Do acute EEG findings add to clinical features in predicting outcomes after status epilepticus and acute symptomatic seizures?

Abstract

Status epilepticus is a potentially life-threatening medical emergency associated with poor functional outcomes. Improving our ability to accurately predict functional outcomes is beneficial to optimizing treatment strategies. Currently, there are four published status epilepticus scores in adults: STESS (Status Epilepticus Severity Score), EMSE (Epidemiology-Based Mortality Score in Status Epilepticus), END-IT (Encephalitis-Nonconvulsive-Diazepam resistance-Imaging-Tracheal intubation), and recently published ACD (Age-level of Consciousness-Duration of status epilepticus) score. The only available scale in the pediatric population is PEDSS (Pediatric CPC scale-EEG (normal vs abnormal)-Drug refractoriness-critical Sickness-Semiology). While these scores are useful research tools, currently there is little evidence to suggest their utility during real-time clinical care. Except for EMSE, none of the scores incorporate EEG findings for prognostication. Adding EEG features improves prognostic accuracy, as has been shown with the EMSE scale with and without the EEG component. Acute symptomatic seizures (AsyS) and early epileptiform abnormalities, especially nonconvulsive seizures, and periodic discharges, markedly increase the risk for subsequent unprovoked seizures. However, many of these patients may not need lifelong anti-seizure medications (ASMs). Continuous EEG monitoring shows that the majority of ASyS are nonconvulsive and can identify epileptic patterns. Dedicated specialty clinics for these patients, known as Post Acute Symptomatic Seizure (PASS) clinics, already exist in the United States. Post Acute Symptomatic Seizure clinics are ideal for both long-term clinical care and answering important research questions related to epileptogenesis, duration of ASM treatment required, and evolution of EEG findings. This topic was presented at the 8th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures held in September 2022. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Keywords: Acute symptomatic seizures; EEG; Epileptiform; Status epilepticus.