Damage and Repair in the Inner Ear: From Experimental Research to Clinical Aspects

In this thesis, fundamental research is performed on the sensory epithelia of the inner ear in guinea pigs and mice. The outcomes of these fundamental studies are discussed in relation to clinical vestibular research. Methods to efficiently, repeatedly and reproducibly damage the sensory epithelia of both the otolith organs and cochlea have been described in chapters 2 (guinea pigs; cochlear and vestibular damage), 3 and 4 (mice; cochlear damage). These methods are crucial for studying regeneration and/or recovery phenomena in the otolith organs or cochlea in the future. Furthermore, these animal models of vestibular disease or deafness may facilitate in studies of regeneration induction or application of tissue-engineering techniques. Using one of these methods the regenerative capacities of the vestibular sensory epithelia were quantified in the guinea pig, which provided only limited evidence for recovery (chapter 5). These animal data speak in favor of intratympanic gentamicin treatment in patients with Ménière’s disease when gentamicin is used as a treatment modality. This modality was studied in a randomized placebo controlled design in chapter 6. Gentamicin had a positive effect on incapacitating dizziness complaints in patients but one of the dosages of gentamicin used inflicted more hearing loss than was accepted in the protocol. Therefore, this study was ended prematurely.