Studies suggest that COVID causes people to lose their sense of smell due to changes in the brain

Sudden loss of odor in some people COVIDAccording to one study, 19 patients could be explained by changes in the brain.

later Coronavirus Because of that COVID-19 first appeared at the end of last year, and loss of smell and taste soon became a possible symptom of the disease. The US Centers for Disease Control and Prevention lists these along with other symptoms such as fever, chills, cough, shortness of breath, and malaise.

Research co-author Maxim sneeze Belgian Institute for Functional Brain Mapping ULB The university and colleagues set out to explore some hypotheses COVID-19 patients lose their sense of smell because the infection affects the cells that support certain neurons that are key to this sensory function.

Inflammation is also thought to prevent certain receptors from picking up odors, and when they subside, the sensation of human odors is restored, Professor Barry Sum.i th,director Center For a sensory study at the University of London, UK, not working on a dissertation Newsweek on mail. If a person loses olfaction in whole or in part over a long period of time, he said, this could be due to an overreaction of the immune system that blocks receptors.

After studying 12 COVID-19 patients, the authors of the paper suggested that there were several reasons why they lost their sense of smell. In some patients, the parts of the brain involved in olfactory processing, such as the olfactory fissure, the olfactory bulb, and what is known as the surrounding nervous tissue, were affected.

The team discovered how the infection appears to affect the parts of the brain involved in this sensation. Metabolize sugar. And the connections of nerve cells that convey information about odors, Coronavirus infection.

The study was submitted as Pre-Print on website medRxiv, Therefore, it has not been peer reviewed.

Twelve patients between the ages of 23 and 60 participated in this study. These patients suddenly lost their sense of smell and Coronavirus.. The team compared the scan with a scan of 26 healthy people aged 22-52. In 7 patients, odor loss was their predominance COVID-19 Symptoms. Five patients have completely or almost recovered from their loss of smell until 10 weeks, and 7 still have problems until 16 weeks later.

Participants underwent tests to measure taste and smell. They also performed MRI scans to look for structural possibilities for brain and organ pathways associated with these sensations. A PET scan was used to examine the metabolism of the brain.

Experts not working on the study said the findings indicate that there may be multiple reasons. COVID-19 patients lose their sense of smell. Chris S. Constantinople, Professor of Neurology, University of Nottingham, Queen’s Medical Center, UK Center,Said Newsweek Due to the small number of participants, email surveys were limited.

Asked why some reasons COVID-19 loses smell and taste, not others. Constantinople He said it was likely related to how much the virus spreads in the upper respiratory tract of humans. He suspects that patients whose other parts of the body, such as blood vessels and the digestive system, are affected by the virus may not lose their sense of smell.

“I was impressed that the imaging technology used by the team could track every part of the nose-brain response,” Smith said. smell Let’s see what goes wrong. “

Smith said: “This study shows negative results, but it is important and excludes a single explanation for the pattern of olfactory loss we see. COVID-19. However, this means that we still have more to know how this virus affects the body and brain. “

He said the study was limited because the team was unable to investigate why some people lost their taste and what might explain this.

Professor Aytug Altundag, Turkish ear, nose and throat disease specialist Birni The university said Newsweek Via email “In my opinion, it’s a much more speculative study and doesn’t directly show the olfactory mechanism. [smell] Loss COVID-19 patients. “

Altundag recently published a paper in the journal on olfactory loss in COVID-19 patients Otorhinolaryngology-Head and Neck SurgerySaid that it was “wrong” to attribute the cause of olfactory loss to “very few data” glucose metabolism.

Dr. James C Denny III, Executive Vice President and CEO of the American Academy of Otolaryngology, talked about head and neck surgery. Newsweek There are many causes for odor loss after a rhinovirus infection.

He said the main limitation of this study was that the team could not study the tissue to make sure it was consistent with the scan, as it was not possible in living patients.
“Still, this acts as a’pilot study’and can be repeated elsewhere over time with more subjects. “

This article has been updated to include information about Professor Altundag.