Preprogramming and control activity of bimanual self-paced motor task in Parkinson's disease

Objective: The authors investigated programming (Bereitschaftspotential or BP) and control activity (Skilled Performance Positivity or SPP) of a biman ual, sequential, skilled motor act in off-therapy Parkinson's disease (PD) patients. Methods: We recorded Movement Related Potentials (MRPs) in 12, non-demented , off-therapy parkinsonian patients and in 17 control subjects who were per forming a skilled, time-locked motor act, which was not routine in their ev eryday life but had to be learned: the Skilled Performance Task (SPT). BP, SPP and correct performances were evaluated in grand average waveforms and in sequential blocks. Results: The analysis of correct performances showed that accuracy in PD pa tients was significantly lower than in the control group and this accuracy did not improve throughout the blocks. A significantly low level of perform ances was associated with an increased BP amplitude (P < 0.05) and decrease d SPP amplitude (P < 0.05) in PD patients. Conclusion: Our findings suggest that skill motor learning is impaired in n on-demented unmedicated PD patients. We discuss the view that PD patients m ay allocate more attentional resources, as suggested by the increased BP am plitude, the decreased SPP amplitude and the low correct performances, in o rder to perform a new skilled motor act. (C) 2000 Elsevier Science ireland Ltd. All rights reserved.