Alternating hemiplegia of childhood successfully treated with topiramate: 18 months of follow-up

Alternating hemiplegia of childhood (AHC) is a rare neurologic syndrome with recurrent hemiplegic attacks shifting from one side to the other and lasting from minutes to several days. The attacks typically begin in infancy, are triggered by emotion or fatigue, and disappear during sleep.1 Additional features are pendular nystagmus, tonic/dystonic attacks, dyspneic episodes, mental retardation, and epilepsy. The etiology of AHC is unknown. Some consider it a variant of migraine1 and differentiation from familial hemiplegic migraine (FHM) may be difficult.2 The majority of AHC cases are sporadic, although a few familial cases have been reported, including one family with a mutation in the ATP1A2 FHM2 gene.2,3 There is no standard therapy for AHC. Flunarizine is the most frequently used drug.1 Topiramate (TPM) is a relatively new agent effective in the prophylactic treatment of both epilepsy and migraine.4,5 It inhibits carbonic anhydrase and displays modulatory effects on voltage-gated Na+ and Ca …