complications Archives - First Washington News

Artwork showing internal brain anatomy. — In people with severe COVID-19, central nervous system complications may be more common than initially estimated. Mental Art + Design/Stocksy

A large international study suggests that around 1 in every 100 patients hospitalized with COVID-19 have brain complications.
These include stroke, brain hemorrhage, and other potentially fatal conditions.
Many of the patients had preexisting illnesses, such as high blood pressure, heart disease, and diabetes.
Previous research has shown that some people who recover from COVID-19 have lingering neurological and psychiatric symptoms.

As the COVID-19 pandemic wears on, experts increasingly recognize that SARS-CoV-2, the virus that causes the disease, affects areas beyond the lungs. It can also infect the kidneys, gut, and blood vessels, for example.

In addition, COVID-19 can cause a range of neurological and psychiatric symptoms.

One telltale symptom is a loss of taste or smell, which indicates that SARS-CoV-2 can infect the peripheral nervous system. But the virus can also affect the central nervous system, producing symptoms such as headaches, dizziness, confusion, and seizures.

Now, a large international study led by researchers at Thomas Jefferson University, in Philadelphia, has found that around 1{cfdf3f5372635aeb15fd3e2aecc7cb5d7150695e02bd72e0a44f1581164ad809} of patients hospitalized with COVID-19 develop potentially fatal brain complications.

These include strokes, bleeding, and inflammation called encephalitis.

“Much has been written about the overall pulmonary [lung] problems related to COVID-19, but we do not often talk about the other organs that can be affected,” says Dr. Scott H. Faro, a professor of radiology and neurology at the university, who also led the study.

“Our study shows that central nervous system complications represent a significant cause of morbidity and mortality in this devastating pandemic,” he explains.

The researchers presented their currently unpublished results at the annual meeting of the Radiological Society of North America, in Chicago. The study has yet to be peer reviewed, and only a summary of the results is available.

The retrospective, observational study involved almost 40,000 patients, who were hospitalized with COVID-19 at any of seven university hospitals in the United States or four in Western Europe.

The participants’ average age was 66 years, and there were twice as many men as women.

Many had preexisting conditions, such as heart disease, diabetes, or high blood pressure, which is also called hypertension.

Among those who had undergone a brain MRI or CT scan, 442 patients had brain-related complications attributable to COVID-19.

This suggests that around 1.2{cfdf3f5372635aeb15fd3e2aecc7cb5d7150695e02bd72e0a44f1581164ad809} of the total patient group had a brain complication as a result of the disease.

The most frequent complications were:

ischemic stroke: 6.2{cfdf3f5372635aeb15fd3e2aecc7cb5d7150695e02bd72e0a44f1581164ad809}.
hemorrhage, or bleeding: 3.72{cfdf3f5372635aeb15fd3e2aecc7cb5d7150695e02bd72e0a44f1581164ad809}.
encephalitis: 0.47{cfdf3f5372635aeb15fd3e2aecc7cb5d7150695e02bd72e0a44f1581164ad809}.

More rare complications included inflammation of the brain and spinal cord, which is called acute disseminating encephalomyelitis, and encephalopathy syndrome, which causes symptoms similar to those of a stroke.

“It is important to know an accurate incidence of all the major central nervous system complications,” Dr. Faro says, noting, “There should probably be a low threshold to order brain imaging for patients with COVID-19.”

Overall, brain complications appeared to be about three times as common among patients in Europe, compared with those in the U.S.

The study could not explain the factors behind this disparity. However, doctors detected strokes more often in COVID-19 patients in the U.S. than in Europe.

“The one feature that is likely a contributing factor is: There was an increase in comorbidities (cardiac, diabetes, and chronic [kidney] failure) in the U.S. population [compared with] Europe,” Dr. Faro told Medical News Today.

Currently, the direct role that the viral infection of the central nervous system plays in the neurological complications is unclear.

Overactivation of the immune system, inflammation, dehydration, and low oxygen levels, an issue called hypoxia, are also likely to be important factors.

“The [central nervous system] complications of COVID-19 are multifactorial and [involve] both the direct spread of the virus from the lungs and nasal mucosa, as well as indirect autoimmune factors and physiological changes (hypoxia, inflammation, dehydration),” Dr. Faro told MNT.

“More research is needed to better [understand] this,” he added.

The acute effects of COVID-19 on the central nervous system may result in lingering neurological and cognitive symptoms.

A study published in October found that some people who recover from the infection experience cognitive impairments, such as problems with concentration and memory, often called brain fog, for several months.

There may also be long-term effects on mental health.

A study published in May found that in the 6 months after recovering from COVID-19, 13{cfdf3f5372635aeb15fd3e2aecc7cb5d7150695e02bd72e0a44f1581164ad809} of participants received a first diagnosis of a neurological or psychiatric condition.

The most common diagnoses were anxiety disorders, mood disorders, substance misuse disorders, and insomnia.

Neurological diagnoses were less common, and included strokes, dementia, and brain hemorrhages.

It is unknown whether COVID-19 was directly responsible for these neurological and psychiatric conditions.

The senior author of this study, Paul Harrison, a professor of psychiatry at the University of Oxford, told MNT that he and colleagues are conducting a follow-up study to see whether the effects continue beyond the 6-month period.

“We are looking at longer-term outcomes now and hope to have [our] study completed early next year,” he said.

Older adult receiving a vaccine from a healthcare worker — A health worker administers the AstraZeneca COVID-19 vaccine at a mass vaccination center at Holm View Leisure Centre on March 2, 2021, in Barry, Wales. Matthew Horwood/Getty Images

Vaccines are proving effective at reducing SARS-CoV-2 infections, hospitalizations, and deaths.
All approved vaccines have been through randomized clinical trials to test their quality, safety, and efficacy.
However, the rapid development of the COVID-19 vaccines means that these trials were not large enough to detect very rare adverse events.
A recent study found that the risk of neurological complications was higher in people with a positive COVID-19 test than in those who had received COVID vaccines.

COVID-19 vaccines undergo testing in large randomized clinical trials before being licensed for use.

The Oxford-AstraZeneca (ChAdOx1 nCoV-19) vaccine underwent testing in more than 11,000 people from across the United Kingdom and Brazil. Additionally, over 43,000 individuals engaged in testing for the Pfizer-BioNTech (BNT162b2) vaccine trial.

Despite the large size of these studies, they were not able to detect very rare adverse events — those that occur in fewer than 1 person out of 10,000.

As more of the world’s population becomes vaccinated against SARS-CoV-2, the risk–benefit evaluations of these vaccines are increasingly important.

Identifying rare adverse events associated with the vaccines is now a global scientific priority.

An increased risk of cerebral venous sinus thrombosis following the Oxford vaccine is one example of a rare adverse event associated with the vaccines. Some countries have limited the use of this vaccine in low-risk individuals until researchers have collected further information.

Scientists in the U.K. recently completed a large, population-based study. They compared the risk of neurological complications in people with a SARS-CoV-2 infection with individuals who had recently received a first dose of either the Oxford-AstraZeneca or Pfizer-BioNTech vaccines.

Their results appear in Nature Medicine.

Although SARS-CoV-2 predominantly affects the respiratory system, there is evidence that coronaviruses can attack the nervous system. This may result in various complications.

Very rare neurological events also have links with COVID-19 vaccines, including transverse myelitis, Guillain-Barré syndrome, and Bell’s palsy.

Researchers at the University of Oxford, U.K., led the recent study to investigate these very rare events by taking real-world data from over 32 million healthcare records of vaccinated people in England.

This data included 2 million individuals with a positive SARS-CoV-2 test — of these, about 90{cfdf3f5372635aeb15fd3e2aecc7cb5d7150695e02bd72e0a44f1581164ad809} tested positive before vaccination.

The scientists calculated the risk of developing neurological complications within 28 days of a first dose of either the Oxford-AstraZeneca or Pfizer-BioNTech vaccines or within 28 days of a positive SARS-CoV-2 PCR test.

The results indicated an increased but low risk of Guillain–Barré syndrome and Bell’s palsy following a first dose of the Oxford–AstraZeneca vaccine. There was also an increased but low risk of hemorrhagic stroke following a first dose of the Pfizer–BioNTech vaccine.

The authors estimated 60 excess cases of hemorrhagic stroke per 10 million people who had received the Pfizer-BioNTech vaccine and 123 extra events of encephalitis meningitis and myelitis per 10 million people with a SARS-CoV-2 infection.

They also estimated 38 excess cases of Guillain–Barré syndrome per 10 million people receiving the Oxford-AstraZeneca vaccine and 145 excess cases per 10 million individuals after a positive SARS-CoV-2 test.

Using a set of data from Scotland, the authors were able to replicate the key finding that the Oxford-AstraZeneca vaccine was associated with an increased risk of subsequent Guillain–Barré syndrome.

These results suggest a greater risk of developing neurological complications following a SAR-CoV-2 infection than following either vaccine.

Prof. Carol Coupland from the University of Nottingham in the U.K. — one of the authors of the paper — says, “this analysis provides important information about which neurological conditions could be linked with COVID-19 vaccination or infection.”

“Overall, the findings from this study show that the risks of hospital admission with nervous system complications associated with COVID-19 infection are greater than the risks associated with COVID-19 vaccinations; highlighting the benefits of the ongoing vaccination programs.”

– Prof. Coupland

The authors of the paper note there were limitations to this study, which need acknowledging:

The data came only from England, although there was some data from Scotland in the secondary analysis. Therefore, rates of complications might vary between populations.

The analysis only looked at hospital admissions and mortality, meaning it may not have included anyone with milder neurological conditions. Therefore, the scientists could have underestimated the overall rates of neurological adverse events from vaccination and infection.

Due to data limitations, the researchers could only examine risks associated with the first vaccine dose.

Scientists will need to monitor these rare events continually as younger people are vaccinated. Although rare, these events can cause lifelong problems, including disabilities, which may require long-term care.

The study authors say that further work is necessary to investigate the link between the Oxford-Astrazeneca vaccine and Guillain-Barré syndrome. They suggest antibodies against the vaccine may react with components of the peripheral nerves.

The authors hope this study provides information that may help with earlier diagnosis and planning the allocation of healthcare resources. Understanding these events will also help establish clinical practice moving forward with a vaccinated population.

Dr. Martina Patone, a medical statistician at the Nuffield Department of Primary Care Health Sciences at the University of Oxford, and co-lead author, tweeted:

“Due to limited sample size, clinical trials cannot detect very rare adverse events [rarer than 1 in 10,000]. Therefore, vaccine surveillance continues after the vaccine is in use. Understanding the adverse events of each vaccine may change or update recommendations and assure their safety.”

Medical News Today spoke with Prof. Saad Shakir, Director of the Drug Safety Research Unit in Southampton, U.K., who was not involved in the study. For him, the take-home message is that “COVID-19 vaccines have been remarkably safe. [And] there has been only a small number of very rare adverse reactions.”

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