This scan shows blood flowing through veins in the neck of a patient with multiple sclerosis. (CBC)

The Italian doctor whose unconventional thinking on the cause of multiple sclerosis is in North America to drum up interest in testing the idea.

Most MS specialists believe the condition is an autoimmune disease caused by immune cells attacking neurons in the brain and spinal cord, leading to inflammation and damage such as paralysis.

But Prof. Paolo Zamboni's idea is that a narrowing of veins in the neck interferes with blood draining from the brain, allowing iron from the blood to build up in the brain and cause a condition known as chronic cerebrospinal venous insufficiency (CCSVI).

Asked about skepticism in the medical community, Zamboni, a professor of medicine at the University of Ferrara, told reporters in Hamilton Monday: "My suggestion is to investigate patients as soon as we can, not to simply criticize. Look and confirm the data."

Zamboni was in Hamilton for two days of meetings. On Sunday, researchers from Jordan, Poland and Buffalo presented their preliminiary findings, which were not released publicly, on using magnetic resonance imaging to look for vein blockages.

Zamboni believes CCSVI is one of the causative factors in MS, not the only cause. Researchers don't know if CCSVI happens just in MS patients, he noted.

To find out more, a team at St. Joseph's Healthcare in Hamilton, Ont., hopes to recruit 200 people for a controlled study — 100 with MS and another 100 healthy people. Investigators will also focus on different types of MS, searching for any differences that patients may have in their blocked veins.

There is a debate within the medical community in Canada about whether there is enough evidence to try using surgery to open up the blockages in patients with MS.

"What the techniques would be have got to be defined yet, so this is early days to understand the association of this very interesting observation of Dr. Zamboni," said Dr. David Higgins, president of St. Joseph's Healthcare.

Tuesday is the deadline for researchers who want to apply for funding from the Multiple Sclerosis Society of Canada. The society will make $100,000 available for each of two years, and will decide which proposals to fund in a few months. The other known applicant is the University of British Columbia.