At the time of
diagnosis, patients typically display an array of motor
impairments including bradykinesia, resting tremor,
rigidity, and postural instability. Although most of the
typical motor impairments are due to the loss of
nigrostriatal dopaminergic neurons, PD affects multiple
neuronal systems both centrally and peripherally,
leading to a constellation of non-motor symptoms
including olfactory deficits, affective disorders, memory
impairments, as well as autonomic and digestive
dysfunctions