[Rapidly progressive parkinsonism that developed one year after ventriculoperitoneal shunting for idiopathic aqueductal stenosis: a case report].

A 46-year-old woman was diagnosed with having idiopathic aqueductal stenosis for which she underwent ventriculoperitoneal (V-P) shunting. One year after the surgery, she developed acute parkinsonism and sylvian aqueduct syndrome. Brain magnetic resonance imaging (MRI) did not reveal any signs of hydrocephalus and fluorodopa positron emission tomography (PET) did not reveal any decrease in accumulation of fluorodopa at the striatum. On admission, the Unified Parkinson Disease Rating Scale (UPDRS) (Part III) score was 30 points. The preliminary diagnosis was parkinsonism associated with V-P shunting: therefore, the levodopa dosage was increased from 200 mg/day to 600 mg/day. Thereafter, the symptoms of parkinsonism and the sylvian aqueduct syndrome markedly improved, and the UPDRS (Part III) score decreased. If such a patient presents without signs of hydrocephalus or shunt malfunction, dopaminergic medication should be used as the initial treatment.