Background There is no data regarding COVID-19 in Multiple Sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) patients in Latin America. Objective The objective of this study was to describe the clinical characteristics and outcomes of patients included in RELACOEM, a LATAM registry of MS and NMOSD patients infected with COVID-19. Methods RELACOEM is a longitudinal, strictly observational registry of MS and NMOSD patients who suffer COVID-19 and Dengue in LATAM. Inclusion criteria to the registry were either: (1) a biologically confirmed COVID-19 diagnosis based on a positive result of a COVID-19 polymerase chain reaction (PCR) test on a nasopharyngeal swab; or (2) COVID-19–typical symptoms (triad of cough, fever, and asthenia) in an epidemic zone of COVID-19. Descriptive statistics were performed on demographic and clinical variables. The cohort was later stratified for MS and NMOSD and univariate and multivariate logistic regression analysis was performed to identify variables associated with hospitalizations/intensive critical units (ICU) admission. Results 145 patients were included in the registry from 15 countries and 51 treating physicians. A total of 129 (89%) were MS patients and 16 (11%) NMOSD. 81.4% patients had confirmed COVID-19 and 18.6% were suspected cases. 23 (15.8%) patients were hospitalized, 9 (6.2%) required ICU and 5 (3.4 %) died due to COVID-19. In MS patients, greater age (OR 1.17, 95% CI 1.05 – 1.25) and disease duration (OR 1.39, 95%CI 1.14-1.69) were associated with hospitalization/ICU. In NMOSD patients, a greater age (54.3 vs. 36 years, p=<0.001), increased EDSS (5.5 vs 2.9, p=0.0012) and disease duration (18.5 vs. 10.3 years, p=0.001) were significantly associated with hospitalization/ICU. Conclusion we found that in MS patients, age and disease duration was associated with hospitalization and ICU admission requirement, while age, disease duration and EDSS was associated in NMOSD.

Switching treatment may be beneficial in patients with relapsing-remitting multiple sclerosis (RRMS) who respond inadequately to first-line immunomodulatory therapy. The objective of this study was to evaluate clinical outcomes after switching treatment in such patients. This prospective longitudinal observational study included 114 patients with RRMS who failed first-line monotherapy and were switched treatments after 3 years. Every 3 months, patients underwent a full neurological examination. Outcome was compared between the 3-year Before Switch and After Switch treatment periods. The primary outcome measure was the annualized relapse rate; secondary outcome measures were the proportion of relapse-free patients and the median change in Expanded Disability Status Scale (EDSS). Patients were switched either from low-dose to high-dose interferon-beta (IFNbeta; n = 31), from IFNbeta to glatiramer acetate (GA; n = 52) or mitoxantrone (n = 13), or from GA to IFNbeta (n = 16). In 3 years after switching, annualized relapse rates fell by 57-78% according to the group. The proportion of relapse-free patients varied from 56% to 81%. Least improved was observed in patients switching between INFbeta preparations. Median EDSS scores remained stable in all groups except the GA to IFNbeta switchers. In conclusion, patients who fail first-line immunomodulatory therapy generally benefit from switching to another class of immunomodulatory therapy.

There are few studies reporting multiple sclerosis prevalence rates in the Buenos Aires region, Argentina (latitude 34 degrees S) (between 12-18.5/100 000 inhabitants), and no studies have been performed in the larger region between parallels 36 degrees and 55 degrees S. The aim of this study is to determine the prevalence rates and clinical features of multiple sclerosis in residents of the Argentine Patagonia. Four cities from the region were selected for this study, giving a sample population of 417 666 inhabitants (approximately 24% of the total Patagonia population). 1(st) March 2002 was determined as prevalence day. Patients were ascertained using multiple case-finding methods. The point prevalence rate was 17.2/100 000 (17.2 age-adjusted to the world population). Prevalence rates were higher for women than for men, 22.1 versus 12.2/100 000 inhabitants (21.4 versus 12.7 sex-adjusted to the world population). The study population was mainly of European descent and mestizoes. Clinical features were similar to those reported in other countries. This study shows that Argentine Patagonia is a medium-risk area with no south-north gradient between parallels 55 degrees and 36 degrees S. The Patagonia population shows recent internal migration that makes it difficult to determine whether the exposure to potential risk factors has been long enough to modify the disease incidence.

We performed an observational, retrospective analysis of outcome in a sequential cohort of patients with relapsing-remitting multiple sclerosis (RRMS) in Argentina. Patients treated for 16 months with interferon beta-1a (Avonex; 30 micrograms intramuscularly, once a week), interferon beta-1a (Rebif); 44 micrograms subcutaneously, thrice weekly), interferon beta-1b (Betaferon; 250 micrograms subcutaneously, every other day) or glatiramer acetate (Copaxone; 20 mg subcutaneously daily) were compared with a non-treated group of patients. The different treatment groups were similar in baseline demographic and clinical variables. A significant fall in the annual relapse rate was observed for all four treatments, with the largest effect observed with glatiramer acetate (81% reduction in relapse rate, compared with pre-treatment values). The proportion of patients remaining relapse-free for the entire 16-month treatment period varied from 37% in untreated patients to 83% in the glatiramer acetate treated group. No statistically significant changes in disability scores were observed over the treatment period. This first such comparative study in Latin America shows that treatment of multiple sclerosis patients with immunomodulatory therapies in the context of current standards of care in Argentina provides clinically important benefit, and suggest that some of these therapies may be better than others.

Memory is consistently impaired in MS patients and disease course differentially affects the pattern of performance. SP patients show greater difficulties and a more pervasive pattern of dysfunction than RR patients. Delayed recall was the most affected memory measure and performance on this task discriminates between RR and SP MS patients. Relapsing remitting patients performed within the mildly impaired range while SP patients showed a moderate to severe impairment.