Evalution of Vestibular Function in Meniere's Disease

描述（由申请人提供）：梅尼埃病由于其破坏性的眩晕和听力损失的发作而导致相当大的发病率和生产力损失。本研究旨在描述梅尼埃病如何影响内耳平衡器官的功能，以及人类内耳如何对日益普遍使用的鼓室内庆大霉素治疗梅尼埃病作出反应。最大限度地减少听力损失的风险，同时实现眩晕控制是理想的目标。定量测试的角度和平移前庭眼反射（VOR）的高频，高加速度刺激和主观视觉垂直和水平的措施提供生理措施的半规管和椭圆囊的功能。这些数据将与临床结果相关联，希望为控制梅尼埃病的眩晕需要多少前庭功能消融提供明确的指导。特别是，将与接受迷路或前庭神经手术破坏的受试者的数据进行比较，以确定是否需要完全消融。动物模型的结果表明，这些治疗之间的关键区别是，自发性前庭传入放电后鼓室庆大霉素，但不是手术前庭消融后保持。这些治疗之间前庭反应的差异可能进一步阐明前庭系统中自发放电的作用。同样，将检查鼓室内庆大霉素与手术前庭破坏后纠正前庭反射缺陷的眼球运动之间的差异，以阐明保留的自发放电在前庭补偿和感觉运动替代策略中的作用。对鼓室内庆大霉素治疗的受试者进行长期随访测试，将显示病变是否为永久性的，如果不是，前庭功能的恢复是否预示着眩晕的复发。比较鼓室内庆大霉素注射后VOR的角度和平移缺陷，可以证明椭圆囊是否比半规管对鼓室内庆大霉素的敏感性低。

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.