Consensus paper: Combining transcranial stimulation with neuroimaging

Abstract

In the last decade, combined transcranial magnetic stimulation (TMS)-neuroimaging studies have greatly stimulated research in the field of TMS and neuroimaging. Here, we review how TMS can be combined with various neuroimaging techniques to investigate human brain function. When applied during neuroimaging (online approach), TMS can be used to test how focal cortex stimulation acutely modifies the activity and connectivity in the stimulated neuronal circuits. TMS and neuroimaging can also be separated in time (offline approach). A conditioning session of repetitive TMS (rTMS) may be used to induce rapid reorganization in functional brain networks. The temporospatial patterns of TMS-induced reorganization can be subsequently mapped by using neuroimaging methods. Alternatively, neuroimaging may be performed first to localize brain areas that are involved in a given task. The temporospatial information obtained by neuroimaging can be used to define the optimal site and time point of stimulation in a subsequent experiment in which TMS is used to probe the functional contribution of the stimulated area to a specific task. In this review, we first address some general methodologic issues that need to be taken into account when using TMS in the context of neuroimaging. We then discuss the use of specific brain mapping techniques in conjunction with TMS. We emphasize that the various neuroimaging techniques offer complementary information and have different methodologic strengths and weaknesses.

Causal interactions between fronto-parietal central executive and default-mode networks in humans

“…Concurrent TMS/fMRI builds on conventional neuroimaging approaches, wherein brain activation correlates are found across tasks or groups, by allowing direct excitation or inhibition of targeted brain regions and their interconnected distal network partners (15)(16)(17). Experimental manipulation of brain activity thereby provides information about causality not possible with correlative neuroimaging alone, and it can be achieved with high reliability and precision, with induced fMRI responses resembling voluntarily evoked brain activity (18).…”

Voltage-sensitive dye imaging of transcranial magnetic stimulation-induced intracortical dynamics

“…Additionally, TMS has proved a valuable tool in basic brain research as its perturbative effects allow area-selective manipulation of immediate cortical function (9)(10)(11), as well as its long-lasting alteration through plasticity and learning protocols (12,13). However, direct measurements of the TMS-induced cortical dynamics at highly resolved spatiotemporal scales are missing because "online approaches" (14), using modern neuroimaging techniques such as functional MRI (fMRI) (15)(16)(17)(18), magnetoencephalography (19), EEG (20), and near-infrared (21) or intrinsic optical imaging (22), are limited in either spatial or temporal resolutions or in both.…”

Noninvasive techniques for probing neurocircuitry and treating illness: vagus nerve stimulation (VNS), transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS)

“…Coupling TMS with imaging (PET, SPECT, fMRI, or BOLD fMRI) allows one to directly stimulate circuits and then image the resultant changes Siebner et al, 2009). With respect to the neuropsychiatric uses of TMS for depression or pain, at a molecular level TMS is known to have similar effects as those seen with ECT, for example, increased monoamine turnover, increased Brain-Derived Neurotrophic Factor, and normalization of the hypothalamic-pituitary-adrenal axis.…”