Postmovement beta synchronization in patients with Parkinson's disease

Event-related synchronization (ERS) after self-paced, voluntary brisk movem ent of the right and left thumb was studied in 17 patients with Parkinson's disease (PD) and 17 age-matched control subjects. All patients were receiv ing L-DOPA and/or DOPA-agonists. The movement-offset-triggered EEG data wer e analyzed in the 12- to 16-Hz, 16- to 20-Hz, and 20- to 24-Hz bands for ei ght time intervals after termination of movement. Significant differences i n postmovement beta synchronization were observed in all three frequency ba nds. As compared with the control group, patients with PD showed a remarkab ly smaller beta ERS. This was the overall main effect for groups, as well a s for interactions concerning side of movement and electrode positions. If beta ERS is a measure of recovery of the primary motor area after movement, our results indicate that this ability is impaired in PD patients.