<qa>  What is the gold standard of rating scales for Parkinsons disease?Objective: Because neuroprotective strategies in Parkinsons disease are primarily aimed at intervening in the early phase of disease, appropriate measures of minor, subtle parkinsonian impairments need to be defined. The gold standard of rating scales for Parkinsons disease is the Unified Parkinsons Disease Rating scale UPDRS, but it covers the gamut of disability levels and does not specifically focus on early impairments. We have developed a series of motor tasks that can be performed with a home-based computer module so that data can be collected frequently and prospectively without obligating the patient to come to a medical center. 