No evidence of vein blockages in MS patients, Canadian study says

Andrea Janus, CTVNews.ca Published Wednesday, August 14, 2013 4:54PM EDT Last Updated Wednesday, August 14, 2013 7:40PM EDT

Canadian researchers say they have found no evidence that restricted blood flow in the veins of the head and neck is linked to the development of multiple sclerosis. The researchers say their findings debunk a controversial theory that suggests vein blockages are responsible for MS symptoms, but critics say the researchers used outmoded techniques to detect the condition.

In a study published online Wednesday in the journal PLOS ONE, researchers from McMaster University in Ontario say they failed to find any blockages in the internal jugular, vertebral or deep cerebral veins in 99 of 100 patients with MS, compared with 100 subjects with no history of the disease.

For the study, the researchers conducted ultrasounds and MRIs on the head and neck veins of all study subjects to look for evidence of chronic cerebrospinal venous insufficiency (CCSVI), essentially blockages in the head and neck veins that prevent blood from properly draining from the brain.

It is Italian researcher Dr. Paolo Zamboni who first suggested that CCSVI is linked to MS, and he reported that patients symptoms were alleviated after undergoing angioplasty to clear the blockages, a treatment that has become known as the liberation therapy.

The Ontario researchers say that this is the first Canadian study to find compelling evidence that CCSVI is not involved in MS.

There will be those who will still want to believe that CCSVI is a real phenomenon, but the reality is that most of the European studies are negative to the theory of CCSVI, lead researcher Ian Rodger, professor emeritus in the Michael G. DeGroote School of Medicine at McMaster, told CTV News.

Our study bolsters that.

Rodger said doctors who are performing angioplasty on patients have to be very confident that you are seeing blocked veins, and we, with our study, do not.

Rodger noted that the ultrasound technician involved in his study spent a week training with Zamboni in Italy.

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No evidence of vein blockages in MS patients, Canadian study says