Department of Movement Sciences, Group Biomedical Sciences, Movement Control & Neuroplasticity Research Group, KU Leuven, 3001 Heverlee, Belgium; REVAL Research Institute, Hasselt University, Agoralaan, Building A, 3590 Diepenbeek, Belgium.
Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Section 714, Kettegård Allé 30, 26500 Hvidovre, Denmark.
Neuroimage. 2021 Jan 1;224:117394. doi: 10.1016/j.neuroimage.2020.117394. Epub 2020 Sep 26.
Over the last decade, there has been an increasing number of studies combining transcranial magnetic stimulation (TMS) and magnetic resonance spectroscopy (MRS). MRS provides a manner to non-invasively investigate molecular concentrations in the living brain and thus identify metabolites involved in physiological and pathological processes. Particularly the MRS-detectable metabolites glutamate, the major excitatory neurotransmitter, and gamma-aminobutyric acid (GABA), the major inhibitory neurotransmitter, are of interest when combining TMS and MRS. TMS is a non-invasive brain stimulation technique that can be applied either as a neuromodulation or neurostimulation tool, specifically targeting glutamatergic and GABAergic mechanisms. The combination of TMS and MRS can be used to evaluate alterations in brain metabolite levels following an interventional TMS protocol such as repetitive TMS (rTMS) or paired associative stimulation (PAS). MRS can also be combined with a variety of non-interventional TMS protocols to identify the interplay between brain metabolite levels and measures of excitability or receptor-mediated inhibition and facilitation. In this review, we provide an overview of studies performed in healthy and patient populations combining MRS and TMS, both as a measurement tool and as an intervention. TMS and MRS may reveal complementary and comprehensive information on glutamatergic and GABAergic neurotransmission. Potentially, connectivity changes and dedicated network interactions can be probed using the combined TMS-MRS approach. Considering the ongoing technical developments in both fields, combined studies hold future promise for investigations of brain network interactions and neurotransmission.
在过去的十年中，越来越多的研究将经颅磁刺激（TMS）与磁共振波谱（MRS）相结合。MRS 提供了一种非侵入性的方法，可以在活体大脑中研究分子浓度，从而鉴定参与生理和病理过程的代谢物。特别是 MRS 可检测到的代谢物谷氨酸（glutamate），即主要的兴奋性神经递质，和γ-氨基丁酸（GABA），即主要的抑制性神经递质，当与 TMS 结合时非常有趣。TMS 是一种非侵入性的脑刺激技术，可作为神经调节或神经刺激工具应用，专门针对谷氨酸能和 GABA 能机制。TMS 和 MRS 的结合可用于评估干预性 TMS 方案（如重复 TMS（rTMS）或成对关联刺激（PAS））后大脑代谢物水平的变化。MRS 还可以与各种非干预性 TMS 方案结合，以确定大脑代谢物水平与兴奋性或受体介导的抑制和易化的测量之间的相互作用。在这篇综述中，我们概述了在健康人群和患者人群中结合 MRS 和 TMS 进行的研究，包括作为测量工具和干预手段。TMS 和 MRS 可能会提供关于谷氨酸能和 GABA 能神经传递的互补和全面的信息。使用联合 TMS-MRS 方法，可能会探测到连接变化和专门的网络相互作用。考虑到这两个领域的技术发展，联合研究有望为脑网络相互作用和神经传递的研究提供未来的前景。
