Multiple sclerosis (MS) that appears to be “genuinely benign” 15 years after diagnosis is evident in a small number of patients, a large population-based study from the U.K. reports.
But, its researchers note, the term “benign” is often not clinically accurate as used, because it is based largely on perceptions of disease impact.
The study “How common is truly benign MS in a UK population?” was published in the Journal of Neurology, Neurosurgery & Psychiatry.
The concept of benign MS is controversial, especially among clinicians. Still, long-term epidemiological studies have consistently identified a small fraction of patients whose MS progresses very slowly over a long span of years.
Determining the prevalence of this type of MS in the population has been difficult, as estimates can vary significantly depending of the definition of “benign” that is adopted.
Researchers sought to determine an accurate estimate of benign MS in the U.K. population, using a rigorous and comprehensive clinical definition of a truly benign disease.
This definition included minimal physical disability (EDSS score of less than 3), and no significant fatigue, mood disturbance, cognitive impairment or interrupted employment in the absence of treatment with disease-modifying therapies over 15 years or more years after symptom onset.
They screened an U.K. population-based registry containing data on 3,062 MS patients to identify those with “unlimited walking ability” 15 or more years after diagnosis.