Sleep and arousal mechanisms in experimental epilepsy: Epileptic components of NREM and antiepileptic components of REM sleep

Abstract

Neural generators related to different sleep components have different effects on seizure discharge. These sleep-related systems can provoke seizure discharge propagation during nonrapid eye movement (NREM) sleep and can suppress propagation during REM sleep. Experimental manipulations of discrete physiological components were conducted in feline epilepsy models, mostly in the systemic penicillin epilepsy model of primary generalized epilepsy and the amygdala kindling model of the localization-related seizure disorder, temporal lobe epilepsy. The sleep-wake state distribution of seizures was quantified before and after discrete lesions, systemic and localized drug administration, and/or photic stimulation, as well as in relation to microdialysis of norepinephrine. We found that (1) neural generators of synchronous EEG oscillations--including tonic background slow waves and phasic "arousal" events (sleep EEG transients such as sleep spindles and k-complexes)--combine to promote electrographic seizure propagation during NREM and drowsiness, and antigravity muscle tone permits seizure-related movement; (2) neural generators of asynchronous neuronal discharge patterns reduce electrographic seizures during alert waking and REM sleep, and skeletal motor paralysis blocks seizure-related movement during REM; (3) there are a number of similarities between amygdala-kindled kittens and children with Landau-Kleffner Syndrome (LKS) that suggest a link among seizures, sleep disorders, and behavioral abnormalities/regression.

The relationship between sleep and epilepsy: Evidence from clinical trials and animal models

“…Studies on feline epilepsy models have suggested the mechanisms of the sleep-wake cycle involved in triggering generalized seizures [37,62,63], including the propagation of generalized seizures by background EEG synchronization, phasic events (K complexes and spindles) and reduced muscle tone [37,62].…”

Toward rational design of electrical stimulation strategies for epilepsy control

“…It is well established that in some epilepsies, certain normal states of vigilance are more conducive to seizure than others34,35,36. Seizure recurrence is also correlated with physiological rhythms24,37 and drug taper38.…”

Jet lag syndrome: circadian organization, pathophysiology, and management strategies

“…During this rebound, REM pressure is increased, as is the associated frequency of sleep paralysis. In contrast to sleep paralysis, seizures are known to be more prevalent during the night, predominantly during NREM sleep 70. The incidence of seizures has also been shown to increase following transmeridian travel 71.…”