Time between the first symptom, diagnosis and treatment of multiple sclerosis in a Brazilian cohort. The impact of early diagnosis.

Introduction: Multiple Sclerosis (MS) diagnosis can be challenging, especially in populations where the disease is rare. In Brazil, the average prevalence is 14/100,000 inhabitants, lower than the worldwide. Early treatment initiation can markedly reduce disease activity and accumulation of disability. Therefore, delayed diagnosis and access to disease modifying therapy (DMT) can have a negative impact on the course of MS.

Objectives: The aim of this study was to estimate the mean time between the first relapse, the diagnosis of MS and initiation of treatment in a cohort of Brazilian MS patients.

Material And Method: We retrospectively analyzed the medical records of MS patients who met the 2017 McDonald diagnostic criteria followed in a MS reference center in Belo Horizonte, Minas Gerais. We assessed demographic and clinical data with focus on time to first symptom, time to diagnosis and treatment begging. The last Expanded Disability Status Scale (EDSS) was collected to access disability. The program GraphPad Prism 8.4.3. was used for the statistical analysis.

Results: Data of 66 patients were analyzed, 77 % (51) were women. The mean age of the first symptom, diagnosis and DMT initiation was, respectively, 30,06 (± 12,43), 35,2 (± 13,59) and 36,10 (± 13,89) years. In 32 (46,38 %) patients the diagnosis was early (<1 year of disease), in 18 (26,09 %) between 1 and 5 years and in 19 (27,54 %) after to five years. Once the diagnosis was established, 65,5 % had access to DMT within 6 months and 79,71 % in the first year. Patients with diagnosis in the two first years had their first symptom at a younger age (p < 0.05). Comparing these two groups, patients with an earlier diagnosis presented less disability (EDSS: 3,5 vs 1,5; p < 0.05).

Conclusion: MS diagnosis can be challenging especially in low prevalence population of diseased and developing countries. Our study demonstrated the importance of early recognition of MS and its precocious intervention, impacting in reducing of disability a long term.