Defining what a cure means in multiple sclerosis

This is an updated post from the 7th March 2010.

I was at a meeting on optic neuritis in central London yesterday (5th April 2012) and we got onto the usual discussion/debate about early aggressive treatment vs. watchful waiting so as not to expose too many MSers, destined for a benign course, to the risks of aggressive therapy. One of the issues that came up afterwards is that if you have a risky treatment that cures a significant proportion of MSers how will you know if it is the treatment or the natural history of the disease that has resulted in the apparent cure (prolonged disease-activity free status)?

I said this would be a nice problem to have. However, the current clinical trials should be mandated to follow-up study participants for a very long time to answer this question. In the interim it would, however, be ideal to be able to offer these aggressive therapies to MSers stating that we don't know the long-term outcomes and let them take the risks themselves. Unfortunately, several of my colleagues remain uncomfortable with this strategy. We may therefore have to find a middle road; i.e. offering this option to MSers with very aggressive disease and keeping the treatment in reserve for those with less active disease. The problem I have with this is that our tools for monitoring MS don't capture all the disease, in particular gray matter pathology, and that MSers can be come disabled waiting for their disease to become more active.

Does anyone know what we need to show to claim someone has been of cured of MS?

At an International CMSC meeting, on MS classification, in Short Hills, New Jersey, in 2010 the following definition was discussed:

"To claim that someone has been cured of MS one would have to show that the person who had the disease had no disease activity for at least 15 years. The latter would be a composite of no MRI activity (new gadolinium-enhancing lesions, new T2 or enlarging T2 lesions and a lack of progressive whole brain atrophy) and no clinical activity (relapses or disease progression)."

It is important to stress that this definition does not mean that established neurological deficits are reversed, but only that no new deficits occur. 
What do you think?