Dreams interrupted: characteristics of REM sleep-associated seizures and status epilepticus.

Study objectives: Seizures are rare in rapid eye movement (REM) sleep. However, seizures sometimes occur in REM sleep, and a small number of focal epilepsy patients display their maximum rate of interictal epileptiform discharges in REM sleep. We sought to systematically identify and characterize seizures in REM sleep.

Methods: We reviewed all admissions to the epilepsy monitoring unit at the Winnipeg Health Sciences Center over 12 months in 2014-2015. American Academy of Sleep Medicine sleep-stage scoring was initially applied in the standard 30-second epochs. Then, to capture sudden changes in sleep-wake state on shorter timescales that are associated with seizure formation and propagation, we rescored ictal and peri-ictal electroencephalography epochs every 1 second. Patients found to have seizures in REM sleep were subject to chart review spanning 3 years pre- and postadmission.

Results: REM sleep seizures occurred in 3 of 63 patients admitted to the epilepsy monitoring unit. Notably, 1 patient exhibited continuous epileptiform activity, consistent with focal nonconvulsive electrographic status epilepticus, throughout REM sleep cycles for each night of her admission. Otherwise, discrete REM sleep seizures constituted a small fraction of the other patients' total seizures (range 5.0-8.3%), occurred shortly after REM sleep onset from stage N2 sleep, and were manifest as minor epileptic arousals.

Conclusions: Our results confirm that REM sleep seizures are rare, while highlighting outliers who widen the known spectrum of heterogeneous sleep effects on seizures/epilepsy. We also report, to our knowledge, the first case of paradoxical status epilepticus in REM sleep.

Citation: McLeod GA, Szelemej PA, Toutant D, McKenzie MB, Ng MC. Dreams interrupted: characteristics of REM sleep-associated seizures and status epilepticus. J Clin Sleep Med. 2025;21(1):23-32.