Dermatomal Mapping with Spinal Cord Functional Magnetic Resonance Imaging

项目摘要/摘要 神经根病是一种常见的脊椎疾病，由脊神经根受压和刺激引起， 导致感觉障碍、肌肉无力和疼痛。皮肤图是临床的一个重要组成部分。 检查并提供有关皮肤感觉和神经系统之间的对应关系的信息。 皮肤感觉缺陷可以帮助定位脊髓疾病中的神经损伤并指导治疗。 然而，皮肤病地图是有限的-它们在神经解剖地图(脊神经， 背根神经节、背角或脊髓(SC)节段)，呈左右对称，无性别 差异，没有提供关于受试者之间可变性的信息，还有待验证。SC功能 磁共振成像(FMRI)可以对人体SC活动进行无创性的在体空间标测。 在这里，我们将使用SC fMRI来测试皮肤瘤图的中心假设，调查 神经损伤对SC感觉加工的影响，发展SC感觉活动的标志物，并检验其诊断 改进SC fMRI方法在神经根型颈椎病中的应用价值要做到这一点，我们将首先加强 我们现有的SC功能磁共振成像方法通过构建研究级通道头颈线圈，测试了一种新颖的空间 归一化方法，说明了SC段的定位，并探索了曲面的使用 肌电监测和消除功能磁共振实验中与运动相关的噪音。我们将比较 改进的SC fMRI方法与我们目前可操作的方法相比，同时表征了SC相关性 使用右侧第三指的电皮肤感觉刺激对感觉刺激强度进行编码 30例健康志愿者手(C7皮肤刀)，年龄20~79岁，女15例，男15例。然后使用 增强的SC功能磁共振成像方法，我们将定量绘制120例右脑SC活动的空间分布。 手部HV(20-79岁，女性60例，男性60例，按年龄分层) 刺激左侧和右侧的第一、第三和第五指(分别为C6、C7和C8皮肤体) 举起手来。我们将开发SC活动空间分布的概率图，评估优劣 活动定位，对比左右刺激和性别之间的活动，并量化- 研究对象的可变性。我们将使用机器学习算法来开发标准化的SC感官标记 预测刺激部位。最后，40例右利手患者右侧颈7神经根病变(30- 79岁、20名女性、20名男性)和40名年龄和性别匹配的HV也将接受相同的SC功能磁共振成像 实验，我们将调查群体中SC活动的差异，以揭示神经损伤的影响 并评价SC感觉标记物的诊断价值。完成我们的 AIMS将改进SC fMRI方法，验证/驳斥皮瘤图的中心假设，以更好地提供信息 它们在临床实践中的应用，促进了我们对健康和损伤患者SC感觉加工的科学认识 并提供了基于MRI的颈神经根病诊断标记物的初步验证。

PROJECT SUMMARY/ABSTRACT Radiculopathy is a common spinal condition resulting from compression and irritation of the spinal nerve roots, leading to sensory deficits, muscle weakness, and pain. Dermatomal maps are a key component of the clinical exam and provide information on the correspondence between cutaneous sensations and the nervous system. Dermatomal sensory deficits can help localize neurological injury in spinal conditions and guide treatment. Dermatomal maps, however, are limited—they contain uncertainty in the neuroanatomy mapped (spinal nerve, dorsal root ganglion, dorsal horn, or spinal cord (SC) segment), assume left-right symmetry and no sex differences, provide no information on between-subject variability, and remain to be validated. SC functional magnetic resonance imaging (fMRI) permits the non-invasive in vivo spatial mapping of human SC activity. Here we will use SC fMRI to test hypotheses central to dermatomal maps, investigate the effects of neurological injury on SC sensory processing, develop markers of SC sensory activity, and test their diagnostic value in cervical radiculopathy while improving our SC fMRI methods. To accomplish this, we will first enhance our existing SC fMRI methods by building a research-grade 64-channel head-neck coil, testing a novel spatial normalization method that accounts for SC segment location, and exploring the use of surface electromyography to monitor and remove motor-related noise during fMRI experiments. We will compare the improved SC fMRI methods against our currently operational methods while characterizing the SC correlates of sensory stimulus intensity encoding using electrocutaneous sensory stimulation of the third digit of the right hand (C7 dermatome) in 30 healthy volunteers (HV) (20-79 years old, 15 females, 15 males). Then using the enhanced SC fMRI methods, we will quantitatively map the spatial distribution of SC activity in 120 right- handed HVs (20-79 years old, 60 females, 60 males, stratified by age) during electrocutaneous sensory stimulation of the first, third, and fifth digits (C6, C7, and C8 dermatomes, respectively) of the left and right hands. We will develop probabilistic maps of the spatial distribution of SC activity, assess the superior-inferior localization of activity, contrast the activity between left and right stimulation and sexes, and quantify between- subject variability. We will use machine learning algorithms to develop normative SC sensory markers by predicting the stimulation site. Finally, 40 right-handed patients with right-sided C7 cervical radiculopathy (30– 79 years old, 20 females, 20 males) and 40 age- and sex-matched HVs will also undergo the same SC fMRI experiment, and we will investigate group differences in SC activity to uncover the effects of neurological injury on SC sensory processing and then assess the diagnostic value of the SC sensory markers. Completing our aims will improve SC fMRI methods, validate/refute hypotheses central to dermatomal maps to better inform their use in clinical practice, advance our scientific knowledge of SC sensory processing in healthy and injured states, and provide preliminary validation of MRI-based diagnostic markers for cervical radiculopathy.