Sensory symptoms in Parkinson's disease: Clinical features, pathophysiology, and treatment.

Parkinson's disease (PD) is one of the most common forms of neurodegenerative disease in the elderly population and is typically manifested by motor symptoms and nonmotor symptoms and signs. Nonmotor symptoms, such as sensory symptoms, have been regarded as the significant features of this disease. These symptoms often occur in early stages of PD and influence quality of life. However, researchers suggest that the sensory symptoms of PD are frequently unrecognized by clinicians and remain untreated. The disorders include pain, olfactory disturbance, and visual dysfunction input on the underlying sensory abnormality. This Review focuses on the clinical features, pathophysiological mechanisms, and treatment strategies for sensory symptoms of PD from both clinical studies and basic research, providing a comprehensive overview of the sensory symptoms in PD. © 2016 Wiley Periodicals, Inc.