Effects of motor skill practice on reaction time and learning retention in Parkinson's disease

One of the prominent disturbances in Parkinson's disease (PD) is bradykinesia. We studied performance of hand-to-mouth reach reaction time (RT) in right-handed PD patients and nine age and sex matched healthy control subjects. Participants practiced hand-to-mouth reach skill in response to a visual stimulus, 120 times a day for a period of one week. Using Kinemetrix 3D Motion Analysis system, the effects of motor skill practice and learning retention were investigated. Pretest performance was compared with performances on the second and seventh day of the study, and also performance on fourteenth day with no further practice for one week. There was a significant reduction in the mean RT in the control group after one week of practice. In PD patients the reduction in the mean RT was significant between pretest and first test sessions (P < 0.01). However, the difference was not significant between the first and second session (P = 0.06) and also between the second and third test sessions (P = 1.0). Short-term practice can improve bradykinesia in patients with PD but it is not long-lasting.