Clinical Trials

The role of free radicals in fibromyalgia is controversial. In this study, 85 female patients with primary fibromyalgia and 80 age-, height-, and weight-matched healthy women were evaluated for oxidant/antioxidant balance. Malondialdehyde is a toxic metabolite of lipid peroxidation used as a marker of free radical damage. Superoxide dismutase is an intracellular antioxidant enzyme and shows antioxidant capacity. Pain was assessed by visual analog scale. Tender points were assessed by palpation. Age, smoking, body mass index (BMI), and duration of disease were also recorded. Malondialdehyde levels were significantly higher and superoxide dismutase levels significantly lower in fibromyalgic patients than controls. Age, BMI, smoking, and duration of disease did not affect these parameters. We found no correlation between pain and number of tender points. In conclusion, oxidant/antioxidant balances were changed in fibromyalgia. Increased free radical levels may be responsible for the development of fibromyalgia. These findings may support the hypothesis of fibromyalgia as an oxidative disorder. Read More on PubMed

The optimal management of fibromyalgia syndrome (FMS) is unclear and comprehensive evidence-based guidelines have not been reported. Read More on PubMed

Patients with chronic pain after whiplash injury and fibromyalgia patients display exaggerated pain after sensory stimulation. Because evident tissue damage is usually lacking, this exaggerated pain perception could be explained by hyperexcitability of the central nervous system. The nociceptive withdrawal reflex (a spinal reflex) may be used to study the excitability state of spinal cord neurons. We tested the hypothesis that patients with chronic whiplash pain and fibromyalgia display facilitated withdrawal reflex and therefore spinal cord hypersensitivity. Three groups were studied: whiplash (n=27), fibromyalgia (n=22) and healthy controls (n=29). Two types of transcutaneous electrical stimulation of the sural nerve were applied: single stimulus and five repeated stimuli at 2 Hz. Electromyography was recorded from the biceps femoris muscle. The main outcome measurement was the minimum current intensity eliciting a spinal reflex (reflex threshold). Reflex thresholds were significantly lower in the whiplash compared with the control group, after both single (P=0.024) and repeated (P=0.035) stimulation. The same was observed for the fibromyalgia group, after both stimulation modalities (P=0.001 and 0.046, respectively). We provide evidence for spinal cord hyperexcitability in patients with chronic pain after whiplash injury and in fibromyalgia patients. This can cause exaggerated pain following low intensity nociceptive or innocuous peripheral stimulation. Spinal hypersensitivity may explain, at least in part, pain in the absence of detectable tissue damage. Read More on PubMed

Although individuals with fibromyalgia syndrome (FMS) consistently report wide-spread pain, clear evidence of structural abnormalities or other sources of chronic stimulation of pain afferents in the involved body areas is lacking. Without convincing evidence for peripheral tissue abnormalities in FMS patients, it seems likely that a central pathophysiological process is at least partly responsible for FMS, as is the case for many chronic pain conditions. Therefore, the present study sought to obtain psychophysical evidence for the possibility that input to central nociceptive pathways is abnormally processed in individuals with long standing FMS. In particular, temporal summation of pain (wind-up) was assessed, using series of repetitive thermal stimulation of the glabrous skin of the hands. Although wind-up was evoked both in control and FMS subjects, clear differences were observed. The perceived magnitude of the sensory response to the first stimulus within a series was greater for FMS subjects compared to controls, as was the amount of temporal summation within a series. Within series of stimuli, FMS subjects reported increases in sensory magnitude to painful levels for interstimulus intervals of 2-5 s, but pain was evoked infrequently at intervals greater than 2 s for control subjects. Following the last stimulus in a series, after-sensations were greater in magnitude, lasted longer and were more frequently painful in FMS subjects. These results have multiple implications for the general characterization of pain in FMS and for an understanding of the underlying pathophysiological basis. Read More on PubMed

Calcium and magnesium ions play a key role in the physiology of muscular contraction: changes in calcium ions concentration may be involved in the pathogenesis of fibromyalgia. Since the plasmatic levels of calcium and magnesium in fibromyalgia patients is always in the normal range, it seemed interesting to evaluate the intracellular calcium and magnesium concentration. Read More on PubMed

Lipid and protein peroxidations were investigated in female patients with magnesium deficit (MD), fibromyalgia (FM) and age matched controls: malondialdehyde and protein carbonyls (PC), as well as serum, leucocyte and erythrocyte magnesium (EMg) were assessed in 20 controls, 25 FM and 16 MD patients. MDA are unchanged in MD and FM. PC are significantly increased (P < 0.01) in FM. EMg is significantly decreased in MD. There is a slight, but not significant, negative correlation between PC and EMg, in controls and MD. Protein peroxidations are demonstrated in FM. Further studies are needed in MD. Read More on PubMed

To develop criteria for the classification of fibromyalgia, we studied 558 consecutive patients: 293 patients with fibromyalgia and 265 control patients. Interviews and examinations were performed by trained, blinded assessors. Control patients for the group with primary fibromyalgia were matched for age and sex, and limited to patients with disorders that could be confused with primary fibromyalgia. Control patients for the group with secondary-concomitant fibromyalgia were matched for age, sex, and concomitant rheumatic disorders. Widespread pain (axial plus upper and lower segment plus left- and right-sided pain) was found in 97.6% of all patients with fibromyalgia and in 69.1% of all control patients. The combination of widespread pain and mild or greater tenderness in greater than or equal to 11 of 18 tender point sites yielded a sensitivity of 88.4% and a specificity of 81.1%. Primary fibromyalgia patients and secondary-concomitant fibromyalgia patients did not differ statistically in any major study variable, and the criteria performed equally well in patients with and those without concomitant rheumatic conditions. The newly proposed criteria for the classification of fibromyalgia are 1) widespread pain in combination with 2) tenderness at 11 or more of the 18 specific tender point sites. No exclusions are made for the presence of concomitant radiographic or laboratory abnormalities. At the diagnostic or classification level, the distinction between primary fibromyalgia and secondary-concomitant fibromyalgia (as defined in the text) is abandoned. Read More on PubMed

Tender point examinations were performed on 1520 consecutive patients with various rheumatic diseases. The mean tender point count was 2.1 (3.6 SD). Four or more tender points were found in 22.9%, 7 or more in 13.6%, 12 or more 4.3%, but 60.1% had no tender points. The tender point count increased gradually with age, reaching a maximum at age 70. Women had more tender points than men, Caucasians more than blacks or Hispanics. Isolated regional clusters of tender points occurred at the shoulder girdle in 7.8%, and the knees in 7.4%. Correlation between tender points and associated peripheral joint tenderness was poor. Read More on PubMed

Of 1,473 consecutive new patients seen in an outpatient rheumatology clinic, 3.7% met criteria for "primary fibrositis." Secondary fibrositis was diagnosed in 12.2% of patients with rheumatoid arthritis (RA), 15.7% of patients with primary neck and back pain syndromes and 6.7% of patients with osteoarthritis (OA). When conditions presumed to be associated with secondary fibrositis were excluded, primary fibrositis was identified in 55 of 405 patients or 13.6%. Two hundred fifteen or 14.6% of all patients had either primary or secondary fibrositis. Fibrositis may be the most common disorder seen in rheumatic disease practice after OA and RA. Read More on PubMed