Evaluation of Paroxysmal Events in Critically Ill Patients: Relationship of Primary Diagnosis to Long-Term Electroencephalogram Yield

Continuous EEG (cEEG) is indicated for the workup of paroxysmal events. We aimed to assess whether primary admission diagnoses predict the yield of cEEG when ordered for evaluating paroxysmal events. We identified patients in the ICU who underwent at least 6 hours of cEEG monitoring to evaluate paroxysmal events. Primary admission diagnoses were categorized into neurological or non-neurological conditions. cEEG results were dichotomized into presence or absence of epileptiform discharges. We identified 159 recordings that were obtained for the evaluation of paroxysmal events. Most patients (n = 100, 63%) were admitted with primary admission diagnoses of neurological disorders, such as ischemic stroke, or intracranial hemorrhage. We found that patients with primary neurological conditions were more likely to have brain surgeries, abnormal brain imaging, and focal neurological deficits on examination compared to those with primary non-neurological conditions. However, there was no significant difference in the prevalence of epileptiform discharges in cEEG among patients with primary diagnoses of neurological or non-neurological disorders. These results suggest that cEEG is often necessary to evaluate paroxysmal events, even among patients without primary neurological disorders.