Idiopathic Parkinson's Disease Unmasked by Valproate-Induced Parkinsonism in a Patient With Vestibular Migraine.

We report a case of idiopathic Parkinson's disease (PD) in a patient with vestibular migraine (VM), initially suspected to have valproate-induced Parkinsonism. Valproate was started at 200 mg/day and titrated to 1,000 mg/day over four months for headache control. Although valproate provided effective headache relief, neurological symptoms, including hand tremor, shoulder stiffness, drooling, and adiadochokinesis, emerged and persisted despite discontinuation of the drug. Subsequent imaging studies, including dopamine transporter-single-photon emission computed tomography and 123I-meta-iodobenzylguanidine myocardial scintigraphy, confirmed the diagnosis of PD by the neurology department. This case highlights the need for careful monitoring of neurological signs during and after valproate therapy in VM patients, as latent PD may be unmasked.