PT  - JOURNAL ARTICLE
AU  - S. Parmigiani
AU  - E. P. Mikulan
AU  - S. Russo
AU  - S. Sarasso
AU  - F. M. Zauli
AU  - A. Rubino
AU  - A. Cattani
AU  - M. Fecchio
AU  - D. Giampiccolo
AU  - J. Lanzone
AU  - P. D’Orio
AU  - M. del Vecchio
AU  - P. Avanzini
AU  - L. Nobili
AU  - I. Sartori
AU  - M. Massimini
AU  - A. Pigorini
TI  - Simultaneous stereo-EEG and high-density scalp EEG recordings to study the effects of intracerebral stimulation parameters
AID  - 10.1101/2021.11.15.468625
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.11.15.468625
4099  - http://biorxiv.org/content/early/2021/11/17/2021.11.15.468625.short
4100  - http://biorxiv.org/content/early/2021/11/17/2021.11.15.468625.full
AB  - Background Cortico-cortical evoked potentials (CCEPs) recorded by stereo-electroencephalography (SEEG) are a valuable clinical tool to investigate brain reactivity and effective connectivity. However, these invasive recordings are spatially sparse since they depend on clinical needs. This sparsity hampers systematic comparisons across-subjects, the detection of the whole-brain spatiotemporal properties of CCEPs, as well as their relationships with classic sensory evoked potentials.Objective To demonstrate that CCEPs recorded by high-density electroencephalography (hd-EEG) are sensitive to changes in stimulation parameters and compensate for the limitations typical of invasive recordings.Methods SEEG and hd-EEG activities were simultaneously recorded during SPES in drug-resistant epileptic patients (N=36). Changes in stimulation parameters encompassed physical (pulse intensity and width), geometrical (angle and position with respect to white/grey matter) and topological (stimulated cortical area) properties. Differences were assessed by measuring the overall responses and the amplitude of N1 and N2 components of the CCEPs, and by their spectral profiles.Results While invasive and non-invasive CCEPs were generally correlated, differences in pulse duration, angle and stimulated cortical area were better captured by hd-EEG. Further, hd-EEG responses to SPES reproduced basic features of responses to transcranial magnetic stimulation and showed a much larger amplitude as compared to typical sensory evoked potentials.Conclusions The present results show that macroscale hd-EEG recordings are exquisitely sensitive to variations in SPES parameters, including local changes in physical and geometrical stimulus properties, while providing valuable information about whole-brain dynamics. Moreover, the common reference space across subjects represented by hd-EEG may facilitate the construction of a perturbational atlas of effective connectivity.HighlightsCCEPs recorded with hd-EEG and SEEG are correlated.hd-EEG recording is highly sensitive to changes in stimulation parameters.hd-EEG responses show higher amplitude responses with respect to non-invasive ones.Simultaneous recordings provide a fixed observation point across subjects.Competing Interest StatementThe authors have declared no competing interest.