46% of diagnosed patients have lost their sense of smell for more than 1 year! Brain scans confirm: This area of the brain shrinks
Confirmed that it affects smell and taste functions? 46% of patients persisted for more than one year
One of the sequelae of COVID-19 infection is the loss of smell and taste functions, which was the main symptom diagnosed in the early stages of the pandemic. However, as virus strains continue to evolve, the proportion of smell and taste abnormalities gradually decreases. The authoritative journal “Nature” reported that a survey of 610,000 confirmed cases in the United States showed that compared with the original virus strain, the proportion of sensory dysfunction caused by infection with the Alpha strain was 50% higher, while the Delta strain dropped to 44%. Recently, The Omicron strain is only 17%.
However, a large proportion of those diagnosed in the early stages of the epidemic still face the sequelae of abnormal sensory function. A 2021 study tracking 100 people diagnosed with mild symptoms found that 46% of patients still continued to have symptoms of olfactory impairment more than a year after infection. As of the end of last year, 7% of infected people had completely lost their olfactory function. For them, , wanting to taste food and smell flowers and plants has become a luxury in daily life.
Could virus cause loss of smell? Brain scans reveal block damage
Why does COVID-19 infection cause smell problems? Research in the early stages of the pandemic suggested that the virus would attack sustentacular cells in the nasal cavity that are responsible for regulating mucosal ion balance. As research on the virus progresses, signs that the new coronavirus affects the brain appear to be becoming increasingly clear. The team of Stavros Lomvardas, professor of chemistry at Columbia University, found that the receptors for detecting odor molecules were reduced in the neurons of people diagnosed with death, and the structure of the cell nuclei was also changed.
Other studies have also attempted to analyze why some diagnosed patients experience longer periods of abnormal smell. Relevant studies have found that individual genes seem to be related to the loss of smell and taste after infection, especially in groups with mutations in UGT2A1 and UGT2A2. These two genes encode proteins that eliminate odor molecules.
Studies have also shown that people diagnosed with the COVID-19 virus will have lasting changes in the brain after losing their sense of smell. A British study of 785 people found structural changes in two brain tomography scans of about 400 infected people, including damage to areas related to the olfactory area. One possibility is related to the lack of “input” stimulation. Due to the reduction of normal cells that detect and perceive odor molecules, the part of the brain that receives and responds to olfactory stimulation may shrink.
Smell training is about one-third effective. There is no effective treatment for loss of smell.
At the same time, many small clinical trials are being conducted on how to help people diagnosed with smell loss restore normal functions. Most researchers prefer to have patients undergo odor training, providing them with strong-smelling samples to sniff and try to identify the differences. The goal is to stimulate the olfactory response to the brain. But this method only helps about one-third of people diagnosed with anosmia.
Other treatments currently being tried, such as steroid treatment and plasma treatment, have no significant improvement in the loss of smell after COVID-19 infection, or the study scale is too small and lacks significant evidence. Carl Philpott, a sinus specialist at the University of East Anglia in England, is conducting a small study of vitamin A to try to find ways to specifically help people with smell loss.
source:
COVID and smell loss: answers begin to emerge
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