Practice as an intervention to improve speeded motor performance and motor learning in Parkinson's disease.

Individuals with Parkinson's disease have difficulty initiating and performing complex, sequential movements. Practice generally leads to faster initiation and execution of movements in healthy adults, however, whether practice similarly improves motor performance in patients with Parkinson's disease remains controversial. To assess the effects of practice on motor performance, patients with Parkinson's disease and control subjects practiced two, rapid arm-reaching tasks with different levels of movement complexity for 120 trials each over 2 days. Response programming was studied by analyzing the overall reaction time latency of each movement and its fractionated sub-components, premotor and motor time. Practice effects were investigated by comparing pretest performance to immediate and delayed retention test performances (10-min and 48-h rest intervals, respectively). Both patients with Parkinson's disease and control subjects improved speeded performance of sequential targeting tasks by practice and retained the improvement across both retention test intervals. Finding a learning effect for persons with Parkinson's disease supports practice as an effective rehabilitation strategy to improve motor performance of specific tasks for patients with Parkinson's disease.