MRI-Navigated 2-Channel TMS with 60-channel EEG Instrument

描述（由申请人提供）：申请资金用于为MGH/MIT/HMS Athinoula a . Martinos生物医学成像中心购买具有同时60通道脑电图（EEG）和6通道肌电图（EMG）记录能力的2通道经颅磁刺激器（TMS）。完全集成的仪器系统包括一个先进的无框立体定向导航器，可以根据个体受试者的磁共振图像（MRI）即时计算受刺激的大脑位置和诱导神经电流的方向和强度。所提出的经颅磁刺激系统允许对特定皮质区域进行非侵入性和安全的抑制或激发，本质上是在短时间内（~几十毫秒）将受刺激的大脑区域打开或关闭，从而增强或中断目标大脑区域正在进行的处理。这项强大的技术是唯一一种允许基于神经成像（fMRI/MEG/EEG/PET）数据对人脑功能模型进行无创验证的方法。需要精确的导航来定位特定的大脑区域，这些区域以前用神经成像工具显示是活跃的。两个经颅磁刺激通道需要同时或快速连续地用经颅磁刺激脉冲刺激两个不同的大脑部位。这是必要的，因为即使是简单的刺激和任务也会激活解剖学上分散的网络，这些网络的节点分布在大脑的各个不同部位，为了探测人脑中的网络特性和并行处理，对一个区域的经颅磁刺激通常不足以显著调节大脑功能和/或行为指标。同时进行的脑电图可以直接在线监测脑功能是如何因经颅磁刺激而被调节的，并估计脑区域之间的功能连接，为实际理解不同脑区域之间的因果关系以及建立脑功能与感知/认知/行为之间的因果关系提供了一个独特的窗口。这种强大的特征组合使得对人脑进行全面的逆向工程成为可能。因此，该仪器将有利于所有正在进行的人类大脑功能组织的研究。此外，我们的一些关注血流动力学-电生理耦合的人体研究应该期望通过使用导航TMS而不是外围感觉刺激来激活大脑，信号噪声增加大约500倍。最后，我们的中风和偏头痛研究将同时使用经颅磁刺激+脑电图来估计皮质活力和兴奋性。Nexstim eXimia导航仪和EEG系统，以及两个美敦力MagPro X100 MagOption刺激器和美敦力线圈被选中，因为我们发现每个最先进的组件最适合为我们广泛的用户群服务。eXimia EEG也是唯一的商用TMS-兼容EEG系统，没有其他组合提供导航和同时在一个无缝的完全集成的仪器系统中TMS和EEG/EMG。

DESCRIPTION (provided by applicant): Funds are requested for acquisition of a 2-channel transcranial magnetic stimulator (TMS) with simultaneous 60-channel electroencephalography (EEG) and 6-channel electromyogram (EMG) recording capability to the MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging. The fully integrated instrument system includes an advanced frameless stereotactic navigator that allows instantaneous calculation of the stimulated brain location and the direction and strength of the induced neural currents based on the individual subject's magnetic resonance image (MRI). The proposed TMS system allows non-invasive and safe inhibition or excitation of specific cortical areas, essentially switching the stimulated brain areas ON or OFF for a short time (~tens of milliseconds), thus enhancing or interrupting ongoing processing in the targeted brain areas. This powerful technology is the only method to allow non-invasive validation of models of human brain functions based on neuroimaging (fMRI/MEG/EEG/PET) data. Accurate navigation is needed to target the specific brain areas previously shown to be active with neuroimaging tools. Two TMS channels are needed to stimulate two different brain locations with a TMS pulse simultaneously or in rapid succession. This is necessary because even simple stimuli and tasks activate an anatomically dispersed network with nodes in widely separate parts of the brain, and in order to probe network properties and parallel processing in the human brain, TMS of one area is often not sufficient to significantly modulate brain function and/or behavioral indices. The simultaneous EEG allows direct on-line monitoring of how brain functions are modulated as a result of TMS and estimating functional connectivity across brain areas, offering a unique window into actually understanding causal connections between different brain areas and establishing causality between brain functions and perception/cognition/behavior. This robust combination of features thus allows full-scale reverse engineering of the human brain. This instrument will therefore benefit all ongoing studies of human brain functional organization. Further, some of our human studies focusing on haemodynamics- electrophysiology coupling should expect roughly 500-fold signal-to-noise increases by using navigated TMS instead of peripheral sensory stimulation for brain activation. Finally, our stroke and migraine studies will utilize simultaneous TMS+EEG to estimate cortical viability and excitability. The Nexstim eXimia navigator and EEG systems, along with two Medtronic MagPro X100 MagOption stimulators and Medtronic coils, were selected because of the individual state-of-the art components were found to be best suited to serve our wide user base. The eXimia EEG is also the only commercially available TMS- compatible EEG system, and no other combination offers navigation and simultaneous TMS and EEG/EMG in a seamless fully integrated instrument system. The navigated TMS+EEG instrument will be regularly employed by a large number of NIH funded projects, each of which is relevant to public health by helping to understand how the human brain works in health and disease. Validation of models (that are typically driven by imaging data) is a key element in any scientific reasoning; yet, in neuroscience, this has mainly relied on animal models or human stroke/lesion studies. This instrument allows safe and noninvasive reverse engineering of human brain functional organization and will thus have a strong impact on the validation of cognitive neuroscience models, while it will also increase our understanding of the haemodynamics-electrophysiology link as well as stroke and migraine pathophysiology.