Multiple sclerosis patients held rallies across the country Thursday, calling on Ottawa and provincial governments to make the controversial "liberation therapy" available in Canada.

The therapy involves angioplasty to widen constricted neck veins, improving blood flow from the brain. But researchers have yet to prove that narrowing of the neck veins -- CCSVI -- is a symptom, or cause, of the disease.

Recent studies suggest not everyone with MS has CCSVI, although it might be more prevalent in those with advanced cases of the disease.

Patients who say liberation therapy has eased their symptoms have had to seek the treatment outside the country. Now politicians like Nova Scotia MLA Alphie MacLeod are joining the cause. His wife suffers from MS, and underwent liberation therapy last summer.

"She has seen an increase in energy and in the quality of life," he told CTV News.

Rallies were held in Halifax, Ottawa, and Montreal, where rain couldn't stop the crowds.

Among the protesters was Janine Baker, who posted videos on YouTube that document her condition before and after she underwent the therapy at a clinic in the United States.

She said the disease debilitated her to the point where she needed the help of a walker to move around.

"I was almost in a wheel chair," she said. "I was living in my own home but was headed for assisted living."

Baker paid for her therapy on June 2, 2010. Afterwards, she said her symptoms eased to the point where she could look after her 90-year-old mother who had suffered a stroke.

"I became her full-time caregiver," said Baker.

She was also able to travel and even do some rock climbing.

"That was like my inner 12-year-old being set free," she said. "It was just fantastic."

But like half of all MS patients who undergo treatment for CCSVI, the improvements seemed to diminish over time. Now Baker is looking at another round of therapy.

Another MS patient, Jamie Chalmers, is in the same position.

"The first three months, I felt like I was 20 again and six months later it's coming back. The monster is coming back," Chalmers said.

Going for a second, third or fourth treatment is costly -- in the thousands of dollars. But the MS Society of Canada has said the liberation therapy in Canada should only be done as part of a clinical study.

The society sent a statement to CTV News on the protests.

"The MS Society of Canada respects the right of individuals to mobilize and voice their opinion on issues important to our community," the statement said. "People living with MS have successfully drawn attention to MS issues resulting in real, positive change. For example, the federal government's recent announcement of a nationwide monitoring system for MS will allow us to better understand the disease and allow people with MS to make better choices about their own care."

But it added that work continues to "understand CCSVI's relationship to multiple sclerosis."

Clinical trials continue across Canada. A study underway in British Columbia is looking at whether those with MS do have blocked veins, while Saskatchewan is expected to announce new research into angioplasty.

Dr. Kirsty Duncan, Liberal MP for the Ontario riding of Etobicoke North, is fighting for clinical trials that may prove the effectiveness of liberation therapy.

"There is absolutely evidence to do clinical trials in Canada," she said. "We need to know if this improves quality of life for MS patients."

With a report from CTV's Medical Specialist Avis Favaro and Lauren Drong