Oculomotor Tests of Otolith Function Using Human Centrifugation

内耳平衡系统（前庭系统）功能障碍的影响可以从轻微的短暂头晕发作到几乎完全丧失能力：患者感到不稳定，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，以确定这种功能障碍是由于大脑问题还是内耳问题，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，在NH和MRC的支持下，我和我的同事开发了一些目前最广泛使用的平衡功能临床测试（见Halmagyi， Cremer和Curthoys 2003年的综述）。在这个项目中，我试图继续开发一种测试平衡系统的一部分（黄斑），目前很少有可接受的测试。我将利用悉尼大学和RPA医院提供的独特设备，向健康的人类受试者和已知前庭功能丧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。这些实验将检验一种假设，即前庭系统的一部分，即黄斑，是如何工作和控制眼球运动的。一种眼动反应，在保持头向左或向右倾斜的过程中，眼球围绕视线转动（称为眼扭转），可能是由于平衡受体的两个区域：脑室和囊状黄斑的联合激活。根据我们最近在两名正常受试者身上进行的直接测试，我们认为应该在已知前庭功能丧失的受试者和患者身上彻底地重新测试这一假设，这样做可以提供对耳石功能的新认识，从而可能导致新的临床试验。

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.