Sleep disorders in Parkinson's disease

Parkinson's disease is a neurogenerative disorder, usually diagnosed after middle age. The non-motor symptoms raise concern, because they can increase morbidity and lead to loss of autonomy. Sleep disorders are among the most disturbing of the non-motor symptoms, and the vast majority of patients with Parkinson's disease suffer from some form of sleep disorder. Although the normal ageing process may disrupt circadian rhythms, disorders of an extended degree are sometimes linked to Parkinson's disease, including insomnia, rapid eye movement (REM) sleep behavior disorders, sleep disordered breathing, restless legs syndrome and excessive daytime sleepiness. The exact incidence of each disorder cannot be estimated, because of variation in the diagnostic criteria. Some sleep disorders appear in the early stages of the disease, while others present later, but at all stages, the early detection and management of sleep disorders are indispensable. These disorders may affect sleep quality, aggravate the course of the disease and have a deleterious impact on the quality of life of the patient.