Stork: Tinnitus and Auditory Cortex; Using Adapted Functional Near-Infrared-Spectroscopy to Expand Brain Imaging in Humans

GREGORY JOSEPH BASURA (2018-05-01 to 2020-04-30) Tinnitus and Auditory Cortex; Using Adapted Functional Near-Infrared-Spectroscopy to Expand Brain Imaging in Humans. Amount: $411322

耳鸣和听觉皮质;利用自适应功能近红外光谱技术扩大人类脑成像

Abstract

Tinnitus, or phantom sound perception, likely results from aberrant central auditory neural activity. Gaps in identifying brain changes in human tinnitus are mainly due to limited compatible technology to map auditory regions in real-time. The ability to identify changes is critical to mapping aberrant brain regions that could objectify the disease. Functional near infrared-spectroscopy (fNIRS) is an ideal brain imaging tool to investigate central auditory changes in human tinnitus. Using fNIRS, we demonstrated increased hemodynamic activity (Issa et al., 2016), and brain connectivity (San Juan et al., 2017) between auditory and non-auditory cortices that may serve as potential objective markers of human tinnitus. A limitation of existing fNIRS technology lies in restricted (to outer cerebral cortex) depth of IR penetration through skin and skull using traditional ?cap? recording configurations. Since brain changes in tinnitus likely extend to deeper cortical/sub-cortical regions, it is necessary to improve IR brain penetration to measure putative tinnitus markers in these regions. The primary goal of this project is to expand brain surveillance using fNIRS by adapting the IR-source and detector pair of conventional probes deeper within the skull through natural openings (ear canal). Physically placing fNIRS probes deeper into the skull using this highly innovative approach will broaden brain surveillance to regions never measured before with fNIRS. The purpose of this application is not to identify/uncover the underlying mechanisms of tinnitus, but rather to use published changes (hemodynamic responses and connectivity) in human tinnitus as a platform to validate the adapted probes. To test our central hypothesis that fNIRS technology adapted to the ear canal will expand brain surveillance beyond traditional probes and provide quantifiable correlates (increased hemodynamic rates and brain connectivity) of tinnitus and potentially, other brain diseases two specific aims will be utilized. Aim 1 will measure changes in human tinnitus and normal controls using simultaneous ?cap? probes and adapted fNIRS probes that contain an IR source or detector placed on the ventral/medial temporal lobe via the ear canal. Here, we expect to validate the adapted probes to determine efficacy/optimal parameters as compared to ?cap? probes to improve anatomic localization and expand brain surveillance. Aim 2 will employ an advanced probe that retains both IR-source and detector on a single-fiber engineered for ear canal placement. The goal here is to optimize this single-fiber to measure hemodynamic changes and brain connectivity as a stand-alone technology not reliant on ?cap? probes. Once validated, single-fiber probes could be adapted to other clinical questions (i.e., frontal lobe studies via the anterior cranial base/nasal cavity) or used to investigate brain regions not measurable with existing fNIRS technology. The proposed adaptation of fNIRS probes could expand brain surveillance beyond cortical studies and provide critical information about brain diseases including tinnitus in a non-invasive, portable manner to be applied to future R01 applications.

摘要耳鸣或幻象声音感知可能是由异常的中枢听觉神经活动引起的。识别人类耳鸣中大脑变化的差距主要是由于有限的兼容技术实时映射听觉区域。识别变化的能力对于绘制可能使疾病客观化的异常脑区域至关重要。功能性近红外光谱(fNIRS)是一种理想的脑成像工具,用于研究人耳鸣的中枢听觉变化。使用fNIRS,我们证明了听觉和非听觉皮质之间的血流动力学活动增加(Issa等,2016)和大脑连通性(San Juan等,2017)可能作为人类耳鸣的潜在客观标志物。现有fNIRS技术的局限在于使用传统的帽子限制(到大脑外皮层)穿透皮肤和颅骨的IR深度?录音配置。由于耳鸣中的大脑变化可能延伸到更深的皮质/皮质下区域,因此有必要改善IR脑渗透以测量这些区域中的假定耳鸣标记物。该项目的主要目标是通过使用fNIRS扩展脑监测,通过自然开口(耳道)调整颅骨深处的红外源和探测器对。使用这种高度创新的方法将fNIRS探针更深入地放入颅骨,将大脑监视扩展到以前从未用fNIRS测量过的区域。本申请的目的不是识别/揭示耳鸣的潜在机制,而是使用人类耳鸣中公布的变化(血液动力学反应和连接性)作为验证适应探针的平台。为了验证我们的中心假设,即适应耳道的fNIRS技术将扩大脑监测范围,超越传统探针,并提供可量化的相关性(血液动力学率和脑连接性增加)以及潜在的其他脑部疾病,可以利用两个特定的目标。目标1将使用同时?cap来测量人耳鸣和正常对照的变化?探针和适应的fNIRS探针,其包含通过耳道放置在腹侧/内侧颞叶上的IR源或检测器。在这里,我们期望验证适应的探针,以确定与?cap相比的功效/最佳参数?探针,以改善解剖定位和扩大脑监测。目标2将使用先进的探头,该探头将IR光源和探测器保留在单纤维上,用于耳道放置。这里的目标是优化这种单纤维来测量血液动力学变化和大脑连接,作为一种独立的技术,不依赖于?cap?探头。经过验证,单纤维探针可以适应其他临床问题(即通过前颅底/鼻腔进行额叶研究),或用于研究现有fNIRS技术无法测量的大脑区域。拟议的fNIRS探针适应可以扩展脑皮质监测以外的大脑监测,并以非侵入性,便携的方式提供关于脑部疾病的关键信息,包括耳鸣,以应用于未来的R01应用。

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