Thenar Muscles H Reflex in Patients With Fibromyalgia: A Case Control Study Pubmed



Azma K¹ ; Raeissadat SA² ; Hosseini A³ ; Mahmoudi H⁴ ; Sepehrian M⁵ ; Salehi Z⁴ Show Affiliations
Source: Acta Reumatologica Portuguesa Published:2016

Abstract

Objective: To delineate Hoffman reflex (H-reflex) parameters and spe cify the diagnostic accuracy measures of thenar muscle H-reflex in fibromyalgia (FM). Methods: The study was a cross sectional study performed on 30 subjects with FM and 30 healthy volunteers in two major referral hospitals. We recorded the number of obtainable thenar H-reflexes and their minimum latency, threshold and amplitude in each group. Results: There was a significantly more chance to elicit the H-reflex in patients with FM. H-reflex threshold and minimum latency were lower in FM group but no significant difference was shown for H wave amplitude. According to our study, thenar H-reflex has 46.7% sensitivity, 86.7% specificity and 66.7% diagnostic accuracy to detect FM. It also has moderate predictive values and positive likelihood ratio but low negative likelihood ratio. Conclusion: Higher rate of thenar muscle H-reflex in FM can be interpreted as a confirmatory finding to central sensitization theory for this disorder. Obtaining H-reflex from thenar muscles could be a helpful diagnos tic tool for FM that increases the confidence in diagn osis. Although it is a weak tool for screening because of low sensitivity, it has a relatively high specificity.