A controversial theory that multiple sclerosis is related to blockages in neck veins has been skewered by a Canadian study that experts on the disease say should end discussion of the matter.
At the same time, lead researcher Anthony Traboulsee said he intends to continue a separate, federally financed $6-million study to explore a central tenet of the theory: That using angioplasty to open blocked veins alleviates symptoms of multiple sclerosis.
Dr. Traboulsee, director of the MS Clinic at the University of British Columbia, reasoned that reports of marked improvements from thousands of people with MS who have had angioplasty were too compelling to ignore.
The study found no significant difference between the rates of vein blockages in people with MS and those without, suggesting that MS is unrelated to what the theory calls chronic cerebrospinal venous insufficiency, or CCSVI.
“Our results confirm that venous narrowing is a frequent finding in the general population, and is not a unique anatomical feature associated with [MS],” Dr. Traboulsee said. “We realize that for many people with MS, this will be a disappointment.”
The study was the second from Canada in as many months that cast doubt on the link between CCSVI and MS, and one of several from across the globe in recent years.
The results were published on Tuesday in the British medical journal The Lancet. An accompanying editorial from the heads of MS research centres in Berlin and Amsterdam said the findings should sound a “death knell” for the CCSVI theory.
“[N]ow it is absolutely clear that no reason exists to allocate any further resources to [CCSVI] research, be they financial or intellectual,” Friedemann Paul and Mike Wattjes wrote.
The theory is the 2009 brainchild of Italian vascular surgeon Paolo Zamboni, whose pioneering angioplasty to widen the veins, known as liberation treatment, took off on the Internet and excited MS patients worldwide. Many who have undergone the procedure have posted videos of themselves online they say show their improved mobility.
The theory ignited a fierce debate in Canada – where MS rates are among the highest in the world – about the merits of publicly financing experimental medical procedures. Liberation treatment is not available in Canada, and experts estimate that 3,000 to 5,000 Canadians have spent upward of $10,000 apiece to have it abroad.
Dr. Traboulsee said more than 500 Canadians with MS have registered to be one of 100 in the study to test the effectiveness of the treatment. Results are expected in late 2015 or early 2016.
Dr. Traboulsee acknowledged the paradox of debunking a theory and moving ahead to test a procedure for it.
He said just because his evidence suggests CCSVI has no causal link to MS, thousands of people who report feeling better after having their veins widened should not be dismissed.
“I’ll be honest, I don’t understand why they’re feeling better,” Dr. Traboulsee said, adding later: “The best-case scenario is we learn more about the disease. Worst-case scenario, we discover a placebo effect.”
Reached via e-mail, Dr. Zamboni declined to comment on the findings, saying only that the results of a study “should be positive or negative.”
The MS Society of Canada, which has committed $700,000 to CCSVI-related research, including the UBC study, said in a statement that it remains committed to funding MS studies. It did not respond to a follow-up query on whether it would finance research related to CCSVI in the future.