You’re spending lots today @coldbear, that’s 2 lots of 2 cents worth 
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He’s a smart to spend it now, in a few months his 2 cents will only be worth 1
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I think I am with @coldbear on this one regarding how these folks measure the IJV. One has to be careful here because numerous careful studies has found that IJVs collapse to more than 50% of its supine diameter when upright presumably to regulate ICP. This is a fact now.
In the case of Jugular Vein Stenosis, supine position imaging is preferred as any narrowing would cause the alternate route vie Condylar Veins (lateral, posterior and anterior Condylar Veins) to become prominent in draining the brain and as @coldbear images indicate, you can see the venous engorgement at Condylar Veins which drain into Sub-occipital Cavernous Sinuses (SOCS) which drain into the Vertebral Artery Venous Plexus (VAVP)/Vertebral Venous Plexus (VVPs) which drain into Deep Cervical Vein. In the presence of normal Jugular flow in the supine position (absent of compression and narrowing), you should see all these network of veins at the skull base return to normal sizes.
If IJVs naturally collapse when upright to regulate ICP what are the implications with stenting the IJV. Wouldn’t that lead to low ICP?
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Good question. I really do not know and there are no good studies out there that looked into this deeply. Blood flow is more complicated and is affected by many things so studying it will require not only looking at the Vein side of the world but also the Artery side of the world taking into considerations of all forces and postures. Let us hypothesize that your statement is true and it could potentially lead to over-drainage of the brain and low ICP. But what if the brain senses that low ICP and increases the heart rate (via Autonomic Nerve System) to pump more blood through the arteries in order to offset the over-drainage. This we do not know unless you are studying all these systems dynamically and it is even more complicated when you introduce stenting. What is known is that the heart rate increases when upright presumably to offset the gravity pull of the blood so that the net blood flow to the brain remains constant.
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Seems like the entire field is understudied. Something I’m also very curious about is the research that is going to come out for astronauts. We already know that long durations in space cause IIH symptoms, and if we’re planning on deep space travel to Mars, it’s only going to get worse.
So I’m curious to see what comes out of NASA trying to solve this issue.
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Well they are all interesting studies but humans evolved on the surface of earth and our body systems need gravity to function optimally. I know this discussion goes way beyond this ES blog and I don’t want to hijack the thread for Sci FI 
but the number of body processes that get affected by gravity goes way beyond the blood circulation (baroreceptor reflex - which regulates the blood pressure). For example, your bone density decreases significantly in space since there are no constant stress brought on by the force of gravity on them. Bones grow with stress that is why weight lifting is good for you to maintain bone density. Your balance system (vestibular system) goes out of whack because there is this fluid in your vestibular system that moves up and down and tells your brain where you are facing, with less gravity this is affected too. These are all effects seen with space travel but one needs to spend years in space to see the full effect of it. It is still tip of the iceberg. For example, what keeps your body together is what is called atmospheric pressure without it, your body might fall apart, that is why astronauts wear pressurized suits among other reasons. It also helps with hearing as sound needs a medium to travel from one place to another. you heard the famous saying, If there is nuclear explosion in space, you would not hear it because it is vacuum and sound does not travel in vacuum. Less oxygen saturation in space because it is a heavy element which is concentrated closer to the surface of the earth due to the pull of gravity and that is why the higher elevations like mountains cause dizziness because the oxygen is less and less as you go up and up. Anyways, enough with this but point being we are creature of the earth and as result are subject to its natural forces.
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That’s what I’ve been thinking of constantly having a backpack on my shoulders…
@KoolDude. You explained a very complex topic in very understandable terms. I loved your closing sentence especially & had never thought all these details through, but to say we are creatures of earth is a great perspective. We are not only subject to its natural forces but were “designed” so to thrive & survive with those natural forces playing on our bodies. When we try to live outside of those parameters, negative physical changes occur.
Thanks Isaiah, I do not want to hijack the thread for space stuff but I admit I describe myself as science enthusiast and very much interested in cosmology as Elijah probably is. So when it comes to explaining complex topic in simple terms regarding the Earth we live on, No one comes closer to the great late Physicist/Astronomer Carl Sagan, whose famous “Pale Blue Dot” speech captured the essence of earth after Voyager 1 probe took a picture of earth 6 billion KM away as it existed the solar system. What appears to be a dot in the circle is indeed how the earth looks 6 billion KM away . It puts everything in perspective.
For those science & space enthusiasts, here is the speech and the Pale Bleu Dot (earth) captured in image. You can also watch the speech by the late Carl Sagan below if you like it to see speech in real life.
Carl Sagan “Pale Bleu Dot” : Carl Sagan unveils the Pale Blue Dot image - YouTube
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I totally know it, just wanted to reiterate my point of view that might sound “unscientific” one. I fully agree that most reliable source is the one peer reviewed, independently verified on significant variety of demographics incl. age, race, gender, height/weight, bmi, co-existing conditions, genetic mutations, anatomical variations and zillions of other things. BUT! As the saying goes, Starliner was built by “professionals” with “decades-long legacy in space industry”, and Crew Dragon by “those weed-smoking graduates”.
What I am saying, very often we, highly educated people, are fooled by the authority bias, because we often have slightly inflated ego even if we don’t want to admit that. We tend to trust those folks with significant professional experience in their fields and downplay “newbies”, amateurs and people who have little experience, ignoring their lateral and associative thinking abilities, as well as their tendency to think “out-of-the-box” exactly because they lack that factual information and have to use creative and unconventional thinking significantly more to fill-in the gaps.
I am very sceptical (like 96.024%) about the prolo stuff, as it seems just too dangerous and working against the common sense (I don’t need more inflammation in my neck as I already have enough of it there).
But when I see the video by the same prolo folks (that I am sceptical about) with the US images showing significant difference in IJV flow based on the neck’s position while the subject is sitting and just changing the angle of their neck, I have no reason to not believe that IJV may collapse/expand even in those postures described in the Nature’s article as “IJVs are collapsed”.
I know how writing scientific articles works, so there is huge possibility the Nature didn’t evaluate so many different postures, neck curvatures and anatomical variations (incl. elongated styloid processes) to cover 100% of all the possible variations and permutations in the world. More likely, to get the right data they must have chosen a few very specific postures and positions of the neck, and repeat that exactly the same (limited) way on all the subjects, and ignore everything in-between. Otherwise the collected data would not belong to the same realm and any conclusion drawn from that sample would be unreliable.
But if they wanted to perform a very extensive research, they would have never been able to finish the research if 50-100 different postures were involved and all demographics covered. Also how could they ensure that every subjects’ neck was moving exactly the same way, muscles (scalenes) engaged the same way in certain “sampling posture X-42” to avoid distortion by extra compression? How could they ensure that other pathways of blood were identically “configured”? For that they would need to use dynamic Xray, fluoroscopy or upright CT scan every single time just before taking the US measurements. When someone is sitting or standing, they might have had so many different “configurations” of the neck muscles, structures and tissue involved, so many different blood paths, that it would make really precise analysis virtually impossible.
I remember my own recent dynamic US. I was watching the red/blue bloodflows on the monitor and noticed how they can rapidly change by me just tensing digastric, scalene or even platysma muscles!
And in general I am very often sceptical with authorities because if I was playing along with the “authorities”, I would have probably never discovered that I had elongated styloids in the first place. But hey, amateur started challenging educated doctors’ with degrees narratives and found something! 
And now that amateur is still amateur, just a bit more educated in this field, but knows much more about this condition than almost any doctor he has met so far!
Based on my own experience (and I know my symptoms [but not necessarily the causes] from “inside” better than anybody looking at me from “outside”), I believe my IJVs tend to pass significantly more blood at certain angles of the neck around C1-C2 when I am sitting or standing, because simply I feel the difference in my headaches, pressure sensation and brainfog just by moving my neck around, so I have no reason to disbelieve it (which is not exact opposite to believe but rather the third state covering “I cannot disprove that (yet)”), exactly because there is very little research in this field.
On the other hand, it might be something else than IJVs too – it’s just my gut (neck/brain, in fact) feeling, plus lots of imaging now.
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Totally reasonable points! You are clearly very thoughtful and objective when it comes to evaluating new findings and claims, regardless of their source. I think that’s the most important trait we can have as patients trying to understand our understudied conditions. I have been a full-time academic biomedical researcher for several decades, and I’d gladly have you on my team 
With that said, I also try to keep folks’ potential motivations in mind. These guys have a pretty clear financial incentive to promote these findings, and if they are as reproducible as they imply in the video - a small clinical trial or study would be very straightforward and inexpensive to complete. And publication of the findings would be fantastic marketing material, so I think the fact that it doesn’t exist is telling. That isn’t to say that academic researchers and more ‘traditional’ clinicians do not have their own conflicts of interest (but at least there is the nominal firewall of ethics committees and peer-review). For example, I think the fact that US doctors almost always do two separate styloid resections boils down to 2 x $$$$$. In my country with socialized healthcare, bilateral procedures is the norm and there is no real debate about the safety of doing it that way.
And for the sake of completeness, this is the paper @vdm is referencing:
https://www.nature.com/articles/s41598-020-73658-0
Nitpicky point: it’s published in Scientific Reports (impact factor 4), which is part of the Nature publishing family but not Nature (impact factor 50) itself.
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Absolutely. I will repeat just in case the main thing that might be too obscure in the long post: I am not a fan of the Caring Medical nor their prolotherapy stuff, but when I hear a quack in the middle of the office, it’s not necessarily a duck, even more than likely it’s the mobile phone’s ring tone.
Talking about the Scientific Reports (Nature) article, the sample was “[…] the 20 included participants (10 men and 10 women) were healthy adults aged 30 to 55 years”.
We aren’t, unfortunately. We are symptomatic. So our bloodflow pathways might be VERY different and our bodies might have just adapted to that over those decades.
And the sample was extremely small to draw any far-reaching conclusion even about all the healthy individuals, to be honest… Strictly speaking, the chance that 1/21 totally (or mostly, to that extens) healthy individuals might have very different blood flow is too high.
I’d be more confident if the study said “we evaluated 1000 healthy individuals”. 0.1% is something more reliable.
We have ~10% of totally healthy people who are left-handed, and, to be honest, I believe they might have significantly different bloodflow dynamics in their necks/brain compared to the right-handed people. None of them might have been taking part in the study…
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@vdm I just want to say that a number of studies found that Jugular Veins collapse in upright position. So it is repeatable as it was replicated numerous times. It is not only confined to the one that appeared in nature article. I know every study has its own limitations with potentially hidden cofounding factors even if you do your best to control it. Here is cool one ( Venous collapse regulates intracranial pressure in upright body positions) from @coldbear’s country Sweden (wonder why they did not recruit him in this study…but I guess he will be cofounding factor since his IJV is already impaired 
). This one even went step further than merely confirming Jugular collapse and predicted ICP based on the elevation angle of our body i.e body posture. Their finding is interesting as the measured ICP and the predicted ICP were almost similar. Granted this area is not widely studied but there is enough evidence to believe that this phenomenon exist in majority of people. I have not yet seen a study that refuted this or found the opposite to it. If found, I reserve the right to change my current believe. That is the beauty of science. It is not dogma. We are willing to change our believe based on scientific evidence.
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That’s exactly what I have been talking about: the article assumes “static” body’s position and just different angle of the upper body by, perhaps, changing the angle of the backrest (of the examination bed/table). I assume absolutely everything else remains “fixed” (the neck, C0-C1 angle, C1-C2 rotation etc.). Kinda as if the subject’s body was a manequene.
Now, I understand that you can’t ask the patient to bob their head with punctured spine while taking the measurements, but what if the subject craned their head? Extended? Flexed? Tilted and extended? Extended and laterally flexed? Shifted sideways? Rotated? Extended and rotated? Totally occluded some collaterals? Did valsalva maneuvre to induce blood back-flow through the vertebral venous plexus?
This study is really cool, but again – it takes a very small number of parameters and only one variable – angle of the examination table, while everything else is as fixed and static as possible to avoid any bias.
I still have to see any single study that compares IJV flows in these two cases:
- the subject is upright with the neck straight
- the subject is upright with the “forward head” posture slightly hunching to maximize the chances that the IJV is loosely hanging and vertebral venous plexus is slightly compressed.
Or, essentially, a study that shows the difference between various head positions while doing something at the desk – writing, typing reading, eating, stretching, looking up, scratching the back.
Also, a study that shows supine body and their head moved around (extended, flexed, body propped up on the elbows, bent sideways, head turned sideways), would be cool to see too.
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Btw, food for thought:
The subject is the same. On the left, upright (Xray). On the right, supine (MRI - about one month before the Xray). Lines connect identical points (or at least I tried to use as closely the same points as I could).
Based on this alone, IJVs and all the other easily-compressible-veins can take very different levels of compression…
As you know studies/experiments are done for numerous reasons but mainly to establish a relationship or causation or to test a hypothesis. In this case, it is by design that they exclude all the provocative neck maneuvers you mentioned below because they wanted to control factors that can potentially affect venous collapses and ICP in general so the only factor that they wanted to establish is that upright position which collapses the Jugular vein does indeed regulate ICP. They are not testing whether different neck movements affect bloodflow or collapses the jugular veins or increase ICP as some medical testing do (which can happen but not the point of the study here). The question is, does venous collapse (IJV in this case) regulate ICP in upright posture in the absence of cofounding factors (IJV compression, provocative neck/head movements that affect venous pressure, unstable heart rate (running or sleeping or anxious)…etc). And the answer was yes, as they could predict with some accuracy what the ICP will be in given elevation angle. In other words, there is relationship between the ICP and the degree of venous collapse (reduced cross-sectional area of IJV in upright position which they also measured in the study).
However, you do have a valid point with regards to conducting a separate study/test that answers some of your questions as shown below.
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@KoolDude I really admire your scientific insights, but re the case above… There were a few more factors that might have affected ICP in my humble non-scientific opinion. The subjects’ legs were kept horizontal in all experiments. Which means, the abdominal pressure is significantly increased when the subject’s posture is more upright. Which means it may cause blood back-pressure through the vertebral venous plexus, vertebral pressure through the spine, compress the spinal canal and reduce CSF circulation, and zillion of other things besides the IJV collapse.
What is missing in this study (unless my late-night eyes skipped it), is how much the ICP increases when the subjects’ IJVs are compressed in the same posture (e.g. supine) vs not compressed. They are easy to compress manually with the US scanner head to make sure there is no flow. Maybe in healthy subjects the collaterals would perfectly compensate the compression and the IJV compression would seem just a postural effect without real effect on the ICP.
What I am challenging in all these studies is… Lack of realistic context. If I have a big meal, I feel more pressure in my head probably not because of the IJVs but some other mechanism - increased abdominal pressure for example.
The conclusion “collapse of the IJVs is the reason of regulated ICP” in my opinion has not been proved by these tests. The link, or correlation, however, has. Correlation is not necessarily the causation, and in this case unfortunately I don’t see anything more than just the correlation of very specific three things: subject’s upper body’s angle, IJV collapse degree, and predicted ICP.
@vdm My fellow Canadian, I am waiting for your paper on this Perhaps, we can take their study bit further by incorporating some of your concerns. After all the way to challenge or make scientific argument is to do one.
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