0693 Polysomnographic Features of Sleep Paralysis

A 15-year-old boy with recurrent isolated sleep paralysis underwent overnight polysomnography and a multiple sleep latency test. During the test, an episode of sleep paralysis lasting approximately 48 seconds was captured on EEG. The recording showed a mixture of rapid eye movement (REM) sleep features—such as muscle atonia and theta waves—alongside faster frequencies and alpha waves typical of relaxed wakefulness. This overlap of REM and wakeful brainwave patterns illustrates the mixed state of consciousness during sleep paralysis, contributing to understanding its neurophysiological basis.

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Abstract

Abstract Introduction We report the electroencephalography (EEG) changes observed in a case of sleep paralysis. Methods We present the case of a 15-year-old boy with recurrent isolated sleep paralysis. As part of the diagnostic evaluation, the patient underwent overnight polysomnography (PSG) and subsequently, a multiple sleep latency test (MSLT). During the MSLT, the patient experienced sleep paralysis, which was captured on the EEG and is detailed in this report. Results In Epoch 27 (30-second segments), the patient exhibited rapid eye movement (REM) sleep. In Epoch 28, while maintaining REM atonia (observed on the chin EMG channel), faster EEG frequencies intruded in the middle of the epoch. In Epoch 29, rapid eye movements and REM atonia persisted, accompanied by EEG patterns displaying faster frequencies and alpha waves consistent with a wakeful state. Sleep paralysis, lasting approximately 48 seconds, was documented from the middle of Epoch 28 to the end of Epoch 29. In Epoch 30, the patient transitioned to wakefulness, reporting the occurrence of sleep paralysis. The EEG during this epoch demonstrated the return of normal awake brainwave patterns. Conclusion REM sleep is often associated with vivid dreaming and muscle atonia. During episodes of sleep paralysis, an overlap of characteristics of REM sleep, including theta waves typically seen during REM sleep, and the presence of alpha brain waves indicative of relaxed wakefulness. The convergence of REM features and alpha waves underscores the mixed state of consciousness experienced during sleep paralysis episodes. These findings contribute to a better understanding of the complex neurophysiological changes associated with sleep paralysis. Support (if any)