Insomnia and excessive daytime sleepiness in Parkinson’s disease

Patients with Parkinson’s disease (PD) are susceptible to a variety of sleep disorders, which undermine quality of life. However, the frequent sleep complaints in PD and other parkinsonian syndromes (PS) have not been adequately addressed until recently. A variety of factors contribute to sleep-wake disturbances in parkinsonism, including psychological, cognitive, and physiological perturbations secondary to the underlying disease, as well as its treatment. Motor symptoms (e.g., mild-to-violent movements in rapid eye movement (REM) sleep behavior disorder (RBD); periodic limb movements; tremor; and painful, early morning “off” dystonia) commonly induce sleep disturbances in parkinsonian patients. Excessive daytime sleepiness (EDS) is also frequent in parkinsonian patients and may be disease-related, iatrogenic, or both. Respiratory disturbances, including the sleep apnea syndrome (SAS), are also frequently responsible for sleep disturbances and EDS.