Sleep and epilepsy

Sleep has a marked influence on local epileptogenicity. Sleep deprivation appears to have an independent activating effect. It is effective in provoking spike-wave paroxysms in primary generalized epilepsy. Sleep recordings help in differentiating between partial and generalized epilepsies. Anterior temporal lobe discharges and partial seizures are facilitated by non-rapid eye movement (NREM) sleep, which also has a facilitatory effect on generalized discharges. Rapid eye movement (REM) sleep may activate frontal lobe, amygdaloid and supplementary motor area seizures, whereas it de-activates partial seizures from other regions, often revealing an occult focus. REM sleep also deactivates generalized seizures. Specific epileptic syndromes are related to the sleep-wakening cycle, i.e. Rolandic epilepsy, other benign partial epilepsies in childhood, and awakening epilepsy. Patients with an uncertain or unknown type of epilepsy should always be examined with routine electroencephalography (EEG) recording, sleep deprivation and spontaneous or sedated sleep recordings.