What is the reason for the decline in the sense of smell in people with the emerging corona virus, which causes "Covid-19?" And does it have anything to do with the brain?
Decreased or lost sense of smell (dysosmia) is a common symptom of "Covid-19" disease, and researchers from Belgium studied this symptom and its links to the brain and metabolism.
The researchers found that some parts of the brain responsible for processing odors, such as the olfactory bulbs, were affected in some Corona patients, and the infection appears to affect how parts of the brain metabolize glucose.
The study was conducted by researchers, including Maxime Nissen from the Erasmus Hospital at the Free University of Brussels in Belgium, and published on the Medrxiv website, and has not yet been peer-reviewed.
The study included 12 patients (two males and 10 females) with an average age of 42.6 years, and ranged from 23 to 60 years, and they were suffering from a sudden decline in their sense of smell, and they were diagnosed with an emerging corona virus, whose scientific name is SARS-CoV-2. 2).
Magnetic resonance imaging (MRI) and positron emission tomography were performed for the participants.
The researchers noted the presence of imbalances in glucose metabolism in the basic olfactory regions of the brain, and said that the findings indicate that the sudden loss of the sense of smell in "Covid-19" patients is associated with brain metabolic changes in the olfactory and high-order cortical regions areas).
How does the sense of smell work?
Evaporating odor molecules (chemicals) floating in the air reach the nostrils, and dissolve in the mucus on the surface of each nostril.
Under the mucus in the olfactory epithelium, scent detects specialized receptor cells called olfactory receptor neurons. These neurons are able to detect thousands of different scents.
The olfactory receptor neurons transmit information to the olfactory bulbs at the back of the nose.
The olfactory follicles contain sensory receptors that are actually part of the brain, and they send messages directly to the brain to the olfactory cortex, and these scents are then distinguished.
The graphic below shows 9 of the most prominent symptoms of Corona virus, and to find out a detailed list of symptoms of Corona infection, click on this link.
A previous study had found that the loss of the sense of smell for 4 smells may indicate infection with the Corona virus.
The study was conducted by a research team, and included 590 participants via an online platform, and they answered questions related to loss of smell and taste and other symptoms associated with "Covid-19", and it was published in the journal "PLOS Medicine".
The researchers found that people who notice a loss in their ability to smell garlic, onions, coffee, and perfumes should isolate themselves and request a test to detect the Coronavirus.