These include risk factors such as Epstein-Barr infection, parental ancestry, date of birth and geographic location. MS is also more common in women, while venous diseases are more common in men. Venous pathology is commonly associated with hypertension, infarcts, edema and transient ischemia, and occurs more often with age, however these conditions are hardly ever seen in MS and the disease seldom appears after age 50. Finally, an organ-specific immune response is not seen in any other kind of venous disease. Iron deposits
Iron deposition as a cause of MS received support when a relationship between venous pressure and iron depositions in MS patients was found in a neuroimaging study, and criticism as other researchers found normal ferritin levels in the cerebrospinal fluid of MS patients. Additionally iron deposition occurs in different neurological diseases such as Alzheimers disease or Parkinsons disease that are not associated with CCSVI. Evidence linking CCSVI and iron deposition is lacking, and dysregulation of iron metabolism in MS is more complex than simply iron accumulation in the brain tissue. Genetics
A small genetic study looked at fifteen MS patients who also had CCSVI. It found 234 specific copy number variations in the human leukocyte antigen focus. Of these, GRB2, HSPA1L and HSPA1A were found to be specifically connected to both MS and angiogenesis, TAF11 was connected to both MS and artery passage, and HLA-DQA2 was suggestive of having an implication for angiogenesis as it interacts with CD4.
The debate regarding funding in Canada has been considered to be specially informative as an example of extreme involvement of politics, due to public pressure, in decisions usually governed by scientific evidence.In 2009, the Multiple Sclerosis Society of Canada committed to funding research on the connection between CCSVI and MS, although later in 2010 it came under criticism for opposing clinical trials of CCSVI therapy. The MS Society of Canada in September 2010 reserved one million dollars toward CCSVI research "when a therapeutic trial is warranted and approved. "At a political level there have been contradictory positions, with some provinces funding trials, others stating that since therapy is unproven they should wait, and others urging for a pan-Canadian trial. British Columbia, Alberta, and Newfoundland and Labrador funded observational studies in which patients who had already received the treatment were included. Over 2 million dollars were allocated to these studies. The province of Saskatchewan was more aggressive and provided 2.2 million dollars for some of its residents to be included in a clinical trial.The Canadian Institutes of Health Research (CIHR), the federal agency responsible for funding health research, recommended in 2010 against funding a pan-Canadian trial of liberation therapy because there was a lack of evidence on the safety or efficacy of the procedure. It suggested a scientific expert working group made up of the principal investigators for the seven MS Society-sponsored studies. The health minister accepted the CIHR recommendation and said that Canada was not going to fund clinical trials.