[Daytime sleepiness and cognitive disorders in elderly patients].

Data on the contribution of daytime sleepiness to cognitive impairment in elderly patients are presented. Currently, diagnostic methods of daytime sleepiness, which include diaries, neurological, clinical and instrumental tools, are used. It has been shown that daytime sleepiness correlates with different types of dementia that suggests the involvement of common neurochemical mechanisms. Multiple studies report that daytime sleepiness increases the risk of dementia in elderly people. Future research of daytime sleepiness could be focused on its clinical and paraclinical presentations to facilitate the prognosis of dementia.