Reversible pseudoatrophy of the brain and mental deterioration associated with valproate treatment

Abstract

Purpose: To describe an 11-year-old girl with symptomatic localization- related epilepsy and normal intelligence who developed reversible mental deterioration and pseudoatrophic brain changes while receiving valproate (VPA). Methods: Assessment of mental function using Wechsler Intelligence Scale for Children-III (WISC) and Raven's Progressive Matrices (PM), EEG recordings while awake and asleep, and brain magnetic resonance imaging (MRI), were performed at the beginning of VPA therapy, after 2 years and 8 months of treatment and following VPA discontinuation. Results: After 2 years and 6 months on VPA (≤26 mg/kg/day) the girl insidiously developed mental deterioration (loss of 18 IQ points and drop in age-adjusted PM score from the 95th to the 50th percentile) associated with MRI-documented pseudoatrophy of the brain. Onset of severe cognitive impairment coincided with serum VPA concentrations near 100 μg/ml. There were no other manifestations of drug toxicity or hyperammonemia. Background EEG activity was normal. Reduction of VPA dosage and subsequent discontinuation 4 months later resulted in disappearance of clinical symptoms with a 20-point improvement at IQ testing and recovery of previous PM score. Repeat MRI showed disappearance of pseudoatrophic changes. Conclusions: The striking cognitive improvement and reversal of pseudoatrophic brain changes following VPA discontinuation strongly suggest a drug-induced condition. Based on this and previous reports, the syndrome of VPA-associated mental deterioration and pseudoatrophy of the brain appears to encompass different but possibly related clinical entities, which include parkinsonism with cognitive deterioration, mental deterioration with signs of VPA-toxicity, and isolated mental deterioration, as seen in our patient. A drug-induced effect should be considered whenever cognitive deterioration and imaging findings of brain atrophy occur in VPA-treated patients.