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. 2021 Jun;164(6):1337-1344.
doi: 10.1177/0194599820965920. Epub 2020 Oct 13.

Olfactory Cleft Measurements and COVID-19-Related Anosmia

Aytug Altundag  1   2 , Duzgun Yıldırım  3   4 , Deniz Esin Tekcan Sanli  5 , Melih Cayonu  6 , Sedat Giray Kandemirli  7 , Ahmet Necati Sanli  8 , Ozge Arici Duz  9 , Ozlem Saatci  10
Affiliations

Olfactory Cleft Measurements and COVID-19-Related Anosmia

Aytug Altundag et al. Otolaryngol Head Neck Surg. 2021 Jun.

Abstract

Objective: This study aimed to investigate the differences in olfactory cleft (OC) morphology in coronavirus disease 2019 (COVID-19) anosmia compared to control subjects and postviral anosmia related to infection other than severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Study design: Prospective.

Setting: This study comprises 91 cases, including 24 cases with anosmia due to SARS-CoV-2, 38 patients with olfactory dysfunction (OD) due to viral infection other than SARS-CoV-2, and a control group of 29 normosmic cases.

Methods: All cases had paranasal sinus computed tomography (CT), and cases with OD had magnetic resonance imaging (MRI) dedicated to the olfactory nerve. The OC width and volumes were measured on CT, and T2-weighted signal intensity (SI), olfactory bulb volumes, and olfactory sulcus depths were assessed on MRI.

Results: This study showed 3 major findings: the right and left OC widths were significantly wider in anosmic patients due to SARS-CoV-2 (group 1) or OD due to non-SARS-CoV-2 viral infection (group 2) when compared to healthy controls. OC volumes were significantly higher in group 1 or 2 than in healthy controls, and T2 SI of OC area was higher in groups 1 and 2 than in healthy controls. There was no significant difference in olfactory bulb volumes and olfactory sulcus depths on MRI among groups 1 and 2.

Conclusion: In this study, patients with COVID-19 anosmia had higher OC widths and volumes compared to control subjects. In addition, there was higher T2 SI of the olfactory bulb in COVID-19 anosmia compared to control subjects, suggesting underlying inflammatory changes. There was a significant negative correlation between these morphological findings and threshold discrimination identification scores.

Level of evidence: Level 4.

Keywords: COVID-19; SARS-CoV-2; Sniffin’ Sticks; anosmia; olfactory cleft; volume; width.

PubMed Disclaimer

Conflict of interest statement

Disclosures: Competing interests: None.

Sponsorships: None.

Funding source: None.

Figures

Figure 1.
Figure 1.
Section through the parasagittal plane of the cribriform plate: cross section from the front one-third to the back two-thirds section perpendicular to the horizontal plane, the plan in which the coronal plan image was obtained.
Figure 2.
Figure 2.
Axial image depicting the total volume of the olfactory cleft (thick-edged rectangle, cm3) and mean density within the voxel of interest (thin double-line edged rectangle).
Figure 3.
Figure 3.
Grayscale and color window coronal T2 cleft magnetic resonance image. The mean region of interest signal intensity value was measured by taking the olfactory cleft mucosa along the height extending from the cleft top to 10 mm inferior.
Figure 4.
Figure 4.
Flowchart of the findings.
See this image and copyright information in PMC

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References

    1. Guan WJ, Ni ZY, Hu Y, et al.. Clinical characteristics of coronavirus disease 2019 in China. N Engl J Med. 2020;382:1708-1720. - PMC - PubMed
    1. Cheng X, Liu J, Li N, et al.. Otolaryngology providers must be alert for patients with mild and asymptomatic COVID-19. Otolaryngol Head Neck Surg. 2020;162:809-810. - PubMed
    1. Vaira LA, Salzano G, Deiana G, De Riu G. Anosmia and ageusia: common findings in COVID-19 patients. Laryngoscope. 2020;130:1787. - PMC - PubMed
    1. Lechien JR, Chiesa-Estomba CM, De Siati DR, et al.. Olfactory and gustatory dysfunctions as a clinical presentation of mild-to-moderate forms of the coronavirus disease (COVID-19): a multicenter European study. Eur Arch Otorhinolaryngol. 2020;277:2251-2261. - PMC - PubMed
    1. Tong JY, Wong A, Zhu D, Fastenberg JH, Tham T. The prevalence of olfactory and gustatory dysfunction in COVID-19 patients: a systematic review and meta-analysis. Otolaryngol Head Neck Surg. 2020;163:3-11. - PubMed

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