Interictal epileptiform discharges and phasic phenomena of REM sleep

Abstract

The objective of this study was to assess the effect of phasic rapid eye movement (REM) sleep events on interictal epileptiform discharges (IEDs). Twelve patients with focal epilepsy and IEDs during REM sleep were examined by video-EEG monitoring. The number of IEDs was calculated in different REM sleep episodes according to the rate of rapid eye movements. A negative correlation was identified between the occurrence of rapid eye movements and IEDs, indicating that the suppression of propagation of IEDs during REM sleep is enhanced by phasic REM sleep events, probably as a result of phasic activation of cholinergic neurons of the ponto-mesencephalic tegmentum. This study demonstrates that the degree of EEG desynchronization and IEDs is influenced by REM density.

EEG desynchronization during phasic REM sleep suppresses interictal epileptic activity in humans

“…In particular, phasic REM sleep exerted a significant suppressive effect on spike production compared to tonic REM sleep . This effect was confirmed with scalp EEG in patients exhibiting IEDs during REM sleep . The present study extended this knowledge by performing a direct controlled comparison of IEDs between segments with rapid eye movement bursts and segments without rapid eye movements in an unselected sample of consecutive patients with therapy‐refractory epilepsy undergoing combined scalp‐intracerebral EEG recording with IEDs occurring at different sites of the brain.…”

“…8 This effect was confirmed with scalp EEG in patients exhibiting IEDs during REM sleep. 30 The present study extended this knowledge by performing a direct controlled comparison of IEDs between segments with rapid eye movement bursts and segments without rapid eye movements in an unselected sample of consecutive patients with therapy-refractory epilepsy undergoing combined scalpintracerebral EEG recording with IEDs occurring at different sites of the brain. Because IEDs are more frequent in intracerebral recording compared to scalp EEG recording, 21 only two patients from the initial sample had to be excluded because of few or no IEDs during REM sleep.…”

“…In humans, there are two studies on IEDs pointing in this direction. 8,30 In patients with mesiotemporal lobe epilepsy, the spiking rate in foramen oval electrodes did not only outnumber the one in scalp electrodes, but also showed a different distribution across the different sleep states. In particular, phasic REM sleep exerted a significant suppressive effect on spike production compared to tonic REM sleep.…”

Association Between Epileptiform Discharges and the Sleep Cycle in 200 Epileptic Patients

“…REM sleep may have an important role in inhibiting the generation and spreading of abnormal EEG activity during this period because of the reticular formation enhanced activity and the desynchronizing brainwaves. Although the EDs in REM sleep are fewer, they may indicate the specific location of lesions [18,19].…”

Interrelationship of sleep and juvenile myoclonic epilepsy (JME): A sleep questionnaire‐, EEG‐, and polysomnography (PSG)‐based prospective case–control study

“…There was no difference in terms of ED indices (p = 0.5) or ED rates (p = 0.7) in light sleep (N1 + N2) between Groups I and II. The EDs are not easily facilitated by REM sleep as it is characterized by irregular tonic activation (resynchronization) of cortical neurons similar to the awake state [21,25,31]. In spite of this, REM sleep also represents a transition of vigilance state from NREM sleep, usually after SWS.…”