EEG as a part of the decision-making process in the emergency department

Although electroencephalography (EEG) is a useful diagnostic tool for patients with a suspected seizure, its value in informing the acute care of patients in the emergency department (ED) remains unclear. The aim of this study is to determine the effects of EEG results on subsequent patient management in or from the ED.

This prospective observational study was carried out in the ED of a tertiary-care university hospital. All patients presenting to the ED with seizure or seizure-mimicking symptoms were included in the study. EEG was advised for all patients after an initial evaluation. Before EEG, the ED physician and neurologist were asked clinical questions about the patient. The consistency between the clinical decision of emergency physicians before the EEG report and the final management of patients determined by the consultant neurologist was analyzed. The interobserver reliability of the physicians was determined.

Overall, 110 patients were enrolled in the study. The sensitivity and specificity of ED physicians' diagnosis of the presence of seizure were both 88% (95% confidence interval, 79-93 and 62-97%). The interobserver reliabilities and κ values of ED physicians and neurologists were found to be 'moderate'. Patients with abnormal EEG results were prescribed new medication (P=0.003) and changes in therapy (P=0.59) were more than for patients with normal results.

As seizure is a clinical event, EEG is not essential for diagnosing the presence of a seizure clinically in the ED. However, the results of EEG provide useful information especially for treatment choices. As the timing of the study affects the diagnostic efficacy of the test, EEG recordings should be performed within 24 h either in ED or in the epilepsy clinic.