P97. The pathophysiology of sudden unexpected death in epilepsy (SUDEP)

Abstract

Sudden unexpected death in epilepsy (SUDEP) is the most common cause of death in people suffering from chronic refractory epilepsy. The underlying pathophysiological mechanisms that are critically involved in SUDEP are still not well understood. Cardiac arrhythmia, depressed autonomic function after seizure activity and also seizure-related respiratory failure have been discussed to be part of the final cascade leading to SUDEP. This final cascade is thought to be triggered by the seizure activity resulting in dramatically elevated levels of epinephrine, norepinephrine as well as other regulatory hormones and neurotransmitters. However, not all cases of SUDEP are directly linked to a seizure suggesting that SUDEP is not an unitary event and most likely caused by multiple factors. We therefore analysed the respiratory patterns, heartbeat and arousals of patients in the epilepsy video-eeg monitoring unit (EMU), before and after the withdrawal of antiepileptic (AED). The frequency, variability of the breathing and heartbeat in correlation with the sleep-stages were analysed. Moreover, the respiratory pattern peri-ictal (before and following generalized tonic–clonic and complex partial seizures) were analyzed, since this period has been identified as the crucial time window for SUDEP.