Spasmodic dysphonia induced by valproic acid

Abstract

Valproic acid (VPA) is an antiepileptic drug (AED) with a broad spectrum of actions. The mechanisms that underlie VPA effects are not clearly elucidated, but may include enhancement of γ-aminobutyric acid (GABA)-mediated inhibition by increasing cerebral GABA levels. Transient extrapyramidal symptoms like parkinsonism have been reported with VPA treatment (1). The precise mechanism of these complications is not clear, although perturbations in basal ganglia neurotransmitters have been suggested. We experienced one case of spasmodic dysphonia in the course of treatment with VPA, which has not been described previously.