A range of non motor symptom (NMS) including dribbling saliva, constipation, depression, sleep disorders, apathy, hallucinations and dementia complicate the lives of people with Parkinson’s disease (PD). However, even though the last 30 years have seen enormous advances in the management of the motor symptoms of PD yet the NMS complex of PD have remained relatively unexplored.

NMS of PD contribute significantly to morbidity and may lead to admission to a nursing home, more than quadrupling the cost of care. Furthermore, recent evidence suggests that NMS such as olfaction, REM behaviour disorder, fatigue and depression may be markers of pre-clinical stage of PD and thus occur in early stage of PD.