Effects of parkinsonism on motor control

Parkinson's disease, which pathology results predominantly from nigrostriatal pathway damage, has been associated with motor dysfunction due to basal ganglia impairment. It is argued that the variability seen within and between individual patients through the course of this neurological disorder may result from abnormal non-uniform neurotransmitter levels as well as functional segregation of neural populations in the basal ganglia. We review evidence that the wide spectrum of motor impairments observed in Parkinsonism may be due to a reduced capability of neurochemical modulation of pallido-thalamocortical activities that impairs movement implementation and execution.