Def: NREM parasomnia arising from deep NREM sleep
Pt gets up and walks, may leave the bedroom or the house
Can range from simple walking to complex tasks like cooking and driving
Tasks done less well than when awake, reduced responsiveness
May include violent or aggressive behavior with forensic consequences
Events last seconds to 30 min, most often a few min
Often overlaps with other NREM parasomnias (confusional arousal, night terrors)
ICSD-3: meets NREM parasomnia criteria + arousals with ambulation and other complex behaviors out of bed
Pathophysiology
Disorder of arousal: incomplete arousal from deep sleep
EEG shows persistent slow wave activity after arousal
Possible dysfunction of SWS regulation, more NREM instability
Genetics
Up to 80% of sleepwalkers have ≥1 affected family member, esp if persisting into adulthood
Up to 10x risk in 1st-degree relatives
Monozygotic twins have 5x higher concordance for adult sleepwalking than dizygotic
Epidemiology
NREM parasomnias seen in ~20% of children
Most outgrow them in teens, up to 25% continue
Adult prevalence ~2-3%
Clinical features
Eyes open, pt appears awake and interacts with surroundings
Usually amnesic, but some recall or dreamlike mentation in >2/3 of pts
Mentation simpler than REM dreams
Sense of urgency and feeling of threat, can lead to protective or violent behavior
Injury risk to pt and bed partner
Assoc with EDS, insomnia, depression and anxiety sx, not as benign as thought
Dx clues
Timing: first 1/3 of night, unusual in first 20-30 min after sleep onset
Number: 1-3 events/night
DDx: nocturnal seizures, RBD, panic attacks, dissociative d/o, confusion from other causes
History and triggers
Ask about triggers, alcohol, family hx, full drug hx incl recreational
Screen for SDB and other sleep d/o
Triggers:
- Sleep deprivation
- Stress
- Alcohol in some pts
- Comorbid OSA and PLMS, cause arousals and sleep disruption
- Z drugs, esp zolpidem, esp with alcohol
FDA 2019 boxed warning: zolpidem, eszopiclone, zaleplon for complex sleep behaviors, contraindicated if prior episode
Diagnostic testing
AASM: PSG not routinely needed for typical, uncomplicated, non-injurious cases with clear hx
Management
Most pts: reassurance and avoiding triggers is enough
Sleep hygiene for all
Avoid excess alcohol if a trigger
Scheduled awakenings 15-30 min before usual event time can help, esp in children
Treat comorbid OSA, has eliminated all events in studies
Meds for frequent, severe or violent events
Clonazepam 0.5-2 mg qhs, sedation limits use, avoid in untreated OSA
Antidepressants and Z drugs can trigger events, monitor after starting
Safety and forensic
Lock doors and windows
Keep objects that could cause harm out of reach
Consider sleeping apart from bed partner
Dx alone is not a sufficient forensic defense
- Oxford Handbook of Sleep Medicine 2022