Prolonged practice is of scarce benefit in improving motor performance in Parkinson's disease

Abstract

Many studies have addressed practice effects in motor sequences in Parkinson's disease (PD). Most studied short-term practice and showed that treated patients with mild-to-moderate disease achieve normal or slightly abnormal improvement. Less attention has focused on practice effects after prolonged training (days), and the results are inconclusive. Here, we studied the kinematic changes induced by prolonged practice in a group of medicated patients with mild-to-moderate PD and a healthy control group. We did so by analyzing an internally determined sequential arm movement performed as fast and accurately as possible before and after a 2-week training period. After 1-day's practice, movement duration, pause duration, and movement accuracy improved similarly in patients and controls, indicating that patients benefitted normally from short-term practice. After 1-week's practice, movement and pause duration improved further in both groups, whereas movement accuracy remained unchanged. After 2-weeks' practice, healthy controls continued to improve but patients did not, indicating reduced prolonged practice benefit in PD. Because short-term practice benefit on motor performance is thought to be mediated predominantly by cerebellar activation, whereas long-term practice benefit relies predominantly on the basal ganglia, we attribute our findings to the underlying basal ganglia dysfunction in PD. Our study may be relevant for planning and executing rehabilitation programs in these patients.

Retention of Implicit Sequence Learning in Persons Who Stutter and Persons With Parkinson's Disease

“…A number of studies have investigated the importance of the striatal system for retention of implicit skills. Studies which examined procedural skills over one session or over a few days found good retention by PPD (Harrington, Haaland, Yeo, & Marder, 1990;Rostami & Ashayeri, 2009), while those that looked over months of practice found increasing differences in skill retention between PPD and control participants (Agostino et al, 2004;Doyon et al, 1998;Kawai, Kawamura, & Kawachi, 1999;Mochizuki-Kawai, Kawamura, Hasegawa, Mochizuki, Oeda, Yamanaka, & Tagaya, 2004;Vakil & Herishanu-Naaman, 1998).…”

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

“…[6] Retention reflects how the kinematic improvement is maintained after ending of the practice. [3] In the present study, maintenance of the performance level after one-week retention period indicated a learning effect of motor skill practice. Movement variables responsible for retention may be encoded in a motor representation stored in distributed network of cortical motor area, including the primary motor, premotor, and parietal cortex.…”

“…[25] Normal learning retention in people with PD may be demonstrated so that during execution of movements, some of the motor areas of cortex show hyperactivity, reflecting an attempt to compensate basal ganglia dysfunctions. [3] From a clinical and rehabilitation viewpoint, although we may not be able to generalize the results of our Beck depression inventory mini-mental state examination Parkinsonُs disease unified Parkinsonُs disease rating scale simple task to the complex daily performances, our finding that patients with mild to moderate PD can improve with motor skill practice, may be helpful in considering practice as a critical method and an effective rehabilitation intervention to decrease bradykinesia. [3,4,6] It should be mentioned that further follow-up studies on advantages at longer terms of motor skill practice and longer retention periods is warranted.…”

“…Studies investigating the effect of prolonged practice, two weeks, had shown reduced benefit in PD. [3] Smiley-Oyen et al, [17] have shown if people with PD are given sufficient practice they can learn and both memory-based and content driven movement sequences. However, the effect of prolonged practice on reaction time (RT) has not been study, hence this study.…”

“…[3,10] Antiparkinsonism drug therapy ('on' period) decreases the time of initiation and execution of movements, though not fully. [11] Most studies investigating the effect of brief period, minutes or hours, of practice have shown that learning is either normal [4,12,13] or slightly impaired [14][15][16] in mild to moderate PD patients.…”