Sleep disorders in Parkinson's disease

Sleep disorders in Parkinson's disease (PD) are frequent and have numerous etiologies. Both nighttime sleep disturbances and daytime sleepiness can occur. The key to effective treatment is appropriate diagnosis. A careful interview of the patient and his or her bed partner provides direction for additional evaluations. Referral to a sleep specialist for quantitative studies is necessary to evaluate for rapid eye movement (REM) sleep behavior disorder, sleep apnea, periodic limb movements, and other sleep disorders. Excessive daytime sleepiness may be attributed to interrupted nighttime sleep or daytime medications (particularly the dopamine agonists) or it may be intrinsic to PD. When the diagnosis is established, treatment is directed toward the primary sleep disturbance. Fragmented sleep due to recurrence of PD symptoms may improve with the use of long-acting preparations of carbidopa/levodopa. Sleep apnea is treated using continuous positive airway pressure, and REM sleep behavior disorder may improve using pharmacologic interventions, although controlled trials are lacking. Restless legs syndrome and periodic limb movements during sleep are treated with direct dopaminergic agonists at bedtime. Excessive daytime sleepiness related to the use of direct dopaminergic agonists may improve with dosage reduction or discontinuation. Stimulants such as modafinil may provide modest benefit.