Figure 3. Nystagmus on REM stage sleep.
On PSG, EOG showing conjugate vertical sharp waves with frequency 3.5 Hz in REM stage in the second half of epoch. The waves are fast frequency-lower amplitude compared to the classic rapid eye movements of stage REM sleep seen in the first half of the epoch. EOG = electrooculogram, PSG = polysomnography, REM = rapid eye movement.
