OLFACTORY TRAINING EFFICIENCY IN POST-COVID-19 PERSISTENT OLFACTORY DISORDERS

ABSTRACTBackgroundPersistent post-viral olfactory disorders (PPVOD) are widely reported after a COVID-19 and estimate to 30% one year after infection. Parosmias are the main qualitative dysosmia associated with olfaction recovery. No treatment is, to date, significantly efficient on PPVOD except olfactory training (OT). The main objective of this work was to evaluate OT efficiency on post-COVID-19 PPVOD.MethodsConsecutive patients consulting to the ENT department with post-COVID-19 PPVOD were included after mainly clinical examination, the complete Sniffin’ Stick Test (TDI), the short version of the Questionnaire of olfactory disorders and the SF-36. Patients were trained to practice a self-olfactory training (professional manufactured olfactory training kit) twice a day for 6 months before coming back and undergo the same complete evaluation.ResultsForty-three patients were included and performed 3,5 months of OT in average. There was a significant improvement in the mean TDI score increasing from 24,7 (±8,9) before the OT to 30,9 (±9,8) (p<0,001). Parosmias increased significantly from 8 (18,6%) to 27 (62.8%) (p<0,001). Based on normative data divided by sex and age, a significant increase in the number of normosmic participants was only found for the Threshold values (p<0,001). Specific and general olfaction-related quality of life improved after the OT.ConclusionsOT seems to be efficient in post-COVID-19 PPVOD, probably on the peripheral regenerative part of the olfactory recovery. Future therapeutic strategies may focus on the central aspects of the post-COVID-19 PPVOD.