Effects of functional endoscopic sinus surgery on olfactory and trigeminal function in chronic rhinosinusitis with...

Chronic rhinosinusitis (CRS) with and without nasal polyps has a prevalence of around 10%, being one of the most common chronic diseases in Europe. It is characterized by a wide range of symptoms leading to a high individual, clinical and socioeconomic burden due to loss of productivity of individual patients and challenging therapeutic processes. This study aimed to investigate the effects of functional endoscopic sinus surgery (FESS) on olfactory function and associated quality of life of CRS patients, particularly regarding postoperative differences in neuronal processes. Using psychophysical and electrophysiological tools, the goal was to quantify postoperative changes to predict the neuronal functions related to olfactory improvements after FESS and ultimately provide better therapeutic recommendations in the future. Twenty-five CRS patients with nasal polyps aged from 30 to 64 years (CRS group) and 20 healthy controls aged from 23 to 54 years (control group) participated in this study. Both groups were tested twice (interval 3 to 6 months), with the first examination of the patients taking place a few days before surgery. Testing included questionnaires (medical history including self-ratings of olfactory function and nasal breathing, SNOT-20 questionnaire), psychophysical methods (Sniffin Sticks for olfactory function [TDI score], Peak Nasal Inspiratory Flow) and electrophysiological methods (olfactory and trigeminal event-related potentials). CRS group patients were also subjected to preoperative clinical examination and preoperative CT-scans. While the CRS group improved in terms of self-ratings of the sense of smell and TDI scores, as well as nasal breathing and quality of life, the control group did not show major longitudinal differences. In addition, electrophysiological measures suggested that trigeminal sensitivity decreased after surgery. CRS patients showed benefits from surgery in terms of olfaction, nasal breathing and quality of life, at least 3-6 months after the intervention. Interestingly, electrophysiological measurements suggested a postoperative decrease of trigeminal sensitivity.