The SUDEP Risk Inventory: Association with postictal generalized EEG suppression

To help identify patients at greatest risk for sudden unexpected death in epilepsy (SUDEP), screening inventories like the SUDEP-7 Inventory can be useful. In this study, we examined the strength of association between this inventory's risk factors and postictal generalized EEG suppression (PGES), a biomarker of SUDEP risk. We reanalyzed data from an epilepsy monitoring unit study of 37 children. We performed a 2 by 2 contingency table analysis to determine the association between "yes" responses on the inventory questions and PGES following >=1 seizure. Having a history of >3 generalized tonic-clonic seizures (GTCS) in the past year had the strongest association with PGES (Pearson chi-square p<0.001, Cramer's V=0.75). Having >=1 GTCS in the past year was also strongly associated with PGES (Pearson chi-square p<0.001, Cramer's V=0.636). Histories of >50 seizures of any type/month (Pearson chi-square p=0.14, Cramer's V=0.241) and intellectual disability (Pearson chi-square p=0.04, Cramer's V=0.337) were not as robustly associated with PGES. Current use of >=3 AEDs had the weakest association with PGES (Pearson chi-square p=0.66, Cramer's V=0.072). Given that all study patients had >=1 seizure per year and epilepsy durations <30 years, the strength of association with these questions and PGES could not be analyzed.