Evalution of Vestibular Function in Meniere's Disease

描述(申请人提供)：梅尼埃病导致相当大的发病率和生产力损失，因为它的破坏性发作眩晕和听力损失。这项研究旨在描述梅尼埃病如何影响内耳平衡器官的功能，以及人类内耳对日益普遍使用的鼓室内庆大霉素治疗梅尼埃病的反应。通过这种治疗将听力损失的风险降至最低，同时实现眩晕控制是理想的目标。定量测试对高频、高加速度刺激的角度和平移前庭眼球反射(VOR)，以及主观视觉垂直和水平测量，为半规管和椭圆形的功能提供生理学测量。这些数据将与临床结果相关联，希望为梅尼埃病患者控制眩晕需要多少前庭功能消融提供明确的指导。特别是，将与接受手术破坏迷路或前庭神经的受试者的数据进行比较，以确定是否有必要完全消融。动物模型的研究结果表明，这些治疗方法之间的关键区别在于，在鼓室内注射庆大霉素后，自发的前庭传入放电得以维持，但在外科前庭消融术后则不能。这些治疗之间前庭反应的差异可能进一步阐明自发放电在前庭系统中的作用。同样，我们将研究鼓室内注射庆大霉素后矫正前庭反射缺陷的眼球运动与手术破坏前庭的眼球运动之间的差异，以阐明保留自发放电在前庭代偿和感觉运动替代策略中所起的作用。在接受鼓室内庆大霉素治疗的受试者中进行的长期随访测试将显示病变是否为永久性的，如果不是，则前庭功能的恢复是否预示着眩晕的复发。比较鼓室内注射庆大霉素后的角度VOR和平移VOR缺陷，应该证明椭圆囊是否比半规管对庆大霉素更不敏感。

DESCRIPTION (provided by applicant): Meniere's disease causes considerable morbidity and lost productivity because of its devastating attacks of vertigo and hearing loss. This study aims to characterize how Meniere's disease affects the function of the balance organs of the inner ear and how the human inner ear responds to the increasingly common use of intratympanic gentamicin for the treatment of Meniere's disease. Minimizing the risk of hearing loss with this treatment while achieving vertigo control is the ideal goal. Quantitative testing of the angular and translational vestibulo-ocular reflexes (VOR) in response to high-frequency, high-acceleration stimuli and measures of subjective visual vertical and horizontal provide physiologic measures of the function of the semicircular canals and utricle. These data will be correlated with clinical outcomes in hopes of providing clear guidelines as to how much ablation of vestibular function is necessary to control vertigo in Meniere's disease. In particular, comparisons will be made to data from subjects who underwent surgical destruction of the labyrinth or vestibular nerve in order to determine if complete ablation is necessary or not. Findings from animal models suggest that the key difference between these treatments is that spontaneous vestibular afferent firing is maintained after intratympanic gentamicin but not after surgical vestibular ablation. Differences in the vestibular responses between these treatments may further illuminate the role of spontaneous firing in the vestibular system. Likewise, differences between the eye movements that correct for vestibular reflex deficits after intratympanic gentamicin versus surgical vestibular destruction will be examined to illuminate the role that retained spontaneous firing plays in vestibular compensation and sensorimotor substitution strategies. Long-term follow-up testing in subjects treated with intratympanic gentamicin will show whether or not the lesion is permanent and, if it is not, whether recovery of vestibular function predicts recurrence of vertigo. Comparisons of angular and translational VOR deficits after intratympanic gentamicin should demonstrate whether or not the utricle is less susceptible than the semicircular canals to intratympanic gentamicin.