The Pathogenesis of Hearing Loss. Things We Can Learn from Animals

We should call sensorineural hearing loss a spectrum disorder (SNHL SD) just as we do with auditory neuropathy, understanding the multiple etiologies and manifestations of the hearing loss. This lecture will review studies in animal models of SNHL in which multiple causes of hearing loss are explored (including drug toxicity, genetic mutations, old age, viral infection, cochlear hypoxia, acoustic trauma etc.) and that cause distinctively different types of structural damage (e.g. to stria vascularis, to outer haircells, to the stereocilia, to the inner haircell synapses and spiral ganglion). The talk will outline how these different types of cochlear lesion result in different forms of functional deficit. Given the extremely wide variation in types of SNHL, why do we rarely attempt a sub-classification? From investigative clinical studies and animal model research we can start to predict deficits based on the cause and an understanding the likely substrate of anatomical damage. If we pay more attention to aetiology we can distinguish classes or sub-types of SNHL. This in turn will narrow our focus on treatment and rehabilitation strategy and provide more accurate prognosis.

Learning Objectives:

• To explore the anatomical damage to the cochlea and associated functional deficits in a range of animal models of sensorineural hearing loss (SNHL).

• To provide a greater understanding of different sub-types of SNHL based on structural deficits and on etiology.

• To encourage the development and clinical use of a sub-classification scheme for SNHL