RT Journal Article
SR Electronic
T1 Patients with Parkinson's disease can employ a predictive motor strategy.
JF Journal of Neurology, Neurosurgery & Psychiatry
JO J Neurol Neurosurg Psychiatry
FD BMJ Publishing Group Ltd
SP 1299
OP 1306
DO 10.1136/jnnp.47.12.1299
VO 47
IS 12
A1 B L Day
A1 J P Dick
A1 C D Marsden
YR 1984
UL http://jnnp.bmj.com/content/47/12/1299.abstract
AB We have tested the hypothesis that predictive motor behaviour is abnormal in Parkinson's disease. In the first experiment elbow movements were performed to track a moving spot on an oscilloscope screen. The performance of 12 patients with Parkinson's disease and eight age-matched control subjects was measured when tracking a repeated pattern under two conditions. In the first condition subjects were not aware of the repetitive nature of the tracking task whilst in the second condition they were. For both groups tracking error and tracking lag were less when aware of the repetition. In the second experiment wrist movements were studied. Five age-matched controls were compared with five patients, studied on and off drugs. In this experiment the performance tracking a repeated pattern was compared to that tracking unpredictable patterns. Tracking lags were reduced to very low values (less than 20 ms) in response to the repeated pattern for both groups. This was true even when the patients were relatively immobile off drugs. We conclude that patients with Parkinson's disease are capable of predictive motor behaviour although such a strategy does not always confer as great an advantage in reducing tracking error in patients compared with control subjects.