Emergency EEG and factors associated with nonconvulsive status epilepticus

The purpose of this study was to identify factors associated with nonconvulsive status epileptics (NCSE) and optimize efficient use of emergency electroencephalography (EEG) services. A retrospective review of medical records identified features associated with NCSE over a 1-year period. Seventy-eight EEGs were identified and divided into four groups. Group I, normal EEG; group II, EEG slowing; group III, epileptiform discharges; and group IV, NCSE. Three risk factors were associated with EEG-confirmed NCSE. These three risk factors are: history of epilepsy, witnessed seizure around the time of presentation, and seizure-like motor activity (SLMA). At least one of these three risk factors was identified in 35 patients, and all of the patients with NCSE were within this group. Forty-three patients had absence of these factors, and none of these patients were found to have NCSE, giving these factors a negative predictive value of 100%. Our study suggests that these three factors are highly associated with NCSE. A prospective study should be done to confirm this finding.