Asymmetric Asterixis Induced by Phenytoin in a Patient with Thalamic Infarction

Asterixis is an abrupt, brief, arrhythmic lapse of tonically contracting muscles. A 64-year old woman with a left thalamic infarction showed asymmetric bilateral asterixis after taking phenytoin for the control of thalamic pain. Though thalamic lesion can cause asterixis, her asterixis may have been induced by phenytoin, because it was bilateral and subsided after stopping phenytoin. We report an unusual case of asymmetric asterixis induced by phenytoin in a patient with a left thalamic infarction.