Thalamocortical Evoked Potentials Inform Short-term Thalamic DBS
Abstract number :
1.184
Submission category :
3. Neurophysiology / 3E. Brain Stimulation
Year :
2022
Submission ID :
2204508
Source :
www.aesnet.org
Presentation date :
12/3/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:25 AM
Authors :
Nicholas Gregg, MD – Mayo Clinic; Dora Hermes, PhD – Mayo Clinic; Harvey Huang, B.S. – Mayo Clinic; Brian Lundstrom, MD, PhD – Mayo Clinic; Kai Miller, MD, PhD – Mayo Clinic; Jamie Van Gompel, MD – Mayo Clinic; Gregory Worrell, MD, PhD – Mayo Clinic
This abstract has been invited to present during the Neurophysiology platform session
Rationale: Deep brain stimulation (DBS) for epilepsy is limited by the absence of real-time biomarkers to guide stimulation parameter optimization. Single pulse electrical stimulation (SPES) evoked potentials measure functional connectivity and excitability of brain networks. On-demand SPES induced thalamocortical evoked potentials (TCEPs) may inform DBS parameter optimization.
Methods: Six individuals had clinical stereo EEG (sEEG) monitoring for seizure onset zone localization and had each an sEEG lead targeting the thalamus. All subjects had SPES (0.2 Hz, 200 microsec pulse width, 3-6 mA, 10-30 pulses) delivered to thalamus sEEG contacts at baseline and following a trial of therapeutic DBS delivered through sEEG electrodes (high frequency (>100 Hz) or low frequency ( < 10 Hz) stimulation, 90-200 microsec pulse width, 3-6 mA, duty cycle or continuous, 1-24 hour duration). Baseline and post-DBS TCEPs were evaluated in thalamocortical circuit regions by spectral amplitude in band (2-10 Hz band, 25-500 millisec post SPES), and TCEP waveform morphology. Time-frequency analyses used the continuous Morlet wavelet transform. Statistical significance was assessed with one-way ANOVA test; 0.05 significance level. This study was approved by the Mayo Clinic Institutional Review Board.
Results: Thalamus sEEG electrodes targeted the anterior thalamic nuclei (ANT) (5 subjects) and pulvinar nucleus (1 subject) (Figure). TCEPs were evident in thalamocortical circuit regions, unique to ANT vs. pulvinar stimulation. There was modulation of TCEP amplitude in band (AIB) and morphology from baseline to post DBS trial, for ANT and pulvinar stimulation. TCEP modulation was dependent on DBS frequency (high vs. low, subject 1), duration (subject 4), and duty cycle pattern (low frequency stimulation was delivered continuously; high frequency stimulation was delivered on a duty cycle, except for subject 6 who received 80 minutes of continuous high frequency stimulation). Notably, duty cycle high frequency stimulation, and continuous low frequency stimulation resulted in suppression of TCEP AIB for all subjects (Figure, bottom panel), while there was no clear suppression of TCEP amplitude for continuous high frequency stimulation (subject 6).
Conclusions: On-demand TCEPs identified DBS frequency, duty cycle, and duration dependent changes in brain connectivity. Pulvinar and ANT DBS shared similar TCEP characteristics. Thalamocortical evoked potentials may be a powerful tool for efficient personalized DBS optimization.
Funding: NIMH R01MH122258; NIH U01-NS073557, R01-NS92882, UH2&3-NS95495
Neurophysiology