New-Onset Confusional Arousals in an Older Adult on Zolpidem
A 71-year-old woman is referred for 'violent sleep behavior.' For 4 months her husband reports that 1-2 hours after sleep onset she sits up, appears confused, mumbles, and sometimes flails or grabs at him; she does not recall these events. Episodes last 1-3 minutes and she returns to sleep. She has no dream enactment, no rigidity, and no REM behavior disorder history. She takes zolpidem 10 mg nightly for insomnia (started 5 months ago), sertraline 50 mg, and amlodipine. Her bed partner has obstructive sleep apnea and snores loudly; she snores intermittently. Neurologic exam is normal. PSG shows an AHI of 9 with supine-predominant events, and the events captured arise from N3 sleep.
1. What is the most likely diagnosis, and how does the PSG timing and stage information support it over REM sleep behavior disorder?
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The most likely diagnosis is confusional arousals (a non-REM parasomnia), likely precipitated by zolpidem in an older adult.
Supporting features:
- Timing: events occur 1-2 hours after sleep onset, when slow-wave sleep predominates - classic for disorders of arousal. RBD events typically occur in the latter half of the night during REM.
- Semiology: confusion, mumbling, and non-directed flailing without dream enactment or directed violence; the patient is amnestic. RBD features dream enactment with coherent, often defensive movements and recall of dream content.
- PSG stage: the captured events arose from N3 sleep, which strongly supports a disorder of arousal and argues against RBD (which arises from REM with loss of atonia).
- No RBD red flags: no dream enactment, no rigidity, normal neurologic exam; RBD would prompt concern for synucleinopathy.
Zolpidem is a recognized precipitant of complex sleep behaviors and confusional arousals, especially in older adults; sertraline can also fragment sleep and has been associated with parasomnias. The supine-predominant mild OSA (AHI 9) may contribute to sleep fragmentation and should be addressed as a possible trigger.
2. Outline your management plan, including medication changes and safety counseling.
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Management:
- Discontinue zolpidem (taper or stop with a plan for rebound insomnia) and avoid other sedative-hypnotics; this is the single most likely reversible trigger. Review sertraline as a possible contributor but do not stop it abruptly without psychiatric input.
- Safety counseling for the bed partner and patient: sleep in a separate room temporarily if events are violent, remove bedside weapons/furniture hazards, avoid sleep deprivation and alcohol (both lower the arousal threshold), and maintain a regular sleep schedule. Advise that injuries can occur and to seek urgent care for any injury.
- Treat contributory sleep fragmentation: address the supine-predominant OSA (positional therapy or PAP depending on symptoms and patient preference); treat any other fragmenting condition.
- Behavioral insomnia therapy for the underlying insomnia, since the hypnotic is being withdrawn - CBT-I is first-line in older adults.
- Follow-up: reassess event frequency after zolpidem withdrawal; if events persist or the semiology changes (dream enactment, injury), reconsider the diagnosis and repeat evaluation, including video-PSG and neurology referral.
- Counsel that disorders of arousal are generally benign and often resolve with trigger removal, and that the absence of dream enactment and the N3 onset make a neurodegenerative cause unlikely.