New-Onset Confusional Arousals in an Older Adult
A 68-year-old woman is brought by her husband because of episodes in which she sits up in bed about 90 minutes after falling asleep, appears confused, mumbles, and once walked into a closet. Episodes last 5–15 minutes, she is difficult to arouse, and she has no memory of them. They began 6 months ago, around the time she started zolpidem 5 mg nightly for insomnia and had a knee replacement. She also snores and has been told she stops breathing. She takes zolpidem, metoprolol, atorvastatin, and oxycodone 5 mg as needed (about 3 times/week) for knee pain. Her BMI is 31. There is no history of dream enactment, no violent behavior, and no seizures.
1. What is the differential diagnosis for her nocturnal episodes, and which features favor confusional arousals versus REM sleep behavior disorder versus nocturnal seizures?
Read the worked answer
Differential:
- Disorders of arousal (confusional arousals / sleepwalking) - most likely.
- REM sleep behavior disorder (RBD) - dream enactment, often violent, occurs in REM (later in the night), patient is arousable and often recalls dream.
- Nocturnal seizures (e.g., frontal lobe) - stereotyped, brief, may have dystonic posturing, incontinence, tongue biting; often multiple per night.
- Obstructive sleep apnea with confusional arousals - OSA can precipitate arousal disorders.
- Medication effect (zolpidem, oxycodone) - complex sleep behaviors reported with zolpidem, especially with other CNS depressants.
- NREM parasomnia vs. sleep-related eating disorder - not described here.
Features favoring confusional arousals: onset ~90 min after sleep onset (first NREM period), confusion and disorientation, difficult to arouse, amnesia for the event, non-violent behavior, no dream recall.
Against RBD: no dream enactment, no violent or injurious behavior, no recall of dreams; RBD typically occurs in later REM periods.
Against seizures: no stereotypy, no incontinence, no tongue biting, duration 5–15 min is long for a seizure.
Key modifiable factors: zolpidem (especially with oxycodone) and possible OSA. Zolpidem has boxed-warning language for complex sleep behaviors; discontinue or taper. Evaluate for OSA with polysomnography.
2. How would you evaluate and manage her, and what would you tell her husband about safety?
Read the worked answer
Evaluation:
- Medication review: Taper/discontinue zolpidem; avoid combining with oxycodone. Consider non-benzodiazepine alternatives for insomnia (CBT-I first-line).
- Polysomnography to evaluate for OSA (snoring, BMI 31, witnessed apneas, and arousal disorders are commonly precipitated by OSA). A PSG can also capture events and characterize them, though a single night may miss episodes.
- Neurologic evaluation if episodes are stereotyped, injurious, or if there are daytime symptoms - consider EEG if seizure is suspected.
- Screen for precipitants: sleep deprivation, alcohol, stress, febrile illness, and new medications.
Management:
- Treat OSA if present (PAP).
- Remove offending agents (zolpidem, minimize opioids).
- CBT-I for insomnia.
- Safety counseling: bedroom safety (remove obstacles, lock doors, alarms on doors, avoid stairs), avoid sleep deprivation, avoid alcohol.
- Reassure that confusional arousals are usually benign and often improve with trigger removal.
What to tell the husband: These episodes are not seizures or violent; she is not conscious during them and will not remember them. Do not try to wake her forcefully; guide her back to bed gently. Seek urgent evaluation if episodes become violent, injurious, or if she leaves the house. Report any new dream-enactment behavior.