Postictal generalized electroencephalographic suppression is associated with generalized seizures

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). Lhatoo et al 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 by Surges failed to reproduce such findings.There seems to be intra-individual variability in both the occurrence and duration of PGES after seizures. For instance, this study reported that PGES was observed after one seizure out of six in one individual and after all four seizures in another with the duration varying from 63 to 128 seconds. In addition, the level of inconsistency increased with the number of seizures recorded from any one individual see Lamberts et al 2013 The evidence has been inconsistent in determining the role of PGES in SUDEP.