Continuous Versus Routine EEG in Critically Ill Patients Without Primary Neurologic Condition: Analysis of a Randomized Controlled Trial

Introduction: Continuous EEG (cEEG) is increasingly used in critically ill patients, driven by its superior seizure detection sensitivity over routine EEG (rEEG). However, cEEG is resource-demanding, and whether its use translates into improved clinical outcomes in patients without primary neurologic conditions remains unknown. Methods: This is a post hoc analysis of the multicenter randomized CERTA trial, in which critically-ill adults were randomized 1:1 to cEEG or two rEEG recordings. Six-month mortality represented the primary outcome, while exploratory outcomes included functional outcome (Cerebral Performance Categories, CPC), detection of seizures/status epilepticus, ictal–interictal continuum features, medication changes, and infections within 4 weeks. Analysis was restricted to patients without primary neurologic injury. Results: Among 364 enrolled patients, 76 lacked a primary neurologic condition (cEEG: n = 34, rEEG: n = 42). Continuous EEG was not associated with mortality (p = 0.970) or functional outcome (CPC 1–2; p = 0.893). No seizures or status epilepticus were detected in either group. Rates of EEG periodic patterns, ictal–interictal continuum features, medication changes, and infections were comparable between groups. Conclusion: In critically ill adults without a primary neurologic condition, cEEG was not associated with measurable benefits in survival, neurological recovery, or epileptiform activity detection compared with repeated rEEG, in a cohort without detected electrographic seizures or status epilepticus. Pending larger, ideally prospective comparative studies, repeated routine EEG may represent a reasonable alternative in resource-limited settings. © 2026 The Author(s). European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.