Hemiparkinsonism with hemiatrophy.

We studied fifteen patients with hemiparkinsonism and ipsilateral hemiatrophy (HP/HA) to better characterize the clinical features of this syndrome and its rate of progression. Patients were distinguished by highly asymmetric parkinsonism with predominant signs on the side of HA, early age of onset (43.7 years versus 60.2 years in our control population of idiopathic Parkinson's disease [IPD], abnormal birth history (7/15), and dystonia occurring prior to levodopa therapy (10/15). In six patients, the mean duration of disease until the initiation of levodopa therapy was 14.2 years, as compared with 4.1 years in our control population of IPD. The slow progression of disease underscores the relatively favorable prognostic significance of HP/HA and its distinction from IPD.