Early intervention in Parkinsonʹs disease: Epidemiologic considerations

This article examines the different forms of movement disorders, with a particular focus an Parkinsonʹs disease. Screening strategies for Parkinsonʹs disease are reviewed; these include biochemical measures, physiologic testing, positron-emission tomography, and early identification of symptoms by interview. Problems posed by the epidemiologic investigation of Parkinsonʹs disease are considered.