Oculomotor Tests of Otolith Function Using Human Centrifugation

内耳平衡系统(前庭系统)功能障碍的影响范围从轻微的短暂眩晕到几乎完全丧失工作能力：当患者感觉不稳定时，他们的姿势不稳定，他们的视力不稳定。为了指导适当的治疗和康复，需要进行诊断测试，以确定功能障碍是由于大脑问题还是内耳问题，以及如果是耳朵问题-内耳系统的哪个部分受到影响。通过将基础研究与临床可行的方法相结合，我和我的同事在NH和MRC的支持下，开发了一些目前可用的最广泛使用的平衡功能临床测试(参见Halmagyi，Cremer和Curthoys 2003)。在这个项目中，我寻求继续开发一种对平衡系统的一部分(椭圆斑)的测试，对于这些测试，几乎没有可接受的测试。为此，我将使用悉尼大学和RPA医院提供的独特设施，向健康受试者和已知前庭缺失的患者提供受控刺激(线性加速)，并使用计算机图像处理技术精确测量他们对这些刺激的眼动反应。这些实验将检验关于前庭系统的一部分--椭圆体黄斑--如何工作和控制眼睛运动的假说。单眼运动反应，在保持侧滚头部倾斜(向左或向右)过程中，眼睛围绕视线滚动(称为眼扭转)，可能是由于平衡感受器的两个区域：椭圆体和球囊黄斑的联合激活。由于最近我们在两名正常受试者身上进行了一项直接测试，我们认为这一假说应该在已知前庭损失的受试者和患者身上进行彻底的重新测试，这样做可以提供对耳石功能的新理解，从而可能导致新的临床测试。

The effects of dysfunction of the balance system of the inner ear (the vestibular system) can range from mild brief episodes of dizziness to almost complete incapacitation: where the patient feels unstable, their posture is unstable, their vision is unstable. In order to guide appropriate treatment and rehabilitation, diagnostic tests are needed to identify whether the dysfunction is due to a brain problem or a problem in the inner ear, and if an ear problem - which part of the inner ear system is affected. By combining basic research with clinically feasible methods my colleagues and I have, with NH and MRC support, developed some of the most widely used clinical tests of balance function available today (see Halmagyi, Cremer and Curthoys 2003 for a review). In this Project I seek to continue the development of a test of part of the balance system (the utricular macula) for which there are few acceptable tests. I will do that by using the unique facilities available at Sydney University and RPA Hospital, presenting controlled stimuli (linear accelerations) to healthy human subjects and patients with known vestibular losses, and measuring precisely their eye movement responses to these stimuli using computerized image processing techniques. The experiments will test an hypothesis about how part of the vestibular system, the utricular macula, works and controls eye movements. One eye movement response, rolling of the eye around the line of sight (called ocular torsion) during maintained roll head-tilts (to the patients left or right) may be due to the joint activation of two regions of the balance receptors: the utricular and saccular maculae. As a result of a recent direct test we have managed to conduct on two normal subjects, we think that hypothesis should be thoroughly re-tested on subjects and patients with known vestibular losses and in doing so provide new understanding of otolith function which may lead to new clinical tests.