Effects of transcranial magnetic stimulation on the human brain recorded with intracranial electrocorticography

COEX 

Knowing the neural mechanisms of transcranial magnetic stimulation (TMS) from the cortex would allow to understand its effects in the stimulated region and in connected areas, and give an interpretation to the responses observed in EEG. Here, I will talk about TMS effects on intracranial electrocorticography (iEEG) in 22 neurosurgical patients. First, I will introduce the safety evaluations in a gel-based phantom, then I will show the intracranial responses to single TMS pulses targeting the dorsolateral prefrontal cortex (dlPFC). Our results show that TMS consistently induces responses in the dlPFC and connected regions, including the anterior cingulate and insular cortex.
The aim of my presentation is to show that TMS can be recorded with intracranial electrodes in humans, and that we observed no adverse effects of TMS-iEEG experiments in twenty-two participants to date. While encouraging, caution must be taken to ensure continued patient safety.
Finally, I will discuss on how TMS-iEEG can be an informative novel methodology in the ongoing efforts to understand the underlying mechanisms of TMS, and consequently the evoked activity observable in TMS/EEG .