Benign Multiple Sclerosis—Does it Exist?
Abstracts & Commentary
Sources: Hawkins SA, McDonnell GV. Benign multiple sclerosis? Clinical course, long-term follow-up, and assessment of prognostic factors. J Neurol Neurosurg Psychiatry 1999;67: 148-152; Sorensen TL, et al. Optic neuritis as onset manifestation of multiple sclerosis. A nationwide long-term survey. Neurology 1999;53:473-478.
Hawkins and mcdonnell monitored the long-lasting clinical course of 259 patients with multiple sclerosis (MS) in Northern Ireland. One hundred eighty-one of these patients had MS for 10 years or longer, of which 36 (20%) patients with a Kurtze Expanded Disability Scale Score (EDSS) of 3.0 or less were defined as having benign disease. The patients with benign MS were predominantly women (ratio 4.1:1 vs 2.1:1 for nonbenign MS), were younger at onset (25.8 vs 31.2 years), and were more likely to present with optic neuritis or sensory disturbance. Conversely, patients with later onset of MS (> 40 years), male sex, and presenting with motor disturbances were more likely to have a progressive course with a higher EDSS.
In a long-term analysis of 118 MS patients from a similar 1987 study, of the 33 patients defined as benign at onset, 28 were available for follow-up (5 died in the intervening period). Only eight patients (28%) continued to fulfill the criteria for benign MS, all of whom initially had an EDSS score of 2 or less. The mean/median disability score in 1987 of 2.3/3.0 advanced in this benign group to 4.6/5.0, and most patients changed from a relapsing-remitting (RR) course to a secondary progressive (SP) course.
In another long-term survey, Sorensen and colleagues followed 6923 patients in the Danish MS registry from 1949 to 1990. Of the 1282 patients (19%) presenting with optic neuritis (ON), the mean age of onset was 31.1 years, compared with 34.8 years for patients with non-ON manifestations of MS (P < 0.001). The mean delay from initial manifestations to clinically definite MS was 6.1 years for ON, and 4.2 for non-ON.
The median survival time from onset of ON in the Danish registry was 40 years in women (compared with 47 years in the age-sex-matched general population) and 30 years in men (compared with 41 years in the general population). The excess death rate was lower for women presenting with ON as an initial manifestation of MS, but not for men with ON, or compared with non-ON presentations in either sex.
Commentary
Longitudinal clinical information from large national health databases has provided an important understanding of the natural history of MS. Such information better enables the neurologist to make an accurate prognostic assessment of MS patients with varied clinical presentations. Thus, less optimal clinical presentations with a greater probability of progressive neurological disability might benefit from early therapeutic intervention.
The eventual neurological disability that occurs at a high rate, even in patients who are initially labeled as benign MS, is sobering. It suggests that, while it may be important for the physician to provide the patient with an optimistic outlook on their disease course, it can be falsely reassuring for both to use misleading labels such as benign MS.
Quantitative MRI data have also documented early subclinical brain atrophy and white matter changes that signal irreversible axonal loss that can occur in the first 10 years of disease preceding the secondary progressive phase of MS (Apatoff BR. Neurol Alert 1999;17(9):65-67). Thus, the natural history data presented in these two studies would support the giving of earlier treatment to MS patients with active disease using immunomodulatory agents to minimize long-term disability. —ba
Which of the following is false? Patients presenting with benign or milder forms of MS are:
a. more likely to present with optic neuritis or sensory disturbance.
b. more commonly female.
c. have a younger age of onset of MS.
d. rarely going to experience increasing neurologic disability.
e. still going to have a clinical indication for immunomodulatory therapy.
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