Yet another Canadian study is casting doubt on a controversial theory that multiple sclerosis is caused by blockages in the neck veins. This time, it’s Calgary doctors who say that there appears to be no link between blood flow constriction in the veins and the debilitating disease.
A new University of Calgary study suggests that chronic cerebral venous insufficiency – or CCSVI – isn’t connected to MS. It’s adding to a growing collection of research that dispels contentious findings.
Italian doctor Paolo Zamboni had argued that CCSVI increased the risk of having MS by 43 times. The vascular condition restricts blood flow to the brain, which could cause muscle weakness and loss of sensitivity, he argued.
By 2008, he introduced “liberation therapy,” an angioplasty that would open up blocked veins in the neck.
In the latest research, the Canadian doctors say that the criteria for CCSVI is generic – or “overly inclusive and non-specific” – according to their findings, and that even healthy subjects could be diagnosed with the condition.
“There have been a large number of studies that have failed to reproduce the findings published by Zamboni and colleagues. Like other investigators, we noted significant concerns regarding the ultrasound criteria used to define CCSVI,” Dr. Fiona Costello, of the University of Calgary, told Global News.
“Our findings cast the validity of these criteria and CCSVI as an entity into doubt,” she said.
Costello is a neurologist and professor specializing in studying biomarkers of disease and progression in MS. Her research was published Monday in the Canadian Medical Association Journal.
Costello said she was “intrigued” by the CCSVI theory and wanted to explore its legitimacy.
Her study looked at any vein abnormalities in 120 MS patients and 60 healthy controls. Using ultrasound technology and venography, radiologists who knew nothing about the health status of either groups studied images of their veins.
About 58 per cent of MS patients and 63 per cent of controls all met at least one of the criteria to receive a CCSVI diagnosis. But there were no stark differences between the groups.
In a 2013 B.C. study, Vancouver doctors found no difference in the narrowness of the veins in MS patients and those without the condition.
Months later, Ontario scientists found no evidence of blockages in MS patients’ veins.
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.
Zamboni’s liberation therapy has stirred up debate – the procedure has helped plenty of patients, but there have been instances of death in the wake of the process.
The therapy is banned in Canada, but right now federal and provincial governments have poured funding into studying the treatment closely.
So what’s Costello’s take on liberation therapy?
“MS is a complicated disease and I believe that the factors that provoke and alleviate symptoms are equally complex, and often unique to any given individual,” she said.
Costello suggests that the disease manifests so differently in its patients – we don’t know why women are affected more than men, and we can’t explain why it’s mild in some people, but severe in others.
Canada has one of the highest rates of MS in the world.
© 2014 Shaw Media