Introduction: The larynx plays a primal role in the maintenance of life. The perfect integration between its afferent and efferent pathways, provided by the superior laryngeal nerve (SLN) and by recurrent laryngeal nerve, avoids foreign body aspiration and maintains the intrinsic laryngeal muscle tone by means of the reflexes elicited by the mucus wave movements. Aspirations and pneumonias as well as dysphonias, more frequently found among the elderly, might be triggered by disorders affecting these same neural pathways. Aim: The aim of this study was to assess the histomorphometryc characteristics of the SLN in elderly subjects in comparison to adults. Materials and method: A fragment of each side of the superior laryngeal nerve was obtained during necropsy examination and two different age groups were gathered. One group was made up of 5 adult subjects averaging 39,6 years of age and one was constituted of 6 elderly subjects averaging 71,7 years of age. The material was examined in a 40x objective lens microscope, connected to a computerized image analyzing system and the nerve’s main parameters as the myelinated fibers frequency, fiber density per mm2, and intraperineural area were found. Results: A statistically significant reduction of the smaller myelinated fibers (1 and 2 mm) was observed in the Elderly group. No difference was noted in the myelinated fiber frequency of the left/right sides. Conclusion: Being the low diameter superior laryngeal nerve myelinated fibers functionally responsible for the reflex of glotic closure, their reduction in the elderly subjects may be related, alongside with other factors, to a greater predisposition to aspiration and voice disorders.
larynx; superior laryngeal nerve; dysphagia; voice disorders
