Functional magnetic resonance imaging in coronavirus disease 2019 induced olfactory dysfunction

Area of Science:

• Neuroscience
• Medical Imaging
• Infectious Diseases

Background:

• Olfactory dysfunction is a common symptom of coronavirus disease 2019 (COVID-19).
• The underlying neural mechanisms of persistent smell loss post-COVID-19 require further investigation.
• Functional magnetic resonance imaging (fMRI) offers a non-invasive method to study brain activity.

Purpose of the Study:

• To investigate functional magnetic resonance imaging (fMRI) alterations in the olfactory structures of COVID-19 patients.
• To correlate these brain changes with persistent olfactory dysfunction.
• To identify specific brain regions affected by COVID-19-induced smell loss.

Main Methods:

• Inclusion of adult patients (25-65 years) with confirmed COVID-19 and persistent olfactory dysfunction (≥2 months).
• Exclusion of patients who received any treatment for their olfactory dysfunction.
• Utilized functional magnetic resonance imaging (fMRI) to assess brain activation patterns in olfactory structures.

Main Results:

• Patients with COVID-19-related olfactory dysfunction exhibited significantly reduced activation in the upper frontal lobe.
• Analysis revealed significantly lower activation in the basal ganglia of affected patients.
• Both the size (cumulative maximum diameter) and number of activation points were significantly reduced in these brain regions.

Conclusions:

• Coronavirus disease 2019-triggered olfactory dysfunction is associated with diminished neural activity in the upper frontal lobe.
• Patients experiencing smell loss due to COVID-19 show reduced activity in the basal ganglia.
• These findings highlight specific neurobiological changes in the brain's olfactory pathways following COVID-19 infection.