Levodopa increases speed of alternating movements in Parkinson's disease patients.

Disturbances of alternating movement execution are a characteristic clinical sign of patients with Parkinson's disease (PD). Objectives were to compare instrumentally measured diadochokinetic motion series carrying out before and 1 h after standardised levodopa intake and to correlate the device results with the respective rating scores of the PD patients. Maximum velocity and interval improved following levodopa application. The amplitude of motions did not differ between both assessment moments. Closer correlations between rating- and diadochokinesimeter outcomes appeared before levodopa intake.