Valproic acid induced encephalopathy - 19 new cases in Germany from 1994 to 2003 - A side effect associated to VPA-therapy not only in young children

Valproic acid (VPA) is a broad-spectrum antiepileptic drug and is usually well-tolerated. Rare serious complications may occur in some patients, including haemorrhagic pancreatitis, bone marrow suppression, VPA-induced hepatotoxicity and VPA-induced encephatopathy. The typical signs of VPA-induced encephatopathy are impaired consciousness, sometimes marked EEG background stowing, increased seizure frequency, with or without hyperammonemia. There is still no proof of causative effect of VPA in patients with encephatopathy, but only of an association with an assumed causal relation. We report 19 patients with VPA-associated encephatopathy in Germany from the years 1994 to 2003, none of whom had been published previously. (C) 2006 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.