Pathophysiology of parkinsonism due to hydrocephalus

We report a patient with hydrocephalus who developed levodopa responsive parkinsonism and severe bradyphrenia associated with shunt malfunction and revision. Magnetic resonance imaging revealed periaqueductal edema involving medial substantia nigra. [F-18] dopa positron emission tomography demonstrated reduced uptake in the caudate and putamen with relative sparing of the posterior putamen. Hydrocephalus associated with shunt malfunction can cause a distinct parkinsonian syndrome with greater dysfunction of projections from the medial substantia nigra to anterior striatum than in idiopathic Parkinson's disease.