Anti-seizure Medication Tapering Correlates with Daytime Delta Band Power Reduction in the Cortex
Abstract number :
1.29
Submission category :
3. Neurophysiology / 3G. Computational Analysis & Modeling of EEG
Year :
2024
Submission ID :
770
Source :
www.aesnet.org
Presentation date :
12/7/2024 12:00:00 AM
Published date :
Authors :
Presenting Author: Guillermo Besne, PhD – Newcastle University
Nathan Evans, Mphys – Newcastle University
Mariella Panagiotopoulou, PhD – Newcastle University
Billy Smith, MSc – Newcastle University
Fahmida A. Chowdhury, MD – University College London
Beate Diehl, MD – University College London
John Duncan, MD – University College London
Andrew McEvoy, MD – University College London
Anna Miserocchi, MD – University College London
Jane de Tisi, BSc – University College London
Mathew Walker, MD – University College London
Peter Taylor, PhD – Newcastle University
Christopher Thornton, PhD – Newcastle University
Yujiang Wang, PhD – Newcastle University
Rationale:
Anti-seizure medications (ASMs) are the primary treatment for epilepsy. Despite their potential impact on research and clinical practice, short-term medication withdrawal effects on background brain activity have not been investigated in humans in detail. As a preparation for resective surgery, long-term intracranial EEG recordings (icEEG) are performed, in some cases, together with ASM tapering. This provides a rare opportunity to study the effects of short-term medication withdrawal in a controlled environment.
Methods:
We examined icEEG recordings in 32 individuals with drug resistant focal epilepsy during long-term monitoring, of which 22 underwent concurrent ASM tapering. We estimated ASM plasma levels based on known pharmaco-kinetics, and defined a 24h time windows of baseline and reduced ASM levels for each individual (Fig. 1). For each window, we extracted the canonical frequency band power from icEEG. We then calculated the difference in band power between baseline and tapered windows in each subject. Spearman’s correlation and hierarchical models are performed to study the dose-dependent effect of ASM tapering. Finally, we differentiated the observed effects by brain region and investigate the impact of circadian effects.
Results:
We found an overall decrease in the all band power around the period of maximum medication withdrawal, and the strongest effect is seen in the delta band (1-4Hz). This observation was independent of epilepsy type or medication combination. The degree of medication withdrawal correlated positively with the magnitude of δ power decrease (Fig. 2). This dose-dependent effect was strongly seen across all recorded cortical regions, but not in sub-cortical regions. We found no evidence of differential effect in seizure onset, spiking, or pathological brain regions. Finally, the band power decrease is seen strongest during daytime.
Conclusions:
The finding of decreased band power during ASM tapering agrees with one previous report, and our observed dose-dependent effect indicates that monitoring ASM levels in cortical regions may be feasible for applications such as medication reminder systems, or closed-loop ASM delivery systems. ASMs are also used in other neurological and psychiatric conditions, making our findings relevant to a general neuroscience and neurology audience.
Funding:
This study was supported by UKRI Future Leaders Fellowships (MR/T04294X/1, MR/V026569/1). JSD, JdT are supported by the NIHR UCLH/UCL Biomedical Research Centre.
Neurophysiology