Abstract
715. Effects of Dorsolateral Prefrontal Cortex Transcranial Magnetic Stimulation Revealed With Intracranial Electroencephalography
Biological psychiatry (1969), Vol.99(10 Supplement), pp.S405-S405
05/15/2026
DOI: 10.1016/j.biopsych.2026.03.949
Abstract
Background
Transcranial magnetic stimulation (TMS) applied to the dorsolateral prefrontal cortex (DLPFC) is thought to modulate the subgenual anterior cingulate cortex (sgACC) and connected brain regions in the service of treating depression, although the exact mechanisms are unknown. Our team pioneered an approach combining TMS with intracranial EEG (TMS-iEEG) to study the effects of TMS in humans with unprecedented spatial and temporal precision.
Methods
Single pulse TMS (spTMS, n=2) and intermittent theta burst TMS (iTBS, n=5), both active and sham, were performed on iEEG patients admitted to the epilepsy monitoring unit. For spTMS, evoked potentials were analyzed using cluster-based permutation testing. For iTBS, the intertrain period was analyzed for power changes using a Morlet wavelet transform to extract continuous power and paired t-tests to assess regional significance in power changes.
Results
DLPFC spTMS showed significant evoked potentials in the sgACC, whereas parietal stimulation did not (p <0.05, 1000 permutations). For patients who showed an sgACC response, adjacent non-sgACC electrodes did not show an evoked response. For iTBS, power changes were identified in multiple oscillatory frequencies, with both positive and negative modulation. The greatest positive modulation was in the theta and high gamma frequencies (FDR-corrected p <0.05).
Conclusions
DLPFC TMS can evoke responses in the sgACC in a stimulation site-specific manner, which supports the hypothesis that TMS can interact with a network of connected brain regions, including regions that are “anti-correlated” with the stimulation site based on functional connectivity MRI. iTBS applied to the DLPFC can evoke widespread brain changes, including in theta and high gamma frequencies.
Details
- Title: Subtitle
- 715. Effects of Dorsolateral Prefrontal Cortex Transcranial Magnetic Stimulation Revealed With Intracranial Electroencephalography
- Creators
- Joshua Tatz - University of Iowa, PsychiatryXianqing Liu - University of IowaZhuoran Li - University of IowaJoel Bruss - University of IowaBenjamin Pace - University of IowaUmair Hassan - Stanford UniversityEric Tsang - University of NebraskaMatthew Howard - University of Iowa, Iowa Neuroscience InstituteCorey Keller - Stanford UniversityAaron Boes - University of IowaJing Jiang - University of IowaNicholas Trapp - University of Iowa
- Resource Type
- Abstract
- Publication Details
- Biological psychiatry (1969), Vol.99(10 Supplement), pp.S405-S405
- DOI
- 10.1016/j.biopsych.2026.03.949
- ISSN
- 0006-3223
- Publisher
- Elsevier Inc
- Language
- English
- Date published
- 05/15/2026
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Neurology; Psychiatry; Stead Family Department of Pediatrics; Iowa Neuroscience Institute; Neurology (Pediatrics); Neurosurgery; Otolaryngology; Health, Sport, and Human Physiology
- Record Identifier
- 9985157606802771
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