Antiseizure medication reduction in long-term video-electroencephalographic monitoring for presurgical evaluation: A multicenter safety and efficacy analysis

Abstract

Objective: In people with refractory focal epilepsy, long-term video-electroencephalographic monitoring (LT-VEEG) is a valuable tool for surgical evaluation. Antiseizure medication (ASM) is often tapered during LT-VEEG. ASM reduction may increase the risk of complications such as status epilepticus, and efficacy has not been established. We characterized contributing factors to successful and safe LT-VEEG within a large multicenter dataset. Methods: Adults and children were included from eight tertiary epilepsy centers in Europe for whom LT-VEEG was part of the preoperative assessment for epilepsy surgery from May 2017 until January 2022. We collected demographics, baseline seizure frequency, ASM use and reductions or complete discontinuation, outcome (successful LT-VEEG), and complications during ASM withdrawal/LT-VEEG. We performed multivariate regression analysis to determine factors contributing to risks of complications and successful LT-VEEG. Results: We included 843 people. LT-VEEG was successful in 70%. ASM was tapered in 756 persons (90%). Five hundred forty-four persons started reduction of ASM before LT-VEEG, of whom 72% reduced it at home. Baseline seizure frequency had a strong influence on ASM withdrawal policy. In people with a lower baseline seizure frequency, ASM was more likely to be tapered, and the reduction was more often initiated before the start of the LT-VEEG. The extent of ASM dose reduction was identified as a critical factor contributing to a successful LT-VEEG. ASM reduction increased the chance of complications; 10% had a complication compared to 1% without reduction. Starting ASM reduction before LT-VEEG did not increase the risk of complications. Significance: ASM reduction contributes to a successful LT-VEEG in people with a lower baseline seizure frequency and is relatively safe, taking specific factors into account. The risk of adverse events is higher when ASM is reduced, regardless of timing or setting (outpatient vs. in-hospital).