High prevalence of undetected carpal tunnel syndrome in patients with fibromyalgia syndrome

Objective. To assess the prevalence of carpal tunnel syndrome (CTS) in patients with fibromyalgia syndrome (FM). Methods. A series of 206 consecutive patients with FM was evaluated for CTS in an unblinded, uncontrolled study. Sixty patients with dermatomal paresthesia in the fingers enervated by the median nerve were evaluated with electromyogram and nerve conduction velocity studies (EMG/NCV), Results. Thirty-three patients showed EMG/NCV findings diagnostic for CTS (16% of the 206 cases, 55% of the 60 EMG studies). Only 2 of the 33 patients with CTS had been diagnosed before rheumatologic evaluation. We compared our results with those reported for women in the general population. The overall prevalence of CTS in women was higher (16 vs 10.2%), but not statistically different. However, in our series, there was a clear difference in the higher rate of undetected CTS in women with FM compared to that of the general population (14.1 vs 6.7%) (p<0.01), Conclusion. (1) CTS is at least as common in patients with FM as in the general population, contrary to that reported in retrospective studies; (2) the rate of underdiagnosed CTS in women with FM is much higher than the rate reported in the general population; (3) NCV studies may be necessary to evaluate underdiagnosed CTS in patients with FM and dermatomal paresthesia in their hands