A few TIMsers reported accessory nerve damage after stent placement high up in the IJVs
if the flow in the jugular veins is obstructed lower down, then flow is diverted to the vertebrals and that leads to collapse of the upper part of the vein. At the level of the carotid bulb, and the high IJ near the skull base.
Dr. Zamboni must have been aware of this as well when he started treating his patients with balloon angioplasty a few years back. I have heard that he didn't find it important to treat these areas, which is why accessory nerve damage does not appear as a side effect of treatment in his papers.
Dr. Simka confirmed the same thing. A quote of him has been posted here: http://www.thisisms.com/ftopic-10028-da ... asc-0.html
: "At Stanford such a narrowing is regarded as real problem, and they usually put a stent in this area. But our interpretation is that it is only a collapse of the vein, which is secondary to diminished flow caused by problems in the lower part of the vein. "
I've been told by a doctor who went to the Hamilton conference that the Buffalo research team and Canadians also agree: narrowings above the clavicle are indeed just collapses, some physiological (i.e. they're found frequently in healthy people and fluctuate with time), and if increased in people with MS are a result of a problem in the lower jugulars, as you say. So this must reassure you, that almost everybody agrees with you on the meaning of upper jugular vein narrowings and that treatment of these areas would not be beneficial for CCSVI/MS.
I have a question about pressure gradients. I have been told that they are not meaningful if measured over large distances in veins. In particular, if there's a pressure gradient of, say, 3 mmHg over the length of such a collapse (say 3 cm), would you consider this reason to treat such an area?