This Is MS Multiple Sclerosis Community: Knowledge & Support

[erinc14]

http://www.everydayhealth.com/columns/t ... -research/

[1eye]

Researchers at the University of Texas Health Science Center at Houston have published additional results from a National MS Society-supported study investigating CCSVI (chronic cerebrospinal venous insufficiency) using imaging techniques to examine blood outflow from the brain.

...

TLV study: Of the 98 people with MS who underwent both ultrasound and MRV scanning, 40 were also examined using transluminal venography (which involves obtaining pictures of the anatomy by surgically inserting a catheter into the vein). These included 29 with relapsing-remitting MS, 8 with secondary-progressive MS, and 3 with clinically isolated syndrome.

One out of 39 people with accessible azygous veins showed minimal narrowing. Internal jugular veins showed degrees of stenosis in 55%, and valves were detected in nearly all of the internal jugular veins. Despite these findings, TLV detected no pressure readings that would indicate functional vein blockages in any of the veins.

The authors note that their findings do not indicate altered vein flow in people with MS, and do not support a significant role for CCSVI in MS.

Why the proportions of the different "types" of "MS"? Age have anything to do with it? I thought the ratio of "RRMS" to "SPMS" was about 50%. Trying to skew the results from the start? pw"SPMS" have worse CCSVI, or so I heard.

Why do these people and Dr. Sclafani get such different results, I wonder?

[SLOV8213]

The trials are a sham to begin with. Just throwing the dog a bone. But keep the donations coming.

[Cece]

Researchers at the University of Texas Health Science Center at Houston have published additional results from a National MS Society-supported study investigating CCSVI (chronic cerebrospinal venous insufficiency) using imaging techniques to examine blood outflow from the brain.

...

TLV study: Of the 98 people with MS who underwent both ultrasound and MRV scanning, 40 were also examined using transluminal venography (which involves obtaining pictures of the anatomy by surgically inserting a catheter into the vein). These included 29 with relapsing-remitting MS, 8 with secondary-progressive MS, and 3 with clinically isolated syndrome.

One out of 39 people with accessible azygous veins showed minimal narrowing. Internal jugular veins showed degrees of stenosis in 55%, and valves were detected in nearly all of the internal jugular veins. Despite these findings, TLV detected no pressure readings that would indicate functional vein blockages in any of the veins.

The authors note that their findings do not indicate altered vein flow in people with MS, and do not support a significant role for CCSVI in MS.

They found stenosed IJVs in 55% of patients. There were no healthy controls to compare this to, because it was invasive catheter venography? It would've been nice to have healthy controls. Valves were found but were they functional valves or thickened roadblock valves? The question of pressure has come up before and whether or not to expect a difference across a stenosis in a vein.

[Cece]

Why do these people and Dr. Sclafani get such different results, I wonder?

You don't see until you're ready to see....

I wouldn't agree that the trials are a sham but there is certainly skepticism involved and what seems to be an unwillingness to entertain the idea of CCSVI fully enough to do an optimal trial design or benefit from collaborative shared experience from the IRs who have engaged with CCSVI.

[1eye]

The question of pressure has come up before and whether or not to expect a difference across a stenosis in a vein.

Yes, if the blood is still moving. Pressure = volumetric flow rate times resistance. If the blood is still _{moving at all} in that vein, believe that. The pressure difference could be zero or the resistance could be high enough to stop the blood. If there is any pressure difference, blood will move.

Note carefully: this is not what you are measuring with an arm cuff. That has more to do with the peaks in the arm during systolic and diastolic intervals. By the time blood reaches jugulars, most pulsatility should be smoothed out, so peaks can't tell as much. If we are NOT talking about the instantaneous peaks found by listening to veins in the arm for comparison purposes, most often to indicate heart status, but instead of that "BP" reading, we are discussing an average pressure in one vein only, it can be, and often is, higher in one place than another, since the resistance changes as you go from large vessels to smaller, and vice versa in the veins.

Where blood is moving, the pressure will DROP across the stenosis, from upstream to down. In fluid terms it is said the pressure difference causes the movement, from the higher to the lower pressure. The pressure drops every time the vessel size changes. Here, we know the heart, not the pressure, is the cause of the movement, but it does this by pumping, which makes the lower venous pressure go back up for the next beat to the lungs, and subsequent organs.

Pressure is always changing, throughout the body, across organs, changes in the number or size of the vessels, etcetera. That is the very local pressure change across a stenosis, not a change in the heart's output pressure, which would be reflected in the BP reading.

[drsclafani]

The question of pressure has come up before and whether or not to expect a difference across a stenosis in a vein.

Yes, if the blood is still moving. Pressure = volumetric flow rate times resistance. If the blood is still _{moving at all} in that vein, believe that. The pressure difference could be zero or the resistance could be high enough to stop the blood. If there is any pressure difference, blood will move.

Note carefully: this is not what you are measuring with an arm cuff. That has more to do with the peaks in the arm during systolic and diastolic intervals. By the time blood reaches jugulars, most pulsatility should be smoothed out, so peaks can't tell as much. If we are NOT talking about the instantaneous peaks found by listening to veins in the arm for comparison purposes, most often to indicate heart status, but instead of that "BP" reading, we are discussing an average pressure in one vein only, it can be, and often is, higher in one place than another, since the resistance changes as you go from large vessels to smaller, and vice versa in the veins.

Where blood is moving, the pressure will DROP across the stenosis, from upstream to down. In fluid terms it is said the pressure difference causes the movement, from the higher to the lower pressure. The pressure drops every time the vessel size changes. Here, we know the heart, not the pressure, is the cause of the movement, but it does this by pumping, which makes the lower venous pressure go back up for the next beat to the lungs, and subsequent organs.

Pressure is always changing, throughout the body, across organs, changes in the number or size of the vessels, etcetera. That is the very local pressure change across a stenosis, not a change in the heart's output pressure, which would be reflected in the BP reading.

The inherent pressures in veins is pretty low. trying to measure a gradient with conventional instruments is unsatisfactory.

[Cece]

Bring on the unconventional instruments....
It seems at least by this research that showing that there is a pressure change from one side of the stenosis to the other would be helpful in establishing evidence for CCSVI. The researchers found stenoses but dismissed them as being of no consequence because they did not find any pressure changes.
1eye, that was a helpful explanation, thanks.

[MrSuccess]

When you have PRESSURE you have RESISTANCE to flow.

When you have FLOW you have -low/no - pressure.

The heart produces FLOW . Not pressure.

CCSVI .... Should result in higher pressure readings on one [ heart side ]side of the obstruction , however , as the heart is a diaphram pump in design .... it WILL NOT continue to increase the pressure BEFORE the obstruction. Those tiny collateral veins [ see Dr.Dake's research] go a long way in skewing the math ....

The human body is an amazing thing.


MrSuccess