I am becoming skeptical...

Cece · Post by **Cece** » Fri Jul 29, 2011 5:58 am

It's like a blood pressure cuff for your neck. The differences between pwCCSVI and healthy controls happen when you sit up. Everyone has some venous congestion upon sitting up but in healthy controls it clears nearly instantly and in pwCCSVI it takes time to clear. I would say whether plethysmography exists or not is a nonissue; it's usefulness in CCSVI is still to be determined by the researchers.

No matter how open a mind might be, hypoxia is hypoxia and numbers are numbers.

Agreed. There are all sorts of diseases that can cause hypoxia to the brain and it is recognised as unhealthy. What is to be determined is if outflow obstructions can cause hypoxia, since it had previously been thought that they could not. From personal experience, with outflow obstructions and now without them, I am better off without them.

sou · Post by **sou** » Fri Jul 29, 2011 6:58 am

I thought that the Zivadinov study and Hubbard's observations prove it. Ok, the observations is an ultra-strong indication, not proof with the mathematical meaning of the word.

Cece · Post by **Cece** » Fri Jul 29, 2011 7:00 am

Hubbard's study is compelling but there was some question raised as to the value of fMRI studies. It was suggested that they may be unreliable or difficult to reproduce. I haven't had a chance to verify that with a fMRI google scholar search but there should be information out there one way or another.

1eye · Post by **1eye** » Fri Jul 29, 2011 8:03 am

Strain gauges: I'm pretty sure they're peizoelectric devices, but I could be wrong on that. Anyway it's a gizmo that senses applied force, and converts it into a proportionate linearly varying voltage, which is then easy to accurately calibrate and use to measure things. I have them in several digital scales I have in my house: one for food, another in the bathroom for my weight. Peizoelectric crystals can be made very small.

Incidentally, I have heard larger ones have been used to capture the energy of a moving dance floor and convert it to electrical power.

I think I have felt some bias against Prof. Haacke's work, possibly because he has no MD qualification. The images seen on his cross-section MRIs and others are not very simple to understand. This is ground-breaking work he is doing, and it is unlikely there have even been any similar studies to some of it. As far as reproducing things, if he could not explain his methods well enough to radiologists, he would not have gotten very far in the MRI field. I, for one, have no fear of that.

Check this out.

Cece · Post by **Cece** » Fri Jul 29, 2011 8:17 am

Here's the thread on Dr. Zamboni's plethysmography: www.thisisms.com/ftopic-14742-days0-orderasc-0.html

I would definitely listen to 1eye over me on the technical details of this one! Peizoelectric....

Here too is the abstract on plethysmography from ISNVD:
http://ccsvism.xoom.it/ISNVD/Abstract-Z ... eening.pdf

Cece · Post by **Cece** » Fri Jul 29, 2011 8:24 am

Cece wrote:Plethysmography collars. Very exciting. It was mentioned at ISNVD this spring, by Dr. Zamboni and also a doctor from the UK if I recall correctly.

The UK doctor was Dr. Simon Shepherd, here is his abstract from ISNVD:
http://ccsvism.xoom.it/ISNVD/Abstract-Shepherd.pdf

The presentation describes the initial mathematical and physical analysis of patient and
control data from the new cervical plethysmography diagnostic technique, introduced by Professor Zamboni, in the diagnosis of CCSVI.

We show that the data produced is consistent with previous recent work which showed that the hydrodynamics of the brain is very closely approximated by a second-order system.

We show that a classical two-parameter characterisation of the second-order response curves to the Heaviside step function could be a powerful classification technique for diagnosis of CCSVI.

'Powerful classification technique for diagnosis of CCSVI' -- sounds promising.