Neuroimaging Evaluations of Olfactory, Gustatory, and Neurological Deficits in Patients with Long-term Sequelae of COVID-19

Overview

Journal Brain Imaging Behav

Publisher Springer

Specialties Neurology
Psychology
Radiology
Social Sciences

Date 2024 Sep 28

PMID 39340624

Authors

Carla Masala

Michele Porcu

Gianni Orofino

Giovanni Defazio

Ilenia Pinna

Paolo Solla

Tommaso Ercoli

Jasjit S Suri

Giacomo Spinato

Luca Saba

Affiliations

Soon will be listed here.

Abstract

The World Health Organization indicated that around 36 million of patients in the European Region showed long COVID associated with olfactory and gustatory deficits. The precise mechanism underlying long COVID clinical manifestations is still debated. The aim of this study was to evaluate potential correlations between odor threshold, odor discrimination, odor identification, and the activation of specific brain areas in patients after COVID-19. Sixty subjects, 27 patients (15 women and 12 men) with long COVID and a mean age of 40.6 ± 13.4 years, were compared to 33 age-matched healthy controls (20 women and 13 men) with a mean age of 40.5 ± 9.8 years. Our data showed that patients with long COVID symptoms exhibited a significant decrease in odor threshold, odor discrimination, odor identification, and their sum TDI score compared to age-matched healthy controls. In addition, our results indicated significant correlations between odor discrimination and the increased activation in the right hemisphere, in the frontal pole, and in the superior frontal gyrus. This study indicated that the resting-state fMRI in combination with the objective evaluation of olfactory and gustatory function may be useful for the evaluation of patients with long COVID associated with anosmia and hyposmia.

Citing Articles

Depression, Anxiety, and Neuropsychiatric Symptom Burden in a Longitudinal Cohort with Persistent Psychophysical Post-COVID Olfactory Dysfunction.

Saak T, Tervo J, Vilarello B, Jacobson P, Caruana F, Spence M Brain Sci. 2025; 14(12.

PMID: 39766476 PMC: 11674626. DOI: 10.3390/brainsci14121277.

References

Conti S, Bonazzi S, Laiacona M, Masina M, Coralli M . Montreal Cognitive Assessment (MoCA)-Italian version: regression based norms and equivalent scores. Neurol Sci. 2014; 36(2):209-14. DOI: 10.1007/s10072-014-1921-3. View

Xydakis M, Albers M, Holbrook E, Lyon D, Shih R, Frasnelli J . Post-viral effects of COVID-19 in the olfactory system and their implications. Lancet Neurol. 2021; 20(9):753-761. PMC: 8324113. DOI: 10.1016/S1474-4422(21)00182-4. View

Huang C, Huang L, Wang Y, Li X, Ren L, Gu X . 6-month consequences of COVID-19 in patients discharged from hospital: a cohort study. Lancet. 2021; 397(10270):220-232. PMC: 7833295. DOI: 10.1016/S0140-6736(20)32656-8. View

Stefanou M, Palaiodimou L, Bakola E, Smyrnis N, Papadopoulou M, Paraskevas G . Neurological manifestations of long-COVID syndrome: a narrative review. Ther Adv Chronic Dis. 2022; 13:20406223221076890. PMC: 8859684. DOI: 10.1177/20406223221076890. View

Plailly J, Radnovich A, Sabri M, Royet J, Kareken D . Involvement of the left anterior insula and frontopolar gyrus in odor discrimination. Hum Brain Mapp. 2006; 28(5):363-72. PMC: 6871452. DOI: 10.1002/hbm.20290. View

Carfi A, Bernabei R, Landi F . Persistent Symptoms in Patients After Acute COVID-19. JAMA. 2020; 324(6):603-605. PMC: 7349096. DOI: 10.1001/jama.2020.12603. View

Porcu M, Cocco L, Cocozza S, Pontillo G, Operamolla A, Defazio G . The association between white matter hyperintensities, cognition and regional neural activity in healthy subjects. Eur J Neurosci. 2021; 54(4):5427-5443. DOI: 10.1111/ejn.15403. View

Lv H, Wang Z, Tong E, Williams L, Zaharchuk G, Zeineh M . Resting-State Functional MRI: Everything That Nonexperts Have Always Wanted to Know. AJNR Am J Neuroradiol. 2018; 39(8):1390-1399. PMC: 6051935. DOI: 10.3174/ajnr.A5527. View

Worsley K, Marrett S, Neelin P, Vandal A, Friston K, Evans A . A unified statistical approach for determining significant signals in images of cerebral activation. Hum Brain Mapp. 2010; 4(1):58-73. DOI: 10.1002/(SICI)1097-0193(1996)4:1<58::AID-HBM4>3.0.CO;2-O. View

10.

Doty R . Olfactory dysfunction in COVID-19: pathology and long-term implications for brain health. Trends Mol Med. 2022; 28(9):781-794. PMC: 9212891. DOI: 10.1016/j.molmed.2022.06.005. View

11.

Muccioli L, Sighinolfi G, Mitolo M, Ferri L, Rochat M, Pensato U . Cognitive and functional connectivity impairment in post-COVID-19 olfactory dysfunction. Neuroimage Clin. 2023; 38:103410. PMC: 10165139. DOI: 10.1016/j.nicl.2023.103410. View

12.

Beck A, Ward C, Mendelson M, Mock J, ERBAUGH J . An inventory for measuring depression. Arch Gen Psychiatry. 1961; 4:561-71. DOI: 10.1001/archpsyc.1961.01710120031004. View

13.

Altunisik E, Baykan A, Sahin S, Aydin E, Erturk S . Quantitative Analysis of the Olfactory System in COVID-19: An MR Imaging Study. AJNR Am J Neuroradiol. 2021; 42(12):2207-2214. PMC: 8805742. DOI: 10.3174/ajnr.A7278. View

14.

Porcu M, Cocco L, Cau R, Suri J, Mannelli L, Yang Q . The mid-term effects of carotid endarterectomy on cognition and regional neural activity analyzed with the amplitude of low frequency fluctuations technique. Neuroradiology. 2021; 64(3):531-541. PMC: 8850244. DOI: 10.1007/s00234-021-02815-7. View

15.

Joshi A, Hornstein H, Thaploo D, Faria V, Warr J, Hummel T . Neural Processing of Odors with Different Well-Being Associations-Findings from Two Consecutive Neuroimaging Studies. Brain Sci. 2023; 13(4). PMC: 10136803. DOI: 10.3390/brainsci13040576. View

16.

Thomasson M, Voruz P, Cionca A, de Alcantara I, Nuber-Champier A, Allali G . Markers of limbic system damage following SARS-CoV-2 infection. Brain Commun. 2023; 5(4):fcad177. PMC: 10320753. DOI: 10.1093/braincomms/fcad177. View

17.

Frosolini A, Parrino D, Fabbris C, Fantin F, Inches I, Invitto S . Magnetic Resonance Imaging Confirmed Olfactory Bulb Reduction in Long COVID-19: Literature Review and Case Series. Brain Sci. 2022; 12(4). PMC: 9029157. DOI: 10.3390/brainsci12040430. View

18.

Landis B, Welge-Luessen A, Bramerson A, Bende M, Mueller C, Nordin S . "Taste Strips" - a rapid, lateralized, gustatory bedside identification test based on impregnated filter papers. J Neurol. 2009; 256(2):242-8. DOI: 10.1007/s00415-009-0088-y. View

19.

Zou Q, Zhu C, Yang Y, Zuo X, Long X, Cao Q . An improved approach to detection of amplitude of low-frequency fluctuation (ALFF) for resting-state fMRI: fractional ALFF. J Neurosci Methods. 2008; 172(1):137-41. PMC: 3902859. DOI: 10.1016/j.jneumeth.2008.04.012. View

20.

Spinato G, Fabbris C, Polesel J, Cazzador D, Borsetto D, Hopkins C . Alterations in Smell or Taste in Mildly Symptomatic Outpatients With SARS-CoV-2 Infection. JAMA. 2020; 323(20):2089-2090. PMC: 7177631. DOI: 10.1001/jama.2020.6771. View