REVERSIBLE VALPROATE-INDUCED EXTRAPYRAMIDAL DISORDERS

We observed transient parkinsonism in 2 young epileptic patients with valproate (VPA) therapy. Complete recovery from extrapyramidal disorde r occurred spontaneously in a few weeks. The lack of apparent suscepti bility related to age and to VPA dosage, the rapid recovery from the e xtrapyramidal reaction, and the prevalence of negative signs such as b radykinesia and bradyphrenia can be considered the main clinical findi ngs of this disease process. Pathophysiologic mechanisms of this rare ''toxic'' reaction remain unknown, although a transient imbalance betw een functionally reciprocal subgroups of GABA pathways leading to reme diable dopamine inhibition might be hypothesized.