patients with fibromyalgia

Patients with chronic pain, including fibromyalgia (FM), may seek treatments outside of mainstream medicine. Medicinal cannabinoids are popularly advocated for pain relief but with limited evidence for efficacy in FM. The extent of use of cannabinoids in FM is unknown. We have documented the self-reported prevalence of cannabinoid use in 457 patients with the diagnosis of FM and referred to a tertiary care pain center. We validated the diagnosis of FM and examined the associations of cannabinoid use in these patients. Cannabinoids were being used by 13% of all patients, of whom 80% used herbal cannabis (marijuana), 24% used prescription cannabinoids, and 3% used both herbal cannabis and prescription cannabinoids. One-third of all men used cannabinoids. Current unstable mental illness (36% versus 23%; P = 0.002), opioid drug-seeking behavior (17% versus 4%; P = 0.002), and male sex (26% versus 7%; P = 0.0002) were all associated with herbal cannabis use. There was a trend for cannabinoid users to be unemployed and receiving disability payments. The diagnosis of FM was validated in 302 patients, with 155 assigned another primary diagnosis. When the FM group was analyzed separately, significant associations were lost, but trends remained. Cannabinoids were used by 13% of patients referred with a diagnosis of FM. The association of herbal cannabis use with negative psychosocial parameters raises questions regarding the motive for this self-medication practice. Although cannabinoids may offer some therapeutic effect, caution regarding any recommendation should be exercised pending clarification of general health and psychosocial problems, especially for those self-medicating.

Percepção de estresse e sintomas depressivos: funcionalidade e impacto na qualidade de vida em mulheres com fibromialgia

Depression is one of the most frequent psychiatric comorbidities in patients with fibromyalgia (FM), and chronic stress might be one of the triggering events of the characteristic FM symptoms. To compare depressive symptoms and stress perception between women with and without FM, in addition to investigate the relationship between those characteristics and the functionality and the impact on the quality of life of those patients. The study included 20 women with FM (FM group) and 20 healthy women (control group). The following instruments were used: Beck Depression Inventory, Perceived Stress Scale-10, Health Assessment Questionnaire, Fibromyalgia Impact Questionnaire, and Visual Analogue Scale for pain (0-10 cm). The FM group showed higher severity of the depressive symptoms (24.10 ± 11.68) and greater perception of stress (25.10 ± 4.82) as compared with those of the control group (10.20 ± 12.78, P < 0.01;and 15.45 ± 7.29, P < 0.01;respectively). A higher incidence of depressive symptoms was observed in the FM group (75%) than in the control group (25%) (χ² = 10.00, P < 0.01). In the FM group, a positive correlation was observed between the depressive symptoms and perceived stress (r = 0.54, P < 0.05), pain (r = 0.58, P < 0.01), impaired functionality (r = 0.56, P < 0.01), and impact on the quality of life (r = 0.46, P < 0.05). In this group there was also correlation between perceived stress and impaired functionality (r = 0.50;P < 0.05). Pain showed no relationship with perceived stress. The relationship between stress, depression and functionality seems to be part of a complex mechanism, which might affect the quality of life of patients with FM.

Responses to Exercise Differ for Chronic Fatigue Syndrome Patients with Fibromyalgia

Chronic fatigue syndrome (CFS) and fibromyalgia (FM) are chronic multisymptom illnesses with substantial clinical and diagnostic overlap. We have previously shown that, when controlling for aerobic fitness and accounting for comorbid FM, CFS patients do not exhibit abnormal cardiorespiratory responses during maximal aerobic exercise compared with healthy controls, despite differences in pain and exertion. The purpose of the present study was to examine cardiac and perceptual responses to steady-state submaximal exercise in CFS patients and healthy controls. Twenty-one CFS patients (13 CFS with comorbid FM (CFS + FM)) and 14 controls completed 20 min of submaximal cycling exercise. Impedance cardiography was used to determine cardiac responses during exercise. Systolic blood pressure (SBP), RPE, and leg muscle pain were also measured. Data were analyzed using a doubly multivariate, repeated-measures MANOVA to model the exercise response. There was a significant multivariate time-by-group interaction (P < 0.05). The CFS + FM group exhibited an exercise response characterized by higher stroke index, ventilatory equivalents for oxygen and carbon dioxide and RPE, lower SBP, and similar HR responses compared to controls. The present results extend on our previous work with maximal exercise and show that CFS and CFS + FM differ in their responses to steady-state exercise. These results highlight the importance of accounting for comorbid conditions when conducting CFS research, particularly when examining psychophysiological responses to exercise.

Assessment of Nutritional Status and Eating Disorders in Female Adolescents With Fibromyalgia

To assess eating disorders, nutritional status, body composition, and food intake in adolescents presenting with fibromyalgia. In a cross-sectional study, we evaluated the nutritional status (z score of body mass index [ZBMI]), waist circumference, body fat percentage by bioelectrical impedance analysis, symptoms of disordered eating, and possible eating disorders (Kids' Eating Disorders Survey [KEDS]) of 23 female adolescents with fibromyalgia and 23 matched healthy control subjects. Median age for both groups was 15 years. In the fibromyalgia group, the median time for diagnosis was 13.5 months. We did not observe a statistically significant difference between the control and fibromyalgia groups in relation to ZBMI, fat mass percentage, food intake, and symptoms of disordered eating (KEDS). In the fibromyalgia group, there was a significant correlation between fat mass percentage and the total KEDS score (r = .587, p = .003); the same correlation was observed for ZBMI (r = .0778, p < .001). This study verified an absence of nutritional and eating disorders in adolescents recently diagnosed with fibromyalgia that, in addition to the correlation between adiposity indexes and KEDS total score, emphasizes the importance of nutritional and body composition assessment, allowing an early and adequate nutritional intervention.

Effective Connectivity Among Brain Regions Associated With Slow Temporal Summation of C-Fiber-Evoked Pain in Fibromyalgia Patients and Healthy Controls

Temporal summation of “second pain” (TSSP) or “windup” results from the summation of C-fiber-evoked responses of dorsal-horn neurons. This phenomenon is dependent on stimulus frequency (≥.33 Hz) and relevant to central sensitization and chronic pain. Our previous neuroimaging studies characterized brain regions associated with TSSP in normal control (NC) and fibromyalgia (FM) groups. During an fMRI scan, subjects received sensitivity-adjusted repetitive heat pulses at .33 on the right foot. FM subjects required significantly lower stimulus intensities than NC to achieve similar TSSP and no significant group differences in the pain-related brain activity were detected. In our current study, we asked whether the effective connectivity among a set of TSSP-related brain regions identified in our previous work differs amongst FM and NC groups. Structural equation modeling was used to characterize the effective connectivity amongst a priori selected brain areas, including the thalamus, S1, S2, posterior insula, and the anterior midcingulate cortex (aMCC) within the left and right hemispheres. This analysis confirmed our a priori models of effective connectivity among these regions mainly confirmed those hypothesized, yet some unpredicted connections were additionally identified (thalamus to aMCC and aMCC to S1). While the models of effective connectivity were not identical in the FM and NC groups, they were very similar. Additionally, the TSSP related effective connectivity of right and left hemisphere regions was very similar. These results provide evidence for significant overlap of the fundamental brain mechanisms that process sensory and affective information related to TSSP in NC and FM groups. PerspectiveModels of effective connectivity involving pain-related processes were estimated with fMRI data from chronic pain and healthy populations. Models were estimated in both hemispheres, and although similar, fibromyalgia was associated with unique models of pain-related processes. Group differences involved the left hemisphere and S1, S2, and posterior insula.

Predicción de la variabilidad de la respuesta a la acupuntura en el tratamiento del dolor crónico

ObjectiveTo evaluate a method to identify which patients with chronic pain could benefit from acupuncture and to compare response to acupuncture between patients with fibromyalgia and those with other types of chronic pain. DesignObservational, prospective, longitudinal, independent evaluation study. SettingAcupuncture Unit, Reina Sofia University Hospital, Cordoba, Spain. ParticipantsA total of 150 consecutive patients with chronic pain referred for acupuncture treatment were divided into a fibromyalgia group and a general chronic pain group. Twenty patients withdrew from the study. InterventionsDung's indirect method was applied in the arm to determine the patient's pain grade and pain sensitivity category before receiving personalized acupuncture treatment. Main outcome measuresDifferences in the pain scale before and after treatment. ResultsMultiple linear regression did not demonstrate that pain reduction was related to the pain grade of the pain sensitivity categories, age, sex or number of acupuncture sessions. Pain reduction was related only to the disease. Response to acupuncture was 57% lower in patients with fibromyalgia in those with chronic pain (p<0.001; 95% confidence interval). ConclusionsResponse to acupuncture in patients with chronic pain does not seem to depend on the categories of pain in Dung's abbreviated predictive method applied in the arm.

The Japanese version of the 2010 American College of Rheumatology Preliminary Diagnostic Criteria for Fibromyalgia and the Fibromyalgia Symptom Scale: reliability and validity

The aim of this study was to investigate the reliability and the validity of the Japanese version of the 2010 American College of Rheumatology Preliminary Diagnostic Criteria for Fibromyalgia (ACR 2010-J), and its quantification scale, the Fibromyalgia Symptom Scale (FS-J). In this study, we divided patients with chronic pain without psychiatric disorders other than depression into two groups according to the 1990 ACR Diagnostic Criteria for Fibromyalgia, a fibromyalgia group and a non-fibromyalgia group (rheumatoid arthritis, osteoarthritis, and gout). Patients in both groups were assessed using the ACR 2010-J and FS-J. Seventy-seven of 94 (82%) patients in the fibromyalgia group met the ACR 2010-J, whereas 9% (4/43) of the non-fibromyalgia group did so, with a sensitivity of 82%, specificity of 91%, positive predictive value of 95%, negative predictive value of 70%, and positive likelihood ratio of 8.8. Mean total scores on the FS-J significantly differentiated the fibromyalgia from the non-fibromyalgia group. The scale had high inter-rater reliability and high internal consistency. With a cutoff score of 10, the positive likelihood ratio was 10.1. Our findings indicate that the ACR 2010-J and FS-J have high reliability and validity, and are useful for assessing fibromyalgia in Japanese populations with chronic pain. As regards the positive likelihood ratio, that of the FS-J might be suitable as a positive test.