Study adds fuel to debate over MS and blocked veins
Posted: Tue Jun 15, 2010 12:14 pm
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Makes you wonder when several other studies have shown a high percentage of venous blockage and this one quite different.scorpion wrote:These results are not very impressive.
http://www.ctv.ca/CTVNews/Health/201006 ... vi-100614/
cheerleader wrote:
These were vascular specialists performing the ultrasounds. Ursula was tested at Charite, and she posted on here and said they were vascular docs.
I really wanted to keep this discussion away from attacking the doctors, and simply looking at what might have been different in their protocol. What I found was that they employed valsalva manuever and looked at internal jugular vein valve insufficiency as a measure of venous reflux and Dr. Zamboni utilized normal breathing. They also measured 2 points, and Dr. Zamboni's protocol looks at the entire jugular. Their TCD machine was different, and they admitted that interpretations of TCD scans are variable. That's all I could find in the German paper...but I'm sure that Dr. Zamboni's team will answer the study, if he is given the opportunity to reply in the Annals of Neurology.
cheer
One more time...the conversation needs to be about the methodology, not people. The doctors claim to utilize Dr. Zamboni's CCSVI doppler protocol. They look for the 5 Zamboni quantifications, but they used different tests to find these In the paper, they state repeatedly, valsalva is an adequate means to test for venous reflux. But it is not. Dr. Zamboni found reflux in absence of valsalva maneuvers. They claim that 2 locations of measurement (one for jugular and one for vertebral veins) are enough. But it is not. Dr. Zamboni's team measured the entire jugular. They claim that there is no real protocol for TCD testing, and so they dismiss it out of hand. Dr. Zamboni has a TCD protocol, and it was not followed.
It was good for me to read the entire paper, because the discrepancies were obvious. For anyone truly concerned, buy the paper online. It will put your mind at ease. I would assume the the Annals of Neurology will publish Dr. Zamboni's reply.
Again, I ask that we stay away from shooting the messenger, and simply look at the science. Thanks-
cheer
[/quocheerleader wrote:Hey guys---got the paper in front of me. They were vascular docs. Here's what I've been writing down in CCSVI land....the conversation began to devolve into neuros vs. vascular, so I'll copy it up here--
cheerleader wrote:
These were vascular specialists performing the ultrasounds. Ursula was tested at Charite, and she posted on here and said they were vascular docs.
I really wanted to keep this discussion away from attacking the doctors, and simply looking at what might have been different in their protocol. What I found was that they employed valsalva manuever and looked at internal jugular vein valve insufficiency as a measure of venous reflux and Dr. Zamboni utilized normal breathing. They also measured 2 points, and Dr. Zamboni's protocol looks at the entire jugular. Their TCD machine was different, and they admitted that interpretations of TCD scans are variable. That's all I could find in the German paper...but I'm sure that Dr. Zamboni's team will answer the study, if he is given the opportunity to reply in the Annals of Neurology.
cheer
One more time...the conversation needs to be about the methodology, not people. The doctors claim to utilize Dr. Zamboni's CCSVI doppler protocol. They look for the 5 Zamboni quantifications, but they used different tests to find these In the paper, they state repeatedly, valsalva is an adequate means to test for venous reflux. But it is not. Dr. Zamboni found reflux in absence of valsalva maneuvers. They claim that 2 locations of measurement (one for jugular and one for vertebral veins) are enough. But it is not. Dr. Zamboni's team measured the entire jugular. They claim that there is no real protocol for TCD testing, and so they dismiss it out of hand. Dr. Zamboni has a TCD protocol, and it was not followed.
It was good for me to read the entire paper, because the discrepancies were obvious. For anyone truly concerned, buy the paper online. It will put your mind at ease. I would assume the the Annals of Neurology will publish Dr. Zamboni's reply.
Again, I ask that we stay away from shooting the messenger, and simply look at the science. Thanks-
cheer
But they were familiar with Zamboni's 5 criteria:The aim of this study was to (i) evaluate the ultrasound findings reported by Zamboni and co-workers suggesting a role of ‘CCSVI’ in the pathogenesis of MS, and (ii) to extend the studies they performed through acquisition of additional ultrasound indices such as blood volume flow (BVF) and internal jugular venous valve competence (Valsalva maneuvre) to more comprehensively evaluate the haemodynamic effects of any suspected cerebro-cervical venous congestion.
It looks like they used the Valsalva maneuver only to test for valve incompetence. They found 38% of the patients and 30% of the controls that had reflux during the Valsalva maneuver. Yet, in their comparison to Zamboni's criteria (in the article text and in the table at the end of the article) they list 0 as the number of patients/controls who showed >.88 sec. of reflux. So, apparently they are not counting those who showed reflux during the valsalva.Assessment of ‘CCSVI’ criteria. A specific effort was undertaken to search for the
presence of one or more of the following criteria by which ‘CCSVI’ has been defined (table 6): (i) a reflux >0.88 sec in the IJV and/or the VV, (ii) reflux in the deep cerebral veins (DCV), (iii) B-mode evidence of proximal IJV stenosis, defined as local reduction of CSA ≥ 50% in a recumbent position (0°), (iv) flow not Doppler detectable in both IJVs and/or both VVs (v) a missing IJV diameter decrease in the sitting position, so called “reverted postural control” of the main cerebral venous outflow pathways.
The authors checked only one spot in the jugular and vertebral veins for the purposes of determining blood flow volume, an additional measurement they added. But for the purpose of testing criteria 3, B-mode evidence of proximal IJV stenosis, they did check the entire vein:In a single patient with RRMS we detected a constant bi-directional flow in the left IJV in a supine position. This flow pattern turned into an orthograde flow when sitting up. In contrast to our findings Zamboni, et al. reported a reflux >0.88 sec in the IJVs and/or VVs in any body position in 70% of the patients with MS.11,12 The Doppler-sonographic observation of bi-directional flow in parts of the IJVs may be caused by a pulsation artifact from the nearby carotid artery and hence be misinterpreted as a venous reflux, particularly if blood flow measurements were not assessed along the entire IJV. VM testing seems a adequate method by which to detect venous reflux. In our study we detected IJVVI in 38% of MS patients, hence slightly more often than in our reference cohort as well as compared to values reported earlier.28 As Zamboni and
co-workers did not report analysis of IJV valve competence using VM it cannot be excluded that what they detected as reflux was rather caused by IJVVI then by stenosis.
I can't say I really understand all of the possible reasons the authors give for their differences with Dr. Zamboni's results. It would be nice if they and Dr. Zamboni could discuss the discrepancies, but realistically this probably won't happen.Regional narrowing of the IJV and VV was assessed by insonating their entire accessible length using the sagittal plane of the B-mode imaging. For assessment of the IJV additional measurements were obtained in the horizontal plane.
Where the IJV was completely flat no CSA and therefore no BVF measurements could be obtained. In case of marked
respiratory variation of CSA and flow velocity measurements within subjects they were asked to briefly hold their breath after a normal exhalation, and measurements were obtained during these episodes of apnoe.Page 7 of 39
http://www.ncbi.nlm.nih.gov/bookshelf/b ... &part=A622To determine the mean jugular venous pressure, the examiner should observe the nadir of the venous column on inspiration and then the crest of this column on expiration. Next, the midpoint of the excursion of the venous pulse during normal respiratory cycles is estimated visually. Exaggerated breathing or breath holding distorts the normal mean venous pressure and should be avoided.
Yes, "...his method was different".cheerleader wrote: ...
Anyhoo...all I know is Zamboni made a big deal in Bologna about no breath holding, no valsalva, his method was different.
...
"The value of cerebral Doppler venous haemodynamics in the assessment of multiple sclerosis"AMcG wrote:...I did not know about them defining reflux as having a duration of greater than 0.88 sec. The figure I remember Zamboni quoting was 0.5 sec. I really don’t think they had a lot of results in the 0.5 to 0.8 range but I do wonder where the 0.88 sec comes from.
...
M.....
1.2.1. Physiologic flow direction in the IJVs and\or VVs with the head in
any position
The physiologic direction of venous flowwas assessed during a short
period of apnea following a normal exhalation, as previously reported,
with the head positioned at 0°, +15°, +30°, +45°, +90° in the four
extracranial venous drainage pathways [11]. We assess the eventual
presence of reflux in the IJVs and VVs in the same experimental
condition and never in a forced condition as Valsalvamanouevre [15,16].
According to a recent study on reflux time cut-off values,we considered
reflux a flow directed toward the brain for a duration >0.88 s
.....