How long is long enough? The utility of prolonged inpatient video EEG monitoring

Video EEG monitoring (VEM) is a valuable tool for the diagnosis of epileptic seizures (ES) and psychogenic nonepileptic seizures (PNES). We sought to determine the benefits of prolonged length of stay (LOS). We retrospectively reviewed the records of patients admitted for VEM. We analyzed LOS for ES and PNES patients to determine if there was reduced utility, as evidenced by a significantly higher inconclusive outcome, beyond a certain duration. We calculated receiver operating characteristic (ROC) curves to determine optimal cut off points for LOS based on futility. Patients admitted with presumed PNES were significantly more likely to have an inconclusive admission (31/150, 20.7%) versus all others (58/446, 13%, p = 0.033). There was no significant difference in the likelihood of having an inconclusive admission if monitoring was continued for any duration in patients with ES (area under curve, AUC, 0.46). For patients with PNES, a LOS ≥5 days was associated with an increased risk of the stay being inconclusive (28% versus 12.5%, p = 0.026). Although the ROC curve suggested a cut off of 5.5 days, it did not predict outcomes well (AUC 0.52, sensitivity 0.55, specificity 0.5). Based on our data, prolonging VEM appears useful for the proper classification and localization of ES.