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购置具有同步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）。Martinos生物医学成像中心。完全集成的仪器系统包括一个先进的无框架立体定向导航器，允许基于个体受试者的磁共振图像（MRI）即时计算刺激的大脑位置以及感应神经电流的方向和强度。所提出的TMS系统允许对特定皮层区域进行非侵入性和安全的抑制或激发，基本上在短时间内（约数十毫秒）打开或关闭受刺激的大脑区域，从而增强或中断目标大脑区域中正在进行的处理。这项强大的技术是唯一一种基于神经成像（fMRI/MEG/EEG/PET）数据对人脑功能模型进行非侵入性验证的方法。需要精确的导航来定位先前用神经成像工具显示为活跃的特定大脑区域。需要两个TMS通道来同时或快速连续地用TMS脉冲刺激两个不同的大脑位置。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，其中节点位于大脑的广泛分离的部分，并且为了探测人脑中的网络特性和并行处理，一个区域的TMS通常不足以显著调节大脑功能和/或行为指数。同步EEG允许直接在线监测大脑功能如何作为TMS的结果进行调制，并估计跨大脑区域的功能连接，为实际理解不同大脑区域之间的因果关系以及建立大脑功能与感知/认知/行为之间的因果关系提供了一个独特的窗口。因此，这种强大的特征组合允许对人脑进行全面的逆向工程。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，我们的一些专注于血液动力学-电生理学耦合的人体研究应该预期通过使用导航TMS而不是用于大脑激活的外周感觉刺激，信噪比增加约500倍。最后，我们的中风和偏头痛研究将利用同时TMS+EEG来估计皮层的活力和兴奋性。选择Nexstim eXimia导航仪和EEG系统沿着两个Medtronic MagPro X100 MagOption刺激器和Medtronic线圈，因为发现各个最先进的组件最适合为我们广泛的用户群服务。eXimia EEG也是唯一一款市售TMS兼容EEG系统，并且没有其他组合在无缝完全集成的仪器系统中提供导航和同时TMS和EEG/EMG。 导航TMS+EEG仪器将定期用于大量NIH资助的项目，每个项目都与公共卫生相关，有助于了解人类大脑在健康和疾病中的工作方式。模型的验证（通常由成像数据驱动）是任何科学推理的关键要素;然而，在神经科学中，这主要依赖于动物模型或人类中风/病变研究。该仪器允许安全和非侵入性的人脑功能组织的逆向工程，因此将对认知神经科学模型的验证产生强烈的影响，同时它也将增加我们对血液动力学-电生理学联系以及中风和偏头痛病理生理学的理解。

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.