Breaking news! COVID-19 can actually damage the brain!

When it comes to the new coronavirus, the first thing that comes to mind is the infection rate and mortality rate. I believe that the sequelae of the new coronavirus are also the focus of everyone's attention. In fact, scientific researchers have been working hard and have observed problems such as decreased sense of smell, decreased memory, and damage to the reproductive system in the early stage.

In the early morning of March 8, the top scientific journal Nature published a study on COVID-19 and brain damage in an accelerated preview.

This is another major study following a series of previous studies on the sequelae of COVID-19, and it also reveals the potential harm caused by COVID-19.

01. Coronavirus and brain damage

Researchers from the University of Oxford and other institutions selected people from the UK Biobank for their study.

A total of 785 cases were included, all of whom underwent two brain imaging sessions, with an average interval of about 141 days.

Among them, 401 cases were infected with the new coronavirus during the two scans, thus forming the experimental group and control group of 401vs384.

Next, their brain images were compared and it was found that significant changes occurred in the brain after infection with the new coronavirus.

Look at the picture directly. The blue line represents the control group, and the orange line represents the COVID-19 patients. The content of the comparison includes four aspects: the left parahippocampal gyrus, the left orbitofrontal cortex, the piriform cortex, and the olfactory cortex. Compared with the control group, these contents of the COVID-19 patients showed longitudinal differences.

In addition, there are obvious changes in the gray matter of the brain. The gray matter of the brain is what we often call the cortex, which is the core part of our thinking and reaction.

Therefore, many people have experienced cognitive decline after being infected with the new coronavirus, which is also reflected in this test.

The above studies also support the patients’ symptoms to a certain extent. For example, some people have decreased cognitive ability, which may be related to the decrease in gray matter thickness, and some people have impaired sense of smell, which is also clearly reflected in the damage to the olfactory-related areas.

In general, the study believes that after being infected with the new coronavirus, the brain will be affected in the following ways:

1. Greater cortical thickness reduction in the left orbitofrontal cortex and left parahippocampal gyrus

2. Partial damage to the olfactory cortex

3. Overall brain volume declines faster.

Left parahippocampal gyrus, left orbitofrontal cortex, piriform cortex, and olfactory cortex

02. About infectious diseases

Many times, we tend to use simple infection rate and mortality rate to measure an infectious disease, and even call the new coronavirus a "large-scale flu." In fact, such an evaluation is somewhat insufficient, because many infectious diseases are not just contagious and lethal, but more of an intermediate state, that is, people are not dead yet, but have left sequelae.

A typical example is poliomyelitis, which was once a rampant infantile paralysis. After infection, this disease will cause serious consequences on the patient's physical development and cause disability.

In addition, many diseases will cause some apparent loss of overall health. For example, some diseases will induce related diseases and shorten their survival period.

ref.

Douaud, G., Lee, S., Alfaro-Almagro, F. et al. SARS-CoV-2 is associated with changes in brain structure in UK Biobank. Nature(2022).

https://doi.org/10.1038/s41586-022-04569-5