Manitoba's health minister is calling for a national clinical trial of a controversial treatment for multiple sclerosis.

Theresa Oswald said Monday a pan-Canadian trial of the so-called liberation treatment is the quickest way to determine whether the procedure is appropriate.

She wants the issue discussed at next month's meeting of federal, provincial and territorial health ministers.

The treatment is based on an unproven theory — put forward by Italian doctor Paolo Zamboni — that blocked veins in the neck or spinal cord are to blame for MS.

However, research released earlier this month in Annals of Neurology, a journal published on behalf of the American Neurological Association, suggests not all MS patients have constricted neck veins.

Some Canadians have flown to clinics in Poland, Bulgaria and India for the procedure.

Some patients have posted testimonials on websites, in chat rooms and in YouTube videos, saying the procedure has reduced their symptoms. That has created political pressure to have the treatment provided in Canada.

Saskatchewan Premier Brad Wall has offered to fund clinical trials in his province, but Oswald said all governments should work together. Saskatchewan has the highest rate of multiple sclerosis among provinces, with an estimated 3,500 residents affected by it.

Oswald also called for the treatment to be discussed by top scientists from Canada and the U.S. when officials from the Canadian Institute of Health Research meet later this month.

With files from CBC News