Investigating the neural effects of TMS using intracranial recordings in humans

Corey Keller; Umair Hassan; Jeffrey Wang; Ethan Solomon; Hiroyuki Oya; Nicholas Trapp; Aaron Boes

doi:10.1016/j.brs.2024.12.126

Back

Investigating the neural effects of TMS using intracranial recordings in humans

Journal article

Open access

Peer reviewed

Investigating the neural effects of TMS using intracranial recordings in humans

Corey Keller, Umair Hassan, Jeffrey Wang, Ethan Solomon, Hiroyuki Oya, Nicholas Trapp and Aaron Boes

Brain stimulation, Vol.18(1), pp.255-256

01/2025

DOI: 10.1016/j.brs.2024.12.126

Files and links (1)

url

https://doi.org/10.1016/j.brs.2024.12.126View

Published (Version of record) Open Access

Abstract

Transcranial magnetic stimulation (TMS) is widely used in research and clinical settings, yet its precise neurophysiological effects remain poorly understood. A deeper understanding of TMS effects could enable more targeted and effective neuromodulation therapies for various neuropsychiatric disorders. To address this limitation, we developed a novel approach combining TMS with intracranial EEG (TMS-iEEG). Safety testing in a phantom brain demonstrated no heating or displacement of electrodes with TMS, and studies in 22 neurosurgical patients demonstrated no adverse effects other than those expected with TMS. In 10 patients, single-pulse TMS to the dorsolateral prefrontal cortex (dlPFC) induced local evoked potentials in 19% of nearby electrodes. Downstream effects were observed in the anterior cingulate cortex (44% of electrodes) and insula (14% of electrodes). Resting state fMRI demonstrated strong dlPFC-ACC connectivity and direct electrical stimulation of dlPFC elicited strong ACC responses. These responses were not observed after parietal TMS. Spectral analyses of these data revealed distinct patterns across brain regions. dlPFC TMS increased theta power (3-8 Hz) in frontal and limbic areas within 500ms of the TMS pulse. dlPFC suppressed high-frequency activity (HFA, 70-110 Hz) in temporal regions while enhancing HFA in limbic regions, driven primarily by effects in the ACC. Taken together, these findings provide insight into the local and network-level effects of TMS on human brain activity. Future studies could use TMS-iEEG to investigate 1) the neural effects of TMS applied to other brain regions, 2) how brain state influences neural responses to TMS, 3) the neuroplastic effects of repetitive TMS patterns of stimulation as well as cumulative neural effects across multiple sessions. Finally, simultaneous scalp EEG recordings and single neuron activity will provide rich data for the neuroscientific community.

Details

Title: Subtitle: Investigating the neural effects of TMS using intracranial recordings in humans
Creators: Corey Keller - Stanford University
Umair Hassan - Stanford University
Jeffrey Wang - Stanford University
Ethan Solomon - Stanford University
Hiroyuki Oya - University of Iowa
Nicholas Trapp - University of Iowa
Aaron Boes - University of Iowa
Resource Type: Journal article
Publication Details: Brain stimulation, Vol.18(1), pp.255-256
DOI: 10.1016/j.brs.2024.12.126
ISSN: 1935-861X
Number of pages: 2
Language: English
Date published: 01/2025
Academic Unit: Roy J. Carver Department of Biomedical Engineering; Neurology; Psychiatry; Stead Family Department of Pediatrics; Iowa Neuroscience Institute; Neurology (Pediatrics); Neurosurgery
Record Identifier: 9984793979102771

Metrics

5 Record Views