Effect of topiramate on enlargement of head in Canavan disease: a new option for treatment of megalencephaly.

Canavan disease (CD) is a rare autosomal recessive genetic disorder characterized by early onset progressive spongy degeneration of the brain involving the axon's myelin sheath. Patients with CD have leukoencephalopathy and megalencephaly; clinically they show a variable course ranging from slow neurodegenerative course to no neurological development or rapid regression. Current treatment is symptomatic including management of seizures and spasticity. Topiramate (TPM) is a novel antiepileptic drug for treatment of a broad spectrum of seizure types in adults and children. We used TPM in two of our patients diagnosed with CD at six months of age. At seven months and 15 months' follow-up, respectively, each patient showed a decrease in head growth velocity. We suggest that TPM can be used in patients with CD and possibly in other childhood neurodegenerative diseases with leukoencephalopathy and megalencephaly. Further studies are required to reveal the underlying mechanisms that lead to decreased head growth velocity, and to conclude whether this ameliorates the clinical course of CD.