Moreover, experienced groups in the use of ultrasound have not been able to show intracranial or extracranial reflux in MS patients or even healthy controls whereas the criterion of absence of flow and the criterion regarding stenosis are considered not valid since they are related to normal physiological processes and not pathology. These problems in the criteria have led some researchers to consider the criteria inadequate and more generally the concept of CCSVI flawed. Treatment
All proposed treatments are experimental
Treatment based on the idea of CCSVI is considered experimental. Further trials are required to determine if the benefits, if any, of the procedure outweigh its risks. Most experts, and medical and patients organizations, including the National Multiple Sclerosis Society of the USA or the Cardiovascular and Interventional Radiological Society of Europe (CIRSE), recommend not using the proposed treatment outside clinical trials until its effectiveness is confirmed by controlled studies. Moreover, the CIRSE has stated that treatment research should begin by a small, placebo-controlled, prospective randomised trial which should be monitored by an independent organization. An exception has been the Society of Interventional Radiology in the US and Canada, which considered research on the effectiveness of CCSVI intervention to be inconclusive as of 2010. In March 2013 a press release indicated that the first prospective, placebo-controlled study of balloon angioplasty for MS had not shown any benefit of the therapy.
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.