Fibromyalgia: Associations Between Fat Infiltration, Physical Capacity, and Clinical Variables.

Background: Obesity is a risk factor for the development of fibromyalgia (FM) and generally most studies report increased Body Mass Index (BMI) in FM. Obesity in FM is associated with a worse clinical presentation. FM patients have low physical conditioning and obesity further exacerbates these aspects. Hitherto studies of FM have focused upon a surrogate for overall measure of fat content, ie, BMI. This study is motivated by that ectopic fat and adipose tissues are rarely investigated in FM including their relationships to physical capacity variables. Moreover, their relationships to clinical variables including are not known. Aims were to 1) compare body composition between FM and healthy controls and 2) investigate if significant associations exist between body composition and physical capacity aspects and important clinical variables. Methods: FM patients (n = 32) and healthy controls (CON; n = 30) underwent a clinical examination that included pressure pain thresholds and physical tests. They completed a health questionnaire and participated in whole-body magnetic resonance imaging (MRI) to determine body composition aspects. Results: Abdominal adipose tissues, muscle fat, and BMI were significantly higher in FM, whereas muscle volumes of quadriceps were smaller. Physical capacity variables correlated negatively with body composition variables in FM. Both body composition and physical capacity variables were significant regressors of group belonging; the physical capacity variables alone showed stronger relationships with group membership. A mix of body composition variables and physical capacity variables were significant regressors of pain intensity and impact in FM. Body composition variables were the strongest regressors of blood pressures, which were increased in FM. Conclusion: Obesity has a negative influence on FM symptomatology and increases the risk for other serious conditions. Hence, obesity, dietary habits, and physical activity should be considered when developing clinical management plans for patients with FM.

Evidence of Mitochondrial Dysfunction in Fibromyalgia: Deviating Muscle Energy Metabolism Detected Using Microdialysis and Magnetic Resonance.

In fibromyalgia (FM) muscle metabolism, studies are sparse and conflicting associations have been found between muscle metabolism and pain aspects. This study compared alterations in metabolic substances and blood flow in erector spinae and trapezius of FM patients and healthy controls. FM patients (n = 33) and healthy controls (n = 31) underwent a clinical examination that included pressure pain thresholds and physical tests, completion of a health questionnaire, participation in microdialysis investigations of the etrapezius and erector spinae muscles, and also underwent phosphorus-31 magnetic resonance spectroscopy of the erector spinae muscle. At the baseline, FM had significantly higher levels of pyruvate in both muscles. Significantly lower concentrations of phosphocreatine (PCr) and nucleotide triphosphate (mainly adenosine triphosphate) in erector spinae were found in FM. Blood flow in erector spinae was significantly lower in FM. Significant associations between metabolic variables and pain aspects (pain intensity and pressure pain threshold PPT) were found in FM. Our results suggest that FM has mitochondrial dysfunction, although it is unclear whether inactivity, obesity, aging, and pain are causes of, the results of, or coincidental to the mitochondrial dysfunction. The significant regressions of pain intensity and PPT in FM agree with other studies reporting associations between peripheral biological factors and pain aspects.

Non-uniform displacement within the Achilles tendon during passive ankle joint motion.

PURPOSE: An initial step in the understanding of Achilles tendon dynamics is to investigate the effects of passive motion, thereby minimising muscle activation and reducing internal joint forces. Internal tendon dynamics during passive ankle joint motion have direct implications for clinical rehabilitation protocols after Achilles tendon surgery. The aim of this study was to test the hypothesis that tendon tissue displacement is different in different layers of the Achilles tendon during controlled passive ankle joint movements. METHODS: Ultrasound imaging was conducted on the right Achilles tendon of nine healthy recreationally active males. Standardised isokinetic passive dorsi-plantar-flexion movements were performed with a total range of motion of 35°. The tendon was divided into superficial, central and deep layers in the resulting B-mode ultrasound images viewed in the sagittal plane. A block-matching speckle tracking algorithm was applied post-process, with kernels for the measurement of displacement placed in each of the layers. RESULTS: The mean (SD) displacement of the Achilles tendon during passive dorsiflexion was 8.4 (1.9) mm in the superficial layer, 9.4 (1.9) mm in the central portion and 10.4 (2.1) mm in the deep layer, respectively. In all cases, the movement of the deep layer of the tendon was greater than that of the superficial one (P < 0.01). CONCLUSIONS: These results, achieved in vivo with ultrasonographic speckle tracking, indicated complex dynamic differences in different layers of the Achilles tendon, which could have implications for the understanding of healing processes of tendon pathologies and also of normal tendon function.

Prevalence of widespread pain and associations with work status: a population study.

BACKGROUND: This population study based on a representative sample from a Swedish county investigates the prevalence, duration, and determinants of widespread pain (WSP) in the population using two constructs and estimates how WSP affects work status. In addition, this study investigates the prevalence of widespread pain and its relationship to pain intensity, gender, age, income, work status, citizenship, civil status, urban residence, and health care seeking. METHODS: A cross-sectional survey using a postal questionnaire was sent to a representative sample (n = 9952) of the target population (284,073 people, 18-74 years) in a county (Ostergötland) in the southern Sweden. The questionnaire was mailed and followed by two postal reminders when necessary. RESULTS: The participation rate was 76.7% (n = 7637); the non-participants were on the average younger, earned less money, and male. Women had higher prevalences of pain in 10 different predetermined anatomical regions. WSP was generally chronic (90-94%) and depending on definition of WSP the prevalence varied between 4.8-7.4% in the population. Women had significantly higher prevalence of WSP than men and the age effect appeared to be stronger in women than in men. WSP was a significant negative factor - together with age 50-64 years, low annual income, and non-Nordic citizen - for work status in the community and in the group with chronic pain. Chronic pain but not the spreading of pain was related to health care seeking in the population. CONCLUSION: This study confirms earlier studies that report high prevalences of widespread pain in the population and especially among females and with increasing age. Widespread pain is associated with prominent effects on work status.

Surgical treatment of hallux valgus and forefoot deformities in Sweden: a population-based study.

BACKGROUND: Although surgical correction for hallux valgus and other toe deformities is one of the most common procedures in foot surgery, its incidence in the general population is not well-known. MATERIALS AND METHODS: The study population comprised patients living in Sweden of a varied age group and both sexes who underwent forefoot surgery. We identified all inpatient cases from 1997 to 2000 and all ambulatory cases in 2000 registered in the National Swedish Patient Register (NSPR). Further, clinical data for the surgical treatment of hallux valgus deformity were extracted from medical records in patients treated in a geographically defined region (Stockholm). RESULTS: In total, 6956 patients with surgically treated forefoot deformities were identified from the adult population, equivalent to a cumulative incidence of 0.8 procedures per 1000 inhabitants for the whole analyzed group. There were regional variations and significant sex differences. The age distribution in both sexes was characterized by a peak in the fifth decade. Forefoot surgery was statistically more frequently performed in private clinics than in public hospitals (p < 0.001). Hallux valgus surgery was by far the most common procedure regarding forefoot surgery. CONCLUSION: The prevalence of forefoot- and hallux valgus surgery was not evenly distributed in the six major regions in Sweden. It is more common in urban than in rural regions. Furthermore, forefoot surgery is performed more frequently in private clinics than in community hospitals despite common financial sources.

Chronic widespread musculoskeletal pain - a comparison of those who meet criteria for fibromyalgia and those who do not.

Fibromyalgia is currently classified as chronic widespread pain with widespread allodynia to pressure pain. There are few data describing pain characteristics, quality of life, consequences for daily living, and psychosocial status in patients who meet the classification criteria for fibromyalgia proposed by the American College of Rheumatology compared with patients with chronic widespread pain but not widespread allodynia. This study used a randomly selected sample from the general population. A postal questionnaire and a pain mannequin were sent to 9952 people. The response rate was 76.7%. The pain drawings showed that 345 people had widespread pain; that is, they noted pain in all four extremities and axially. Clinical examination, which included a manual tender point examination, was performed in 125 subjects. These people answered commonly used questionnaires on pain, quality of life, coping strategies, depression, and anxiety. Compared with chronic widespread pain without widespread allodynia, fibromyalgia was associated with more severe symptoms/consequences for daily life and higher pain severity. Similar coping strategies were found. Chronic widespread pain without widespread allodynia to pressure pain was found in 4.5% in the population and fibromyalgia in 2.5%.

Prevalence of current and chronic pain and their influences upon work and healthcare-seeking: a population study.

OBJECTIVE: To investigate the prevalence of current and chronic pain and their relationship to pain intensity, sex, age, income, employment status, citizenship, marital status, urban residence, occupational activity, and healthcare-seeking based on a representative sample from a Swedish county. METHODS: A cross-sectional survey using a postal questionnaire was sent to a representative sample (n = 9952) of the target population (284,073 people, age 18-74 yrs) in a county (Ostergötland) in southern Sweden. A questionnaire was mailed and followed by 2 postal reminders if necessary. RESULTS: The participation rate was 76.7% (n = 7637); nonparticipants were on average younger, male, and earned less money. The overall point prevalence of pain was 48.9%. The corresponding one-month period prevalence was 63.0%, and pain on several occasions during the previous 3 months was reported by 61.3% of participants. The prevalence of chronic pain (pain > 3 months) was 53.7%. Female sex, age, and sick leave/early retirement were generally of significant importance in the regressions of pain. No sex factor was found in the regressions of pain frequency and pain intensity. Chronic pain especially frequent and intensive pain showed clear associations with healthcare-seeking and occupational activity. CONCLUSION: High prevalence of current pain (48.9%) and chronic pain (53.7%) were found in this community-based study. Being female, older, and on sick leave or early retirement were generally of significant importance in the regressions of pain. Chronic pain showed clear associations with healthcare-seeking and occupational activity, indicating considerable socioeconomic costs.

Subclinical myositis is common in primary Sjögren's syndrome and is not related to muscle pain.

OBJECTIVE: Although muscle pain is common in primary Sjögren's syndrome (SS), the underlying mechanisms are mainly unknown. We studied all patients with SS at our rheumatology unit with respect to muscle pain in general and to fibromyalgia (FM), and correlated clinical data to muscle biopsy findings. METHODS: We investigated 48 patients with SS according to the modified European diagnostic criteria. The ACR criteria for FM were used to subgroup the patients. Muscle biopsy was performed in 36 patients. Light microscope morphology and immunohistochemical expression of MHC class I, MHC class II, and membrane attack complex (MAC) were studied. RESULTS: We found 44% of patients complained of muscle pain; 27% fulfilled the ACR criteria for FM, whereas 17% had other forms of myalgia. Muscle pain could not be related to histopathological findings. Signs of inflammation were found in 26 of 36 biopsies (72%), and inflammation combined with degeneration/regeneration (i.e., histological signs of polymyositis) in 17 biopsies (47%). However, only 5 patients (14%) had clinical as well as histological signs of polymyositis. Eight muscle biopsies (22%) showed histological features of inclusion body myositis (IBM). However, no patient had clinical symptoms suggestive of this disease. Abnormal expression of MHC class I, MHC class II, and MAC was found in 18 (50%), 16 (44%), and 27 (75%) patients, respectively. CONCLUSION: Muscle pain, especially FM, is common in SS. Histopathological signs of myositis are very common in SS. However, muscle symptoms are not related to histological signs of muscle inflammation. IBM-like findings may represent vacuolar myopathic degeneration due to previous subclinical muscle inflammation rather than a specific clinical entity.

Quantitative EMG and muscle tension in painful muscles in fibromyalgia.

Examinations were performed in 22 female fibromyalgic patients and in 9 healthy controls. The biceps brachii, trapezius, and tibial anterior muscles were examined electromyographically. The changes found were minor and non-specific. This implies that there is no important loss of motor units and no conspicuous muscle fiber degeneration in fibromyalgia. Our investigation also failed to demonstrate any electrically detectable muscle activity in muscles where the patients during the examination reported pain (paraspinal, trapezius and tibial anterior muscles). This means that muscle tension cannot be a prominent pathogenetic factor in fibromyalgia and that factors other than muscle tension are responsible for maintaining the pain in fibromyalgia.

Diagnostic epidural opioid blockade in primary fibromyalgia at rest and during exercise.

Nine patients with primary fibromyalgia participated. The patients were studied prior to, during and immediately after 4 identical periods of exercise (bicycle ergometer) each performed 30 min after injection with saline, repeated saline, an opioid and naloxone. All substances were given epidurally, except for naloxone which was given intravenously. Finally, with the patients resting in bed, lignocaine was injected epidurally. Physiological variables, general exertion, dyspnoea, lower extremity exhaustion, pain and tender points in the lower half of the body were examined. Resting pain and tender points diminished significantly after the opioid injection. Lignocaine completely abolished resting pain and tender points. Lower extremity exhaustion was reduced by the opioid. General exertion and dyspnoea were unaffected by the opioid. In conclusion the results support the hypothesis that the pain in fibromyalgia is of peripheral nociceptive or spinal origin. We raise the hypothesis that the fatigability is, at least partly, due to inhibition because of pain.