A new study has cast doubt on the theory that blocked or narrowed veins are a main cause of MS, study author Dr. Robert Zivadinov of the University of Buffalo said.

The findings published Wednesday in the journal Neurology were consistent with thinking that the condition — also known as chronic cerebrospinal venous insufficiency, or CCSVI — is more common in patients with multiple sclerosis but not to the degree first reported by Italian doctor Paolo Zamboni.

"These findings indicate that CCSVI does not have a primary role in causing MS," said Zivadinov, who has worked with Zamboni.

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Dr. Paolo Zamboni, left, and Dr. Robert Zivadinov, right, talk before speaking at the Neurologist Seminar in Toronto on Wednesday, April 14, 2010. (Nathan Denette/Canadian Press)

Zamboni proposed that multiple sclerosis may be linked with vascular problems, and that using angioplasty, or ballooning, to open blocked neck veins can help treat MS symptoms by changing blood flow patterns.

We present abridged interviews with two doctors, knowledgeable about multiple sclerosis, who give us their reaction to this latest study on the causes of MS.

Dr. Jock Murray is a Halifax neurologist and MS expert. He feels the study again says that people should be hesitant about going off to other countries and paying large amounts of money for something that has not been clarified to be beneficial as yet.

Canadian Dr. Joseph Hewett has been doing neck vein angioplasty for about 15 years. He now performs balloon angioplasty on people with MS in southern California. He says the latest study has flaws and that he will continue doing the surgery until there's a "gold standard" study.