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.

Case 3. FT is a 62-year-old man who comes to your office concerned about acting out his nightmares. His wife reports that several times in the past 3 months, FT has begun violently thrashing around in bed and yelling in the middle of the night. Once, he jumped out of bed and bruised his forehead on the nightstand but had no memory of the episode the following morning. FT takes for hypertension and sertraline for depression. He reports no prior difficulty sleeping.