Welcome to another video. This is gonna be another topic on Covid 19. And another one that has to do with autopsies.
So, Autopsies, in general, are actually pretty rare these days compared to the old days.
Because family members don't typically want to give consent for someone to do an autopsy on their family member.
And this is even more so the case with covid 19 because there's actually a risk,
that even though the person is no longer live, they can still spread the virus to the medical examiner.
So these autopsies are pretty rare and when there is an opportunity to do them,
we really have to cherish the medical information that we can glean from them.
So now there's another study that came out where there are 18 cases of people who died of Covid 19,
where they did the autopsies. So if you've seen my previous videos on autopsies that were done on Covid 19 patients.
It's pretty clear by now that when patients do die of this virus, it's because of the lungs.
Either because of all the inflammation in the lungs with pneumonia and cytokine storm and ARDS
and sometimes with multi organ failure or they died because of a major blood clot that develops in the lungs.
Sometimes though blood clots show up in other parts of the body as well
for example, in some cases, clots can travel to the brain and lodge in the blood vessels there causing decreased blood flow to certain regions of the brain
This is known as a stroke. But this virus in a different manner could cause neurologic symptoms in some people
Such as headache, confusion, and Anosmia meaning loss of sense of smell.
But we don't know why this virus is causing these symptoms.
Is it because the virus travels in the bloodstream to the brain? Maybe, after all, there are h2 receptors that are located within the brain.
Is it because the virus gets in our nose and uses the olfactory nerves that are there to gain entry into our brain?
Maybe.
Or Are these symptoms more related to the effects of the cytokine storm? Actually pretty common with infections in general whether that be from pneumonia or something else
Now in this recent study in The New England Journal of Medicine,
They looked at brain findings from autopsies were done on 18 patients who died of COVID in a single teaching hospital,
All 18 of these patients had nasopharyngeal swab samples that were positive for SARS coronavirus 2 on pcr
So 14 out of the 18 were men, the median age was 62 years old.
12 out of 18 had diabetes, 11 had high blood pressure and 5 had other cardiovascular disease
4 of them had chronic kidney disease and another 4 had a history of a stroke and another 4 had dementia
When they went to the hospital, 3 of the patients presented with myalgias meaning muscle aches or body aches
2 patients presented with headache
and 1 patient had a decreased sense of taste and smell.
So the patient's had presented a median of two days after the onset of the first symptoms of sars-cov-2 infection
and were hospitalized for a median of six days before they end up dying. 11 patients ended up requiring mechanical ventilation, meaning of breathing tube.
so interestingly it was noted that all of the ventilated patients
had a confusional state or a decreased arousal from sedation for the ventilation.
so whenever we have patients on the ventilator, we have them sedated so that they're comfortable with that breathing tube that's going down their throat.
The way that I interpret this is that when they pause the sedation
meaning they temporarily stop the sedation to assess their mental status.
The patient was not able to follow commands during that time which in general is not uncommon
but this does seem to occur more often with Covid patients and this is something that I've been finding in my Kovac patients in the ICU.
So on these 11 mechanically ventilated patients
they didn't do a brain MRI or any EEG testing or any lumbar puncture to look at the cerebrospinal fluid the CSF aka a spinal tap.
This is likely because doing these tests is more challenging
and someone who's intubated and sedated who has this extremely contagious virus
So there's always the concern of potentially exposing more medical staff to the virus and spreading that virus throughout the hospital
However, they did do a CT scan of the head on 3 of the patients
and for all 3 of these patients they didn't find any acute structural abnormalities
on average these patients died about 10 days after being admitted to the hospital.
so when they did these autopsies they looked at the brain as a whole and also they sampled 10 different areas of the brain
and then looked at those samples underneath the microscope.
so there was thesaurus chlorosis in 14 out of 18 cases and there weren't any that had any stroke or abnormalities to the olfactory bulb.
The olfactory bulb is the part of the brain that is responsible for a sense of smell.
So microscopic examinations showed that there was acute hypoxic injury in some regions of the brain.
So acute hypoxic injury means tissue was damaged as a result of not getting enough oxygen.
so there was a cute hypoxic injury in the cerebrum, which is the part of the brain that allows us to think and be conscious.
There's also a cute hypoxic injury in the cerebellum in all of the patients.
And there were no blood clots in the brain and there wasn't any vasculitis meaning there was no inflammation of the blood vessels.
And it's significant that there was an absence of vasculitis.
We know that in kids there's this Kawasaki like a disease in a multi-system inflammatory syndrome, that occurs with Covid which is essentially a vasculitis.
So at least in these 18 adult cases, we can say there is no vasculitis in the brain.
In 1 case there was focal leptomeninges inflammation, which means there was inflammation of the meninges meaning the lining of the brain
so essentially it's sort of like a meningitis.
So another thing that we want to know is, Is the virus actually invading the cells of the brain?
So in this study they actually tested the brain tissue for the virus with RT-PCR
and 2 patients they see both 10 different sections of the brain
For the other 16 patients, they sample 2 different sections 1 from the frontal lobe and the olfactory nerve
which kind of is lumped as one and then the other part was the medulla
so for all the 18 patients they only found the virus in 3 of them.
And when they found it, it was located in the section where the frontal lobe next to the olfactory nerves
it's actually in the olfactory nerves in the frontal lobe and then the other part of the brain they found it was in the medulla oblongata
So in conclusion for all 18 of the patients really the only brain damage or brain injury
was a result of not getting enough oxygen to the brain
The reason why these patients had hypoxic brain injury is because their heart could not pump enough blood to the brain
which happens when the body is in severe shock and also what happens when people go into cardiac arrest
So when there's not enough oxygen getting to the brain, it could be due to 1 or a combination of these reasons
It can be either due to the heart not pumping enough blood there
or it could be because the lungs aren't getting enough oxygen into the blood or it could be both reasons
So also what's been demonstrated in other studies which I made a video on this called
12 autopsy cases we know that when people die as a result of Covid, it's either because of the massive inflammation in their lungs
Which means ARDS and multi-organ failure. But also the other reason why they died is because they have big-time blood clots in their lungs.
So either one of these can lead to the heart not being able to pump enough blood to the brain.
So this is a state of shock
and also eventually this leads to the heart-stopping or cardiac arrest. So when someone's in severe enough shock
and/or cardiac arrest that the heart can't pump that blood to the brain
and that's why you start seeing the brain cells having hypoxic brain injury there.
so it's still not clear why some people have neurologic symptoms with respect to Covid. it's possible that the olfactory nerve
which has nerve endings in the nose it's possible that the virus invades this area and that could
be a possible explanation for anosmia. After all, we know that there are h2 receptors in the nose.
As for the other symptoms like confusion and headache that could be due to the cytokine storm that takes place.
Which is initially triggered in the lungs with the massive inflammation there.
We know that certain participants in the cytokine storm like il 1 and il 6 and interferon-gamma.
They can cause body aches and headache which is the same reason why people often have these symptoms with the flu
and confusion and/or delirium is actually a very common phenomenon in the ICU
way before covid came along. So just being sick enough to actually require a stay in the ICU
is enough to cause delirium. So it's hard to know if Covid itself is making people more prone to delirium or not
and there are more and more studies that are coming out every day and we keep learning
new things all the time. So stay tuned on this channel for more covid knowledge and other medical talk
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