%0 Journal Article %T Thenar muscles H reflex in patients with fibromyalgia: A case control study. %A Azma K %A Raeissadat SA %A Hosseini A %A Mahmoudi H %A Sepehrian M %A Salehi Z %J Acta Reumatol Port %V 41 %N 2 %D Apr-Jun 2016 %M 27606474 %F 1.375 %R %X OBJECTIVE: To delineate H-reflex parameters and specify 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.
CONCLUSIONS: Higher rate of thenar muscle H-reflex in fibromyalgia can be interpreted as a confirmatory finding to central sensitization theory for this disorder. Obtaining H-reflex from thenar muscles could be a helpful diagnostic tool for fibromyalgia that increases the confidence in diagnosis. Although it is a weak tool for screening because of low sensitivity, it has a relatively high specificity.