People with a medical condition linked to multiple sclerosis are unfairly denied safe and proven treatment in Canada because many neurologists cling to outdated thinking about the disease, the head of an Ontario advocacy group charged Saturday.

Linda Hume-Sastre, president of a nascent organization to support people with a controversial condition called chronic cerebro-spinal venous insufficiency, or CCSVI, made the statement outside an Ottawa conference attended by more than 200 CCSVI sufferers, family members, caregivers and medical and scientific experts.

“All neurologists do is they give you drugs that don’t work for an auto-immune disease theory that’s never been proven,” said Hume-Sastre, referring to a traditional medical diagnosis and treatment for MS, which attacks the central nervous system. The cause is unknown.

Many of Saturday’s participants signed a petition calling on the House of Commons to support a recently-introduced private member’s bill by Liberal MP Kirsty Duncan demanding Health Canada expedite development of a national CCSVI strategy, including a firm timetable for clinical trials announced in June. A similar bill has been introduced in the Senate.

CCSVI is a blocking or narrowing of veins in the brain and neck that some researchers believe causes MS in some individuals and is the foundation of the “liberation therapy” for MS sufferers. It was unveiled in 2009 by Italian vascular surgeon Dr. Paolo Zamboni.

CCSVI researchers say if the veins in the neck and chest that drain the central nervous system are not functioning properly, the central nervous system will not function properly. In particular, they say, protective myelin-making cells around the smallest veins, called venules, will be damaged; inflammation will set in, nerve cells will eventually die causing blindness, weakness, loss of normal sensation, imbalance, memory and cognitive deficiencies.

Treatment consists of unclogging the veins with balloon angioplasty, the same technique used to clear blocked coronary arteries. An estimated 15,000 people have undergone treatment worldwide, including thousands of Canadians seeking help in the United States, Europe and India.

But it has not been approved in Canada, where an estimated 55,000 to 75,000 people have MS, one of the highest rates in the world.

About two-thirds of treated patients, including several people attending the Ottawa conference, report dramatic or moderate reduction of their MS symptoms. For many, however, the symptoms eventually return. Some report renewed improvements after additional liberation therapy.

In June, Health Canada Minister Leona Aglukkaq characterized CCSVI as an “important issue” and directed the Canadian Institutes of Health to begin preparing for clinical trials. Further details, including funding, have not been announced.

But Hume-Sastre and other members of CCSVI Ontario, one of several new CCSVI support and advocacy groups across the country, argue sufficient safety and efficacy data on liberation therapy exists in the U.S. and elsewhere to allow Canadian researchers to move to directly to a Phase III clinical trial with randomized controlled studies on large patient groups.

They also insist health officials consult physicians and others who have direct experience with CCSVI treatment.

At present, “they’re listening to people who have no experience in testing or treating CCSVI,” said Hume-Sastre.

New Canadian research reported in the Canadian Medical Journal in October confirmed people with MS are significantly more likely to have abnormalities in the veins draining blood from the brain than people without MS.

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 CCSVI.

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.