Correlation of seizure frequency and medication down-titration rate during video-EEG monitoring.

Abstract

The three important questions in video-EEG monitoring are (1) whether it is productive to monitor patients with low outpatient seizure frequency, (2) whether rapid down-titration of antiepileptic drugs (AEDs) during EMU admission helps generate more recorded seizures, and (3) how long a patient who has not yet had a seizure should be monitored in the EMU. This study aimed to answer these three questions. Preadmission seizure frequency, times of AED administration, and times of seizure occurrence were collected on all adult patients admitted to the EMU at the Medical University of South Carolina (MUSC) between 2012 and 2014 - a total of 439 patients. The correlations between EMU seizure frequency and both (1) preadmission seizure frequency and (2) rate of antiepileptic drug (AED) down-titration were evaluated. The time of occurrence of seizures was evaluated. There was no correlation between patient-reported outpatient seizure frequency and EMU seizure frequency. In patients who were tapered off AEDs during monitoring, the rate of AED taper correlated with the EMU seizure frequency. Patients whose AEDs were more quickly tapered had higher EMU seizure frequencies. In order to record a first event in patients of unknown seizure type, approximately 3.5days of EMU monitoring was required. Clinicians should not hesitate to admit patients with low preadmission seizure frequency to the EMU since many of these patients will have a seizure during monitoring. Faster AED down-titration in the EMU increases EMU seizure frequency. In patients who have not yet had a seizure in the EMU, monitoring should continue for at least four days.