OBJECTIVE: Hypohidrosis, often associated with hyperthermia, has been reported, mostly in children, as a rare and reversible adverse effect of topiramate, an anticonvulsant drug with a broad spectrum of antiepileptic activity. The aim of our study is to detect a possible skin innervation involvement as the mechanism underlying hypohidrosis in children treated with topiramate. METHODS: A neurophysiological study has been performed on 2 children who have developed hypohidrosis under topiramate treatment. Electrophysiological data have been recorded during topiramate treatment and compared with a control group. Sympathetic skin responses have been recorded during topiramate assumption and after its discontinuation. RESULTS: In our 2 cases with hypohidrosis related to topiramate, electrophysiological study showed normal function of both beta and delta sensory fibers and absent sympathetic skin responses that recovered to normal after topiramate discontinuation. CONCLUSIONS: Our findings confirm that topiramate might induce a transitory specific carbonic anhydrase block at the level of sweat glands, without involvement of peripheral nervous system.
OBJECTIVE:Hypohidrosis, often associated with hyperthermia, has been reported, mostly in children, as a rare and reversible adverse effect of topiramate, an anticonvulsant drug with a broad spectrum of antiepileptic activity. The aim of our study is to detect a possible skin innervation involvement as the mechanism underlying hypohidrosis in children treated with topiramate. METHODS: A neurophysiological study has been performed on 2 children who have developed hypohidrosis under topiramate treatment. Electrophysiological data have been recorded during topiramate treatment and compared with a control group. Sympathetic skin responses have been recorded during topiramate assumption and after its discontinuation. RESULTS: In our 2 cases with hypohidrosis related to topiramate, electrophysiological study showed normal function of both beta and delta sensory fibers and absent sympathetic skin responses that recovered to normal after topiramate discontinuation. CONCLUSIONS: Our findings confirm that topiramate might induce a transitory specific carbonic anhydrase block at the level of sweat glands, without involvement of peripheral nervous system.