Bilateral transient olfactory bulb edema during COVID-19–related anosmia

Laurendon, Thomas; Radulesco, Thomas; Mugnier, Justine; Gérault, Mélanie; Chagnaud, Christophe; Ahmadi, Ahmed Ali El; Varoquaux, A.

doi:10.1212/wnl.0000000000009850

Cited by 133 publications

(146 citation statements)

References 1 publication

Supporting

Mentioning

139

Contrasting

Unclassified

Order By: Relevance

“…22 Emerging autopsy reports have shown SARS-CoV-2 tracking along the olfactory bulb, gyrus rectus, and medulla of a patient with COVID-19related anosmia who subsequently died. 23,24 More recent imaging reports in the literature show evidence of hyperintense signal and edema of the olfactory bulb, which subsequently resolved, 25,26 giving further support to a central mechanism of anosmia in this group. The limitation of this study is the small number and variable duration from onset of symptoms to CT scan and endoscopy, unavoidable due to the restrictions on both travel and access to imaging and endoscopy.…”

Section: Discussionmentioning

confidence: 58%

Clinical and Radiological Evaluations of COVID‐19 Patients With Anosmia: Preliminary Report

et al. 2020

Self Cite

View full text Add to dashboard Cite

Objectives/Hypothesis: To investigate clinical and radiological features of olfactory clefts of patients with mild coronavirus disease 2019 (COVID-19). Study Design: Prospective non controlled study. Methods: Sixteen COVID-19 patients were recruited. The epidemiological and clinical data were extracted. Nasal complaints were assessed through the 22-item Sino-Nasal Outcome Test. Patients underwent psychophysical olfactory testing, olfactory cleft examination, and computed tomography (CT) scans. Results: Sixteen anosmic patients were included. The mean Sniffin' Sticks score was 4.6 AE 1.7. The majority of patients had no endoscopical abnormality, with a mean olfactory cleft endoscopy score of 0.6 AE 0.9. The olfactory clefts were opacified in three patients on the CT scan. The mean radiological olfactory cleft score was 0.7 AE 0.8. There were no significant correlations between clinical, radiological, and psychophysical olfactory testing. Conclusions: The olfactory cleft of anosmic COVID-19 patients is free regarding endoscopic examination and imaging. The anosmia etiology is not related to edema of the olfactory cleft.

show abstract

Section: Discussionmentioning

confidence: 58%

Clinical and Radiological Evaluations of COVID‐19 Patients With Anosmia: Preliminary Report

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…Other finding was perivascular leukocyte infiltration in the basal ganglia. The olfactory bulb edema has also been demonstrated on cranial MRI of patients with COVID-19 infection [95]. His anosmia and dysgeusia improved by 14 days and olfactory bulb edema also subsided on repeat MRI at 24 days of illness.…”

Section: Olfactory and Gustatory Dysfunctionmentioning

confidence: 83%

Neuromuscular presentations in patients with COVID-19

et al. 2020

View full text Add to dashboard Cite

COVID-19 is caused by the coronavirus SARS-CoV-2 that has an affinity for neural tissue. There are reports of encephalitis, encephalopathy, cranial neuropathy, Guillain-Barrè syndrome, and myositis/rhabdomyolysis in patients with COVID-19. In this review, we focused on the neuromuscular manifestations of SARS-CoV-2 infection. We analyzed all published reports on SARS-CoV-2-related peripheral nerve, neuromuscular junction, muscle, and cranial nerve disorders. Olfactory and gustatory dysfunction is now accepted as an early manifestation of COVID-19 infection. Inflammation, edema, and axonal damage of olfactory bulb have been shown in autopsy of patients who died of COVID-19. Olfactory pathway is suggested as a portal of entry of SARS-CoV-2 in the brain. Similar to involvement of olfactory bulb, isolated oculomotor, trochlear and facial nerve has been described. Increasing reports Guillain-Barrè syndrome secondary to COVID-19 are being published. Unlike typical GBS, most of COVID-19-related GBS were elderly, had concomitant pneumonia or ARDS, more prevalent demyelinating neuropathy, and relatively poor outcome. Myalgia is described among the common symptoms of COVID-19 after fever, cough, and sore throat. Duration of myalgia may be related to the severity of COVID-19 disease. Few patients had muscle weakness and elevated creatine kinase along with elevated levels of acute-phase reactants. All these patients with myositis/rhabdomyolysis had severe respiratory complications related to COVID-19. A handful of patients with myasthenia gravis showed exacerbation of their disease after acquiring COVID-19 disease. Most of these patients recovered with either intravenous immunoglobulins or steroids.

show abstract

“…Emerging autopsy reports have shown SARS-CoV-2 tracking along the olfactory bulb, gyrus rectus and medulla of a patient with COVID related anosmia who subsequently died [18,19]. More recent imaging reports in the literature show evidence of hyperintense signal and oedema of the olfactory bulb which subsequently resolved [20,21], giving further support to a central mechanism of anosmia in this group. Previous models of olfactory injury have demonstrated the regenerative capacity of the olfactory epithelium, showing that the basal cells may regenerate and grow new axons back to the olfactory bulb [22].…”

mentioning

confidence: 77%

Anosmia: an evolution of our understanding of its importance in COVID-19 and what questions remain to be answered

Saussez

Lechien

Hopkins

2020

Eur Arch Otorhinolaryngol

View full text Add to dashboard Cite

Background From the start of the pandemic, many European otolaryngologists observed an unprecendented number of anosmic patients. Early reports proposed that anosmia could be the first or even the only symptom of COVID-19 infection, prompting calls for self-isolation in affected patients. Methods In the present article, we review the COVID-19 anosmia literature and try to answer the following two questions: first, why is COVID-19 infection responsible for such a high incidence of anosmia? Second, in patients with more severe forms is anosmia really less prevalent and why? Results In terms of the etiology of olfactory dysfunction, several hypotheses were proposed at the outset of the pandemic; that olfactory cleft inflammation and obstruction caused a localized conductive loss, that there was injury to the sustentacular supporting cells in the olfactory epithelium or, given the known neurotropic potential of coronavirus, that the virus could invade and damage the olfactory bulb. Olfactory cleft obstruction may contribute to the olfactory dysfunction in some patients, perhaps most likely in those that show very early resolution, it cannot account for the loss in all patients. Moreover, disordered regrowth and a predominance of immature neurons have been shown to be associated with parosmia, which is a common finding amongst patients with Covid-related anosmia. A central mechanism therefore certainly seems to be consistent with the group of patients with more prolonged olfactory deficits. Sustentacular cells showing ACE-2 immunohistochemical expression 200 to 700 times greater than nasal or tracheal epithelia seem to be the main SARS-CoV-2 gateway. As the pathophysiology of COVID-19 anosmia seems to be better understood, the question of why patients with a moderate to severe form of COVID-19 infection have less olfactory involvement remains unresolved. Different potential explanations are discussed in this review. Conclusions The last 5 months have benefited from great international collaborative research, first highlighting and then proving the value of loss of smell and taste as a symptom of COVID-19. Adoption of loss of smell into the case definition by international public health bodies will facilitate control of disease transmission.

show abstract

Bilateral transient olfactory bulb edema during COVID-19–related anosmia

Abstract: An asymptomatic 27-year-old physician is diagnosed SARS-CoV-2 by occupational medicine after contagion (RT-PCR).

Cited by 133 publications

References 1 publication

Clinical and Radiological Evaluations of COVID‐19 Patients With Anosmia: Preliminary Report

Clinical and Radiological Evaluations of COVID‐19 Patients With Anosmia: Preliminary Report

Neuromuscular presentations in patients with COVID-19

Anosmia: an evolution of our understanding of its importance in COVID-19 and what questions remain to be answered

Contact Info

Product

Resources

About