Slowness, blurriness, lack of intellectual clarity… a feeling of mental fog has been felt by many people who have suffered from a coronavirus infection during the Covid-19 pandemic. At present, the way in which the virus can affect our brain is of increasing interest to researchers.
Studies have established that the coronavirus leaves a mark on the brain, but more work needs to be done to understand how it works and develop curative treatments.
Ziyad Al-Aly, chief of research and development at the VA St. Louis Health Care System and a clinical epidemiologist at Washington University in St. Louis, USA, has studied the effects of long Covid. In a paper published by The Conversation, It takes stock of what scientists have discovered about how coronavirus infection can affect the brain.
A profound change in the brain
People who had Covid-19 were at increased risk of cognitive deficits such as memory problems. Studies have found reduced brain volume and altered brain structure after infection. The virus triggers a fusion of brain cells that short-circuits the brain’s electrical activity. It also causes inflammation in the brain and changes the ability of brain cells to regenerate.
A study of people who had mild to moderate Covid-19 found prolonged brain inflammation, as well as changes estimated to correspond to 7 years of normal brain aging. In severe cases, cognitive decline can be equivalent to 20 years of normal aging. Covid-19 also increases the risk of developing dementia in people over 60.
Intelligence quotient down
Dr. Ziyad Al-Aly reports that a study conducted on 113,000 people who had Covid-19, and published in the New England Journal of Medicinerevealed the presence of significant deficits in memory and performance in executive tasks. Individuals who have contracted the delta and omicron variants are also affected.
« In the same study, cognitive decline equivalent to a loss of three intelligence quotient (IQ) points was observed in people who had contracted mild forms of Covid-19, and in whom the disease had been cured without complications. “, adds the researcher.
« Patients with unresolved symptoms, such as persistent shortness of breath or exhaustion, lost six IQ points. Individuals who had been admitted to intensive care units lost nine IQ points. Reinfection with the virus contributed to an additional loss of two IQ points. »
“Years, even decades of concerted effort”
Another study conducted between March 2020 and April 2023, involving more than 100,000 people, once again reveals a deterioration in memory function, up to 36 months after obtaining a positive result from a SARS-CoV-2 screening test.
« Overall, the results of these studies indicate that COVID-19 poses a serious risk to brain health, even when the disease presents in a mild form. “, worries Ziyad Al-Aly.
In 2022, nearly 15% of Europeans reported experiencing memory and concentration problems. The consequences of Covid-19 are vast. They concern both the health of individuals, but also society and the economy. Unraveling the causes of these cognitive disorders, and in particular the origin of brain fog, will require years, if not decades, of concerted effort, involving researchers from around the world. “, concludes the researcher.
Source: www.topsante.com
