This Is MS Multiple Sclerosis Community: Knowledge & Support

[Dr. Zamboni] is conducting a new round of tests in which subjects will wear a collar fitted with a strain gauge to measure neck volume differences in the upright and prone positions. This will allow him to measure the time it takes for for blood to drain through the neck in MS vs. control subjects. This technique is called plethysmography and is less operator-dependent than Doppler ultrasound.

Chest. 1991 Aug;100(2):371-5.
Noninvasive measurement of central venous pressure by neck inductive plethysmography.
Bloch KE, Krieger BP, Sackner MA.
Division of Pulmonary Disease, University of Miami School of Medicine, Mount Sinai Medical Center, Miami Beach.
Abstract
Bedside estimation of the height at which the internal jugular veins collapse, referenced to a standard hemodynamic location, theoretically reflects central venous pressure. This method has never been demonstrated as accurate when compared to invasive CVP measurements because of the great clinical skills and time required to visually identify the internal jugular venous waveform. Since the principles of the bedside method are sound, we utilized them in conjunction with the neck inductive plethysmograph, a device which has the capability of recording internal jugular venous and carotid arterial waveforms. The respiratory distortion of these vascular waveforms was eliminated by employing a digital bandpass filter, making it easy to identify the venous and arterial waveforms on the videoscreen of a personal computer. The upper torso was positioned while observing the videoscreen until the vascular waveform was seen as a mixed arteriovenous waveform, signifying intermittent internal jugular venous collapse. The height of the internal jugular vein above the phlebostatic axis was obtained by external measurement and recorded as CVPni in cm H2O. In 43 patients, 86 percent of CVPni (NIP) values fell within 20 percent CVPi (invasive catheter measurements) over a range of CVP from 0 to 19 cm H2O. In an additional seven patients, CVPi was greater than the height that the upper torso could be elevated and an arterial waveform could not be obtained. Here, CVPni was recorded as the value at least exceeding the value measured. In two other patients, obstruction of an internal jugular vein gave spuriously low values of CVPni. Our study indicates that this new neck inductive plethysmographic method is accurate compared to invasive catheter measurements of CVP and should serve as a safe, noninvasive alternative in situations where such measurements are required.

If CVPi is greatly elevated, then the maximal upright
distance between the neck and the phlebostatic axis
may be insufficient to achieve collapse of the internal
jugular veins. This occurred in three patients with a
small vertical torso related to kyphoscoliosis, in three
patients in whom recent abdominal surgery prevented
full upright positioning, and in one patient who had
extreme orthostatic hypotension. Nevertheless, in all
these patients, despite this limitation, CVPni revealed
elevated values above the upper limit of normal of 7
cm H2O.’#{176}

Doesn't this contraption measure venous pressure and not flow? Wasn't there a debate here before about CCSVI being about flow and not pressure?? Someone explain this to me, I'm feeling denser than usual.

One of the major regulators of cerebral venous outflow is posture, due to the gravitational gradient between the cerebral parenchymal veins and the base of the neck (␣30mmHg).2 The authors demonstrate a much larger change in blood flow volume in normal subjects compared to MS patients when the subjects go from a supine to an upright position. They find a change of 128ml/min and 56ml/min for the right and left sides, respectively, for MS patients. But they find a much larger change of 266ml/min and 105ml/min for their normal subjects. This result actually suggests the presence of chronic cerebrospinal venous insufficiency (CCSVI). Possible causes include intra-luminal septum, membrane, and immobile valve affecting the hydrostatic pressure gradient in the upright position. The presence of such blockages in the extracranial and extravertebral cerebral veins has been proven also by using catheter venography, the unquestionable gold standard in medicine.3,4

Doesn't this contraption measure venous pressure and not flow? Wasn't there a debate here before about CCSVI being about flow and not pressure?? Someone explain this to me, I'm feeling denser than usual.

Great report and additional information. Somehow I can't believe wev aren't needing to also think of the Haacke protocol and the great benefits he is able to show with his MR Imaging knowledge and technique. His MRI reports are also invaluable to science and the patient giving hard data that patients can hold onto for both first and ongoing treatment. The data is extremely revealing and proficient (for lack of better word) to science. We cannot forget the importance of a more detailed data on our veins. More soon again. Tired. It's now 1:50 AM.

If blood stays in the neck, and does not return to the heart in a timely manner, you have a health issue. Thanks to the Doepp study for making that clear.