After reading the article and all the previous posts, I have the following remarks.
The only mention to the methodology regarding testing for CCSVI is the following
“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:
(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.”
It is not clear if the testing was correctly performed.
“Blood volume flow in the IJVs was assessed as apical as possible in the upper region of the neck close to the mandibular angle. Vertebral vein (VV) flow was assessed either between intervertebral segments C4/C5 or C5/C6. Measurements were obtained at an identical site in supine and upright body position. Ultrasound assessments were performed in an identical fashion in patients and controls.”
refers to the measurement of the blood flow (volume and velocity), which is something that has not been tested by Zamboni’s team. It is not clear if they used this method also to test CCSVI criteria 1 and 4.
Blood flows were averaged without a note to the total number of measurements. This may be problematic since they note:
“Where the IJV was completely flat no CSA and therefore no BVF measurements could be obtained.”
Regarding CCSVI criterion number 1, they argue that
“The Doppler-sonographic observation of bi-directional flow in parts of the IJVs [by Zamboni’s team] 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.”
Regarding CCSVI criterion number 2, they managed to test several of the DCVs and the flow was almost always orthograde (except for the straight sinuses of one pwMS). They managed to test 96% of the Basal veins of Rosenthal, 64% of the deep middle cerebral veins, 19% of the straight sinuses, and 40% of the transverse sinuses (data for pwMS). The percentages are not high enough for having a definitive answer.
Regarding CCSVI criterion number 3, they say that
“Regional narrowing of the IJV and VV was assessed by insonating their entire accessible length using the sagittal plane of the B-mode imaging. A local CSA reduction of ≥ 50%, following the suggestion by Zamboni et al. was considered a stenosis.
Actually, Zamboni used the B mode of the Doppler to identify stenosis due to membranes, septa etc. The suggestion that a stenosis means a ≥ 50% reduction in the CSA refers to a PTA.
Regarding CCSVI criterion number 4, they argue that
“Depending on different ultrasonographic indices e.g. the pulse repetition frequency, blood flow may not be detectable using the duplex technique, especially when the BFV is low. The BFV is often low in the VVs and also decreases with age leading to a lower detection rate in the elderly. With respect to the IJVs, a wide vessel lumen and/or a state of exsiccation (leading to low central venous pressure) may reduce the BFV immensely and render detection of the vessel in the duplex mode impossible.”
They found that the criterion was fulfilled for 5/56 of pwMS and for 1/20 of HC.
Finally, 4/56 pwMS fulfilled CCSVI criterion number 5 (and 3/20 of HC)