[The patterns of the bioelectrical activity of motor units in different forms of parkinsonism]

The correlation between the motor units activity patterns and clinical forms of parkinsonism has been investigated by means of surface electromyography. Grouped electromyogram, characteristic of parkinsonism shaking was found to be generated on the basis of double, triple discharges of the motor unit (doublets and triplets), or long-term synchronization of motor units discharges as well as by means of simultaneous recruitment of both above mechanisms. Stationary electromyogram, characteristic of akinetic-rigid form, was shown to correlate with asynchronous, stable activity of the motor units that impulse at the frequencies 9-10 Hz. Mixed forms of parkinsonism (shaking-rigid and rigid-shaking) were characterized by large amount of the motor units that impulse with high variability of interspike intervals and have a tendency to form doublets (unstable motor units). Different combinations of doublets, triplets and long-term synchronization of motor units with stable, asynchronous motor units activity were also found in mixed forms of parkinsonism.