Diagnostic value and therapeutic contribution of emergency EEGs

To evaluate the diagnostic and therapeutic contribution of emergency electroencephalography (EEG) in the emergency department (ED) and intensive care units (ICUs), and to identify predictors of EEG-driven treatment changes.

We retrospectively analyzed adults (≥18 years) who underwent at least one emergency EEG between January 2021 and December 2022. Demographic and clinical data, EEG findings, neuroimaging results, and subsequent diagnostic and therapeutic decisions were collected. For patients with multiple EEGs, the first conclusive study was used for patient-level analyses. Logistic regression identified independent predictors of therapeutic contribution.

We included 316 patients (150 F; mean age 55.0 ± 20.0 years) with 414 EEGs; 59.6% of recordings were requested from the ED. The most frequent EEG abnormalities were focal or generalized background slowing, while 34.6% of patients had normal studies and 22.2% showed epileptiform activity. EEG contributed to diagnosis and/or treatment in 289 patients (91.4%): diagnostic only in 49.1%, therapeutic only in 26.0%, and both in 24.9%. Epileptiform abnormalities were strongly associated with antiseizure medication (ASM) initiation or dose escalation (p < 0.001). Structural lesions on neuroimaging were linked to epileptiform discharges and EEG-driven ASM modification. In multivariable analysis, EEGs requested from the ED independently predicted therapeutic contribution (OR 1.94; p = 0.028).

Emergency EEG has a high clinical yield in acute care, particularly for guiding ASM therapy in patients with epileptiform discharges or structural lesions. ED-requested EEGs are especially likely to influence management, supporting their routine integration into acute neurological care.