Linking trigeminal and visual sensitivity in migraine

项目摘要 过敏症是偏头痛的典型特征，伴随着光(畏光)和触摸(面部)的疼痛 头痛)出现在发作期头痛，有时也出现在发作期。头痛 偏头痛患者三叉神经信号的fl增强可能与面部痛觉异常有关。这个相同的机制可能 这也是恐光症的原因。视网膜神经节细胞的一部分表达光色素黑素， 使它们具有内在的光敏性(“ipRGC”)。啮齿动物研究表明，这些细胞投射到 丘脑和脑干部位，也接受三叉神经的躯体感觉输入，提供一个点 躯体和视觉信号的神经相互作用。这种有希望的生物模型--从动物身上衍生出来的 研究--说明人类偏头痛感觉症状的特点？为了探讨这个问题，我们 需要一个量化的假设检验框架，以及一个可重复的、客观的三叉神经测量 对超阈值刺激的敏感性。我们建议创建这个实验平台并测试以下关键要素 三叉神经超敏反应模型。我们已经用Modifi开发了一个商用的“Blink ReflExeter”来测量 角膜闪烁参数Reflex到分级喷气刺激。我们将测试(目标1)偏头痛患者 发作间期畏光与无头痛对照相比，在以下方面有系统性的组间差异 此Refl的斜率存在敏感函数或在不适报告中。此外，我们将确定(目标2)是否 同时光刺激中的渐变与产生这些光的喷气强度相互作用 显性和重fl兴奋反应，从而测试视觉和三叉神经体细胞的解剖会聚 信号。

Project Summary Hypersensitivity is a canonical feature of migraine, with pain from light (photophobia) and touch (facial allodynia) present during the ictal headache phase, and sometimes the inter-ictal period as well. Headache and facial allodynia appear to reflect potentiation of trigeminal signals in migraine. This same mechanism may account for photophobia as well. A subset of retinal ganglion cells express the photopigment melanopsin, rendering them intrinsically photosensitive (the “ipRGCs”). Rodent studies show that these cells project to thalamic and brainstem sites that also receive somatosensory input from the trigeminal nerve, providing a point of neural interaction of somatic and visual signals. Can this promising biological model—derived in animal studies—account for the properties of sensory symptoms in human migraine? To explore this question, we require a quantitative hypothesis testing framework, and a reproducible, objective measure of trigeminal sensitivity to supra-threshold stimuli. We propose to create this experimental platform and test key elements of the trigeminal hypersensitivity model. We have modified a commercial “blink reflexometer” to measure parameters of the corneal blink reflex to graded air-puff stimulation. We will test (Aim 1) if people with migraine and inter-ictal photophobia, as compared to headache-free controls, have a systematic, group difference in the slope of this reflexive sensitivity function or in a report of discomfort. Further, we will determine (Aim 2) if graded variation in a simultaneous light stimulus interacts with air-puff intensity in the production of these explicit and reflexive responses, thereby testing for anatomical convergence of visual and trigeminal somatic signals.