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步60通道脑电(EEG)和6通道肌电(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架立体定向导航仪，它可以根据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。建议的TMS系统允许非侵入性和安全地抑制或兴奋特定的皮质区域，本质上是在短时间(~数十毫秒)内打开或关闭刺激的脑区，从而增强或中断目标脑区正在进行的处理。这项强大的技术是唯一能够基于神经成像(fMRI/MEG/EEG/PET)数据对人类大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以前被证明是活跃的神经成像工具的特定大脑区域。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一个在解剖上分散的网络，该网络在大脑的广泛分离部分具有节点，并且为了探测人类大脑中的网络属性和并行处理，一个区域的TM通常不足以显著调节大脑功能和/或行为指数。同时的EEG可以直接在线监测TMS导致的大脑功能如何调节，并评估大脑各区域的功能连通性，为实际了解不同大脑区域之间的因果关系提供了一个独特的窗口，并确定了大脑功能和感知/认知/行为之间的因果关系。因此，这种强大的功能组合允许对人脑进行全面的逆向工程。因此，这一仪器将有益于所有正在进行的人脑功能组织研究。此外，我们的一些专注于血流动力学-电生理耦合的人类研究应该预计，通过使用导航TMS而不是外周感觉刺激来激活大脑，信噪比应该会增加大约500倍。最后，我们的中风和偏头痛研究将利用同时的TMS+EEG来评估皮质的活性和兴奋性。Nexstim eXimia导航仪和EEG系统，以及两个Medtronic MagPro X100 MagOption刺激器和美敦力线圈，之所以被选中，是因为我们发现单个最先进的组件最适合为我们广泛的用户群服务。EXimia EEG也是市面上唯一一款与TMS兼容的商业EEG系统，其他任何组合都无法在无缝集成的仪器系统中提供导航和同步TMS和EEG/EMG。 导航TMS+EEG仪器将被NIH资助的大量项目定期使用，每个项目都与公共健康相关，有助于了解人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/损伤研究。该仪器允许对人脑功能组织进行安全和非侵入性的逆向工程，因此将对认知神经科学模型的验证产生重大影响，同时它还将增加我们对血液动力学-电生理学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.