Prevention and Treatment of Noise-Induced Tinnitus.

摘要

The studies examined mechanism based therapies to prevent or treat noise induced tinnitus. Our studies showed a military relevant small arms fire-like noise will induce tinnitus in approximately 33% of exposed rats. There is increasing evidence that noise induced loss of connections between sensory cells and the auditory nerve can induce tinnitus. Studies therefore examined if anti-oxidant and or anti-excitotoxicity therapy could decrease the loss of these connections from the small arms fire-like noise and if so, prevent tinnitus. Results first showed that a combination of Piribedil and Memantine (anti-excitoxicity) plus Vitamins A, C and E plus magnesium (anti-oxidants) provided protection, with significantly reduced loss of connections. Studies next tested if this treatment would then reduce tinnitus. The results showed decreased incidence of tinnitus following noise in the group receiving this combined treatment prior to the noise compared to groups of noise exposed animals without treatment. The next set of studies targeted the auditory brain stem and treatment rather than prevention. Studies tested treatment with sarcosine, which increases inhibitory influence by decreasing uptake of glycine from synapses. The studies found that sarsosine given shortly after the noise exposure or shortly before the noise did not influence the incidence of tinnitus. However, sarcosine when provided over a 4 - 6 week period following the noise showed a trend towards inducing recovery in animals that developed tinnitus. Future studies will be needed to follow up on this finding.