eprintid: 10087976 rev_number: 22 eprint_status: archive userid: 608 dir: disk0/10/08/79/76 datestamp: 2019-12-16 14:47:45 lastmod: 2021-10-07 22:03:08 status_changed: 2019-12-16 14:47:45 type: article metadata_visibility: show creators_name: Casula, EP creators_name: Maiella, M creators_name: Pellicciari, MC creators_name: Porrazzini, F creators_name: D'Acunto, A creators_name: Rocchi, L creators_name: Koch, G title: Novel TMS-EEG indexes to investigate interhemispheric dynamics in humans ispublished: pub divisions: UCL divisions: B02 divisions: C07 divisions: D07 divisions: F84 keywords: EEG, Interhemispheric balance, Interhemispheric inhibition, TMS note: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. abstract: OBJECTIVE: To validate two indexes of interhemispheric signal propagation (ISP) and balance (IHB) by combining transcranial magnetic stimulation (TMS) and electroencephalography (EEG). METHODS: We used TMS-EEG to non-invasively stimulate the two hemispheres of 50 healthy volunteers and measured interhemispheric dynamics in terms of ISP and IHB. We repeated our evaluation after three weeks to assess the reliability of our indexes. We also tested whether our TMS-EEG measures were correlated with traditional interhemispheric inhibition (IHI), as measured with motor-evoked potentials (MEPs). RESULTS: Our main results showed that ISP and IHB (1) have a high reproducibility among all the participants tested; (2) have a high test-retest reliability (3) are linearly correlated with IHI, as measured with MEPs. CONCLUSIONS: The main contribution of this study lies in the proposal of new TMS-EEG cortical measures of interhemispheric dynamics and in their validation in terms of intra- and inter-subject reliability. We also provide the first demonstration of the correlation between ISP and IHI. SIGNIFICANCE: Our results are relevant for the investigation of interhemispheric dynamics in clinical populations where MEPs are not reliable. date: 2020-01 date_type: published official_url: https://doi.org/10.1016/j.clinph.2019.09.013 oa_status: green full_text_type: other language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 1721081 doi: 10.1016/j.clinph.2019.09.013 pii: S1388-2457(19)31242-8 lyricists_name: Casula, Elias lyricists_name: Rocchi, Lorenzo lyricists_id: EPCAS14 lyricists_id: LROCC06 actors_name: Rocchi, Lorenzo actors_id: LROCC06 actors_role: owner full_text_status: public publication: Clinical Neurophysiology volume: 131 number: 1 pagerange: 70-77 event_location: Netherlands issn: 1388-2457 citation: Casula, EP; Maiella, M; Pellicciari, MC; Porrazzini, F; D'Acunto, A; Rocchi, L; Koch, G; (2020) Novel TMS-EEG indexes to investigate interhemispheric dynamics in humans. Clinical Neurophysiology , 131 (1) pp. 70-77. 10.1016/j.clinph.2019.09.013 <https://doi.org/10.1016/j.clinph.2019.09.013>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10087976/3/Rocchi_Novel%20TMS-EEG%20indexes%20to%20investigate%20interhemispheric%20dynamics%20in%20humans_AAM.pdf