Parkinsonism and cognitive impairment associated with chronic valproic acid therapy

Among the side-effects attributed to valproic acid (VPA), the occurrence of Parkinsonian syndromes and cognitive impairment is very uncommonly reported. We describe five cases of reversible associated Parkinsonism. These cases were observed in epileptic patients, 57 to 74 years old, two women and three men. Extrapyramidal disorders appeared after various durations of treatment (from 6 months to 10 years). Dementia characterized by an insidious onset was associated in three cases and bradypsychia in one case. Brain pseudoatrophy was present in three patients. In all cases the signs and symptoms improved some weeks or months after discontinuation of WA. In the literature some cases, usually in young adults or children, have been reported. In a prospective study, Armon st al.(5) found various abnormal symptoms and signs related to motor and cognitive function impairment in patients with long-term WA therapy. These side-effects may be related to a disturbance in the gabaergic pathways in the basal ganglia system. It is of interest to consider that delta 2-valproic acid, a metabolite of VPA, is especially accumulated in selected areas of the brain: the substantia nigra, superior and inferior colliculus, hippocampus and medulla.