Postictal generalized electroencephalographic suppression is associated with generalized seizures

Postictal generalized electroencephalographic suppression (PGES) may be involved in sudden unexpected death in epilepsy (SUDEP). We examined whether the occurrence of PGES depends on seizure type and whether PGES occurs more frequently in people with epilepsy who died suddenly. EEG recordings of people with pharmacoresistant focal epilepsies who died from SUDEP after presurgical video/EEG telemetry were compared with recordings of living controls. To test if PGES depends on seizure type, EEG recordings of people with temporal lobe epilepsy who had complex partial seizures (CPS) and secondarily generalized tonic-clonic seizures (GTCS) were reviewed. A total of 122 seizures in 57 individuals have been included. PGES was observed in 15% of all seizures in 26% of all individuals. Secondarily GTCS were significantly associated with PGES. Neither presence nor duration of PGES differed between the SUDEP and control groups. In conclusion, PGES is facilitated by secondarily GTCS, but does not seem to be an independent risk factor for SUDEP.

Research highlights
► Postictal generalized EEG suppression (PGES) may be involved in sudden unexpected death in epilepsy.
► We have examined whether PGES depends on seizure type and whether it predicts sudden unexpected death in epilepsy.
► Generalized tonic -clonic seizures (GTCS) were significantly associated with PGES.
► Neither presence nor duration of PGES differed between those who died from sudden unexpected death and living controls.
► We conclude that PGES is facilitated by GTCS, but does not predict increased risk of sudden unexpected death in epilepsy.