People with multiple sclerosis are significantly more likely to have abnormalities in the veins draining blood from the brain than people without MS, new Canadian research is reporting.
After pooling the results from eight studies, Toronto and Calgary researchers found that MS patients were between four and 14 times more likely to have chronic cerebrospinal venous insufficiency, or CCSVI — a blocking or narrowing of veins in the brain and neck that some researchers claim causes MS and is the foundation of the so-called "liberation therapy" for MS sufferers.
But there was such a huge variation in the findings — with the frequency of CCSVI in MS patients ranging from 100 per cent, to zero, depending on the study — scientists say it is still impossible to say conclusively whether CCSVI causes MS or not.
"I think one of the messages — and I don't want to sound pejorative here — is that both sides in this controversy need to acknowledge that there's uncertainty and wait for the results" of ongoing studies, said lead author Dr. Andreas Laupacis, executive director of the Li Ka Shing Knowledge Institute at Toronto's St. Michael's Hospital.
"Anybody who says, 'I know for sure CCSVI causes MS,' I think this study suggests they don't know that for sure," he said.
"Similarly, some who have said, 'This is a ridiculous theory and there's nothing to it,' I don't think that holds up either, because clearly some studies are finding something to it."
The study appears in this week's issue of the Canadian Medical Association Journal.
In an accompanying commentary, U.S. neurologist Dr. Robert Fox says that science "is still far from proving" whether CCSVI is a paradigm shift in MS "or just another fad."
Fox says CCSVI may just be a phenomenon of a diseased brain that isn't specific to MS. "It may be seen in Alzheimer's disease, it may be seen in other inflammatory disorders of the brain," says Fox, medical director of the Mellen Centre for Multiple Sclerosis at the Cleveland Clinic. "It may just be a final end result of an injured brain and not related to causing MS."
Canadians suffering from the often-crippling disease have travelled abroad to Bulgaria, Poland, Mexico, the United States and other countries for liberation therapy, a controversial treatment that involves opening blocked veins in the neck that was developed by Italian doctor Paolo Zamboni.
Fox is warning patients away from the procedure. "There are patients who have died from complications from this procedure, there are patients who have had very serious complications needing open-heart surgery as a result of this procedure," he says.
"It is not risk free."
The Canadian researchers analyzed eight studies from Italy, Germany, Jordan and the U.S. that involved 664 MS patients in total. The studies looked at how frequently CCSVI was found in people with MS compared to healthy people or those with other neurological disorders such as Parkinson's disease.
One of the studies — Zamboni's — found CCSVI in 100 per cent of people with MS, and zero per cent of people without the disease. Other studies found the vein abnormalities in people who didn't have MS.
Overall, when the results were combined, people with MS were 13.5 times more likely to have CCSVI. Even when the study by Zamboni — which generated the excitement about CCSVI — was removed, the syndrome was 3.7 times more common in people with MS.
Yet many of the studies were small, none reported whether the person conducting the ultrasound knew whether or not the patient had MS and the studies may have used different ultrasound techniques.
Laupacis said the results of the ultrasound could depend on how it's performed. "You can press a little harder, or, if you get patients to breathe deeply or not, it can affect the blood flow of the veins draining the brain."
In addition, "If someone limps into the examining room compared to someone who walks in normally, it's likely that the person who limps has MS and the other person doesn't," he said. "I'm not suggesting that people are lying, but if you really believe in CCSVI there might be an inadvertent tendency to call a borderline abnormality 'positive" if you know someone has MS and 'negative' if you know they don't."
It could also work the other way "if you don't believe in CCSVI," he said.
For all these reasons, "we remain pretty cautious."
Fox, of the Cleveland Clinic, says he has never seen a situation where social media has driven a theory of a disease the way it has for CCSVI and liberation therapy.
"Patients are struggling out there with this disease, they really don't like it and they really want us to find a cure," he said.
"And when they feel like there's a cure out there that is not being given its full shake, they're going to talk about it and try to influence what's being done."
Fox said that a finding of CCSVI in a patient with MS might simply be due to dehydration. People with MS are more likely to have problems with their bladder, causing a more frequent need to urinate. The natural response, he says, is to drink less. "Many of our MS patients prefer to be mildly dehydrated because they just don't have to shuffle off to the bathroom as often," he said.
But when people are dehydrated, they have less blood volume; that might change the flow of blood within the venous system, he said.
In June, the federal Conservative government announced that it will fund clinical trials into liberation therapy for MS patients.
Canada has one of the highest rates of MS in the world.
skirkey@postmedia.com
http://www.edmontonjournal.com/health/studies+lend+some+credence+conclusions+liberation+therapy/5494281/story.html?cid=megadrop_story