Persisting olfactory dysfunction improves in patients 6 months after COVID-19 disease

Otte, Martin Sylvester; Bork, Marie-Luise; Zimmermann, Philipp; Klußmann, Jens Peter; Lüers, Jan Christoffer

doi:10.1080/00016489.2021.1905178

Cited by 21 publications

(33 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In order to reduce the impact of this bias, all patients were instructed to fulfill an efficacy online questionnaire before the physical consultation with the investigator who only performed the psychophysical olfactory evaluations. Patients were followed to 2 months and therefore it is possible that with longer term follow-up the same end point would have been reached in all patients [42]. For these reasons, it will be essential to replicate the findings in a placebo controlled randomised study, but our preliminary data supports the need for such a study.…”

Section: Discussionmentioning

confidence: 83%

Short-Term Efficacy and Safety of Oral and Nasal Corticosteroids in COVID-19 Patients with Olfactory Dysfunction: A European Multicenter Study

et al. 2021

View full text Add to dashboard Cite

Background: The objective of this study was to investigate the efficacy and safety of early administration of oral corticosteroids (OC) or nasal corticosteroids (NC) as an add-on to olfactory training (OT) versus OT alone in patients with olfactory dysfunction (OD) related to coronavirus disease 2019 (COVID-19). Methods: Patients with a positive diagnosis of COVID-19 and OD were prospectively recruited from March 22 to December 15, 2020 from 4 European hospitals. Patients had confirmed OD on psychophysical testing. All patients undertook OT, with add-on 10 days of OC (group 1: OC + OT), or 1 month of NC (group 2: NC + OT) or olfactory training alone (group 3: OT). Olfactory evaluations (Sniffin’Sticks tests) were carried out at the time of inclusion, 1 and 2 months after the start of the therapeutic course. Results: A total of 152 hyposmic or anosmic patients completed the study. Group 1, 2 and 3 included 59, 22 and 71 patients, respectively and all patient groups were comparable regarding baseline Sniffin’Sticks tests. The median Sniffin’Sticks test values significantly improved from pre- to post-intervention in all groups. The increase of Sniffin’Sticks test values was higher in group 1 (OC + OT) compared with groups 2 and 3 (p < 0.001) at one month after treatment but did not remain so at 2 months. Groups 1, 2 and 3, respectively, presented parosmia in 20/71 (28.2%), 9/22 (40.9%) and 42/71 (59.2%) patients. This difference was statistically significant between group 1 and 3 (p < 0.001). There were no patients with a worsening of the disease or an increase of the severity of the COVID-19 symptoms. Conclusions: The use of OCs in patients with OD related to mild COVID-19 is generally well-tolerated without any case of deterioration of symptoms. OC is associated with greater improvement in psychophysical olfactory evaluations at 1-month post-treatment but there was no difference at 2 months. Parosmia may be reduced following treatment with OC and NC. On the basis of these preliminary results, it is possible to state that considering the 2 months efficacy of OC and NC with respect to the OT alone and the risk-benefit ratio, the benefit to start a specific treatment of COVID-19 related OD cannot be demonstrated and there is a need for a randomised controlled trial to assess this further.

show abstract

Section: Discussionmentioning

confidence: 83%

Short-Term Efficacy and Safety of Oral and Nasal Corticosteroids in COVID-19 Patients with Olfactory Dysfunction: A European Multicenter Study

et al. 2021

View full text Add to dashboard Cite

show abstract

“…The higher rate of clumping in COVID-19 anosmia might be related to a more robust regeneration attempt within the subacute phase of OD as compared to post-infectious OD. The sustentacular cells have a good regenerative capacity which improves recovery of olfaction [ 43 ; 44 ].…”

Section: Discussionmentioning

confidence: 99%

A Comparative Olfactory MRI, DTI and fMRI Study of COVID-19 Related Anosmia and Post Viral Olfactory Dysfunction

et al. 2022

View full text Add to dashboard Cite

Objective : To evaluate how COVID-19 anosmia imaging findings resembled and differed from post-infectious olfactory dysfunction (OD). Material and Methods : A total of 31 patients presenting with persistent COVID-19 related OD and 97 patients with post-infectious OD were included. Olfactory bulb MRI, DTI and olfactory fMRI findings in both groups were retrospectively assessed. Results : All COVID-19 related OD cases were anosmic, 18.6% of post-infectious OD patients were hyposmic and remaining 81.4% were anosmic. Mean interval between onset of OD and imaging was 1.5 months for COVID-19 related OD and 6 months for post-infectious OD. Olfactory bulb volumes were significantly higher in COVID-19 related OD than post-infectious OD. Deformed bulb morphology and increased olfactory bulb signal intensity was seen in 58.1% and 51.6% with COVID-19 related OD; and 63.9% and 46.4% with post-infectious OD; without significant difference. Significantly higher rate of olfactory nerve clumping and higher QA values at orbitofrontal and entorhinal regions were observed in COVID-19 related OD than post-infectious OD. Absence of orbitofrontal and entorhinal activity showed no statistically significant difference between COVID-19 related OD and post-infectious OD, however trigeminosensory activity was more robust in COVID-19 related OD cases. Conclusion : Olfactory bulb damage may play a central role in persistent COVID-19 related anosmia. Though there is decreased olfactory bulb volume and decreased white matter tract integrity of olfactory regions in COVID-19 related anosmia, this is not as pronounced as in other post-infectious OD. Trigeminosensory activity was more robust in COVID-19 related OD. These findings may reflect better preserved central olfactory system in COVID-19 related OD compared to COVID-19 related OD.

show abstract

“…However, in about 50% of patients, a reduction in olfaction can be measured even after three months [13]. Olfactory function improves in most patients during the course of the disease, but in some patients limitations of the olfactory function can be measured even 6 months after the disease [14]. Impairments in chemesthesis have been described in SARS-CoV-2 infected patients [3], but data is very limited compared to olfactory impairment.…”

Section: Discussionmentioning

confidence: 99%

Patients with COVID-19-associated olfactory impairment also show impaired trigeminal function

et al. 2022

Self Cite

View full text Add to dashboard Cite

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

show abstract

Persisting olfactory dysfunction improves in patients 6 months after COVID-19 disease

Cited by 21 publications

References 11 publications

Short-Term Efficacy and Safety of Oral and Nasal Corticosteroids in COVID-19 Patients with Olfactory Dysfunction: A European Multicenter Study

Short-Term Efficacy and Safety of Oral and Nasal Corticosteroids in COVID-19 Patients with Olfactory Dysfunction: A European Multicenter Study

A Comparative Olfactory MRI, DTI and fMRI Study of COVID-19 Related Anosmia and Post Viral Olfactory Dysfunction

Patients with COVID-19-associated olfactory impairment also show impaired trigeminal function

Contact Info

Product

Resources

About