Dr Brian Chambers and colleagues at the Austin Hospital, Melbourne, have published further findings from their MS Research Australia-funded ultrasound study into the prevalence of cerebrospinal venous abnormalities in people with clinically isolated syndrome (the earliest signs of possible MS) and mild MS.
In the initial publication of their findings, the research team had demonstrated that there were no significant differences between people in the earliest stages of MS and healthy individuals when the anatomy of the extracranial veins (draining the brain and spinal cord) were examined using the ultrasound techniques first defined by Dr Paolo Zamboni (for further details see the earlier news item here).
In an extension of this investigation, the team have now published further findings in the online version of the journal Phlebology on their measurements of blood volume flow in the extracranial veins.
Ultrasound techniques were used to compare blood flow in the internal jugular and vertebral veins in 66 people with MS and 4 people with CIS and 70 age and sex-matched healthy control individuals. No significant differences in blood volume flow were found between the patients and controls. The authors conclude that the ’findings further refute the concept of CCSVI having a pathogenic role in the development of MS but do not exclude the possibility of CCSVI occurring as a secondary phenomenon in more advanced MS’.
In the third of the seven major CCSVI prevalence studies funded jointly by the USA National MS Society (NMSS) and the MS Society of Canada to publish its findings, Professor Traboulsee and colleagues from the University of British Columbia, Canada have shown that CCSVI occurs equally in both people with MS and healthy individuals. Their results were published in the top medical journal The Lancet.
The Canadian team used both ultrasound and catheter venography (where a tiny tube is inserted into the vein to inject a contrast agent, before x-rays are taken of the veins) to examine 79 people with MS, 55 healthy siblings and 43 unrelated healthy control individuals. The average age of people with MS and controls was 47.8 and 48.7 respectively and the people with MS had an average Expanded Disability Status Score of 2.7 and average disease duration of 16 years.
By ultrasound, the team found that two or more types of abnormality, which is required for a diagnosis of CCSVI according to the Zamboni criteria, were present in 45% of people with MS, 32% of healthy siblings and 45% of unrelated healthy participants.
Catheter venography showed that narrowing of greater than 50% of any major vein was present in 74% of people with MS, 66% of healthy siblings and 70% of unrelated controls. These differences were not statistically significant. It was very rare for people with MS or healthy individuals to meet CCSVI criteria by venography.
The detection rate of venous abnormalities as seen by ultrasound with subsequent catheter venography was very low. The authors conclude that their results provide no evidence that the anatomy of extracranial veins differs between patients with MS, their unaffected siblings, and unrelated healthy controls.
For summaries of the other Canadian and US studies underway and the results published to date you can visit the website of the NMSS here.
