Sleep and wakefulness disturbances in Parkinson's disease.

Patients with Parkinson's disease experience prominent difficulties in maintaining sleep, painful night-time abnormal movements, and daytime sleepiness, sometimes culminating in sleep attacks. Recent insights into the pathophysiology of sleep disorders in PD points to a complex interaction between movement disorders, side-effects of dopamine agents and lesions in sleep-wake regulating systems. Treatment with dopamine agonists provides a twice higher risk of daytime sudden sleep episodes than levodopa, with no difference between ergotic and non ergotic compounds. Insomnia can be improved by a better control of night-time disability, restless legs syndrome and dystonia using subthalamic nucleus stimulation or night-time levodopa. A specific REM sleep disorder contributes to REM sleep behavior disorder and also to hallucinations (suggesting they could be awake dreams) and excessive daytime sleepiness. The management of sleep and alertness problems requires to analyze their potential causes, to monitor night-time and daytime sleep, and to subtly adjust psychotropic and dopaminergic treatment.