Diagnostic testing in nontrauma patients presenting to the emergency department with recurrent seizures: A systematic review

Abstract

Background: There is a lack of consensus regarding the role of investigations among patients presenting to the emergency department (ED) with recurrent seizures. The aim of this systematic review was to determine the frequency and utility of commonly requested investigations for nontrauma patients presenting to the ED with recurrent seizures.

Methods: The MEDLINE, EMBASE, and Cochrane Library databases were searched (March 2021) for articles on this topic using search terms related to recurrent seizures, investigations, and the ED. The inclusion criteria required that articles include adult nontrauma patients presenting to the ED. Studies exclusively investigating first-episode seizures, trauma patients, and status epilepticus were excluded. Eligible studies were assessed for bias using the Newcastle-Ottawa scale. Results of studies were presented using proportions.

Results: There were six cohort studies included that contributed data from 36,595 patients. All six studies assessed at least one of our primary outcomes for computed tomography (CT) brain scans. The proportion of patients who underwent a head CT ranged from 13% to 42%. The rates of abnormal head CT findings ranged from 8% to 21%. One study reported on magnetic resonance imaging (MRI) and found it used infrequently in 0.79% of cases. The proportion and yield of nonneuroimaging investigations were not well evaluated in this patient population. Only one study reported on the utility of sodium levels or blood glucose results for this population and reported abnormalities in sodium levels for 19% of patients and abnormalities in glucose levels in 50% of patients.

Conclusions: In this population, CT brain scans appeared to be performed uncommonly but with moderate rates of abnormal findings. In the absence of prolonged alteration of consciousness, a history of brain tumor, or positive neurologic findings, however, neuroimaging was of low yield. Given the heterogeneity and potential limitations of these studies, further research on this topic is required.

Keywords: emergency medicine; epilepsy; neuroimaging; seizures; tomography; x-ray computed.