Researchers at Stanford University have halted treatments for chronic cerebrospinal venous insufficiency (CCSVI) according February's edition of the journal Annals of Neurology.

The decision came after two people experienced serious side effects following stenting of the jugular veins, a procedure thought to correct CCSVI. One patient died from a brain haemorrhage following the procedure in August and another required emergency open heart surgery in November after a jugular vein stent dislodged into the right ventricle of the heart.

Dr Jeffrey Dunn, associate director of Stanford's MS centre, called on other neurologists to speak out about the potential "dangers" of the unproven procedure: "If I can do anything to protect MS patients from the potentially devastating effects of false hopes or the risks of invasive and unproven treatment, I am happy to do so".

The theory that CCSVI may play a role in causing MS was developed by Italian Cardiovascular Surgeon Dr Paolo Zamboni and has resulted in much debate and controversy. It has also sparked interest in many of the 2.5 million people with MS world-wide as a potential cause of MS.

Dr John Richert, executive vice president for research and clinical programs at the National Multiple Sclerosis Society in the USA said, "When dealing with a disease like MS, where we don't know the cause or have many therapeutic options, it's important to think outside the box. Dr Zamboni is doing this, but his techniques need to be confirmed.

He went on to add, "All of the evidence today is preliminary. There is not even enough evidence to say that obstruction of veins might be a factor in MS, or to determine when this obstruction may occur in the course of disease."

MS Societies around the world have emphasised that new research studies will be pivotal in determining the link between CCSVI and MS before surgical procedures should be made available to treat CCSVI.

Researchers in Buffalo NY are investigating the prevalence of CCSVI in people with MS. Dr Robert Zivadinov, Director of the Buffalo Neuroimmaging Analysis Centre and principle investigator of the Buffalo says: "If we can prove our hypothesis, that cerebrospinal venous insufficiency is the underlying cause of MS, it's going to change the face of how we understand MS", but he added that media coverage of CCSVI so far has been premature and "unrealistic".

Annals of Neurology