Multiple Sclerosis after the age of 50: A comparative analysis of late and adult onset

Abstract

Background: The incidence of Multiple Sclerosis among elderly patients is increasing. Some of these patients develop the disease after the age of 50, a condition known as Late-Onset Multiple Sclerosis (LOMS). In our study, we aim to characterize MS in older patients, comparing LOMS with Adult-Onset Multiple Sclerosis (AOMS). Methods: We performed a retrospective data analysis from 230 patients with age between 50 and 75 from a Portuguese tertiary referral centre. Results: The AOMS group consisted of 189 patients with a median age of 58 (54-63) years and the LOMS group had 41 patients with a median age of 63 (61-70) years. Female sex was the most predominant in both groups (LOMS 70.7% vs. AOMS 75.1%). Primary Progressive MS was more common among LOMS (19.5% vs. 8.0%; p=0.025) and both groups had similar proportion of Relapsing-emitting MS (LOMS 53.7% vs. 59.0%; p=0.55). LOMS patients had a higher EDSS at diagnosis (2; 1-4; p=0.025) but similar current EDSS values (LOMS 3; 1-4 vs. AOMS 2; 1-4; p=0.56). The proportion of patients under disease modifying treatment was higher in LOMS (97.6%; p=0.022). Patients with a later onset had more frequently infratentorial involvement at 5 years follow-up (87%; p=0.013). No statistically significant differences regarding cognitive impairment and lumbar puncture results were found. Conclusions: LOMS patients present with higher EDSS scores at diagnosis, reaching similar levels of disability compared to AOMS patients despite a shorter disease course.