Investigation of the topographical differences in somatosensory sensitivity of the human nasal mucosa.

Abstract

Previous investigations in humans suggest topographical differences in intranasal trigeminal chemosensitivity with the highest sensitivity in the anterior part. The present study aimed to investigate whether different sites in the human nasal mucosa react differently to unspecific electrical stimuli. Participants were 50 young, healthy volunteers (24 men, 26 women; age 22-38 years). Detection and pain threshold of electrical trigeminal stimuli were investigated at 5 different sites: anterior septum, posterior septum, inferior turbinate, middle turbinate and anterior lateral wall. In healthy subjects, a significantly higher trigeminal sensitivity was found at the anterior parts of the nose compared to the posterior part. There was a similar distribution pattern of the sensitivity for detection and pain thresholds. Results suggest that there are consistent topographical differences in the arrangement of trigeminal receptors of the human nasal cavity; highest somatosensory sensitivity seems to be located in the anterior part. This finding is compatible with the idea that the trigeminal system acts as a sentinel of the human airways with regard to toxic agents.