Isolated sleep paralysis elicited by sleep interruption.
Sleep June 1, 1992 T Takeuchi, A Miyasita, Y Sasaki et al.
A sleep interruption schedule—waking normal subjects after 40 minutes of NREM sleep—produced sleep-onset REM periods (SOREMPs) 71.9% of the time and successfully elicited isolated sleep paralysis (ISP) in 9.4% of interruptions. Nearly all ISP episodes occurred from SOREMP, showing a close link. During ISP, subjects reported inability to move while aware of their surroundings, and most experienced auditory or visual hallucinations and unpleasant emotions. Polysomnography revealed a dissociated REM/W stage with abundant alpha EEG and persistent muscle atonia. ISP differs from lucid dreaming, nocturnal panic attacks, and REM sleep behavior disorder.