Relapses and Disability, Part I
As I have discussed in previous posts, the characteristic feature of MS, at least is its early stages, is relapses- also known as attacks, exacerbations, or flares. Prevention of relapses is also the main criteria by which treatments for MS are measured. It is this aspect of the disease that, quite understandably, creates significant anxiety in newly diagnosed patients with MS. Many of my patients are fearful that they will wake up one morning unable to walk, or with some other significant disability.
I would like to discuss several recent papers that I hope will help allay these fears. The first of these was entitled “What is the risk of permanent disability from a multiple sclerosis relapse?” It was published in the journal neurology in 2010. This paper tracked 1,078 patients who experienced a total of 2,587 relapses. In this large group of patients, only seven had relapses that permanently resulted in an EDSS higher than 6.0. The EDSS is the main scale used to measure disability in MS and a score of 6 is defined as: intermittent or unilateral constant assistance (cane, crutch or brace) required to walk 100 meters with or without resting. I personally can only recall a very small number of patients with MS who have had such relapses. So while significant and permanently disabling relapses do occur in MS, they are quite rare.
The second paper was published in the journal Neurology in 2009 and is entitled “Impact of multiple sclerosis relapses on progression diminishes with time.” This study tracked nearly 2,500 patients and 12,000 relapses and found that over the long-run, the number of relapses had very little impact on a patient’s overall outcome. Only patients with MS for less than 5 years had relapses that had an impact on long term disease progression, and even in these patients the long-term impact of the relapses was negligible. For patients who had MS for over 10 years, relapses barely mattered at all in terms of disability- at least as measured by the EDSS.
To me, these papers are a classic example of “Is the glass half empty or half full?” MS patients should know that relapses are unlikely to be the devastating events they so often fear. On the other hand, just because a patient is not experiencing relapses, this does not mean that they are disease-free. The current thinking about MS is that it is both an inflammatory disorder, where the inflammation manifests as relapses, and a neurodegenerative disorder (like Alzheimer’s or Parkinson’s disease), where there is the slow, steady progression of symptoms over months to years. The inflammatory part of MS predominates early in the disease course, while the neurodegenerative process is a later feature. Unfortunately, much of the disability from MS occurs in the progressive phase, and there is no evidence that most medications in MS have an impact on this stage of the illness.