Abstracts

Closed-Loop Neuromodulation for Seizure Suppression and Forecasting with Thalamic Stimulation Using Medtronic’s Percept PC

Abstract number : 3.473
Submission category : 3. Neurophysiology / 3E. Brain Stimulation
Year : 2023
Submission ID : 1458
Source : www.aesnet.org
Presentation date : 12/4/2023 12:00:00 AM
Published date :

Authors :
Presenting Author: Zachary Sanger, MS – University of Minnesota

Hafsa Farooqi, PhD – Post Doctoral Researcher, Biomedical Engineering, University of Minnesota; Robert McGovern, MD – Staff Neurosurgeon/Assistant Professor, Neurosurgery, University of Minnesota; Theoden Netoff, PhD – Professor, Biomedical Engineering, University of Minnesota

Rationale:
While deep brain stimulation (DBS) is an FDA-approved and effective therapeutic approach for epilepsy, the response varies among individual patients. Currently, stimulation parameters are determined based on the settings employed in the SANTE clinical trial, with amplitude modulation being the primary variable adjusted in clinical practice. Medtronic’s Percept PC device, however, offers the unique capability of simultaneous stimulation through lead contacts 1 and/or 2, while concurrently recording from adjacent contacts on the same lead. This functionality can be harnessed for quantitative biomarker feedback, potentially paving the way for advanced closed-loop neuromodulation tools. Such tools could further individualize DBS treatments, potentially leading to enhanced seizure outcomes.

Methods:
In this poster, we analyze neural signals captured using PERCEPT and address the influence of stimulus artifacts, electrode impedance, and noise originating from the implantable pulse generator (IPG) electronics. Additionally, we investigate the use of recorded neural signals for closed-loop neuromodulation of the anterior nucleus of the thalamus (ANT) activity and identify biomarkers for forecasting seizures based on patient reported seizure times. The data showcased in this poster originate from an ongoing Institutional Review Board (IRB) approved clinical study (#NCT05493722) at the University of Minnesota (N=10).

Results:
We demonstrate the necessary data acquisition considerations when collecting and interpreting Percept generated local field potentials (LFPs) in the clinic and at home. In the clinic, data streamed at 250Hz—while concurrently stimulating at varied frequencies and pulse-widths—indicated that neural signals change in response to different stimulation parameters. During extended at-home recordings where we measured power in the alpha band (7-12Hz) in 10-minute averages, we detected ultradian, diurnal, weekly, and even monthly fluctuations in the alpha band power. Seizures are seen to be phase locked to some of these rhythms and combining several rhythms provides accurate prediction of times when patients are at high risk of seizures.

Conclusions:
The Medtronic Percept PC device provides new closed-loop neuromodulation methodology for delivering and analyzing deep brain stimulation treatments in epilepsy populations. We observe that neural activity is significantly modulated by different stimulation parameters.  We also have found that seizures are phase locked to rhythms in alpha band power. Using multiple rhythms of the alpha band, it is possible to forecast seizures with high accuracy. The additional use of wearables in conjunction with Medtronic Percept patient reporting will allow for future validation and discovery of biomarkers for developing and refining closed-loop tools.

Funding:
NIH U01NS124616

Neurophysiology