Older Age at Multiple Sclerosis Onset Is an Independent Factor of Poor Prognosis: A Population-Based Cohort Study

Area of Science:

• Neurology
• Clinical Epidemiology

Background:

• Late-onset multiple sclerosis (LOMS), defined as onset at age ≥50 years, often presents with a primary progressive (PP) course, which is associated with severe disability.
• Understanding the prognostic implications of age at onset, independent of disease course, is crucial for managing LOMS patients.

Purpose of the Study:

• To evaluate the independent prognostic role of age at multiple sclerosis (MS) onset on disability progression.

Main Methods:

• A population-based cohort study involving 3,597 patients.
• Cox regression modeling was used to assess the association between age at onset (adult-onset MS [AOMS] vs. LOMS) and time to Expanded Disability Status Scale (EDSS) scores of 4 and 6.

Main Results:

• LOMS was diagnosed in 245 patients and was associated with a less frequent relapsing-remitting (RR) disease course compared to AOMS (51.8% vs. 90.8%).
• LOMS independently predicted a shorter time to reaching EDSS 4 and 6 (HR 2.0 and 2.3, respectively), irrespective of PP course or male gender.
• The impact of LOMS on disability progression was more pronounced in patients with RR disease than in those with PP disease.

Conclusions:

• Late-onset MS is a significant independent predictor of poor prognosis and accelerated disability progression.
• Age at onset is a critical factor in determining long-term outcomes in multiple sclerosis patients.