Epidemiological and clinical aspects of multiple sclerosis in a reference center in Amazonas

Abstract

Background: Multiple sclerosis (MS) is a chronic autoimmune inflammatory neurological disease of the central nervous system (CNS) that mainly affects young adults, with a higher incidence in women with caucasian characteristics, particularly in temperate-climate countries. In the Brazilian Amazon, epidemiological data remain scarce, and local studies are essential to better understand the clinical profile and disease progression in this population. Objective: Describe the clinical and epidemiological characteristics of patients diagnosed with MS from 2014 to 2026 at the Demyelinating Neurological Diseases Outpatient Clinic of the Hospital Universitário Getúlio Vargas (HUGV). Methods: This is a descriptive, retrospective, single-center, cross-sectional study analyzing patients diagnosed with MS in the Amazon region. Data collection was performed through medical record review from January 2014 to February 2026. The variables analyzed included sex, age, skin color, ancestry, current treatment, previous treatment, time between symptom onset and diagnosis (in years), MS classification (relapsing-remitting MS – RRMS, secondary progressive MS – SPMS, and primary progressive MS – PPMS), Expanded Disability Status Scale (EDSS) at disease onset, and EDSS at the last consultation. Results: A total of 70 patients were included, with a mean age of 39.8 years, predominantly female (68.6%) compared to male (31.4%). The mean duration of symptoms before diagnostic confirmation was 2.6 years. Regarding skin color, there was a predominance of mixed-race (“pardo”) individuals (72.9%), followed by white (22.9%) and black (4.3%). Concerning ancestry, 48.6% had Indigenous ancestry, 41.4% European ancestry, and 10% African ancestry. Regarding disease classification, 90% were classified as RRMS, 5.7% as SPMS, and 4.3% as PPMS. The mean EDSS score at diagnosis was 2.67, while the current mean EDSS was 3.1. Regarding current treatment, the majority of patients were receiving Natalizumab (37.7%) and Ocrelizumab (21.7%), followed by dimethyl fumarate (15.9%), fingolimod (10.1%), cladribine (8.7%), rituximab (1.4%), and teriflunomide (1.4%), with 7.2% of patients not receiving any medication. Among previously administered therapies, 57.1% had used interferon beta-1a, 27.1% natalizumab, 20% fingolimod, 15.7% glatiramer acetate, 10% teriflunomide, 7.1% prednisone, 5.7% dimethyl fumarate, 1.4% azathioprine, and 1.4% mitoxantrone, while 15.7% had not received prior treatment. Conclusion: The findings demonstrate female predominance, a majority of cases classified as the relapsing-remitting subtype, and a mean age close to 40 years among patients evaluated in the Amazon, corroborating findings described in the literature, except for the higher prevalence among mixed-race individuals and those with Indigenous ancestry. These data highlight the importance of epidemiological studies on MS in the Northern region of Brazil to better characterize the clinical profile of patients, support research funding, and promote public health strategies.