Quand faut-il explorer le sommeil chez la personne âgée ?

Sleep disturbances are common in the elderly.The frequency of sleep disordered breathing (SDB), periodic limb movement in sleep (PLMS), restless legs syndrome and insomnia increases with age. Diagnosis of sleep disorders in this population is challenging due to many reasons. These pathologies are thus often under diagnosed in the elderly people, causing major consequences. Sleep's exploration remains indispensable in many sleep's disorders in the elderly but their indications must be appropriate to this population. Sleep logs and sleep questionnaires are difficult to be filled out by patients with impaired cognition and often require help from their family. It may be completed or replaced by actigraphy in sleep assessment of demented patients. Daytime sleepiness may be under reported by elderly patients and must be evaluated by objective tests. Polysomnography (PSG) is indicated to diagnose SDB, PLMS and in patient with suspected narcolepsy or with violent behavior-related sleep. The indication of PSG must be enlarged in elderly patients with inexplicable insomnia, narcolepsy with worsening of symptoms and may be suggested in patients with inexplicable atypical clinical features such as asthenia, falls of undetermined etiologies, episodes of “transient loss of muscle tone”, rapid cognitive impairment, depression, nocturnal polyuria,etc. Findings of behavioural disorders in REM-sleep, could be helpful for the diagnosis of some neuro degenerative disorders. The feasibility and the utility of PSG need to be assessed because of some particular situations in this population.