An electroclinical case-control study of sudden unexpected death in epilepsy

A major proposed mechanism of SUDEP is the concept of electro-cerebral shutdown, seen on scalp EEG as prolonged post-ictal generalized EEG suppression (PGES). PGES is usually after generalized tonic-clonic seizures and is seen on scalp EEG as diffuse “flattening” after seizure ends. PGES has been recorded in a few cases of SUDEP and has generated debate over the potential role of this phenomenon both as a predictor of future SUDEP risk. Proponents of PGES hypothesize that the electrical flattening represents an “electrocerebral shutdown”, which precipitates the terminal cardiopulmonary events.

In this case-control study, Dr. Lhatoo reports that prolonged PGES (>50 seconds) appears to identify refractory epilepsy patients who are at risk of SUDEP and risk of SUDEP may be increased in direct proportion to duration of PGES. This study seemed to be a breakthrough in SUDEP research since it identified a potential biomarker to define and target prevention strategies. Unfortunately, subsequent studies produced mixed resultsSee PGES is associated with generalized seizures by Surges .