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Case Reports
. 2021 May 23;11(6):686.
doi: 10.3390/brainsci11060686.

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

Tom Wai-Hin Chung  1 , Hui Zhang  2 , Fergus Kai-Chuen Wong  3 , Siddharth Sridhar  1   4   5 , Kwok-Hung Chan  1 , Vincent Chi-Chung Cheng  1 , Kwok-Yung Yuen  1   4   5   6 , Ivan Fan-Ngai Hung  4   7 , Henry Ka-Fung Mak  2   8   9
Affiliations
Case Reports

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

Tom Wai-Hin Chung et al. Brain Sci. .

Abstract

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%)].

Keywords: COVID-19; olfactory dysfunction; resting-state fMRI; smell training; vitamin A.

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Conflict of interest statement

S.S. has received speaker’s honoraria from Sanofi-Aventis Hong Kong Limited and Abbott laboratories Limited. The other authors declare no conflicts of interest.

Figures

Figure 1
Figure 1
Three-dimensional (3D) representations of the primary and secondary olfactory cortical network (OCN) areas.
Figure 2
Figure 2
Olfactory network functional connectivity (FC) images using the left caudate as the seed region, as represented in the (A) sagittal, (B) coronal, and (C) axial planes.
See this image and copyright information in PMC

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