[Heterogeneity of excessive daytime sleepiness in Parkinson's disease].

For the recent years, a special attention is given to the non-motor symptoms of Parkinson's disease, including sleep/wake disorders representing one of the leading symptoms. Daytime sleepiness occurs in 30-55% of patients depending on duration and stage of the disease, leading to severe maladjustment. This symptom seems to be multifactorial by nature and identification of it's causes could have a great importance for the therapy. The main factors of the development of daytime sleepiness in Parkinson's disease and key points of the pathogenesis of «primary» daytime sleepiness are discussed. Diagnostic methods and treatment opportunities are considered as well.