eprintid: 10178844 rev_number: 8 eprint_status: archive userid: 699 dir: disk0/10/17/88/44 datestamp: 2023-10-13 14:51:13 lastmod: 2023-10-13 14:51:13 status_changed: 2023-10-13 14:51:13 type: article metadata_visibility: show sword_depositor: 699 creators_name: Casula, Elias P creators_name: Leodori, Giorgio creators_name: Ibáñez, Jaime creators_name: Benussi, Alberto creators_name: Rawji, Vishal creators_name: Tremblay, Sara creators_name: Latorre, Anna creators_name: Rothwell, John C creators_name: Rocchi, Lorenzo title: The Effect of Coil Orientation on the Stimulation of the Pre–Supplementary Motor Area: A Combined TMS and EEG Study ispublished: pub divisions: UCL divisions: B02 divisions: C07 divisions: D07 divisions: F84 keywords: Transcranial magnetic stimulation; electroencephalography; motor evoked potentials; TMS–EEG; presupplementary motor area; coil direction note: Copyright © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). abstract: Studies using transcranial magnetic stimulation (TMS) have demonstrated the importance of direction and intensity of the applied current when the primary motor cortex (M1) is targeted. By varying these, it is possible to stimulate different subsets of neural elements, as demonstrated by modulation of motor evoked potentials (MEPs) and motor behaviour. The latter involves premotor areas as well, and among them, the presupplementary motor area (pre–SMA) has recently received significant attention in the study of motor inhibition. It is possible that, similar to M1, different neuronal populations can be activated by varying the direction and intensity of TMS; however, the absence of a direct electrophysiological outcome has limited this investigation. The problem can be solved by quantifying direct cortical responses by means of combined TMS and electroencephalography (TMS–EEG). We investigated the effect of variable coil orientations (0°, 90°, 180° and 270°) and stimulation intensities (100%, 120% and 140% of resting motor threshold) on local mean field potential (LMFP), transcranial evoked potential (TEP) peaks and TMS–related spectral perturbation (TRSP) from pre–SMA stimulation. As a result, early and late LMFP and peaks were larger, with the coil handle pointing posteriorly (0°) and laterally (90°). This was true also for TRSP in the β–γ range, but, surprisingly, θ–α TRSP was larger with the coil pointing at 180°. A 90° orientation activated the right M1, as shown by MEPs elicitation, thus limiting the spatial specificity of the stimulation. These results suggest that coil orientation and stimulation intensity are critical when stimulating the pre–SMA. date: 2022-10 date_type: published publisher: MDPI official_url: https://doi.org/10.3390/brainsci12101358 oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 1986208 doi: 10.3390/brainsci12101358 medium: Electronic pii: brainsci12101358 lyricists_name: Rothwell, John lyricists_name: Latorre, Anna lyricists_id: JCROT52 lyricists_id: ALATO85 actors_name: Rothwell, John actors_id: JCROT52 actors_role: owner funding_acknowledgements: 798957 [European Commission] full_text_status: public publication: Brain Sciences volume: 12 number: 10 article_number: 1358 pages: 14 event_location: Switzerland issn: 2076-3425 citation: Casula, Elias P; Leodori, Giorgio; Ibáñez, Jaime; Benussi, Alberto; Rawji, Vishal; Tremblay, Sara; Latorre, Anna; ... Rocchi, Lorenzo; + view all <#> Casula, Elias P; Leodori, Giorgio; Ibáñez, Jaime; Benussi, Alberto; Rawji, Vishal; Tremblay, Sara; Latorre, Anna; Rothwell, John C; Rocchi, Lorenzo; - view fewer <#> (2022) The Effect of Coil Orientation on the Stimulation of the Pre–Supplementary Motor Area: A Combined TMS and EEG Study. Brain Sciences , 12 (10) , Article 1358. 10.3390/brainsci12101358 <https://doi.org/10.3390/brainsci12101358>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10178844/1/The%20Effect%20of%20Coil%20Orientation%20on%20the%20Stimulation%20of%20the%20Pre-Supplementary%20Motor%20Area%20A%20Combined%20TMS%20and%20EEG%20Study.pdf