Age-related Changes in Human Laryngeal Nerves

Objectives: We sought to perform a morphometric analysis of myelinated fibers from laryngeal nerves with the aim of verifying quantitative changes due to the aging process.

Methods: A 1-cm fragment was collected from the superior laryngeal nerves and recurrent laryngeal nerves from 12 cadavers during autopsy. The sample was divided in two groups: an adult group (aged <60 years) and an elderly group (aged > or =60 years).

Results: The total number of myelinated fibers from the superior laryngeal nerves was similar in both groups (adult group = 9017 +/- 1692, elderly group = 7918 +/- 1624; P = 0.79). The adult group had a higher total number of myelinated fibers in the recurrent laryngeal nerves than that of the elderly group (adult group = 3276 +/- 383, elderly group = 2381 +/- 669; P = 0.005), as well as a higher total number of fibers in the laryngeal nerves (both superior and recurrent) than the elderly group (P = 0.02).

Conclusions: The adult group has a higher total number of myelinated fibers in the laryngeal nerves than the elderly group.