Video/EEG monitoring in the evaluation of paroxysmal behavioral events: duration, effectiveness, and limitations.

To establish the number of monitoring days needed to distinguish psychogenic nonepileptic seizures (PNES) from epileptic seizures (ES) in adult patients admitted for video/EEG monitoring (VEM), we performed a retrospective chart review on 199 consecutive admissions for behavioral event diagnosis with VEM. Of the 199 adult patients admitted for VEM, 83.9% (n = 167) had a clinical event during admission, and a definitive diagnosis was made in 75.9% (n = 151). Of patients who had clinical events, 87.7% (n = 143) had their first event on admission day 1 or 2. Factors associated with ES (vs PNES) included an abnormal baseline EEG (P < 0.001), an abnormal brain MRI (P = 0.01), and history of events lasting less than 1minute (P = 0.01). There was no association between time to first event and discharge diagnosis. VEM differentiated between ES and PNES in the majority of adult patients evaluated. Most behavioral events were characterized within 2 days of admission.