Biomarkers of Short-term Response to Neurostimulation in Epilepsy Patients
Abstract number :
2.165
Submission category :
3. Neurophysiology / 3E. Brain Stimulation
Year :
2024
Submission ID :
276
Source :
www.aesnet.org
Presentation date :
12/8/2024 12:00:00 AM
Published date :
Authors :
Presenting Author: Bethany Stieve, PhD – University of Wisconsin
Dillon Scott, BS – University of Wisconsin
Aaron Struck, MD – University of Wisconsin-Madison
Andrew Knox, MD – University of Wisconsin School of Medicine
Rationale: Neuromodulation therapy holds the potential to help the millions of people with drug-resistant epilepsy who have uncontrolled seizures. However, efficacy is limited by identification of effective stimulation parameters. Previous studies show data-driven paradigms can identify effective stimulation parameters in animal models. However, seizures are relatively rare events in humans, and more immediate biomarkers of responsiveness to stimulation parameters are necessary to translate data-driven paradigms to clinical applications. Previous work suggests that cortico-cortical evoked potential (CCEP) amplitude and gamma power may be immediate biomarkers of effective neurostimulation parameters. To test this hypothesis, we systematically study the short-term effects of neurostimulation parameters on CCEPs and gamma power.
Methods: In this prospective clinical study, individuals undergoing phase two epilepsy workup with stereotactic depth electrodes receive both high (100 Hz) and low (7 Hz) frequency stimulation at 6-8 stimulation sites. CCEPs and gamma power are measured prior to and immediately following stimulation.
Results: An initial dataset from 9 patients (4 adult, 5 pediatric) includes 750 recorded CCEPs across 649 channels and 17,676 total EEG pre- and post-stimulation recordings. In channels with detected CCEPs, stimulation-induced changes in CCEP amplitude and gamma power are significantly frequency-dependent (Wilcoxon rank sum test; p< 0.001). Specifically, high frequency stimulation is more likely to reduce CCEP amplitude (see Fig. 1) and increase gamma power, compared to low frequency stimulation.
Conclusions: This study suggests that CCEP amplitude and gamma power may be biomarkers of short-term responses to neurostimulation, a critical first step towards data-driven and individualized parameter optimization for neurostimulation. Such approaches have the potential to substantially improve the efficacy and utility of neurostimulation, decreasing time to seizure freedom and improving quality of life for patients with epilepsy.
Funding: University of Wisconsin’s Institute of Translational and Clinical Research TL1 Fellowship
Neurophysiology