Timing of seizure occurrence and response of medical staff in video-EEG monitoring for drug-resistant epilepsy

Abstract

Purpose: The purpose of this study was to determine the optimal duration of long-term videoEEG monitoring (VEEG) in patients with epilepsy. The response time of medical staff to seizures was also evaluated from the viewpoint of safety of the monitoring. Methods: We estimated the optimal duration of VEEG from the seizure onset pattern. We retrospectively investigated all VEEG sessions performed in our department during the period between June 2005 and July 2016. Sessions with no seizures and with only non-epileptic seizures were excluded. Using 91 sessions from 69 patients, information on the onset time and response time of medical staff to seizures was collected. Results: The median duration from the start of VEEG to the first seizure was 2 days. Seventy-seven percent of first seizures occurred within 3 days of VEEG. The median duration from the first seizure to the third seizure was 2 days. Eighty percent of third seizures occurred within 3 days of the first seizure. There was no significant diurnal distribution of seizure occurrence. Medical staff did not respond to 20% of generalized seizures and 69% of focal seizures. The overlooking of generalized seizures occurred mainly during the hours of 1-2 pm and 8-9 pm but there was no significant diurnal pattern in overlooking generalized and focal seizures. Conclusion Based on these findings, we suggest that VEEG can be terminated when no seizure occurs within 4 days after onset. In our VEEG protocol, in which all antiepileptic drugs were discontinued before the start of a session, there was no diurnal pattern of seizure occurrence. This is the first study investigating the diurnal pattern of overlooking seizures by medical staff during VEEG. Since there was no diurnal pattern to the overlooking, medical staff should pay equal, 24- hour attention to patients on VEEG.