Presbyacusis--loss of neurons in the human cochlear nuclei.

In six patients suffering from presbyacusis, light microscopical studies and calculations of the population of neurons were performed. A loss of neurons was found in 12 ventral and dorsal cochlear nuclei. The average loss of neurons was about 50 per cent, compared to the numbers calculated in presumably normal hearing individuals by other investigators. This loss of neurons was statistically significant. The results show that not only the cochlea but also the cochlear nuclei are involved in the degenerative processes occurring in advancing age.