Non-motor symptoms: identification and management.

Non-motor symptoms are an important part of Parkinson's disease (PD) symptoms complex. They cause a significant burden on the quality of life of patients and their carers and remain a major cause of hospitalisation. Treatment of non-motor symptoms can be challenging as these symptoms are often unresponsive to conventional dopaminergic therapy. However, awareness that these symptoms are related to PD is vital as research into treatment and causation will be the cornerstone for delivering a comprehensive modern treatment for PD.