Only recently, scientists began to discover that the effects of the emerging coronavirus do not depend on the respiratory system, and that in some cases, which do not necessarily have a record of previous chronic diseases, they have affected the brain and nervous system as well. These findings appear after a number of medical personnel have been able to autopsy the victims. In this article from the newspaper "Neweastest", the researcher and writer, Jessica Hamzelu, discusses what this discovery means regarding the treatment method and the forecast of the course of the disease.
Jennifer Frontera had been treating ICU patients for years, but had never had an experience like the Covid-19 pandemic before, and the New York-based doctor says: "These patients are among the sickest people I've ever encountered." But strangely enough, Frontera is not a lung specialist or even a virus specialist, she is a neurologist, and the potential effect of coronavirus on our brains is what causes her concern.
The matter was at the beginning of the outbreak in New York when Frontera and her colleagues began to notice neurological symptoms in Covid-19 مرض patients, as people lost consciousness before being admitted to hospitals, and as soon as medical personnel started responding until some abnormal movements appeared, some suffered seizures Neurological symptoms, while others have suffered strokes, and similar reports come from other hospitals around the world.
This is an amazing discovery in a disease that was generally considered to attack the air passages as much as a restless discovery. One of the important questions is how the emerging corona virus causes all of these symptoms, as increasing evidence indicates that the virus may reach the brain and attack nerves directly. If that is the case already, we may have to reconsider some of the treatments that are currently being developed for Covid-19 ″, and we must also prepare for chronic long-term neurological conditions in some survivors.
Millions of people around the world have been infected with the emerging coronavirus, but we still do not know how it works. This may be the whole tale for many people who have had either mild or no symptoms at all, but some will get very sick, showing flu-like symptoms that can develop into pneumonia that makes breathing difficult.
Initial symptoms reported by the World Health Organization initially included fever, fatigue, dry cough, sore throat, headache and sporadic soreness, along with cold, nausea or diarrhea in some cases. But in response to increasing reports of people losing their sense of smell and taste, the World Health Organization and the US Centers for Disease Control and Prevention have expanded the list of symptoms to include a loss of these senses. A study of 214 patients who had been hospitalized with HIV in China found that 5.6% of people had temporarily lost their sense of taste, while 5.1% of those who had lost their sense of smell temporarily.
While reports from Europe indicate that these symptoms may be more prevalent than that, as a survey of 417 patients treated in 12 hospitals across Belgium, France, Spain, and Italy found that about 86% of those affected had a degree of change in their ability to Smell, and that 89% of people have experienced a "low or deformed" ability to taste flavors.
There are other neurological symptoms that are emerging, with some people with "Covid-19" experiencing headaches and dizziness, while those who have more serious diseases can test for neurological attacks or strokes, and some of them are young adults who do not have any previous medical condition, and it is believed that results This type is rare, but we don't know the exact numbers yet. An evaluation of 214 patients in China found that 6% of those with serious diseases had developed a condition in which the infected blood reached the brain, says Frontera, who works at New York University's Langon Hospital: “We have seen cases of strokes and bleeding,” other reports have indicated. Cerebral inflammation and brain damage in people who have had severe cases of Covid-19.
But in some diseases, the nerve damage is associated with other problems inside the body, not as a result of the nurse, who attacks the nervous system directly. But in this case as well, it is possible for the virus to find its way into the brain and nervous system, which is what many viruses that infect humans do, including corona viruses. Pierre Talbot of the National Institute for Scientific Research in Quebec, Canada has been studying corona viruses since the 1980s, and much of his research work has focused on two corona viruses known to be infected with humans; The "HCoV-OC43" virus and the "HCoV-229E" virus, both commonly cause the common "cold" role.
We know that both viruses are able to infiltrate the nervous system and the brain, and Talbot says: “When I insert the OC43 virus into the lab’s mouse nostril, the virus goes straight to the brain through the olfactory nerve, and when the brain reaches it, it spreads”, here the virus can Killing nerves and causing encephalitis. Similar effects have been observed, but more rarely, in people with the "OC43" virus, and Talbot refers to the condition of an 11-month-old infant who had a weak immune system and died of encephalitis, and an autopsy revealed the presence of "OC43" in his brain, which is what Confirm the involvement of the virus.
When Talbot and his colleagues searched for "229E" and "OC43" viruses in the brains of 90 people who donated their bodies to science before death, they had found at least one of these viruses, or both in some cases, in almost half of the cases, where 44% had Of them, "229E" and 23% were "OC43" in the brain.
The SARS virus, another Corona virus similar to the Covid virus, appears to behave in similar ways. The first outbreak of the SARS virus occurred between 2002 and 2003, killing 8,000 victims. Like the Corona virus that causes Covid-19 مرض disease, the SARS virus also causes lung disease that can lead to fatal pneumonia in about 10% of infected cases. But the autopsy performed after the outbreak ended reveals that the virus can It also reaches the brain. In 2005, a medical team looked at eight bodies whose owners had died from SARS and found the virus in their brains.
When the researchers inserted the virus through the lab mice, they later found the virus in the brain stem, and the brain stem falls between the brain and spinal cord and is also responsible for regulating breathing, says Igor Corralink, of the University of Northwestern University Medical School in Chicago, who studies diseases that Infecting the central nervous system: "You can expect that this could exacerbate respiratory failure in these patients."
What about the new Corona virus? Several reports claim to have found the virus in the cerebrospinal fluid in people with "Covid-19 ″," which indicates that it has reached the brain and nervous system, says Avendra Nath of the US National Institute of Neurological Disorders and Strokes.
However, there is a possibility for this virus to reach a sample of the fluid without infecting the brain. If the virus is in someone’s blood, this may contaminate the sample taken during a lumbar puncture, for example. Neurological symptoms can also be caused by a lack of oxygen. People who die as a result of “Covid-19” suffer serious lung damage, as the surface surfaces of the alveoli increase in thickness, making it harder for oxygen to enter the blood, says Sanjay Mukabadiye from Cleveland Ohio Clinic.
That may explain why there are signs of brain damage during a CT scan of these Covid-19 survivors after they have been treated with respirators, says Frontera. This damage could be a result of a lack of oxygen in the brain. And the response of the immune system to infection can be a cause of brain damage as well, as an overreaction of the immune system can lead to what is known as a cytokine storm, an acute activation of immune cells that can exacerbate inflammation and organ damage. But given the evidence we have up to now, it makes sense to assume that the virus reaches the brain, says Nath. If true, it will be crucial for us to learn how to attack the virus in the brain, as "that will make a big difference in how we treat patients," he says.
Currently, many antiviral therapies under development to counter Covid-19 will focus on delivering medications to the lungs, and delivering medications to the brain is another type of challenge altogether. For a start, any treatment will have to cross the blood-brain barrier, a protective layer in the brain that controls how we got there, and most medications can't do it, as Nath says, "the treatment approach will be completely different."
Based on the evidence in our hands, it appears that the virus passes into the brain, and if true, then this means that the disease will have long-term neurological consequences. We know that some viruses have the ability to hide inside the nerves, in order to revitalize themselves so that the patient is harmed at a time Later in his life. The herpes simplex virus, for example, usually causes skin ulcers or genital warts, but in some people it can cause encephalitis, once a person has it, the virus hides in his nerves so that he will reactivate himself later in his life.
"It is not impossible that Corona virus has the same continuity in the brain," Talbott says. "We have seen both viruses 229E and OC43 in human brains. The virus appears to be hiding there, and it is expected that it will be able to reactivate itself by causing a patient neurological disease." Some neurological effects can be accompanied by permanent damage to people recovering from “Covid-19 ″, nerve attacks and strokes can cause brain damage that have long-term consequences, for example, and many of those who experience this kind of consequences will They need aftercare and rehabilitation.
The virus can also return to longer-term secondary problems, some of which can come in the form of post-virus fatigue syndromes. There is also concern about Guillain-Barre syndrome, which is diagnosed with impaired peripheral nerve function; "As if it is an ascending paralysis, it starts at the feet and continues upwards," Nath says. Some cases are temporary, while others experience a permanent disability that may end in death.
There is growing evidence that Gillane Barre can develop in some people recovering from "Covid 19". To date, reports on this matter have been received in a number of countries. For example, across three hospitals in northern Italy, over a three-week period in March, doctors observed five cases of Guillain Barre between 1,000 and 1,200 cases recovering from "Covid-19 ″," and Corralink says: "This number is very large, It is much larger than what you would expect in a population in the absence of "Covid-19, and we will likely see more of these cases."
It is not yet clear which cases develop neurological symptoms and which develops secondary disorders, but it is clear that many people in health care and those with "Covid-19" who have recovered will need subsequent health care from their care centers, perhaps for years. Some of Frontera's patients who were already on ventilators are showing signs of severe brain damage, and they say "their awakening is very low." While it is still unclear after the possibility of injuries of this type are less severe, she adds: "We are still learning about Covid, and it will take months before we have a good idea of the expectations of the course of the disease."
Beyond the temporary loss of smell and taste, most neurological effects seem to occur only in acute cases of Covid-19. And if we do not yet have exact numbers, but it seems that only a limited group of people who will cause severe damage to their brains and nervous systems, Nath says that it is possible, in some cases, brain damage to be permanent, and he adds that "brain diseases can affect what we are Therefore, it can change our personality, the way we speak and move, and cause all kinds of long-term consequences, even if the percentage is simple, then the scale of the destruction can be great, and we must not underestimate the matter. "
The autopsies carried out on the victims of "Covid-19" will help clarify many questions about whether the virus is able to access the brain and what it does with it, but until now there are very few tests that have been done in this regard, where Avendra Nath says that " Many of the autopsies are not equipped to deal with this type of injury, and many institutions have refused to perform autopsies on these patients. "
And for those who perform the autopsies, it is very difficult to hold the brain tissue, says Desiree Marshall of the University of Washington, Seattle: "Removing the skull requires the use of a bone saw that generates the aerosol that can carry the virus," and this type of procedure should It is performed with dissection uniforms that have special suction systems that prevent the air from penetrating into other rooms, and pathologists need appropriate equipment.
To date, Marshall's team has conducted four tests of the brains of people who died after Covid-19 ″, among them a brain that appears to show signs of damage that is evident through very slight bleeding above the surface of the brain and in the bloodstream.
Michelle Osborne, who oversaw the development of the autopsy services at the newly built Nightingale Hospital in the London Excel Center, was also looking for signs of damage caused by "Covid-19", and until the moment he and his team had completely dissected six bodies.
In these bodies, they discovered changes in the blood vessels of the brain, which affect the amount of oxygen-carrying blood that can reach the brain. In these cases, it appears that the brain tissue has been damaged due to the lack of adequate oxygen, but it is difficult to know if this is a direct effect of the virus that reaches the brain or as a result of breathing difficulties.
Both teams will have to search for the same virus in brain tissue, but that will not be easy either, and Osborne says that "brain tissue requires a lot of time in analysis." Looking at them together, these challenges mean that we still don't know yet if the virus is attacking brain cells directly. "We haven't found a virus in the brain yet, but I wouldn't be surprised if the rest of the teams did that," she said.
Covid-19 disease is first and foremost a disease that affects the air passages and causes severe damage to the lungs, but doctors have been seeing signs of damage throughout the body. While hospitals were trying to increase the number of respirators they had, they were running out of dialysis equipment for "Covid-19" patients who were suffering from kidney failure.
Problems in the digestive system were also observed, and while many people died from hypoxia-induced blood deficiency as a result of breathing difficulties, others died from multi-organ failure, such as heart and liver damage.
What is going on? It is possible that the virus reaches a number of organs traveling through the vascular channels, says Mocabadiye of the Cleveland Ohio Clinic. We know about the virus that connects to the lungs, the device that has huge blood supply, and says, "It is easy for these infections to reach the duct." Bloody blood, and as soon as the virus enters the blood, any organ becomes in its net. "
But inflicting the virus directly into these organs remains another matter, as organ failure is usually caused by a serious disease, usually due to the behavior of the body's immune system. People who live on respirators are struggling to get enough oxygen, and there is a special risk that surrounds them. “When people develop this severe degree of lung injury, many other organs fail, and this is not strange to Coffed,” he says. Disease experts, including Mocabadiye, are now beginning to search for the virus within organs that have been donated by people who have died from the disease.
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This report is translated from New Scientist and does not necessarily reflect the location of Meedan.