Thanks for this paper, Cece...really interesting. Another Italian group, not affiliated with Dr. Zamboni, looking at blood flow and postural changes in MS. The negative ΔCVF (seated) value is explained here...
Global CVF was the sum of the offline calculated products obtained by multiplying the venous CSA areas of both IJV and VV with the time averaged blood flow velocities assessed during short apnoea after a normal exhalation over at least 5 s in supine and sitting position [21,22]. The difference of CVF in supine and in seated position (ΔCVF) was calculated as a functional index of abnormal postural control of the venous outflow.
It was the negative CVF, or elongated venous return in the seated position, that was linked to disability.
an altered postural control of venous outflow was more prevalent in MS patients, particularly in PP phenotype and in more disabled patients. According to Monti et al, such an explanation may be a no efficient Spinal Epidural Veins outflow as an additional drainage pathway in the seated position.
This is exactly what Dr. Zamboni was seeing with his plethysmography testing in MS. Longer time for blood to leave the head when pwMS were in the seated position compared to controls. Dr. Zamboni believes it is due to obstructed venous return. Here's what he says about this problem.
http://www.sciencedirect.com/science/ar ... 1412002339
In our study, when the subjects were tilted backward into the supine position, the silicone collar was able to detect the redistribution of blood coming from the subdiaphragmatic part of the body into the IJVs, causing the blood to pool and plateau (Fig 3 and Fig 4). The filling phase seems to be also hampered in the CCSVI group (Table I). If the venous pathways back to the heart are impeded by obstructive lesions, then the blood will tend to accumulate at a faster rate in the necks of the patients with CCSVI when supine compared with the HCs. Consequently, the FT is shorter and the FG steeper in the CCSVI cohort (Fig 4). When the HCs were returned to the upright position, the gravitational gradient meant that the blood could readily escape through the cervical veins with the result that they exhibited a short ET and steep EG. By comparison, in the CCSVI cohort, this drainage route seems to have been impaired in many of the patients, resulting in a shallower EG and a high RV.
The real question is....can venoplasty change this, and does it help disability? Dr. Zamboni's testing is showing that in preliminary results (presented at ISNVD), it does help pwMS.
cheer