Melbourne: Scientists are extremely concerned about a new situation that has emerged in recent times, ‘Long Covid’. Covid patients have to deal with the symptoms of this disease for a long time. Research shows that at least 5-24 percent of the symptoms persist after three to four months. The risk of prolonged covid is no longer believed to be directly linked to age or the initial severity of covid disease. Therefore, younger people, and those with initially mild covid, may still develop symptoms of long-term covid. In some people, long-term covid symptoms start early and persist, while others appear well after the initial infection has passed. Its symptoms include extreme fatigue and difficulty in breathing. Chronic covid sufferers experience difficulties with tasks such as concentrating and planning – known as “brain fog”. In such a situation, the question arises that how does Covid affect the brain?
How does the corona virus reach our brains?
In the records of the Spanish flu pandemic of 1918, cases of dementia, loss of perception, and difficulties with physical activity and sleep abound. Evidence from the SARS outbreak in 2002 and the MERS outbreak in 2012 suggests that about 15–20 percent of people who have recovered from these infections experienced depression, anxiety, memory difficulties and fatigue. There is no conclusive evidence that the coronavirus that causes COVID-19 can penetrate the blood-brain barrier, which normally protects the brain from large and dangerous blood-borne molecules entering the bloodstream. But statistics are showing that it can reach the brain through the nerves connecting our nose to the brain. Researchers suspect this because in many infected adults, the genetic material of the virus was found in the part of the nose that starts the process of smell.
How does Covid damage the brain?
These nasal sensory cells connect to an area of the brain called the “limbic system”, which is involved in emotion, learning, and memory. In a UK-based research released as pre-print online in June, researchers compared images of people’s brains before and after exposure to Covid. They found that the size of parts of the limbic system decreased in infected people compared to non-infected people. This may indicate vulnerability to brain diseases in the future and may play a role in the emergence of long-term covid symptoms. COVID can also indirectly affect the brain.
The virus can damage blood vessels and cause either bleeding or blockage, resulting in a blockage in the supply of blood, oxygen, or nutrients to the brain, especially in areas responsible for problem solving. The virus also activates the immune system, and in some people, it increases the production of toxic molecules that can impair brain function. Although research is going on on this, but the effects of Covid on the nerves that control the function of the intestine should also be looked at. It can affect digestion and the health and composition of gut bacteria, which are known to affect brain function. The virus can also affect the function of the pituitary gland.
The pituitary gland, often referred to as the “master gland”, controls hormone production. This includes cortisol, which controls our response to stress. When cortisol is deficient, it can contribute to chronic fatigue. Given the already large proportion of brain disorders in the global burden of disability, the potential long-term impact of COVID on public health is enormous. The answers to key questions about long-term covid are not yet known, including how the disease is caught, what the risk factors may be and the extent of the consequences, as well as the best way to treat it. No matter how many questions there are, one thing is certain that we will have to keep making every effort to stop the increase in the cases of Covid, which includes getting the Covid vaccine as soon as possible.