A Case of Valproate-induced Reversible Parkinsonism

ABSTRACT

Valproate is one of the most popular conventional anti-epileptic drugs. It has many side effects and in rare cases, it may result in the development of parkinsonian syndromes. The parkinsonism with valproate shows insidious onset and reversible symptoms after drug withdrawal. We observed a 69-year-old woman with resting tremor, bradykinesia, cog-wheel rigidity after 2 months of valproate use. She had been suffering from epilepsy for 30 years. Her seizures were well controlled with valproate, but parkinsonian symptoms slowly progressed with doses of 1200 mg/day of valproate. After 4 months, we discontinued the doses of valproate which led to subjective and objective improvement of the parkinsonian features. The mechanism of this side effect is not well established, but GABAergic neurotransmission or mitochondrial respiratory chain may possibly be related.