May 4, 2001
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Summary: An international panel, organized and supported by the National MS Society, with additional financial support from the MS International Federation, has recommended revised diagnostic criteria for multiple sclerosis.
Background: It has been 20 years since the criteria for the diagnosis of MS were considered for revision. Because there is not any single test that can be used to accurately determine an MS diagnosis, the process of diagnosis has involved evidence from clinical examination and history and evidence gathered from a variety of laboratory tests, all intended to rule out other possible causes of disease and to gather data consistent with a diagnosis of MS.
In these 20 years, however, understanding of the disease has greatly improved, disease types have been more fully described, and magnetic resonance imaging (MRI) has become fully integrated into studying the disease. Increasing numbers of clinical trials for new MS treatments and the availability of disease-modifying treatments make accurate diagnosis of MS more important than ever before. In July 2000, the National MS Society convened a group comprised of MS experts from around the world to evaluate current diagnostic criteria and consider possible revisions. The panel set out to create guidelines that could be used by practicing physicians and adapted to clinical trials, while retaining the useful features of the current criteria for diagnosing MS.
Recommendations: Traditional diagnostic criteria for MS require two separate attacks of disease, separated in time and space, and also mandate that there be no better explanation for the disease than a diagnosis of MS. Both of these key elements have been retained in the revised criteria. The new criteria provide guidelines for using MRI, analysis of cerebrospinal fluid and analysis of visual evoked potentials as means of ascertaining the second “attack” that is required.
The revised criteria delineate the role of MRI compared to other tests such as evoked potentials and examination of cerebrospinal fluid. Well-defined criteria are presented to help physicians evaluate individuals who have had only one attack suggestive of demyelinating disease such as MS, or individuals who have had no attacks, but have had steady progression of disability from onset. Finally, the group concluded that the outcome of a diagnostic work-up should be “MS,” “possible MS” (if the evaluation is ambiguous) or “not MS,” if the examination excludes MS as a diagnosis.
The panel recognizes that the steps for accurate diagnosis must evolve as we learn more about the specificity and sensitivity of diagnostic tools. Additionally, the authors emphasize that the new recommendations depend on the availability of the highest quality, state-of-the-art technology for both laboratory tests and imaging. New technologies and information should be incorporated on an ongoing basis.
We have designed a chart (available in the PDF version of this bulletin) for physicians to use as a “tip sheet,” to remind them of the new criteria for diagnosing MS. Full details of the criteria can be obtained from the paper in Annals of Neurology.
Although the panel’s revised criteria for diagnosing MS emphasize objective
clinical, imaging and laboratory evidence, the diagnosis of MS remains
a partly subjective process. The diagnosis is best made by an expert who
is familiar with the disease and who can interpret imaging and laboratory
evidence that can supplement the clinical diagnostic process.