Researchers are learning that the coronaviruses can cause long-term damage.
Kateryna Kon is a science source.
Many people are still struggling with memory problems months after a bout with COVID-19. The disease can cause long-term harm to the brain.
A lot of people are suffering according to a professor.
A study led by Frontera found that more than a third of hospitalized patients had developed a new neurological disorder after being exposed to COVID-19. Half of the patients who survived were still having cognitive problems six months later, according to a follow-up study.
Bleeding, blood clot, inflammation, oxygen deprivation, and disruption of the protective blood-brain barrier are threats to the brain. There is new evidence that the virus may kill certain brain cells.
Geidy Serrano is the director of the laboratory of neuroscience at Banner Sun Health Research Institute. She says that anything that affects the brain could be significant.
Scientists at the California National Primate Research Center at UC Davis have come up with some new insights into how COVID-19 affects the brain.
John Morrison, a neurology professor who directs the research center, says that when COVID-19 arrived in the U.S., the team set out to understand how the virus was infecting the animals' lungs and body tissues.
Morrison suspected that the virus might be infecting an organ that hadn't received much attention.
He says he wanted to take the brains. We have a collection of brains from various experiments and we're just starting to look at them.
A result of that research has generated a lot of interest among scientists.
Morrison presented some of the research at the Society for Neuroscience meeting in November.
There is conflicting evidence on whether the brain cells are being affected by the virus.
The monkeys' brains are easier to study because they come from a close relative of humans, and scientists know exactly how and when each animal brain was exposed to the disease.
The monkey model is not perfect. COVID-19 tends to produce milder symptoms in animals than in people.
Morrison says that scientists are likely to find human neurons if they look closely.
He says that they are looking at individual neurons at very high resolution so that they can see evidence of an illness.
He suggests that the monkeys have some important COVID-19 risk factors with people.
The monkeys appeared to have an infections that started with the nose. Morrison says that within a week the virus had spread to other areas of the brain.
"This is where you get into some of the neurologic symptoms that we see in humans, like cognitive impairment, brain fog, memory issues, and changes in mood," he says. I think the virus is in the regions that are involved in those behaviors.
That hasn't been confirmed by people. Other researchers have found evidence that the virus can be passed on.
A draft of a study of brains from 20 people who died of COVID-19 found that four of them contained genetic material indicating that they had been exposed to the disease.
Serrano says that the virus seemed to have entered through the nose.
She says that the olfactory bulb is located on top of your nose. She says that it could be a route for the virus to get from the respiratory system to the brain.
Serrano says the virus appears to be able to kill nerve cells in the olfactory bulb, which may explain why many COVID patients lose their sense of smell.
The team found less evidence of infections in other brain areas.
That could mean that the virus is damaging the brain in other ways.
Studies show that the virus can cause infections in the cells that line the blood vessels and in the brain. When the immune system goes after these cells, it could kill nearby neurons and cause neurological problems.
COVID-19 can cause blood clot or bleeding that can cause a stroke. It can damage the protective cells that create what's known as the blood-brain barrier, allowing entry to harmful substances. A person's lungs can be so damaged by the disease that their brain is no longer getting enough oxygen.
The indirect effects appear to be a bigger problem than the direct infections of the neurons.
She says that people have seen the virus in brain tissue. She says that the brain tissue is not next to where there is injury or damage.
The virus doesn't have much effect on brain cells, and that's what Frontera suspects. Some scientists think the virus may be removed from the brain after it has caused long term damage.
COVID-19 presents a serious threat to the brain regardless of the mechanism.
A team of researchers studied levels of toxic substances in older COVID patients who were hospitalized.
The levels were higher than what we see in patients with Alzheimer's disease, which is a very severe level of brain injury.
It's not clear how long the levels are high. She is concerned that COVID-19 may be causing brain injuries that increase the risk of developing Alzheimer's later in life.
According to research, patients who experience severe neurological problems tend to improve over time.
She says that patients had improvement in their cognitive scores.
Half of the patients in the study weren't back to normal after a year. "We need to speed up our processes to offer some kind of therapy for these people," says Frontera.
It's important to treat the person early in the disease, rather than when the disease has advanced so much that it can't be reversed.
The best way to prevent brain damage is to get a vaccine.
