Non-motor symptoms in Parkinson's disease.

Parkinson's disease is a hypokinetic movement disorder with cardinal motor features of bradykinesia, resting tremor and rigidity. However, non-motor symptoms, such as cognitive, neuropsychiatric, sleep, autonomic and sensory disturbances are gaining increasing attention. These non-motor symptoms may be intrinsic to the disease pathology or may be results of treatment with dopaminergic agents. Given that most, if not all, patients with Parkinson's disease will experience non-motor symptoms, it is important to be sensitive to these phenomena, especially since some non-motor signs may precede motor impairment. Treatment may include interventions independent of traditional, dopaminergic anti-Parkinson therapy or may be tailored to increase or reduce dopamine responsiveness of the symptom.