Parasomnias

Parasomnias are sleep disorders involving undesirable physical events or experiences occurring during sleep onset, while sleeping, or on arousal. They include non–rapid eye movement (REM) parasomnias (eg, confusional arousals, sleep terrors, sleepwalking) and REM–related parasomnias (eg, nightmare disorder, REM sleep behavior disorder, sleep paralysis). Notable among these is REM sleep behavior disorder, which is closely linked to neurodegenerative conditions such as Parkinson disease. Early detection of this disorder is essential because it often precedes the motor symptoms of neurodegenerative conditions. Diagnostic evaluation of parasomnias typically involves polysomnography, in some cases with video monitoring, to differentiate parasomnias from other conditions. Nonpharmacologic treatments, including sleep hygiene and sleep safety measures, are first-line approaches. Cognitive behavior therapy is also effective. Pharmacotherapy may be required in severe cases. Referral to a sleep specialist is recommended for patients with complex or dangerous parasomnias and for patients with frequent sleep paralysis.