Cece wrote:
It's insane that they considered the presence of valve leaflets as a disqualification when that's what CCSVI is: outflow obstructions, as drsclafani recently put it, either from stenosis or very frequently from malformed valves. I have malformed valves on both sides, yet would not be counted as CCSVI in this study.
.
From the paper I believe presence of leaflets was excluded so as not to have false positives caused by prominent IJV valves which may be unrelated to MS.
"In comparison, Zamboni et al.’s series
included 35 RRMS patients with mean disease duration
of 4 years, all of whom had evidence of EVS.
The difference between our results and those of Zamboni
and colleagues can be due to many factors.
Extracranial SV is not routinely used in neurological
practice and therefore lacks standards for ‘normals’,
which is reflected by the paucity of series in the literature
addressing the subject. The caliber of the IJV is
dependent on many factors including patient’s position,
breathing (inspiration vs. expiration), compression by
nearby structures (such as sternocleidomastoid muscle
or carotid artery for IJV and esophagus in the case of
AV), and
prominent IJV valves, all of which can give a
picture of pseudostenosis (Figure 3). Furthermore, congenital
variations in the size of the IJVs are common,
particularly on the left which is commonly smaller than
the right (see Figure 2). One of our patients had an
absent IJV on the left side, with drainage occurring
through the external jugular network. We rigorously
excluded all those confounding factors in our SV studies,
and performed all contrast injections during held
inspiration to avoid misdiagnosis. Moreover, a diagnosis
of EVS was contingent on the presence of delay in
contrast clearance across the lesion which reflects a
functional consequence of the venous stenosis."
