COVID-19-induced anosmia associated with olfactory bulb atrophy

Andrew Chiu, Nancy Fischbein, Max Wintermark, Greg Zaharchuk, Paul T Yun, Michael Zeineh, Andrew Chiu, Nancy Fischbein, Max Wintermark, Greg Zaharchuk, Paul T Yun, Michael Zeineh

Abstract

As the global COVID-19 pandemic evolves, our knowledge of the respiratory and non-respiratory symptoms continues to grow. One such symptom, anosmia, may be a neurologic marker of coronavirus infection and the initial presentation of infected patients. Because this symptom is not routinely investigated by imaging, there is conflicting literature on neuroimaging abnormalities related to COVID-19-related anosmia. We present a novel case of COVID-19 anosmia with definitive olfactory bulb atrophy compared with pre-COVID imaging. The patient had prior MR imaging related to a history of prolactinoma that provided baseline volumes of her olfactory bulbs. After a positive diagnosis of COVID-19 and approximately 2 months duration of anosmia, an MRI was performed that showed clear interval olfactory bulb atrophy. This diagnostic finding is of prognostic importance and indicates that the olfactory entry point to the brain should be further investigated to improve our understanding of COVID infectious pathophysiology.

Keywords: Anosmia; COVID-19; Olfactory bulb.

Conflict of interest statement

The authors declare that they have no conflict of interest. Specifically, Dr. Chiu, Dr. Fischbein, Dr. Zaharchuk, and Dr. Zeineh have nothing to disclose. Dr. Yun reports personal fees from Intersect ENT, outside the submitted work.

Figures

Fig. 1
Fig. 1
Coronal T2 fat-suppressed 3-mm thick images a before and b after diagnosis of COVID-19. Notice the smaller size of olfactory bulbs (anatomic left in yellow arrows) within the olfactory grooves, as evidenced by increased CSF (blue arrows) above the nerve. c Timecourse of patient’s olfactory bulb size over 5 years, with a pronounced decrease on the most recent timepoint on the far right, occurring after diagnosis of COVID-19

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Source: PubMed

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