Age-related change of the neuronal number in the human medial vestibular nucleus: a stereological investigation.

An unbiased stereological method was used to assess the effect of aging on the number of neurons in the human medial vestibular nucleus. We studied 13 normal brainstem specimens (age at death from 40 to 93 years) that were part of a prior study that counted neuronal profiles and used a correction factor to estimate the number of neurons in the human vestibular nucleus. On average, we found 151.10(3) (CV = 0.15) neurons in the medial vestibular nucleus, which is 18% more than that in the prior study. Regression analysis showed a significant decrease in the number of neurons with aging. This age-related neuronal loss in the vestibular nucleus could have important functional implications regarding the well-known deterioration in balance that occurs with aging.