Parasomnias
NREM parasomnias
Disorders of arousal include sleepwalking, sleep terrors, and confusional arousals. They arise from slow-wave sleep, often in the first third of the night, and are more common in children. They may be triggered by sleep deprivation, stress, fever, or alcohol. Management emphasizes safety and reassurance; treatment of triggers and occasionally medications (benzodiazepines) for severe cases.
REM parasomnias
REM sleep behavior disorder (RBD) involves dream enactment with loss of normal REM atonia, often in older men; it can precede synucleinopathies such as Parkinson disease. Diagnosis is by PSG showing REM without atonia. Treatment includes melatonin and clonazepam, plus safety measures. Nightmares are common in PTSD and can be treated with imagery rehearsal therapy.
Traps
Distinguish NREM arousal disorders (confusion, amnesia, early night) from RBD (dream recall, later night, injury). Sleep terrors differ from nightmares by lack of recall and autonomic arousal. Do not overlook medication-induced parasomnias (e.g., Z-drugs).
Rule of thumb: Dream enactment with injury in an older adult suggests RBD and warrants PSG and neurologic follow-up; sleepwalking in a child usually needs only safety counseling.