Authors :
Presenting Author: Arjit Misra, BS – Carle Illinois College of Medicine
Sounak Dey, BSE – Carle Illinois College of Medicine
Aaron Anderson, PhD – University of Illinois Urbana Champaign
Fadi Mikhail, MD – Carle Foundation Hospital
Graham Huesmann, MD, PhD – Carle Foundation Hospital
Rationale:
The prognostic utility of seizures on EEG in post-cardiac arrest patients remains uncertain, particularly within the early hours post-resuscitation. While some evidence suggests seizures may indicate preserved cortical function, others associate them with poor outcomes. We aimed to characterize seizures and BIRDs (Brief Ictal Rhythmic Discharges) to determine which intra-seizure properties best predict neurological outcomes.Methods:
Continuous scalp EEG recordings from post-cardiac arrest patients were analyzed at two time intervals: early (0–10 hours) and late (70–80 hours) post-resuscitation. Data was sourced from the publicly available ICARE dataset. Ictal bursts were classified as seizures, BIRDs, SW, etc. in accordance with ACNS guidelines. We extracted multiple quantitative EEG (qEEG) features, including amplitude, spectral power by region, duration, and channel spread. For single-feature analysis, ROC curves were fit for each single feature of interest independently and AUC calculated. A p< 0.001 was considered significant for AUC >0.5. AUC ≥ 0.7 was considered to indicate prognostic utility.
Results:
At 0-10h, high seizure amplitude strongly predicted poor outcome (AUC 0.96), while longer seizure duration paradoxically predicted better outcome (AUC 0.84). Posterior-predominant seizures at 0–10h were associated with good outcome (AUC 0.89), Spectral content had limited prognostic value at 0-10h. At 70–80h, seizure duration and amplitude were less informative. However, a greater cortical spread involved predicted poor outcome (AUC 0.76). Anterior-dominant alpha/theta power within seizures at 70-80h predicted favorable outcome (AUC 0.83). For BIRDs, widespread involvement predicted poor outcome at 70-80h (AUC 0.74), while higher alpha/beta and theta/beta power correlated with better outcomes (AUC 0.75) and (AUC 0.74) respectively. For spike-and-waves at 0-10h, longer duration was favorable (AUC 0.76), while greater amplitude and spikiness were associated with worse outcomes (AUC 0.68, 0.66). Increased intra-burst alpha, alpha/delta, and alpha/theta ratios at 0-10h also predicted poor outcome (AUC 0.69, 0.72, 0.75), though these effects diminished at 70-80h.Conclusions:
Seizure features such as amplitude and topography early after ROSC may carry prognostic significance, whereas at later intervals, regional spectral content and spatial spread become more informative. BIRDs demonstrate distinct prognostic patterns, suggesting their inclusion in EEG monitoring strategies may be warranted. These findings—particularly the association between high-amplitude seizures and poor outcome, as well as the lack of clear prognostic value of seizure activity itself—align with prior studies.Funding: -