Motor Features of Parkinson's Disease.

The most characteristic motor feature of Parkinson's disease is bradykinesia. Other cardinal motor features of Parkinson's disease include tremor (particularly rest tremor), rigidity, and postural instability/gait changes. Additional motor features common to the disease include dystonia, postural abnormalities, speech and swallowing dysfunction, and levodopa-related dyskinesias. The pathophysiology of many of these motor features remains poorly understood. During the natural course of the disease, nonmotor features (discussed elsewhere) often precede the onset of motor features and meaningfully contribute to motor disability and the gradual decline in the quality of life.