Relapses and Disability, Part 2

In my last post I briefly summarized two papers that showed that relapses in MS were only very rarely sources of permanent disability.  But does this mean that relapses don’t matter?  Does this mean that by using medications to prevent relapses we are tricking ourselves into thinking that we are having an impact on the course of the disease?  This is the opinion of several well-respected MS neurologists and is a great source of controversy in the field.   After all, about 15% of patients have a variant of MS known as primary progressive MS. These patients do not have relapses at all, yet they generally accumulate disability at faster rate than patients with the relapsing-remitting form of the illness.

The Significance of Relapses for Patients

I believe that relapses do matter even though they are not likely to be permanently devastating events and even if much of the disability in MS occurs during the progressive phase of the illness.

First of all, even if relapses have minimal effect on patient’s physical disability, they can cause overwhelming emotional distress. I have seen many patients who are having what might appear to be a “minor” relapse, pay a significant emotional toll in knowing that their disease in not under control.  

Second of all, the studies I discussed in my last post used the EDSS to measure disability, as do most studies in MS.  I have already discussed the problems with this scale in a previous post.  Briefly, the EDSS is a scale that is heavily dependent on a patient’s ability to walk.  However, I have seen patients suffer relapses characterized by significant pain, visual difficulties, and cognitive disturbances.  Who can argue that these relapses do not matter?  Yet, based on the EDSS, these patients might not be deemed as having significant disability, as long as their ability to walk was not affected. 

Understanding Why Short-Term Disability Matters

Finally, while the prevention of long-term disability is what most doctors and patients care about, the short-term should not be undervalued. It is very common that patients do not heal entirely from their relapses and are left with abnormal sensations, weakness, visual disturbances, and others.  While these symptoms may not make a difference in how someone is doing twenty years after the relapse, they can make a huge difference how someone is doing twenty days after a relapse. Why should this not matter?

So what does this means in terms of treating MS?  If a medication were invented tomorrow that completely eliminated relapses, it is doubtful that MS would cured.  Yet, there is evidence that over periods lasting several years, patients who take medicines for MS have less disability than those given placebo in the clinical trials, indicating to me that relapse prevention in MS is no trivial matter.  I prescribe medications for MS patients with confidence that they have a positive influence on the course of their illness, while at the same time recognizing there is much work to be done before the disease can be conquered.