An approach to non-motor symptoms of Parkinson's disease: an update on pathophysiology and treatment

The diagnosis of Parkinson's disease (PD) is based on the identification of at least two of the cardinal motor signs of the disease: rest tremor, bradykinesia, rigidity, and in progressive state the loss of postural reflexes. The disease is manifested mainly by motor signs but several non-motor features are present in patients with PD. Often, these non-motor symptoms can precede the motor features of the disease. We review part of the different non-motor symptoms that can be present in patients with PD. In many cases, the non-motor symptoms could cause important Limitations in the functionality of the patients, no less than the motor symptoms, and they are often difficult to treat.