Altered auditory brainstem evoked responses in the ferret model for Reye's syndrome

The effects of influenza B, aspirin and hyperammonemia on the functional integrity of the cochlea were examined using the ferret model for Reye's syndrome. Auditory brainstem evoked responses (ABR) were recorded from treated ferrets and compared to those recorded from controls. Delayed latencies of all waves, as well as increased I-IV Interwave latencies were observed in recordings from treated ferrets. Importantly, the latencies of Wave I, nerve generator potential from the eighth nerve, and Wave IV, response potential from the brainstem nuclei, increased on Days 3 and 5 of the study. However, recorded ABR from treated ferrets on Day 10 showed that while the latencies of Wave IV were approximate to those of controls, Wave I remained delayed. These results suggest that systemic effects of influenza B, aspirin and hyperammonemia may lead acutely to both peripheral and central auditory dysfunction, and that the functional integrity of the central auditory system may recover more quickly than that of the peripheral system. Furthermore, these results suggest that such effects may lead to acute transient hearing impairment in patients with Reye's syndrome.