Nearly 3% of patients with multiple sclerosis (MS) are estimated to have a truly benign course of disease over at least 15 years without the use of disease-modifying therapy, based on findings from a U.K. population-based study that also showed how poorly benign disease tracks with disability measures and lacks agreement between patients and physicians.
“The study of the individuals with extremely favorable outcomes may uncover insights about disease pathogenesis or repair. However, the insensitivity of EDSS [Expanded Disability Status Scale]–based definitions of benign MS and the discrepancy between patient and clinician perception of benign MS undermine use of the term ‘benign’ in the clinical setting,” Emma Clare Tallantyre, MD, of Cardiff (Wales) University, and her colleagues wrote in the Journal of Neurology, Neurosurgery & Psychiatry.
Dr. Tallantyre and her colleagues found that, of 1,049 patients with disease duration longer than 15 years, 200 had a recent EDSS score of less than 4.0. Of those 200, 60 were clinically assessed and 9 (15%) were found to have truly benign MS, defined as having an EDSS less than 3.0 and having no significant fatigue, mood disturbance, cognitive impairment, or disruption to employment in the absence of disease-modifying therapy at least 15 years after symptom onset.
The investigators extrapolated these data to estimate that 30 patients in the study population of 1,049 had truly benign MS, for a prevalence of 2.9%. However, of the 60 patients who were clinically assessed, 39 thought they had benign MS based on the lay definition provided: “When referring to illness, ‘benign’ usually means a condition which has little or no harmful effects on a person. There are no complications and there is a good outcome or prognosis.”
Patients who self-reported benign MS had significantly lower EDSS scores, fewer depressive symptoms, lower fatigue severity, and lower reported MS impact than did patients who did not report benign MS. “Self-reported benign MS status showed poor agreement with our composite definition of benign MS status and only fair agreement with EDSS-based definitions of benign MS status,” the investigators wrote.
SOURCE: Tallantyre EC et al. J Neurol Neurosurg Psychiatry. 2018 Sep 3. doi: 10.1136/jnnp-2018-318802.