EEG Delays May Worsen Outcomes in Status Epilepticus

TOPLINEProlonged waiting times for diagnostic EEG among patients with nonconvulsive status epilepticus (SE) were associated with higher 2-year all-cause mortality rates and neurologic deficits at discharge, a retrospective study showed.METHODOLOGYResearchers conducted a retrospective cohort study including data from 163 adults with first-time, nonanoxic, EEG-verified nonconvulsive SE treated in a single center in Denmark between 2008 and 2017.EEG delay was defined as the time from the last antiseizure treatment or a clinical suspicion of SE to EEG confirmation. The median delay was 11.7 hours.Researchers assessed potential associations between EEG delay and new neurologic deficits at discharge (defined as an increase in the National Institutes of Health Stroke Scale [NIHSS]) and the rate of 2-year all-cause mortality.External validation was conducted using data from two retrospective German cohorts with similar inclusion criteria (n = 906) classified according to whether EEG was available on weekends and then whether admission occurred over the weekend or on a workday.Patients were stratified into quartiles based on EEG delay: quartile 1 (Q1) underwent EEG within 3.5 hours, Q2 between 3.5 and 11.7 hours, Q3 between 11.7 and 22.6 hours, and Q4 after more than 22.6 hours.TAKEAWAYLonger EEG delay correlated with an increased rate of new neurologic deficits at discharge, with median changes in NIHSS scores of 2.5 in Q1, 5 in Q2/Q3, and 10 in Q4 (P < .001).Lower survival was observed in patients with longer EEG delays, with Q3/Q4 patients having significantly lower 2-year survival than Q1/Q2 patients (log-rank P = .007).After adjusting for brain-damaging etiology and components of the SE Severity Score, early EEG access was associated with adjusted odds of survival of 2.2 at 12 months compared with not having early access (P = .03).In the validation cohort without weekend EEG access, survival was significantly lower among patients with weekend vs weekday admissions for acute symptomatic etiologies (P = .04) and new remote symptomatic etiologies (P = .01). No such difference was observed in centers with weekend EEG availability.IN PRACTICE“The availability of daily EEG diagnostics appears to offer a simple way to improve the outcome for patients with SE due to the link between EEG delay and worse neurological outcome and mortality,” the investigators wrote.SOURCEThe study was led by Vinna Tran, Odense University Hospital, Odense, Denmark. It was published online on July 14 in the Journal of Neurology, Neurosurgery and Psychiatry.LIMITATIONS The definition of EEG delay was based on personal experience rather than systematic evaluation or consensus. The validation cohort used day of admission as a proxy for EEG delay due to weekend unavailability. The study was further limited by many of the observed associations being numerically weak; the possibility of residual confounding; the retrospective design; a small sample size; and the lack of accounting for the time necessary for EEG report description, communication with treating neurologists, or timing and adequacy of subsequent treatment steps.DISCLOSURESThe study was funded by the Lundbeck Foundation. The investigators reported no relevant conflicts of interest.This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.