Multiple sclerosis (MS) patients do not suffer from narrowing of the veins to a significantly greater degree than the general population, a new study has suggested.
There is no statistically significant difference between the rates of venous narrowing among MS patients, their unaffected siblings and unrelated people who do not have MS, according to findings published in the Lancet.
A controversial theory claims that a disorder known as chronic cerebrospinal venous insufficiency (CCSVI) can be a key part of MS.
Proponents believe that venous blockages and flow abnormalities can occur where there is narrowing of the veins running from the brain to the heart - extracranial veins - and that some MS patients can be effectively treated through angioplasty techniques to widen the veins, sometimes referred to as the liberation procedure.
However, Dr Friedemann Paul and Dr Mike Wattjes say in a linked comment that the new study should sound a “death knell” for that theory.
The research was led by Dr Anthony Traboulsee at the University of British Columbia and Vancouver Coastal Health in Vancouver and Dr Katherine Knox at the University of Saskatchewan in Saskatoon, Canada. It was one of a series of projects funded by the MS Society of Canada.
They examined the extracranial veins of 79 people with MS, 55 of their unaffected siblings and 43 unrelated healthy volunteers by using both ultrasound and catheter venography - the latter of which involves injecting the vein with a dye and taking an X-ray.
By comparing the width of extracranial veins with a normal segment of vein from below the jaw, the scientists discovered that at least two-thirds of each study group had narrowing of the extracranial veins greater than 50%.
The researchers said differences in venous narrowing were not statistically significant, as it occurred in 74% of people with MS, 66% of their unaffected siblings and 70% of the unrelated controls.
“Our results confirm that venous narrowing is a frequent finding in the general population, and is not a unique anatomical feature associated with multiple sclerosis,” said Dr Traboulsee.
Are you able to Speak Out Safely? Sign our petition to put pressure on your trust to support an open and transparent NHS.