Heman-Ackah, Selena2015-11-062015-11-062015-07https://hdl.handle.net/11299/175462University of Minnesota Ph.D. dissertation. July 2015. Major: Otolaryngology. Advisors: Rick Odland, Steven Juhn. 1 computer file (PDF); vi, 159 pages.Presbycusis, or age-related hearing loss, is one of the most common conditions impacting the aging population, characterized by progressive sensorineural hearing loss and impairment in speech discrimination capability. Current management is limited to auditory rehabilitation with the assistance of hearing aids or cochlear implants in advanced cases. There currently exists no effective treatments available for the prevention or attenuation of hearing loss in association with presbycusis. The purpose of this study was to evaluate the potential of a combination antioxidant therapy in the prevention and treatment of presbycusis. The objectives of this randomized controlled animal study were to: identify an anesthetic which would allow for repeated reliable longitudinal auditory brainstem response (ABR) testing in a mouse model, identify a combination antioxidant which targets multiple sites within the oxidative pathway and assess its ability to prevent age-related threshold shifts and to arrest further age-related threshold shifts in C57BL6 mice with documented age-related threshold shifts. Mice were randomized to one of three groups: an early treatment group, a late treatment group, or a control group. The treatment groups of mice were fed with a combination agent comprised 6 antioxidant agents. ABRs were performed comparing Avertin to ketamine/xylazine with no significant difference in test thresholds. ABR thresholds were recorded at baseline and every 3 months following initiation of treatment in the 3 randomized groups. Threshold shifts from baseline were decreased in the treatment groups when compared to the control group at all tested frequencies and time points.Presbycusis, or age-related hearing loss, is one of the most common conditions impacting the aging population, characterized by progressive sensorineural hearing loss and impairment in speech discrimination capability. Current management is limited to auditory rehabilitation with the assistance of hearing aids or cochlear implants in advanced cases. There currently exists no effective treatments available for the prevention or attenuation of hearing loss in association with presbycusis. The purpose of this study was to evaluate the potential of a combination antioxidant therapy in the prevention and treatment of presbycusis. The objectives of this randomized controlled animal study were to: identify an anesthetic which would allow for repeated reliable longitudinal auditory brainstem response (ABR) testing in a mouse model, identify a combination antioxidant which targets multiple sites within the oxidative pathway and assess its ability to prevent age-related threshold shifts and to arrest further age-related threshold shifts in C57BL6 mice with documented age-related threshold shifts. Mice were randomized to one of three groups: an early treatment group, a late treatment group, or a control group. The treatment groups of mice were fed with a combination agent comprised 6 antioxidant agents. ABRs were performed comparing Avertin to ketamine/xylazine with no significant difference in test thresholds. ABR thresholds were recorded at baseline and every 3 months following initiation of treatment in the 3 randomized groups. Threshold shifts from baseline were decreased in the treatment groups when compared to the control group at all tested frequencies and time points.enage related hearing lossantioxidantoxidative injurypresbycusispreventiontreatmentThesis or Dissertation