Mortality rates remain low. Ho-hum.
Americans will be stupider than they used to be. You can thank Trump for
dumbing you down even more:
How Covid-19 can damage the brain
Some scientists suspect that Covid-19 causes respiratory failure and
death not through damage to the lungs, but the brain and other
symptoms include headaches, strokes and seizures.
For Julie Helms, it started with a handful of patients admitted to her
intensive care unit at Strasbourg University Hospital in northeast
France in early March 2020. Within days, every single patient in the ICU
had Covid-19 and it was not just their breathing difficulties that
They were extremely agitated, and many had neurological problems
mainly confusion and delirium, she says. We are used to having some
patients in the ICU who are agitated and require sedation, but this was
completely abnormal. It has been very scary, especially because many of
the people we treated were very young many in their 30s and 40s, even
Helms and her colleagues published a small study in the New England
Journal of Medicine documenting the neurological symptoms in their
Covid-19 patients <https://www.nejm.org/doi/full/10.1056/NEJMc2008597>,
ranging from cognitive difficulties to confusion. All are signs of
encephalopathy (the general term for damage to the brain) a trend
that researchers in Wuhan had noticed in coronavirus patients there in
Now, more than 300 studies from around the world have found a prevalence
of neurological abnormalities in Covid-19 patients, including mild
symptoms like headaches, loss of smell (anosmia) and tingling sensations
(arcoparasthesia), up to more severe outcomes such as aphasia (inability
to speak), strokes and seizures. This is in addition to recent findings
that the virus, which has been largely considered to be a respiratory
disease, can also wreak havoc on the kidneys
heart <https://onlinelibrary.wiley.com/doi/abs/10.1002/ejhf.1871>, and
just about every organ system in the body.
We dont know yet if the encephalopathy is more severe with Covid-19
than with other viruses, but I can tell you weve been seeing quite a
lot of it, says neurologist Elissa Fory of the Henry Ford Foundation in
Detroit, Michigan. As the number of cases increases, you will start to
see not only the common manifestations but also the uncommon
manifestations and were seeing them all at once, which is not
something any of us have encountered in our lifetimes.
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Estimates of exact prevalence vary, but it seems that roughly 50% of
patients diagnosed with Sars-CoV-2 the virus responsible for causing
the illness Covid-19 have experienced neurological problems.
The extent and severity of these neurological issues has flown largely
under the radar. Most people, including physicians, may not recognise
neurological abnormalities for what they are when they appear someone
experiencing a seizure may simply look dazed, without any trembling or
shaking. With its beeping machinery, sedative drugs and bed-bound
isolation, an ICU environment can exacerbate and induce delirium,
confounding our ability to link any symptom to the virus.
Further complicating matters, many people suffering from the effects of
Sars-CoV-2 are never actually tested for the virus, especially if they
do not exhibit a cough or fever. It means that if they have neurological
symptoms, we may never know if this was linked to Sars-CoV-2.
In fact, there is a significant percentage of Covid-19 patients whose
only symptom is confusion they don't have a cough or fatigue, says
Robert Stevens, associate professor of anaesthesiology and critical care
medicine at Johns Hopkins Medicine in Baltimore, Maryland.
We are facing a secondary pandemic of neurological disease.
*A different disease
Since the start of the pandemic, it has become increasingly clear that
Sars-CoV-2 is not just a turbo-charged version of the virus that causes
the common cold: it has a number of quirky, unusual and sometimes
For example, most viral pandemics (including influenza) have a U
shaped mortality curve, killing the very young and the very old. But
Sars-CoV-2 typically only causes mild symptoms in children
The novel coronavirus also disproportionately affects men: up to 70% of
people admitted to ICUs worldwide have been male, though men and women
have been infected at equal rates. /(Read more about how Covid-19
affects men and women differently
Happy hypoxia is another mystery. Our blood normally features oxygen
saturation levels of around 98%. Anything below 85% should lead to a
loss of consciousness, coma or even death. But a large number of
Covid-19 patients have been found to have oxygen saturation levels below
70%, even below 60%, yet remained fully conscious and cognitively
Then theres the fact that an enormous percentage of people who carry
the virus have no symptoms. Estimates vary, but one mass-testing report
from Iceland found that fully 50% of the population who carried the
virus expressed no symptoms whatsoever.
Perhaps most unnerving: while about 80% of people who develop Covid-19
shake off the virus easily, a small percentage quickly worsen and within
days die from respiratory weakness and multi-system organ failure. Many
of these patients are elderly or have particular underlying health
conditions <https://www.bbc.co.uk/news/health-51674743>, but not all
Weve now learned that the disease affects many different organ
systems: patients can die not only from lung failure, but also
kidney failure, blood clots, liver abnormalities, and
neurological manifestations Robert Stevens
If we have learned anything over the past couple of months, it is that
this disease, Covid-19, is extremely heterogeneous in presentation,
says Stevens. Weve now learned that the disease affects many different
organ systems: patients can die not only from lung failure, but also
kidney failure, blood clots, liver abnormalities, and neurological
Ive had patients in the ICU recover in two to three days. Ive got
others who have been in hospital now for months.
There are other quirks that Stevens has noticed but cannot explain.
Covid-19 patients seem to have a lack of sensitivity to the drugs we
normally use weve had to use five to 10 times the amount of drugs for
sedation that we would normally use, he says.
Virologists will spend years trying to understand the biomechanics of
this invader. And though researchers have scrutinised the virus and its
victims for six months, publishing scientific studies at a rate never
before seen with any disease, we still have more questions than answers.
The newest to be added is: can the virus infect the brain?
Most researchers believe the neurological effect of the virus are an
indirect result of either oxygen starvation to the brain (the happy
hypoxia exhibited by many patients), or the byproduct of the bodys
inflammatory response (the famed cytokine storm). Both Fory and Helms
believe the neurological effects are cytokine-mediated.
Others arent so certain: evidence is starting to accumulate
demonstrating that the virus can actually invade the brain itself.
If you had asked me a month ago if there was any published
evidence that Sars-CoV-2 could cross the blood-brain barrier, I
would have said no. But there are now many reports showing that
it absolutely can Stevens
If you had asked me a month ago if there was any published evidence
that Sars-CoV-2 could cross the blood-brain barrier, I would have said
no but there are now many reports showing that it absolutely can,
In Japan, researchers reported the case of a 24-year-old man who was
found unconscious on the floor
<https://www.ijidonline.com/article/S1201-9712%2820%2930195-8/pdf> in a
pool of his own vomit. He experienced generalised seizures while being
rushed to hospital. An MRI scan of his brain revealed acute signs of
viral meningitis (inflammation of the brain), and a lumbar puncture
detected Sars-CoV-2 in his cerebrospinal fluid. Chinese researchers also
found traces of the virus in the cerebrospinal fluid of a 56-year-old
male <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7269702/> patient
suffering from severe encephalitis. And in a post-mortem examination of
a Covid-19 patient in Italy, researchers detected viral particles
<https://pubmed.ncbi.nlm.nih.gov/32314810/> in the endothelial cells
lining the blood vessels of the brain itself. In some countries such as
France, autopsies of Covid-19 patients are highly restricted (or
outright banned), making the Italian finding all the more important
In fact, some scientists now suspect that the virus causes respiratory
failure and death not through damage to the lungs but through damage to
the brainstem, the command centre that ensures we continue to breathe
even when unconscious.Loading Image...
Radiology staff attend a patient being scanned to produce a MRI of their
brain (Credit: Science Photo Library)
The brain is normally shielded from infectious diseases by what is known
as the blood-brain barrier a lining of specialised cells inside the
capillaries running through the brain and spinal cord. These block
microbes and other toxic agents from infecting the brain.
If Sars-CoV-2 can cross this barrier, it suggests that not only can the
virus get into the core of the central nervous system, but also that it
may remain there, with the potential to return years down the line.
Though rare, this Lazarus-like behaviour is not unknown among viruses:
the chickenpox virus Herpes zoster, for example, commonly infects the
nerve cells in the spine, later reappearing in adulthood as shingles
roughly 30% of people who experienced chickenpox in childhood will
develop shingles at some point in their lives.Loading Image...
The Herpes zoster virus, which causes chicken pox, later reactivates as
shingles in nearly a third of people (Credit: Science Photo Library)
Other viruses have caused far more devastating long term impacts. One of
the most notorious was the influenza virus responsible for the 1918
pandemic, which caused permanent and profound damage to the dopamine
neurons of the brain and central nervous system. (While its long been
assumed that influenza cannot cross the blood-brain barrier, some
scientists now think that it can
<https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4266681/>). An estimated
five million people worldwide were hobbled by a form of extreme
exhaustion known as sleepy sickness or encephalitis lethargica.
Among those who survived, many remained in a state of suspended
animation. They neither conveyed nor felt the feeling of life; they
were as insubstantial as ghosts, and as passive as zombies, wrote
Oliver Sacks in his 1973 memoir Awakenings. He described patients
remaining in this stupor for decades until being revived by the drug
L-DOPA, replenishing levels of the neurotransmitter dopamine. /(Read
more about why the 1918 flu was so deadly
David Nutt, professor of neuropsychopharmacology at Imperial College
London, says he himself treated many patients in the 1970s and 1980s who
had suffered from severe clinical depression ever since the 1957
influenza pandemic in the UK.
Their depression was enduring and it was solid it was if their
emotional circuits had all been switched off, he says, warning that we
could see the very same thing happen again, but on a much larger scale.
People who are discharged from the ICU with Covid-19 need to be
monitored systematically long-term for any evidence of neurological
damage and then given interventionist treatments if necessary.Loading Image...
Doctors treat an influenza patient in New Orleans in 1918; some five
million survivors of the pandemic experienced a long-term state of
extreme exhaustion (Credit: Getty Images)
Patients who exhibit symptoms should be moved into interventional
trials, such as of selective serotonin reuptake inhibitors (SSRI)
anti-depressants or beta interferons (naturally-occurring proteins often
administered as drugs for conditions such as multiple sclerosis) to
mitigate the damage and prevent further long-term effects. But this
simply isnt being done, he says: What really bugs me is that every
health trust in the UK is looking at the symptoms of Covid but nobody
is looking at the neurological mechanisms, such as the amount of
serotonin in the brain.
Nutt plans to enroll 20 Covid-19 patients who developed depression or
another neuro-psychiatric condition into a study that will use
Imperials state-of-the-art PET scanners to look for signs of brain
inflammation or abnormalities in neurotransmitter levels.
In Baltimore, Stevens is also planning a long-term study on Covid-19
patients discharged from the ICU, which will also conduct brain scans as
well as detailed cognitive tests on functions such as memory capacity.
And in Pittsburgh, through the Global Consortium Study of Neurological
Dysfunction in Covid-19, Sherry Chou, a neurologist at the University of
Pittsburgh, has coordinated scientists from 17 countries to collectively
monitor the neurological symptoms of the pandemic
including through brain scans.
The viruss impact on the nervous system could be far larger and
more devastating than its impact on the lungs
Although the viruss impact on the lungs is the most immediate and
terrifying threat, the lasting impact on the nervous system be far
larger and far more devastating, says Chou.
Even though neurological symptoms are less common in Covid-19 than lung
problems, recovery from neurological injuries is often incomplete and
can take much longer compared to other organ systems (for example,
lung), and therefore result in much greater overall disability, and
possibly more death, she says.
Neurological symptoms are less common among Covid-19 patients than lung
problems, but recovery from these symptoms can take longer (Credit:
In France, Helms knows better than almost anyone how intense the
neurological impacts can be. We needed to delay her interview with the
BBC after one of her Covid-19 patients who was discharged from the
hospital two months ago, but is still suffering from viral fatigue and
severe depression required urgent consultation for suicidal risk. And
that patient is not unique she has seen many people in similar states
She is confused, she cannot walk, and she just wants to die, its
really awful, says Helms. Shes only 60, but she has said to me Covid
has killed me meaning it has killed her brain. She just doesnt want
anything more in life.
This has been especially difficult because we dont know how to prevent
this damage in the first place. We just dont have any treatments that
will prevent any damage to the brain.
Patients experiencing lung failure can be put on a respirator, and
kidneys can be rescued with a dialysis machine and, with some luck,
both organs will bounce back. But there is no dialysis machine for the