An estimated 3% of patients with multiple sclerosis (MS) have a benign course of disease, according to findings from a population-based UK study published online ahead of print September 3 in Journal of Neurology, Neurosurgery & Psychiatry. The term “benign MS” remains problematic, however.
“The study of the individuals with extremely favorable outcomes may uncover insights about disease pathogenesis or repair. However, the insensitivity of Expanded Disability Status Scale [EDSS]–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,” said Emma Clare Tallantyre, BMBS, PhD, Clinical Senior Lecturer in Neurosciences at Cardiff University in the UK, and her colleagues.
The investigators found that of 1,049 patients with a disease duration of longer than 15 years, 200 had a recent EDSS score of less than 4.0. Of those patients, 60 were clinically assessed, and nine (15%) had benign MS, which was defined as an EDSS score less than 3.0 and lack of significant fatigue, mood disturbance, cognitive impairment, and disruption to employment in the absence of disease-modifying therapy at at least 15 years after symptom onset.
Extrapolating these data, the investigators estimated that 30 patients in the study population of 1,049 had benign MS, yielding a prevalence of 2.9%. Of the 60 patients who were clinically assessed, 39 thought they had benign MS, based on the following definition: “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,” said the investigators.
Tallantyre EC, Major PC, Atherton MJ, et al. How common is truly benign MS in a UK population? J Neurol Neurosurg Psychiatry. 2018 Sep 3 [Epub ahead of print].