Neurosensory Rehabilitation and Olfactory Network Recovery in Covid-19-related Olfactory Dysfunction

• Main Authors: Tom Wai-Hin Chung, Hui Zhang, Fergus Kai-Chuen Wong, Siddharth Sridhar, Kwok-Hung Chan, Vincent Chi-Chung Cheng, Kwok-Yung Yuen, Ivan Fan-Ngai Hung, Henry Ka-Fung Mak
• Format: Article
• Language: English
• Published: MDPI AG 2021-05-01
• Series: Brain Sciences
• Subjects: COVID-19; olfactory dysfunction; vitamin A; smell training; resting-state fMRI
• Online Access: https://www.mdpi.com/2076-3425/11/6/686
• ISSN: 2076-3425

Non-conductive olfactory dysfunction (OD) is an important extra-pulmonary manifestation of coronavirus disease 2019 (COVID-19). Olfactory bulb (OB) volume loss and olfactory network functional connectivity (FC) defects were identified in two patients suffering from prolonged COVID-19-related OD. One patient received olfactory treatment (OT) by the combination of oral vitamin A and smell training via the novel electronic portable aromatic rehabilitation (EPAR) diffusers. After four-weeks of OT, clinical recuperation of smell was correlated with interval increase of bilateral OB volumes [right: 22.5 mm³ to 49.5 mm³ (120%), left: 37.5 mm³ to 42 mm³ (12%)] and improvement of mean olfactory FC [0.09 to 0.15 (66.6%)].