Efficient high-resolution TMS mapping of the human motor cortex by nonlinear regression

Dosing Transcranial Magnetic Stimulation of the Primary Motor and Dorsolateral Prefrontal Cortices With Multi-Scale Modeling

“…Instead, in most cases, we observed maximal neuronal activation in the gyral rim and crown regions, where the E TOTAL was the highest. The present results are conceptually compatible with the findings of Numssen et al ( 2021 ), who found that the peak-to-peak amplitudes of MEPs can be best explained by the E TOTAL and E T strength in the gyral rim and crown regions in the precentral gyrus. This location corresponded to the premotor cortex in 13 out of 14 participants in their sample.…”

“…Transcranial magnetic stimulation (TMS), a non-invasive brain stimulation technique, induces electric fields (E-fields) in the brain that modulate the neuronal activity (Barker et al, 1985 ; Thielscher et al, 2015 ). The intracranial E-field properties (i.e., strength and direction) are important determinants of the biological responses to TMS (Fox et al, 2004 ; Opitz et al, 2013 ; Bungert et al, 2017 ; Aonuma et al, 2018 ; Laakso et al, 2018 ; Weise et al, 2020 ; Numssen et al, 2021 ). Repetitive TMS (rTMS) produces periodic E-fields and can induce lasting aftereffects in brain activity and function (e.g., cortical excitability and cognition) (Pascual-Leone et al, 1991 ; Huang et al, 2005 ; Fitzgerald et al, 2006 ; Hamada et al, 2007 ).…”

Addressing the inconsistent electric fields of tDCS by using patient-tailored configurations in chronic stroke: Implications for treatment

“…For some subjects, no motor task-related components were found due to excessive noise in the EEG recording. Furthermore, EEG source localization has a lower spatial resolution than alternative methods such as functional MRI or TMS-based identification of the stimulation target ( Numssen et al, 2021 ). Therefore, it might be that the actual source of brain activity and modelled equivalent dipole did not completely match.…”

M2M-InvNet: Human Motor Cortex Mapping from Multi-Muscle Response Using TMS and Generative 3D Convolutional Network

“…The advancement of biophysical modeling of the induced E-field generated by TMS has precipitated efforts to move past ascribing muscle activations induced by TMS to a single point on the scalp. Recently, there have been several concerted efforts to link resulting muscle activation to the complex spatial distribution of the induced electric field [9], [34], [35]. Our model can aid such efforts by providing a framework for describing and testing the assignment of stimulated cortical territory to physiological effects on muscle activity.…”

“…TMS mapping of cortical muscle topography has shown clinical utility [3], for example, to quantify cortical muscle topography associated with abnormal muscle activation patterns due to stroke and track changes during recovery [4], [5], and to perform the presurgical evaluation of motor, speech, or language functions for patients requiring resections in eloquent areas [6], [7]. Advances in modeling of the TMS-induced E-field [8], [9] have allowed greater resolution in the estimation of the cortical representations underlying evoked muscle activation. Recently, work from our group has proposed that TMS may be used to study patterns of multi-muscle activation that have been theorized to form the basis of modular control of coordinated movement [10], [11].…”