Long term COVID-19
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  • Following recovery from severe COVID, there is evidence that it may cause long-term health changes 
  • Study reports "cognitive decline", equivalent to 8.5 IQ points less
  • This is equivalent to a cognitive decline by 10 years in severe-COVID-19 patients, research shows
  • The study’s results are likely to focus on the so-called "long COVID" cases

Dubai: Researchers have reported a brain-wasting effect of COVID-19, which until recently was commonly described as chronic fatigue and "brain fog". And it's a growing cause of concern among survivors of "long-COVID" as well as the medical fraternity. This, researchers said, could possibly lead to a "lasting mental damage". In the worst-case scenarios, this damage triggers "cognitive decline" — equivalent to the brain aging 10 years or losing 8.5 IQ points.

A team from Imperial College London made this claim and published their research in Medrexiv pre-print research server on October 21, 2020 (their work has yet to be peer-reviewed). The researchers stated they poured through data from medical records of 84,285 people.


decline in IQ of survivors of "long-COVID" suffering from a so-called "brain fog"

Their key hypothesis: the “brain fog” many survivors report experiencing in the weeks — and months — after recovering from the disease could be a symptom of "more serious cognitive defects". Moreover, people who recovered at home experienced an average deficit equivalent to aging five years or a drop of 4 IQ points. “In real terms, this is a large enough difference that as an individual you would notice an impact on the ability to cope with your normal job and everyday life,” said Dr Adam Hampshire, the lead researcher.

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A study published by British researchers recently gave a rather grim explanation of the mystery surrounding the so-called "brain fog" reported by many severe COVID-19 sufferers who, even months after recovery, say they are unable to concentrate on work or focus how they did before.

Dr Hampshire, who works with the Department of Brain Sciences, was supported by the UK Dementia Research Institute and Biomedical Research Centre at Imperial College London, as well as the Institute of Psychiatry, Psychology and Neuroscience at the King's College London.

Brain damage

Among the long-COVID survivors, the team detected varying degrees of brain damage, depending on disease severity. Case studies revealed neurological problems in severely-affected survivors. It is not clear how long the effect lasts, the researchers pointed out.

"Long COVID" and "Long haulers"
The team defines the "worst-hit" patients as those who required artificial respirator or were treated in intensive care. The term "long COVID" has been used to describe long-term health changes past acute symptoms, following infection of SARS-CoV-2 as confirmed by a polymerase chain reaction test.

"Long-COVID" is used as an alternate term for “long-haulers”, used to define COVID-19 patients who have continued showing symptoms for months after the resolution of the initial infection. They are a group of people reporting neurological problems — confusion and difficulty concentrating ("brain fog"), as well as headaches, extreme fatigue, mood changes, insomnia and loss of taste and/or smell.

Key findings: Cognitive deficits

As of part of the study, tens of thousands of individuals who recovered from suspected or confirmed COVID-19, were asked to undergo a standard assessment, via a detailed cognitive test and questionnaire data. What they found: the "long-COVID" sufferers performed worse on cognitive tests in multiple domains than would be expected given their age and demographic profiles.

The datasets were collected in collaboration with BBC2 Horizon. Their findings bolster the view that there are "chronic cognitive consequences" of having COVID-19.

"Shocking" results

Dr Hampshire warned that the “shocking” results did not only apply to patients who ended up in hospital. "This deficit scales with symptom severity and is evident amongst those without hospital treatment," they wrote, adding: "These results should act as a clarion call for more detailed research investigating the basis of cognitive deficits in people who have survived SARS-COV-2 infection."

The virus had been blamed for lung scarring, heart and kidney damage, as well as blood clots and strokes even in younger patients. Today, neurologists are only just beginning to understand the ways in which virus that has infected more than 46 million people globally and killed 1.2 million (as of November 1, 2020) — and counting — attacks the body. The pandemic has also decimated millions of jobs across the world.

CDC warning

A recent CDC warning states that it takes longer to recover from COVID-19 than the 10- to 14-day quarantine, initially touted as the recovery "window" throughout the pandemic.

In fact, one in five young adults under 34 was not back to their usual health up to 21 days (three weeks) after testing positive. And 35% of surveyed US adults overall had not returned to their normal state of health when interviewed two to three weeks after testing positive. A study on a smaller number of patients, 60 COVID-19 sufferers, published in The Lancet, found that 55% of them were still displaying such "neurological" symptoms during follow-up visits three months later.

Memory loss: what brain scans show

When doctors compared brain scans of these 60 COVID patients with those of a control group (not COVID-19 infected), they found the brains of the COVID patients showed structural changes correlating with memory loss and smell loss. The changes are not limited to adults. A case study published in JAMA Neurology in June highlighted four UK children with multisystem inflammatory syndrome, a severe and potentially fatal condition that appears to be linked to COVID-19.

These children developed neurological manifestations such as headaches, muscle weakness, confusion and disorientation. While two of the kids recovered, the other two continued to show symptoms, including muscle weakness so severe that they needed a wheelchair.


Indeed, the most severe illness and complications appear to stem from the body’s immune response to the viral invader, as opposed to the virus itself causing damage. There also some preliminary studies that suggest that this immune response could damage the nervous system.

In September, the University College of London warned about a potential brain damage “epidemic” caused by COVID-19 in the journal "Brain". The study examined 43 COVID patients treated in London in April and May, and found 10 cases of “temporary brain dysfunction” and delirium; 12 cases of brain inflammation; eight cases of strokes; and eight cases of nerve damage.

“We should be vigilant and look out for these complications in people who have had COVID-19,” said joint senior author Dr. Michael Zandi in a statement. “Whether we will see an epidemic on a large scale of brain damage linked to the pandemic — perhaps similar to the encephalitis lethargica outbreak in the 1920s and 1930s after the 1918 influenza pandemic — remains to be seen.”

Precedents in previous pandemics

There is evidence that a pandemic creates a wave of neurological health problems. Svenn-Erik Mamelund, a social scientist who has studied the demography of epidemic diseases for more than 20 years, was quoted as saying that there was a jump in reports of neurological and psychiatric problems worldwide for years after the 1918 "Spanish flu" pandemic.

Survivors complained of trouble sleeping, dizziness, depression and difficulties at work. And many people reported similar neurological symptoms after the 1889 Russian flu and the 2009 H1N1 pandemic.

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Survivors of the so-called "Spanish Flu" (1918-1920) complained of trouble sleeping, dizziness, depression and difficulties at work. And many people reported similar neurological symptoms after the 1889 Russian flu and the 2009 H1N1 pandemic.

US media quoted Dr. Zijian Chen, the medical director of Mount Sinai’s Center for Post-COVID Care in New York, as saying that has also been seeing patients with extreme fatigue and difficulty concentrating — for several weeks to months — after "recovery". “And this is important because, despite their illness being ‘over,’ they are having a lot of trouble returning to normal life,” he said.

Dr Chen said it’s too soon to say whether such post-COVID conditions will be chronic, but is worried about recovered patients being able to return to work and school. “Patients are going to be somewhat debilitated, so their ability to work, their contribution to the workforce, to the domestic product, is going to be reduced,” he said. “It will affect society on many levels if the rates [of infection and long-term illness] persist to be this great.”

Myalgic encephalomyelitis, chronic fatigue syndrome
A condition known as myalgic encephalomyelitis, also known as chronic fatigue syndrome (or ME/CFS), is described as similar in presentation to these long-term symptoms. ME/CFS is a neuroimmune syndrome marked by "brain fog" and extreme fatigue. It is a disabling and complex illness. People with ME/CFS are often not able to do their usual activities.

At times, ME/CFS may confine them to bed. People with ME/CFS have overwhelming fatigue that is not improved by rest. In the US, ME/CFS has caused an estimated $24 billion impact on the economy, based on medical bills and lost income from many patients being unable to work. Source: CDC].

Virus in spinal fluid, brain cells

To better understand how and why COVID-19 affects the brain, other research teams are at work. Some early hypotheses, listed by Johns Hopkins University, include severe cases of infection attacking the brain or spinal cord. In China and Japan, there were some cases that reportedly found the SARS-CoV-2 genetic material in spinal fluid. In the US, a case in Florida found viral particles in brain cells.

At the same time, some researchers think that the body's immune system could mount an overaggressive response to the viral infection, which cloud lead the body to inadvertently attack itself. Some other effects of the virus, such as fevers or organ failure in worst-case scenarios, could also cause brain dysfunction.

“So much of the focus right now still is how many people are getting sick and how many people are dying,” Dr. Chen said. “But it’s not just black and white, about getting better or dying,” he said. “There’s a whole gray spectrum of illness that can happen after COVID-19 that we haven’t even fully learned about yet.”