Lack of association between fibromyalgia syndrome and abnormalities in muscle energy metabolism

Prescription of exercises for the treatment of chronic pain along the continuum of nociplastic pain: A systematic review with meta-analysis

BACKGROUND AND OBJECTIVE

To compare different exercise prescriptions for patients with chronic pain along the continuum of nociplastic pain: fibromyalgia, chronic whiplash-associated disorders (CWAD), and chronic idiopathic neck pain (CINP).

DATABASES AND DATA TREATMENT

Randomized controlled trials comparing different exercise parameters were included. The search was performed in the databases Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CINAHL and PEDro. Data on the parameters for the physical exercise programs for pain management were extracted for analysis.

RESULTS

Fifty studies with 3,562 participants were included. For fibromyalgia, both aerobic strengthening exercises were similar and better than stretching exercises alone. Exercises could be performed in 50- to 60-min supervised sessions, 2 to 3 times a week, for 13 weeks or more. For CWAD, body awareness exercises were similar to combined exercises, and there was no difference in adding sling exercises to a strengthening exercise program. The exercises could be performed in 90-min supervised sessions, twice a week, for 10 to 16 weeks. For CINP, motor control exercises and nonspecific muscle strengthening had a similar effect. Exercises could be performed in 30- to 60-min supervised sessions, 2 to 3 times a week, for 7 to 12 weeks.

CONCLUSIONS

The choice of parameters regarding exercises should emphasize global exercises in nociplastic pain conditions (such as fibromyalgia and CWAD) and specific exercises in non-nociplastic pain conditions (such as CINP) and be based on patient's preference and therapist's skills.

PROSPERO REGISTRATION NUMBER

CRD42019123271.

SIGNIFICANCE

The pain mechanism must be considered to optimize exercise prescription in patients with different chronic pain profiles. The main message of this article is that low to moderate intensity global exercises performed for a long period of treatment should be performed in patients with nociplastic pain predominance. Additionally, focused and intense exercises for a short period of treatment can be prescribed for patients with nociceptive pain predominance.

Fibromyalgia in Primary Care

Fibromyalgia is a common disorder and has substantial impact on quality of life. The cause remains unknown, but current evidence points to multifactorial involvement of pain processing. Clinical diagnosis is aided by evidence-based diagnostic criteria with subscores for widespread pain and symptom severity. Nonpharmacologic treatments, including cognitive behavioral therapy, sleep hygiene, and regular aerobic exercise, form the cornerstone of management. Pharmacologic intervention is an important adjunct, but benefit is variable. There is no cure for fibromyalgia at this time, but persistence and patience in management may lead to a satisfactory lifestyle.

Cardiorespiratory fitness among adults with fibromyalgia

This review presents and addresses the conflicting results on cardiorespiratory fitness among adults with fibromyalgia. The heterogeneity in study designs, symptom severity and the assessment protocols might partly explain these conflicting results. It also presents the possible relationship between cardiorespiratory fitness and exercise prescription, attrition from exercise/rehabilitation programmes and independence with activities of daily living. Cardiorespiratory fitness might impact aerobic exercise and independence in daily activities of patients with fibromyalgia, which is often concomitantly diagnosed in patients with sleep disordered breathing, including patients with obstructive sleep apnoea. Therefore, cardiorespiratory fitness evaluation should be considered by general and respiratory physicians as well as physiotherapists who treat patients diagnosed with fibromyalgia for more accurate diagnosis, exercise prescription and monitoring of patients' status.

Key points

Adults with fibromyalgia often present with reduced cardiorespiratory fitness.Reduced cardiorespiratory fitness might have an important impact on functional capacity and quality of life.Adults with fibromyalgia who have a secondary condition affecting their ventilatory anaerobic threshold and/or V'_O2peak, for example chronic obstructive pulmonary disease, might present with a greater reduction of their cardiorespiratory fitness which may not be entirely related to their lung disease.

Educational aims

To better understand the cardiorespiratory fitness results among adults with fibromyalgia in general, and when taking into account differences in assessment protocol (maximal versus submaximal testing protocol; cycle ergometer versus treadmill testing protocol) and symptom severity (fibromyalgia severity level).To better understand how cardiorespiratory fitness among adults with fibromyalgia could: 1) assist in exercise prescription; 2) minimise dropout rates from exercise/rehabilitation programmes; and 3) promote independence with activities of daily living.To learn why fibromyalgia might be important to consider in adults who have concurrent fibromyalgia and lung disease.

Balance deficiencies in women with fibromyalgia assessed using computerised dynamic posturography: a cross-sectional study in Spain

OBJECTIVES

Our aims were (1) to compare the sensory organisation of balance control and balance strategies between women with fibromyalgia (FM) and healthy women; (2) to investigate which sensory component, that is, vestibular, visual or somato-sensory, is the most affected in FM and (3) to determine the associations between the functional independence measure (FIM) and balance responses in FM.

DESIGN

Cross-sectional observational study.

SETTING

Urban regional hospital and university (Universidad Rey Juan Carlos, Madrid, Spain).

PARTICIPANTS

Twenty women with FM and 20 matched healthy women.

PRIMARY/SECONDARY OUTCOME MEASURES

The sensory organisation test (SOT) was used to determine postural sway and balance during six different conditions with subjects in a standing position. The FIM was used to determine the level of functional independence in daily life activities (ADL). Between-group differences were analysed with analysis of covariance, and the Spearman's test was used for correlations.

RESULTS

Significant differences between-groups and between-conditions were found for all SOT conditions (all, p<0.001): women with FM showed lower scores being the vestibular score the most affected. Different correlations between SOT conditions and some specific ADL were observed in the FM group: bathing activity and balance condition 6 (r_s=0.541; p<0.001), bed transfers activity and conditions 2 (r_s=0.491; p<0.001) and 3 (r_s=0.510; p<0.001), positioning strategy six and dressing the upper (r_s=0.530; p<0.001) or lower (r_s=0.562; p<0.001) body, and toileting (r_s=0.521; p<0.001): the greater the loss of balance, the greater the interference on some daily life activities.

CONCLUSIONS

Women with FM exhibited balance deficiencies and used different strategies for maintaining their balance in standing, which was associated with a negative impact on functional independence.

Gray Matter Atrophy within the Default Mode Network of Fibromyalgia: A Meta-Analysis of Voxel-Based Morphometry Studies

Over the years, studies have demonstrated morphological changes in the brain of fibromyalgia (FMS). We aimed to conduct a coordinate-based meta-analytic research through systemic review on voxel-based morphometry (VBM) imaging results to identify consistent gray matter (GM) difference between FMS patients and healthy subjects. We performed a comprehensive literature search in PubMed (January 2000–December 2015) and included six VBM publication on FMS. Stereotactic data were extracted from 180 patients of FMS and 123 healthy controls. By means of activation likelihood estimation (ALE) technique, regional GM reduction in left medial prefrontal cortex and right dorsal posterior cingulate cortex was identified. Both regions are within the default mode network. In conclusion, the gray matter deficit is related to the both affective and nonaffective components of pain processing. This result also provided the neuroanatomical correlates for emotional and cognitive symptoms in FMS.

Fibromyalgia: A Critical and Comprehensive Review

Fibromyalgia is a disorder that is part of a spectrum of syndromes that lack precise classification. It is often considered as part of the global overview of functional somatic syndromes that are otherwise medically unexplained or part of a somatization disorder. Patients with fibromyalgia share symptoms with other functional somatic problems, including issues of myalgias, arthralgias, fatigue and sleep disturbances. Indeed, there is often diagnostic and classification overlap for the case definitions of a variety of somatization disorders. Fibromyalgia, however, is a critically important syndrome for physicians and scientists to be aware of. Patients should be taken very seriously and provided optimal care. Although inflammatory, infectious, and autoimmune disorders have all been ascribed to be etiological events in the development of fibromyalgia, there is very little data to support such a thesis. Many of these disorders are associated with depression and anxiety and may even be part of what has been sometimes called affected spectrum disorders. There is no evidence that physical trauma, i.e., automobile accidents, is associated with the development or exacerbation of fibromyalgia. Treatment should be placed on education, patient support, physical therapy, nutrition, and exercise, including the use of drugs that are approved for the treatment of fibromyalgia. Treatment should not include opiates and patients should not become poly pharmacies in which the treatment itself can lead to significant morbidities. Patients with fibromyalgia are living and not dying of this disorder and positive outlooks and family support are key elements in the management of patients.

Neurobiology of fibromyalgia and chronic widespread pain

Fibromyalgia is the current term for chronic widespread musculoskeletal pain for which no alternative cause can be identified. The underlying mechanisms, in both human and animal studies, for the continued pain in individuals with fibromyalgia will be explored in this review. There is a substantial amount of support for alterations of central nervous system nociceptive processing in people with fibromyalgia, and that psychological factors such as stress can enhance the pain experience. Emerging evidence has begun exploring other potential mechanisms including a peripheral nervous system component to the generation of pain and the role of systemic inflammation. We will explore the data and neurobiology related to the role of the CNS in nociceptive processing, followed by a short review of studies examining potential peripheral nervous system changes and cytokine involvement. We will not only explore the data from human subjects with fibromyalgia but will relate this to findings from animal models of fibromyalgia. We conclude that fibromyalgia and related disorders are heterogenous conditions with a complicated pathobiology with patients falling along a continuum with one end a purely peripherally driven painful condition and the other end of the continuum is when pain is purely centrally driven.

How to diagnose fibromyalgia

This review discusses the basic pathophysiological mechanisms that are necessary to understand the principles of diagnosis and management of fibromyalgia, and outlines a practical diagnostic approach to patients presenting with chronic widespread pain.

Fibromyalgia: A Clinical Update

Fibromyalgia is a common chronic syndrome defined by core symptoms of widespread pain, fatigue, and sleep disturbance. Other common symptoms include cognitive difficulty, headache, paresthesia, and morning stiffness. Fibromyalgia is increasingly understood as 1 of several disorders that are referred to as central sensitivity syndromes; these disorders share underlying causes and clinical features. Tender points are often detected in patients with fibromyalgia and were formerly required for diagnosis. Newly proposed criteria, however, rely on patients' reports of widespread pain and other somatic symptoms to establish the diagnosis of fibromyalgia. The management of fibromyalgia requires a multidimensional approach including patient education, cognitive behavioral therapy, exercise, and pharmacologic therapy. The present review provides an update on these various aspects of treating a patient with fibromyalgia.

Metabolic rate, cardiac response, and aerobic capacity in fibromyalgia: a case-control study

OBJECTIVES

Several studies report reduced aerobic capacity in patients with fibromyalgia (FM). The purpose of our study was to investigate whether a reduction in aerobic capacity in these patients is accompanied by alterations in metabolic rate and heart rate (HR) response.

METHOD

Twelve women with FM and 12 healthy controls (HCs) matched on sex and age, and with similar leisure time physical activity, participated in the study. All subjects performed an incremental submaximal cycle ergometer test to anaerobic threshold [AT; i.e. blood lactate concentration (bLa) ≥ 4 mmol/L], followed by a stepwise test to exhaustion to estimate maximal oxygen consumption (VO(2max)).

RESULTS

Oxygen consumption and workload were lower among patients than HCs both at AT and at termination of the VO(2max) test (p < 0.011 for all comparisons). Two patients (18%) and nine HCs (75%) reached VO(2max) criteria. The relationship between metabolic rate and workload did not differ between groups at exercise below AT. At exercise above AT, the metabolic rate increased disproportionally to workload in the patients. Although the patients had a higher anaerobic contribution to the total metabolic rate at the end of the submaximal test, the anaerobic contribution at the end of the maximal test did not differ between groups. HR responses were largely similar between groups.

CONCLUSIONS

The current study indicates that patients with FM have similar metabolic and cardiovascular responses to submaximal exercise as HCs. However, these patients have reduced ability to reach VO(2max) and a possible deficit in the metabolic system when exercising above the AT.

Decreased muscle concentrations of ATP and PCR in the quadriceps muscle of fibromyalgia patients--a 31P-MRS study

BACKGROUND AND METHODS

Fibromyalgia (FMS) has a prevalence of approximately 2% in the population. Central alterations have been described in FMS, but there is not consensus with respect to the role of peripheral factors for the maintenance of FMS. 31P magnetic resonance spectroscopy (31P-MRS) has been used to investigate the metabolism of phosphagens in muscles of FMS patients, but the results in the literature are not in consensus. The aim was to investigate the quantitative content of phosphagens and pH in resting quadriceps muscle of patients with FMS (n = 19) and in healthy controls (CONTROLS; n = 14) using (31) P-MRS. It was also investigated whether the concentrations of these substances correlated with measures of pain and/or physical capacity.

RESULTS

Significantly lower concentrations of adenosine triphosphate (ATP) and phosphocreatinine (PCr; 28-29% lower) were found in FMS. No significant group differences existed with respect to inorganic phosphate (Pi), Pi/PCr and pH. The quadriceps muscle fat content was significantly higher in FMS than in CONTROLS [FMS: 9.0 ± 0.5% vs.

CONTROLS

6.6 ± 0.6%; (mean ± standard error); P = 0.005]. FMS had significantly lower hand and leg capacity according to specific physical test, but there were no group differences in body mass index, subjective activity level and in aerobic fitness. In FMS, the specific physical capacity in the leg and the hand correlated positively with the concentrations of ATP and PCr; no significant correlations were found with pain intensities.

CONCLUSIONS

Alterations in intramuscular ATP, PCr and fat content in FMS probably reflect a combination of inactivity related to pain and dysfunction of muscle mitochondria.

Should Rheumatologists be Managing Fibromyalgia?

Fibromyalgia has always struggled to be taken seriously. The vague mixture of aches, pains, stiffness and fatigue with no clear clinical or investigational findings has led many to doubt its very existence. Evidence is accumulating, however, of demonstrable abnormalities of pain processing and psychosocial factors in fibromyalgia subjects. These may ‘prove’ its existence, but do they suggest it is rheumatological?

Decreased muscle blood flow in fibromyalgia patients during standardised muscle exercise: A contrast media enhanced colour doppler study

The aim of the study was to investigate if contrast enhanced ultrasound (US) imaging of muscular blood flow during and following exercise could detect alterations in vascularity in fibromyalgia (FM) patients. Ten FM patients and 10 matched controls were examined with US during standardised static and directly following static and dynamic muscular contractions of the infraspinatus muscle. Doppler ultrasound evaluation was performed before and after the administration of ultrasound contrast media. The FM patients had lower magnitude of muscle vascularity following dynamic (p<0.001) and during (p<0.002) static exercise compared to controls. The immediate flow response to muscular activity was not only of a lower magnitude, but also of a shorter duration in FM patients following dynamic exercise (p<0.001) and during static exercise (p<0.01). There were no statistically significant group differences in blood flow intensity or duration following static contraction. In conclusion, contrast enhanced US was found useful to study real-time muscle blood flow changes during and following standardised, low-intensity exercise in FM patients and healthy controls. Our results support the suggestion that muscle ischemia can contribute to pain in FM, possibly by maintaining the central nervous changes such as central sensitisation/disinhibition. US with contrast can be a new valuable approach to assess muscle perfusion in pain patients during standardised exercise.

The prevalence of fibromyalgia in other chronic pain conditions

Central sensitivity syndromes (CSS) include fibromyalgia syndrome (FMS), irritable bowel syndrome, temporomandibular disorder, restless legs syndrome, chronic fatigue syndrome, and other similar chronic painful conditions that are based on central sensitization (CS). CSS are mutually associated. In this paper, prevalence of FMS among other members of CSS has been described. An important recent recognition is an increased prevalence of FMS in other chronic pain conditions with structural pathology, for example, rheumatoid arthritis, systemic lupus, ankylosing spondylitis, osteoarthritis, diabetes mellitus, and inflammatory bowel disease. Diagnosis and proper management of FMS among these diseases are of crucial importance so that unwarranted use of such medications as corticosteroids can be avoided, since FMS often occurs when RA or SLE is relatively mild.

Fibromyalgia: from pathophysiology to therapy

Individuals with fibromyalgia generally experience chronic widespread pain, which can be accompanied by further symptoms including fatigue, sleep disturbances, cognitive dysfunction, anxiety and depressive episodes. As the recognition and diagnosis of fibromyalgia has improved, the availability of therapeutic options for patients has increased. Furthermore, research into the neurobiological mechanisms that contribute to the chronic pain and concomitant symptoms experienced by patients with fibromyalgia has advanced our understanding of this debilitating disorder. In this Review, we aim to provide an overview of existing pathophysiological concepts. The roles of biological and psychological stress, genetic factors, and pain and sensory processing in the pathophysiology of fibromyalgia and related conditions are discussed. In addition, pharmacological treatments, including monoamine modulators, calcium channel modulators and γ-aminobutyric acid modulators, as well as nonpharmacological treatment options are considered.

Quantitative electroencephalographic abnormalities in fibromyalgia patients

There is increasing acceptance that pain in fibromyalgia (FM) is a result of dysfunctional sensory processing in the spinal cord and brain, and a number of recent imaging studies have demonstrated abnormal central mechanisms. The objective of this report is to statistically compare quantitative electroencephalogram (qEEG) measures in 85 FM patients with age and gender matched controls in a normative database. A statistically significant sample (minimum 60 seconds from each subject) of artifact-free EEG data exhibiting a minimum split-half reliability ratio of 0.95 and test-retest reliability ratio of 0.90 was used as the threshold for acceptable data inclusion. FM subject EEG data was compared to EEGs of age and gender matched healthy subjects in the Lifespan Normative Database and analyzed using NeuroGuide 2.0 software. Analyses were based on spectral absolute power, relative power and coherence. Clinical evaluations included the Fibromyalgia Impact Questionnaire (FIQ), Beck Depression Inventory and Fischer dolorimetry for pain pressure thresholds. Based on Z-statistic findings, the EEGs from FM subjects differed from matched controls in the normative database in three features: (1) reduced EEG spectral absolute power in the frontal International 10-20 EEG measurement sites, particularly in the low- to mid-frequency EEG spectral segments; (2) elevated spectral relative power of high frequency components in frontal/central EEG measurement sites; and (3) widespread hypocoherence, particularly in low- to mid-frequency EEG spectral segments, in the frontal EEG measurement sites. A consistent and significant negative correlation was found between pain severity and the magnitude of the EEG abnormalities. No relationship between EEG findings and medicine use was found. It is concluded that qEEG analysis reveals significant differences between FM patients compared to age and gender matched healthy controls in a normative database, and has the potential to be a clinically useful tool for assessing brain function in FM patients.

[Etiology and pathophysiology of fibromyalgia syndrome and chronic widespread pain]

OBJECTIVE

To write a systematic review on the etiology and pathophysiology of the fibromyalgia syndrome (FMS) and of chronic widespread pain (CWP).

METHODS

An interdisciplinary level-3 guideline (i.e. systematic literature search and assessment, logic analysis, formal consensus procedure) for the diagnosis and therapy of FMS was created in cooperation with 10 medical and psychological societies and 2 patient self-help organizations. A literature search was performed covering all available review articles on the etiology and pathophysiology of FMS and CWP using the Cochrane Collaboration Reviews (1993-12/2006), Medline (1980-2006), PsychInfo (1966-12/2006), and Scopus (1980-12/2006). For the assignment of evidence classes the system of the Oxford Centre for Evidence-Based Medicine was applied. Consensus was achieved by a multi-step nominal group procedure.

RESULTS

FMS aggregates in families (evidence level 2c). Physical and psychological stress at the workplace are risk factors for the development of CWP and FMS. Affective disorders are risk factors for the development and maintenance of FMS. Operant learning mechanisms and sensitization are risk factors for the chronification of FMS (evidence levels 2b). Several factors are associated with the pathophysiology of FMS, but the causal relationship is unclear. This includes alterations of central pain pathways, hyporeactivity of the hypothalamus-pituitary-adrenal axis, increased systemic pro-inflammatory and reduced anti-inflammatory cytokine profiles and disturbances in the dopaminergic and serotonergic systems.

CONCLUSIONS

FMS is the common final product of various etiological factors and pathophysiological mechanisms.

Biology and therapy of fibromyalgia. Evidence-based biomarkers for fibromyalgia syndrome

Researchers studying fibromyalgia strive to identify objective, measurable biomarkers that may identify susceptible individuals, may facilitate diagnosis, or that parallel activity of the disease. Candidate objective measures range from sophisticated functional neuroimaging to office-ready measures of the pressure pain threshold. A systematic literature review was completed to assess highly investigated, objective measures used in fibromyalgia studies. To date, only experimental pain testing has been shown to coincide with improvements in clinical status in a longitudinal study. Concerted efforts to systematically evaluate additional objective measures in research trials will be vital for ongoing progress in outcome research and translation into clinical practice.

Ottawa Panel evidence-based clinical practice guidelines for strengthening exercises in the management of fibromyalgia: part 2

BACKGROUND AND PURPOSE

The objective of this study was to create guidelines for the use of strengthening exercises in the management of adult patients (>18 years of age) with fibromyalgia (FM), as defined by the 1990 American College of Rheumatology criteria.

METHODS

Following Cochrane Collaboration methods, the Ottawa Methods Group found and synthesized evidence from comparative controlled trials and formed the Ottawa Panel, with nominated experts from key stakeholder organizations. The Ottawa Panel then developed criteria for grading the recommendations based on experimental design (I for randomized controlled trials, II for nonrandomized studies) and strength of evidence (A, B, C+, C, D+, D, or D-). From the rigorous literature search, 5 randomized controlled trials were selected. Statistical analysis was based on Cochrane Collaboration methods. Continuous data were calculated with weighted mean differences between the intervention and control groups, and dichotomous data were analyzed with relative risks. Clinical improvement was calculated using absolute benefit and relative difference in change from baseline. Clinical significance was attained when an improvement of 15% relative to a control was found.

RESULTS

There were 5 positive recommendations: 2 grade A and 3 grade C+. All 5 were of clinical benefit.

DISCUSSION AND CONCLUSION

The Ottawa Panel recommends strengthening exercises for the management of fibromyalgia as a result of the emerging evidence (grades A, B, and C+, although most trials were rated low quality) shown in the literature.

Central sensitization: a biopsychosocial explanation for chronic widespread pain in patients with fibromyalgia and chronic fatigue syndrome

In addition to the debilitating fatigue, the majority of patients with chronic fatigue syndrome (CFS) experience chronic widespread pain. These pain complaints show the greatest overlap between CFS and fibromyalgia (FM). Although the literature provides evidence for central sensitization as cause for the musculoskeletal pain in FM, in CFS this evidence is currently lacking, despite the observed similarities in both diseases. The knowledge concerning the physiological mechanism of central sensitization, the pathophysiology and the pain processing in FM, and the knowledge on the pathophysiology of CFS lead to the hypothesis that central sensitization is also responsible for the sustaining pain complaints in CFS. This hypothesis is based on the hyperalgesia and allodynia reported in CFS, on the elevated concentrations of nitric oxide presented in the blood of CFS patients, on the typical personality styles seen in CFS and on the brain abnormalities shown on brain images. To examine the present hypothesis more research is required. Further investigations could use similar protocols to those already used in studies on pain in FM like, for example, studies on temporal summation, spatial summation, the role of psychosocial aspects in chronic pain, etc.

Antidepressants and cognitive-behavioral therapy for symptom syndromes

Somatic symptoms are common in primary care and clinicians often prescribe antidepressants as adjunctive therapy. There are many possible reasons why this may work, including treating comorbid depression or anxiety, inhibition of ascending pain pathways, inhibition of prefrontal cortical areas that are responsible for "attention" to noxious stimuli, and the direct effects of the medications on the syndrome. There are good theoretical reasons why antidepressants with balanced norepinephrine and serotonin effects may be more effective than those that act predominantly on one pathway, though head-to-head comparisons are lacking. For the 11 painful syndromes review in this article, cognitive-behavioral therapy is most consistently demonstrated to be effective, with various antidepressants having more or less randomized controlled data supporting or refuting effectiveness. This article reviews the randomized controlled trial data for the use of antidepressant and cognitive-behavior therapy for 11 somatic syndromes: irritable bowel syndrome, chronic back pain, headache, fibromyalgia, chronic fatigue syndrome, tinnitus, menopausal symptoms, chronic facial pain, noncardiac chest pain, interstitial cystitis, and chronic pelvic pain. For some syndromes, the data for or against treatment effectiveness is relatively robust, for many, however, the data, one way or the other is scanty.

Acute heavy-resistance exercise–induced pain and neuromuscular fatigue in elderly women with fibromyalgia and in healthy controls: Effects of strength training

OBJECTIVE

To examine heavy-resistance exercise-induced acute neuromuscular fatigue, blood lactate concentration, and muscle pain in elderly women with fibromyalgia (FM) and in healthy controls before and after a period of strength training.

METHODS

Thirteen elderly women with FM (mean+/-SD age 60+/-2 years) and 10 healthy women (mean+/-SD age 64+/-3 years) performed a heavy-resistance fatiguing protocol (5 sets of leg presses with 10 repetitions maximum) before and after a 21-week strength training period. Maximal isometric force and electromyography (EMG) activity of leg extensors and blood lactate concentration were measured during the loading. Pain was assessed by visual analog scale.

RESULTS

The strength training led to large increases in maximal force and EMG activity of the muscles and contributed to the improvement in loading performance (average load/set) at week 21. The fatiguing loading sessions typically applied in strength training before and after the experimental period caused remarkable and comparable acute decreases in maximal force and increases in blood lactate concentration in both groups. Acute exercise-induced muscle pain increased similarly in both groups, and the pain level in women with FM was lowered after the 21-week training period.

CONCLUSION

The increased strength in women with FM improved high-load performance and also seemed to attenuate perceived pain. Acute exercise-induced neuromuscular changes and the time course of muscle pain in women with FM were comparable with findings in healthy controls, which suggests a typical fatiguing process and a similar trainability of the muscles in elderly women with FM.

Is fibromyalgia a muscle disorder?

The presence of abnormalities in fibromyalgia muscle using current methodological approaches is well established. The more serious abnormalities are demonstrated by histologic studies particularly on electron microscopy: disorganisation of Z bands and abnormalities in the number and shape of mitochondria. Biochemical studies and P 31 magnetic resonance spectroscopy show inconstant abnormalities of ATP and phosphocreatine levels. Mitochondrial abnormalities reduced capillary circulation and thickened capillary endothelium may result in decreased availability of oxygen and impaired oxidative phosphorylation as well as ATP synthesis. These abnormalities do not seem to be the consequences of the much-discussed deconditioning of muscles although these consequences are not well known. Further studies of energy metabolism of the muscle during exercise are needed.

Are tender points associated with cervical radiculopathy?

OBJECTIVE

To determine if there is an association between cervical radiculopathy and tender spots in the neck and upper extremity on the side of radiculopathy.

DESIGN

Prospective cross-sectional study.

SETTING

Outpatient spine clinic within an academic institution.

PARTICIPANTS

Convenience sample of 16 subjects with unilateral cervical radiculopathy. Twelve subjects had C7 radiculopathy and 4 had C6 or C8 radiculopathy.

INTERVENTION

Bilateral pain-pressure threshold measurement (14 muscles) of the neck and upper extremity.

MAIN OUTCOME MEASURE

Side-to-side difference in pain-pressure threshold.

RESULTS

Differences in frequency of tender spots were found only in the deltoid and flexor carpi radialis. Overall, more tender spots were found on the side of radiculopathy (75 vs 34, P < .01). Among subjects with C7 radiculopathy, the number of tender spots in C7 innervated muscles was greater on the side of radiculopathy (23 vs 7, P < .02). In contrast, no significant difference in the number of tender spots between sides was found when only non-C7 innervated muscles (P > 0.1) were considered.

CONCLUSIONS

Cervical radiculopathy was associated with increased tender spots on the side of radiculopathy, with predilection toward muscles innervated by the involved nerve root.

[A comparative study of fibromyalgia treatment: ultrasonography and physiotherapy versus sertraline treatment]

OBJECTIVE

To compare the efficacy of sertraline versus physical therapy (ultrasonography and physical therapy) in fibromyalgia.

DESIGN

A 6-month comparative, prospective, randomised study of 70 female patients, aged 42 to 52, with fibromyalgia according to the criteria of the American College of Rheumatology. One group (N=36) underwent 6-month treatment with sertraline, 50 mg/24 h. The other group (N=34) received 15 sessions of 1 W/cm2 ultrasonography on the cervical trigger points plus physical therapy. Variables analyzed on a visual 10-point scale were pain and morning stiffness and sleep disorders by use of the sleep questionnaire of the Medical Outcome Study (MOS). Measurements were taken at the beginning of the study and at 3-month and 6-month follow-up.

RESULTS

Pain significantly diminished in the sertraline group during the entire study (visual numeric scale: 7.2+/-1.1 initially, 5.3+/-?? at 3 months and 3+/-0.7 at 6 months, P<0.05). Morning stiffness and sleep disorder scores were positive only for the sertraline group during the entire 6 months (P<0.05). Results from the MOS questionnaire showed improvement only for the sertraline group. Of the Sertraline group, 83% evaluated the treatment as good or very good, as compared with only 6% of the ultrasonography group. No patient withdrew from the study.

CONCLUSION

Patients treated with sertraline had a better outcome in terms of pain, morning stiffness and sleep disorders, than the group treated with ultrasonography and physical therapy.

Evidence for abnormal pain processing in fibromyalgia syndrome

OBJECTIVE

To review the pathophysiology of fibromyalgia syndrome.

DESIGN

Review of the literature available on Medline (1965-2001).

RESULTS

Fibromyalgia syndrome is a chronic pain syndrome that predominantly afflicts women. It is characterized by widespread pain, insomnia, fatigue, and the presence of multiple tender points. Despite intensifying research, the etiology of fibromyalgia has remained unclear. Importantly, neither infections, trauma, nor psychiatric abnormalities consistently precede the onset of pain in patients with this syndrome. There is, however, mounting evidence for central pain processing abnormalities in almost all fibromyalgia patients. These anomalies include hyperalgesia, allodynia, abnormal temporal summation of second pain, neuroendocrine abnormalities, and abnormal activation of pain-related brain regions.

CONCLUSIONS

Multiple abnormal findings in fibromyalgia patients strongly indicate a neuropathic pain syndrome, reminiscent of complex regional pain syndrome or postherpetic neuralgia. In addition, fibromyalgia syndrome seems to share similar characteristics with these neuropathic pain syndromes, including ineffective response to many analgesics.

Increased DNA fragmentation and ultrastructural changes in fibromyalgic muscle fibres

OBJECTIVE

To determine whether there is evidence of increased DNA fragmentation and ultrastructural changes in muscle tissue of patients with fibromyalgia (FM) compared with healthy controls.

METHODS

Muscle tissues from 10 community residents with FM and 10 age and sex matched healthy controls were examined "blindly" for the presence of DNA fragmentation by two different methods: terminal deoxynucleotidyl transferase (TdT) staining (TUNEL) and the FragEL-Klenow DNA fragmentation detection kit. Ultrastructural analysis of tissue was performed by electron microscopy.

RESULTS

DNA fragmentation was detected by both methods in 55.4 (SEM 2.5)% of the nuclei in muscle tissue of patients with FM compared with 16.1 (4.1)% (p<0.001) of the nuclei in healthy controls. Contrary to expectation, no typical features of apoptosis could be detected by electron microscopy. The myofibres and actin filaments were disorganised and lipofuscin bodies were seen; glycogen and lipid accumulation were also found. The number of mitochondria was significantly lower in patients with FM than in controls and seemed to be morphologically altered.

CONCLUSION

The ultrastructural changes described suggest that patients with FM are characterised by abnormalities in muscle tissue that include increased DNA fragmentation and changes in the number and size of mitochondria. These cellular changes are not signs of apoptosis. Persistent focal contractions in muscle may contribute to ultrastructural tissue abnormalities as well as to the induction and/or chronicity of nociceptive transmission from muscle to the central nervous system.

Dimensions of psychological dysfunction in patients with fibromyalgia: development of an Italian questionnaire

Our objective was to observe whether dysfunctional psychological dimensions of pain could be detected in fibromyalgia patients through the development of a new questionnaire. An original questionnaire composed of 51 items was given to 250 patients (185 females and 65 males, mean age 55+/-12.8 years) suffering from chronic fibromyalgia according to the criteria of the Multicenter Criteria Committee of the American College of Rheumatology. A Varimax computerized program of factorial analysis with orthogonal and oblique rotation of the axes was used to analyze the data. Five strong independent factors were identified: 1) catastrophizing and 2) external control beliefs (cognitive); 3) alexithymia (emotional); 4) restless behavior (behavioral); and 5) need for support (relational). Our questionnaire is a preliminary development of an Italian language psychological characterization of FM patients which may be a relevant and useful tool for the evaluation of the outcome of clinical/psychological treatment of FM.

Muscle metabolism in fibromyalgia studied by P-31 magnetic resonance spectroscopy during aerobic and anaerobic exercise

OBJECTIVE

To investigate mechanisms underlying the reduced work capacity of fibromyalgia (FM) patients were compared to healthy controls at specified workloads, using P-31 magnetic resonance spectroscopy (MRS).

METHODS

The forearm flexor muscle group was examined with MRS at rest, at sub maximal and at maximal controlled dynamic work as well as at maximal isometric contraction. Aerobic fitness was determined by bicycle ergonometry.

RESULTS

Metabolite concentrations and muscle pH were similar for patients and controls at lower workloads. At maximal dynamic and static contractions the concentration of inorganic phosphate was lower and at static contractions the pH decrease was smaller in patients. The performed work by patients was only 50% compared to controls and the patients experienced more pain. Maximal oxygen uptake was lower in the fibromyalgia group. Expired gas-analysis in this group showed ventilatory equivalents at similar relative levels of maximal work capacity.

CONCLUSION

Fibromyalgia patients seem to utilise less of the energy rich phosphorous metabolites at maximal work despite pH reduction. They seemed to be less aerobic fitted and reached the anaerobic threshold earlier than the controls.

Childhood adversities in patients with fibromyalgia and somatoform pain disorder

Primary fibromyalgia is regarded as disorder with a complex symptomatology, and no morphological alterations. Findings increasingly point to a dysfunction of the central nervous pain processing. The study aims to discuss vulnerability for fibromyalgia from a developmental psychopathological perspective. We investigated the presence of psychosocial adversities affecting the childhood of adult fibromyalgia patients (FM) and compared them to those of patients with somatoform pain disorders (SOM) and a control group (CG) with medically explained chronic pain. Using the structured biographical interview for pain patients (SBI-P), 38 FM patients, 71 SOM patients, and 44 CG patients were compared on the basis of 14 childhood adversities verified as relevant regarding longterm effects for adult health by prospective studies. The FM patients show the highest score of childhood adversities. In addition to sexual and physical maltreatment, the FM patients more frequently reported a poor emotional relationship with both parents, a lack of physical affection, experiences of the parents' physical quarrels, as well as alcohol or other problems of addiction in the mother, separation, and a poor financial situation before the age of 7. These experiences were found to a similar extent in the SOM patients, but distinctly less frequently in the CG. The results point to early psychosocial adversities as holding a similar etiological meaning in fibromyalgia as well as in somatoform pain disorders. The potential role of these factors as increasing the vulnerability for fibromyalgia is discussed.

Temporal summation of pain from mechanical stimulation of muscle tissue in normal controls and subjects with fibromyalgia syndrome

Individuals diagnosed with fibromyalgia syndrome (FMS) report chronic pain that is frequently worsened by physical activity and improved by rest. Palpation of muscle and tendinous structures suggests that nociceptors in deep tissues are abnormally sensitive in FMS, but methods of controlled mechanical stimulation of muscles are needed to better characterize the sensitivity of deep tissues. Accordingly, force-controlled mechanical stimulation was applied to the flexor digitorum muscle of the forearm in a series of brief contacts (15 stimuli, each of 1s duration, at 3 or 5s interstimulus intervals). Repetitive stimulation was utilized to determine whether temporal summation of deep muscular pain would occur for normal subjects and would be enhanced for FMS subjects. Moderate temporal summation of deep pain was observed for normal controls (NC), and temporal summation was greatly exaggerated for FMS subjects. Temporal summation for FMS subjects occurred at substantially lower forces and at a lower frequency of stimulation. Furthermore, painful after-sensations were greater in amplitude and more prolonged for FMS subjects. These observations complement a previous demonstration that temporal summation of pain and after-sensations elicited by thermal stimulation of the skin are moderately enhanced for FMS subjects. Abnormal input from muscle nociceptors appears to underlie production of central sensitization in FMS that generalizes to input from cutaneous nociceptors.