Controlling Focality and Intensity of Non-invasive Deep Brain Stimulation Using Multipolar Temporal Interference
Abstract number :
3.18
Submission category :
3. Neurophysiology / 3E. Brain Stimulation
Year :
2022
Submission ID :
2204671
Source :
www.aesnet.org
Presentation date :
12/5/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:26 AM
Authors :
Boris BOTZANOWSKI, MS – Institut de Neurosciences des Sytèmes; Emma ACERBO, MS – Institut de Neurosciences des Systèmes; Sebastian lehmann, PhD – Department of Physiology and Pharmacology; Sarah Kearsley, MS – Department of Physiology and Pharmacology; Viktor JIRSA, PhD – Institut de Neurosciences des Systèmes; Brian Corneil, PhD – Department of Physiology and Pharmacology; Adam WILLIAMSON, PhD – Institut de Neurosciences des Systèmes
Rationale: Temporal interference (TI) stimulation is a unique method of non-invasive brain stimulation (DBS) using transcutaneous electrodes which allows the targeting and stimulation of deep brain structures without unwanted stimulation of shallower cortical structures.1 The impact of TI as a DBS for epilepsy has been previously demonstrated, by decreasing the number of interictal spikes and fast ripples.2 However, the problem of decoupling stimulation focality from stimulation intensity has not been addressed. In this paper, we directly solve the problem with a novel method of multipolar TI (mTI) stimulation which allows to control the size of the region stimulated and the intensity of stimulation in the region. We implemented this new method on two non-human primates (NHP) to demonstrate the increase of stimulation focality to match what it is already done via implantable electrode. Also, these experiments allowed us to assess the safety of this new method of noninvasive deep brain stimulation.
Methods: The mTI method uses multiple carrier frequencies (8 pairs of skin electrodes, all >1KHz) to create multiple overlapping envelopes allowing the size of the stimulated region to be modified independently of the intensity of the stimulation. We analyzed electrophysiological data (spiking activity) from NHP (Rhesus Monkeys) under deep anesthesia to see if by adding 6 pairs of stimulation to standard TI (2 pair of electrodes) we were able to modulate brain activity. Finally, we performed stimulation in an awake NHP to assess the safety of mTI.
Results: We showed that it is possible to influence the spiking activity in the temporal region, significantly correlated with the amplitude of the stimulation (r=0.55, p-value=0.034*). This effect cannot be achieved with standard TI stimulation where there is no more correlation in between electrophysiological activity and amplitude of stimulation (r=-0.39, p-value=0.15). In awake NHP, neither blinking, scratching nor pain has been observed during mTI and TI stimulations.
Conclusions: The study presents both a theoretical explanation of the concept of mTI along with experimental data gathered from Rhesus Monkeys comparing our technique’s focality to the focality of the standard temporal interference stimulation technique. We demonstrated that we were able to increase the focality and be able to evoke electrophysiological activity at depth in anesthetized and awake monkeys. Multipolar stimulation allows to reduce the size and the amount of injected current per stimulator to finally be able to stimulate small nucleus in the brain as it would be with an implantable DBS electrode.
References:
1. Grossman, N. et al. Noninvasive Deep Brain Stimulation via Temporally Interfering Electric Fields. Cell 169, 1029-1041.e16 (2017).
2. Acerbo, E. et al. Focal Non-invasive Deep-brain Stimulation with Temporal Interference for the Suppression of Epileptic Biomarkers. http://biorxiv.org/lookup/doi/10.1101/2022.03.29.486252 (2022) doi:10.1101/2022.03.29.486252.
Funding: This research was supported by funds from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement starting grant No. 716867 and POC No 963976).
Neurophysiology