TORONTO — Yet another Canadian study is opposing a controversial theory that multiple sclerosis is caused by blockages in the neck veins. This time, Vancouver doctors say that there is no difference in the narrowness of the veins in MS patients and those without the condition.
Just months after Ontario researchers poked holes in an Italian doctor’s theory he named chronic cerebrospinal venous insufficiency (CCSVI), a University of British Columbia study is casting further doubt on what causes MS and the value of “liberation therapy.”
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“Our results confirm that venous narrowing is a frequent finding in the general population, and is not a unique anatomical feature associated with multiple sclerosis,” lead author Dr. Anthony Traboulsee said in a statement.
Traboulsee is a neurology professor at UBC and director of the MS Clinic at Vancouver Coastal Health.
His team used two methods to examine the veins of 79 people with MS, 55 of their unaffected siblings and 43 unrelated volunteers.
Ultrasounds and catheter venography — an x-ray of the vein after injecting it with a dye — were used to study the size and shape of veins.
The width of the subjects’ veins between the brain and heart was examined. Results showed that at least two-thirds of each of the groups had a narrowing of veins that was greater than 50 per cent.
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Narrowed veins were present in 74 per cent of people with MS, 66 per cent of their unaffected siblings and 70 per cent of the unrelated healthy group.
“This is the first study to find high rates of venous narrowing in a healthy control group, as well as the first to show that the ultrasound criteria usually used to ‘diagnose’ CCSVI are unreliable. The connection between venous narrowing and MS remains unknown, and it would certainly appear to be much more complicated than current theories suggest,” Traboulsee said.
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The medical community is still unsure of what causes MS. It’s an unpredictable disease that often disables the body’s central nervous system and could lead to difficulty in walking or speaking and a loss of muscle sensitivity.
It was Paolo Zamboni, an Italian doctor at the University of Ferrara, that argued that CCSVI increased the risk of having MS by 43 times.
By 2008, he introduced “liberation therapy,” an angioplasty that would open up blocked veins in the neck.
There’s been heated debate about the procedure – while it’s helped plenty of patients, there have been instances of death in the wake of the contentious process.
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The therapy is banned in Canada, although federal and some provincial governments have poured funding into studying the treatment.
In August, researchers at McMaster University in Hamilton, Ont. say they found no evidence of any blockages in MS patients’ veins.
In that case, they used ultrasounds and MRIs on 100 MS patients and 100 people who had no history of the neurological condition.
Results showed that there were no “abnormalities” in MS patients and their counterparts. Only one person with MS satisfied the criteria for CCSVI.
“This now adds a lot of ammunition to say that you’ve got to be particularly careful if you’re going to go for any interventions,” lead author Dr. Ian Rodger told Global News.
Still, Traboulsee is leading another Canadian study that’s zeroing in on “liberation therapy.” In this study, his team is providing both angioplasty and a sham treatment to 100 MS patients. Results from this trial are expected in late 2015.
The Globe and Mail reached Zamboni via email and said he declined to comment on the UBC study’s results. He did not yet respond to Global’s request for comment.
In a statement, the MS Society of Canada says that it’ll continue to investigate the treatment of MS symptoms.
Traboulsee’s findings were published Tuesday in the British medical journal The Lancet. A commentary accompanied the report.
carmen.chai@globalnews.ca
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