Globe and Mail - Multiple sclerosis: Suspicions of bias on all sides of MS debate

Champions of blocked-vein theory say naysayers are beholden to drug companies; others point to Paolo Zamboni's own commercial links after he failed to disclose that he has worked closely for years with a leading Italian manufacturer of imaging devices used to detect the condition he calls chronic cerebrospinal venous insufficiency. Having a researcher work so closely with a company can raise eyebrows.

"If you are financially interested in seeing a given product make it to commercialization, you may be less inclined to collect and report information that's adverse," said Jonathan Kimmelman, an expert in biomedical ethics at McGill University.

Money, however, is not the only source of conflict, according to Prof. Kimmelman. Personal attachment also can skew a researcher's judgment.