Electroencephalographic monitoring in the emergency department.

EEG is the single most important test in diagnosing epilepsy and related conditions. We urge immediate EEG for patients with persistent, unexplained, altered consciousness. In our prospective study, 37% of patients referred for emergency EEG had combined EEG and clinical evidence of SE that was not tonic-clonic that would have gone undetected without EEG. In some cases, EEG provides useful diagnostic information or clarifies the severity of brain dysfunction in comatose patients. Finally, EEG is essential in monitoring patients who require pentobarbital coma for refractory SE.