Reversible cortical atrophy and cognitive decline induced by valproic acid

An 18-year-old male suffered from familial progressive myoclonic epilepsy from the age of 7 years. In addition to seizures, there was a marked decline in school performance. At the age of 14 years, sodium valproate was started as add-on therapy; 2 weeks later he was hospitalized in a stuporous state. The serum level of valproate was within the therapeutic range. Cognitive evaluation disclosed moderate mental retardation. No metabolic abnormalities were detected. Valproate was discontinued and during the 4 following months, a slow but significant improvement was documented in cognitive functions. Repeated assessment was within the range of mild mental retardation. Initially, magnetic resonance imaging (MRI) showed mild cortical atrophy. A subsequent MRI study performed 2 years later was normal.