Researchers Report on Follow-Up of People with “Benign” MS

February 13, 2007

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A new study of 169 people who had mild courses of MS 10 years after onset also known as “benign” MS shows that by 20 years after onset, the disease in almost half of these individuals had progressed to the point of no longer being considered benign, and 36 (21.3%) had developed severe disability. Ana-Luiza Sayao, MD and colleagues (University of British Columbia, Vancouver, Canada) report their results in the February 13 issue ofNeurology. This study supports the fact that at present it is not possible to reliably predict whose MS will remain mild, and suggests that this uncertainty should be taken into consideration when physicians discuss treatment options with their patients with apparently mild MS.

Doctors define benign MS in different ways, but in general the term refers to individuals who have had MS for an extended period of time but whose disability continues to be very mild. Dr. Sayao’s team selected people from the British Columbia MS clinic database who, 10 years after the onset of MS, had a score of 3 or lower on the EDSS (a scale that measures physical activity; a score of 3 or less means that, at most, some disability is present but the person is fully mobile). They obtained 20-year follow-up EDSS scores for 169 patients, and report that 88 (52.1%) continued to have a mild MS course, whereas 81 (nearly 50%) had progressed beyond the definition of benign MS (EDSS 3.5 and higher), including 36 (21.3%) developing severe disability and mobility restrictions (EDSS score of 6 or more; an EDSS of 6 means that the person needs a single cane, crutch, or brace in order to walk).

Dr. Sayao and colleagues also examined whether certain factors were associated with a benign course of MS. Age at MS onset, gender, or the types of early symptoms (e.g., inflammation of the optic nerve) were not linked with the resulting MS course.  “While just more than half of the patients in our study continued benign it remains a challenge to predict reliably who these patients are,” say the authors.

These findings provide new information on an important question in MS management how do you treat people with mild courses of disease? In an editorial that accompanies the Sayao study, Sean J. Pittock, MD (Mayo Clinic, Rochester, MN) advocates the “watchful waiting” approach. “The ‘watchful waiting’ approach should not be misconstrued as a ‘never treat’ approach,” he points out. “If the decision is made to delay treatment in a patient with a favorable disease profile, yearly clinical and radiologic surveillance is advised, with appropriate initiation of DMA [disease-modifying agent] should the clinical (relapses) or radiologic (new/enhancing lesions) status or patient wishes change.”

However, this new study shows that what presents as “benign” MS may not be so benign. The National MS Society’s Medical AdvisoryBoard recommends that treatment with an immunomodulating drug (such as FDA-approved interferons or glatiramer acetate) be considered as soon as possible following a definite diagnosis of MS with active disease (i.e., recent relapses and/or new lesions on MRI), and may also be considered for some patients with a first attack who are at high risk of developing MS (known asclinically isolated syndrome).Because at the time of diagnosis and for some years thereafter it is impossible to know if disease will be benign or more active, this recommendation holds for people who present with a mild disease course.

-- Research & Clinical Programs