Study: Even Mild COVID-19 Cases Linked to Brain Changes
2022-03-15
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1A new study provides additional evidence that COVID-19 can damage parts of the brain.
2The study said that even people with mild sickness can suffer brain tissue shrinkage and damage to areas that control smell.
3The research was led by scientists at Britain's Oxford University.
4The researchers said their study provides "strong evidence" of "brain-related abnormalities in COVID-19."
5The team noted that past studies have also found links between COVID-19 and changes to the brain.
6But those studies centered mainly on COVID-19 patients who were hospitalized with severe sickness.
7The latest study recently appeared in the publication Nature.
8The team said further study is needed to find out whether the brain changes are long lasting and can be fixed.
9The study involved 785 subjects in Britain between the ages of 51 and 81.
10All were given two brain scans to measure differences during the experiment.
11A total of 401 subjects were found to be infected with COVID-19 between the scans.
12Most of them had only minor sickness.
13The researchers reported a number of brain effects in the patients.
14The subjects experienced the effects, on average, four-and-a-half months after infection.
15The changes included "a greater reduction in gray matter thickness" after individuals were infected with COVID-19.
16Gray matter in the brain helps people control movement, memory and emotions.
17The greatest reduction was seen in areas of the brain linked to smell.
18In addition, some infected patients also showed "a reduction in whole brain size," the researchers reported.
19On average, subjects infected with COVID-19 also showed "greater cognitive decline" linked to an area of the brain related to cognition.
20Gwenaëlle Douaud is a professor at Oxford and the lead writer of the study.
21She said in a statement that losses in gray matter and the tissue damage in infected individuals led to a reduction in their abilities to perform complex tasks.
22"All these negative effects were more marked at older ages," Douaud noted.
23"A key question for future brain imaging studies is to see if this brain tissue damage resolves over the longer term," she added.
24The study was carried out when the Alpha version of COVID-19 was widespread in Britain.
25Past studies have found that some COVID-19 patients suffered from "brain fog," or a lack of mental clarity.
26The condition can cause memory problems and reduce a person's ability to be attentive, concentrate and process information normally.
27The researchers did not say whether vaccination against COVID-19 had any influence on the brain changes.
28But the UK Health Security Agency said released findings on the issue last month.
29The agency said an examination of 15 studies found that vaccinated people were about half as likely to suffer long-term effects of COVID-19 compared with unvaccinated people.
30I'm Bryan Lynn.
1A new study provides additional evidence that COVID-19 can damage parts of the brain. 2The study said that even people with mild sickness can suffer brain tissue shrinkage and damage to areas that control smell. 3The research was led by scientists at Britain's Oxford University. The researchers said their study provides "strong evidence" of "brain-related abnormalities in COVID-19." 4The team noted that past studies have also found links between COVID-19 and changes to the brain. But those studies centered mainly on COVID-19 patients who were hospitalized with severe sickness. 5The latest study recently appeared in the publication Nature. 6The team said further study is needed to find out whether the brain changes are long lasting and can be fixed. 7The study involved 785 subjects in Britain between the ages of 51 and 81. All were given two brain scans to measure differences during the experiment. A total of 401 subjects were found to be infected with COVID-19 between the scans. Most of them had only minor sickness. 8The researchers reported a number of brain effects in the patients. The subjects experienced the effects, on average, four-and-a-half months after infection. 9The changes included "a greater reduction in gray matter thickness" after individuals were infected with COVID-19. Gray matter in the brain helps people control movement, memory and emotions. The greatest reduction was seen in areas of the brain linked to smell. In addition, some infected patients also showed "a reduction in whole brain size," the researchers reported. 10On average, subjects infected with COVID-19 also showed "greater cognitive decline" linked to an area of the brain related to cognition. 11Gwenaëlle Douaud is a professor at Oxford and the lead writer of the study. She said in a statement that losses in gray matter and the tissue damage in infected individuals led to a reduction in their abilities to perform complex tasks. 12"All these negative effects were more marked at older ages," Douaud noted. "A key question for future brain imaging studies is to see if this brain tissue damage resolves over the longer term," she added. 13The study was carried out when the Alpha version of COVID-19 was widespread in Britain. Past studies have found that some COVID-19 patients suffered from "brain fog," or a lack of mental clarity. The condition can cause memory problems and reduce a person's ability to be attentive, concentrate and process information normally. 14The researchers did not say whether vaccination against COVID-19 had any influence on the brain changes. But the UK Health Security Agency said released findings on the issue last month. The agency said an examination of 15 studies found that vaccinated people were about half as likely to suffer long-term effects of COVID-19 compared with unvaccinated people. 15I'm Bryan Lynn. 16Reuters and the University of Oxford reported on this story. Bryan Lynn adapted the reports for VOA Learning English. 17We want to hear from you. Write to us in the Comments section, and visit our Facebook page. 18________________________________________________________________ 19Words in This Story 20scan - v. to use a special machine to read or copy (something, such as a photograph or a page of text) into a computer 21decline - v. to refuse something 22cognition - n. the use of conscious metal processes 23task - n. a piece of work to be done 24negative - adj. bad or harmful 25concentrate - v. to direct attention or efforts toward a particular activity, subject or problem