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).

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. However, the evidence has been inconsistent in determining the role played by PGES in SUDEP Postictal generalized electroencephalographic suppression is associated with generalized seizures. PGES is seen most often after generalized tonic-clonic seizures, which is a well-known risk factor for SUDEP but it is not a consistent post-ictal finding.

Ryvlin et al 2013 reported that PGES was found to be more common at night and suggested that nocturnal PGES may reflect post-ictal cardio-pulmonary dysfunction. Two other studies failed to support this hypothesis (Lee et al 2013, Mosley et al 20113).The significance of PGES in SUDEP and its possible role as a bio-marker of increased SUDEP risk remains to be established.