How common is truly benign MS in a UK population?

Area of Science:

• Neurology
• Clinical Research
• Epidemiology

Background:

• The definition and prevalence of benign multiple sclerosis (BMS) are debated, with current criteria primarily relying on the Expanded Disability Status Scale (EDSS) and often failing to capture the full disease impact.
• Understanding the factors contributing to favorable outcomes in multiple sclerosis (MS) is crucial for improving patient care and management.

Purpose of the Study:

• To comprehensively characterize patients with low Expanded Disability Status Scale (EDSS) scores after prolonged disease duration.
• To evaluate the discrepancy between clinician-defined benign multiple sclerosis (BMS) and patient self-perception of disease status.

Main Methods:

• Screened a population-based registry of 3062 individuals with MS to identify those with unlimited walking ability at disease durations exceeding 15 years.
• Conducted detailed clinical assessments on a representative cohort, applying criteria for BMS including EDSS score <3, absence of significant fatigue, mood disturbance, cognitive impairment, disrupted employment, and no prior disease-modifying therapy.
• Compared patient-reported perceptions of MS status with EDSS-based definitions.

Main Results:

• Of 1049 patients with >15 years disease duration, 19.1% had an EDSS <4.0. Detailed assessment of 60 patients revealed only 15% met strict BMS criteria, with cognitive impairment (57%) and employment effects (52%) being common exclusion factors.
• A significant portion (69%) of patients considered their MS benign, despite not meeting formal BMS criteria.
• The population frequency of BMS was estimated at 2.9%.

Conclusions:

• A small minority of individuals with MS demonstrate genuinely benign disease after 15 years, suggesting potential insights into disease pathogenesis.
• Discrepancies between patient and clinician perceptions of BMS highlight limitations in using the term 'benign' in clinical practice.
• Comprehensive assessment is necessary to accurately define and understand benign presentations of multiple sclerosis.