Neuromyelitis Optica Spectrum Disorder in Latin America: State-of-the-Art and Current Challenges.

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune disease of the central nervous system characterized by severe attacks of optic neuritis, myelitis, and/or area postrema. Advances in understanding the pathophysiology of NMOSD have led to improved diagnostic and therapeutic approaches. There has been a notable increase in research efforts worldwide, including in Latin America (LATAM). In recent years, LATAM has witnessed a surge in research on NMOSD, resulting in a growing body of evidence on various aspects such as epidemiology, clinical manifestations, paraclinical features (including AQP4-IgG [Aquaporin-4-immunoglobulin G] and imaging), acute and long-term treatment strategies, as well as accessibility to diagnostic tests. This narrative review aims to present the most relevant findings from different NMOSD cohorts in LATAM, providing a comprehensive overview of the current understanding of the disease in the region, while considering its unique characteristics and challenges. LATAM-focused evidence is crucial for adding valuable information to the international dataset and is therefore summarized in this review.

Occurrence of area postrema syndrome during follow-up: phenotype and influence over NMOSD activity in LATAM in real-world settings.

INTRODUCTION: We aimed to assess the frequency, duration, and severity of area postrema syndrome (APS) during follow-up in neuromyelitis optica spectrum disorder (NMOSD) patients, as well as its association with inflammatory activity and prognostic factors of APS severity in a real-world setting. METHODS: We conducted a retrospective study on a cohort of Latin American (LATAM) NMOSD patients who had experienced APS during their follow-up. Patients from Mexico, Peru, Brazil, Colombia, Panama, Chile and Argentina patients who met 2015 NMOSD criteria were included. We evaluated data on symptom type (nausea, vomiting and/or hiccups), frequency, duration, severity (measured by APS severity scale), association with other NMOSD core relapses, and acute treatments (symptomatic and immunotherapy or plasmapheresis). Logistic regression was conducted to evaluate factors associated with APS severity (vs. mild-moderate). RESULTS: Out of 631 NMOSD patients, 116 (18.3%) developed APS during their follow-up. The most common APS phenotype was severe. Inflammatory activity (i.e., relapses) significantly decreased after the onset of APS. Half of the patients experienced isolated APS with a median duration of 10 days, and the most frequently used acute treatment was IV steroids. All three symptoms were present in 44.6% of the patients. APS symptoms resolved following immunotherapy. Logistic regression did not identify independent factors associated with the severity of APS. CONCLUSIONS: Our findings indicate that 18.3% of NMOSD patients developed APS during the follow-up period, with most patients fulfilling criteria for severe APS. The inflammatory activity decreased after the onset of APS compared to the previous year.

Neuromyelitis optica spectrum disorders relapses and seasonal influence in an equatorial country cohort. / Recaídas del trastorno de espectro de la neuromielitis óptica e influencia estacional en una cohorte de un país ecuatorial.

INTRODUCTION: Information about seasonal distribution of Neuromyelitis optica spectrum disorders (NMOSD) attacks, particularly in tropical countries, has rarely been described and the reported data are diverse. OBJECTIVE: To evaluate influence of seasonal variation in NMOSD relapses in an equatorial country. PATIENTS AND METHODS: Exploratory observational, retrospective ecological study in a cohort of patients with NMOSD followed from January 2008 to December 2019. Data of demographic, clinical information, characteristics of relapses and seasonal temporal variation were recorded. Also, the annual, monthly and intra-annual seasonal variation of relapses was quantified. A negative binomial regression was used to estimate the associations between the number of relapses and climatic and temporal variables. RESULTS: One hundred thirteen patients were included, most of them were female (89.38%), with a mean age at NMOSD diagnosis was 44.97 (±13.98) and the median of relapses per patient were 2 relapses (IQR 1-3). The patients presented 237 relapses, most of these in AQP4 seropositive patients (87.76%) and longitudinal extensive myelitis was the most frequent type of relapse (53.59%). According to the temporal variation, relapses were more common in the second rainy season (28.69%) during November and December. However, there weren't significant differences in the number of relapses between seasons and climatic variables in the multivariable model. CONCLUSION: The number of NMOSD relapses in this equatorial country cohort did not exhibit any significant associations with climatic variations, including changes in rainy or dry seasons.

TITLE: Recaídas del trastorno de espectro de la neuromielitis óptica e influencia estacional en una cohorte de un país ecuatorial.Introducción. La evidencia sobre la distribución estacional de las recaídas del trastorno del espectro de la neuromielitis óptica (NMOSD), especialmente en países tropicales, es limitada y diversa. Objetivo. Evaluar la influencia de las variaciones estacionales en las recaídas del NMOSD en un país localizado sobre la línea ecuatorial. Pacientes y métodos. Se llevó a cabo un estudio ecológico, con información retrospectiva de una cohorte de pacientes con NMOSD atendida entre enero de 2003 y diciembre de 2020 en Medellín, Colombia. Se recolectaron datos demográficos y clínicos de los pacientes, así como información sobre variables estacionales y climáticas. Se calculó la frecuencia de recaídas por estación, mes y año, y se realizó una regresión binomial negativa para evaluar la asociación entre el número de recaídas, y las variables estacionales y climáticas. Resultados. Se incluyó a 113 pacientes, de los cuales el 89,38% eran mujeres, con una edad media en el momento del diagnóstico de NMOSD de 44,97 (±13,98) años y una mediana de tres recaídas (rango intercuartílico: 1-2). Se registraron 237 recaídas, la mayoría en pacientes seropositivos para anticuerpos antiacuaporina 4 (87,76%) y con mielitis longitudinal extensa como la presentación clínica más común (53,59%). Las recaídas se presentaron con mayor frecuencia durante la segunda temporada lluviosa (28,69%; n = 68), y en los meses de noviembre y diciembre. Sin embargo, en la regresión binomial negativa no se observó una asociación significativa entre el número de recaídas y las variables climáticas y estacionales, los meses y los años. Conclusión. Las variables climáticas y los patrones estacionales no muestran una asociación significativa con cambios en el número de recaídas del NMOSD en pacientes residentes en un país localizado sobre la línea ecuatorial.

Measuring the economic burden of neuromyelitis optica spectrum disorder in Colombia.

OBJECTIVE: To assess the economic burden of neuromyelitis optica spectrum disorder (NMOSD) in the Colombian context. METHODS: Analyses were conducted from a societal perspective using the prevalence-based approach. Costs were expressed in 2022 US dollars (1 USD = $3,914.46 COP). Direct medical costs were assessed from a bottom-up approach. Indirect costs included loss of productivity of the patient and their caregivers. The economic burden of NMOSD in Colombia was estimated as the sum of direct and indirect costs. RESULTS: The direct cost of treating a patient with NMOSD was USD$ 8,149.74 per year. When projecting costs nationwide, NMOSD would cost USD$ 7.2 million per year. Of these costs, 53.5% would be attributed to relapses and 34.4% to pharmacological therapy. Indirect costs potentially attributed to NMOSD in Colombia were estimated at USD$ 1.5 million per year per cohort. Of these, 78% are attributable to loss of patient productivity, mainly due to reduced access to the labor market and premature mortality. CONCLUSIONS: The NMOSD has a representative economic burden at the patient level, with direct costs, particularly related to relapses and medicines, being the main component of total costs. These findings are useful evidence that requires attention from public policymakers in Colombia.

Neuromyelitis Optica spectrum disorders in Argentina: A hospital-based study.

BACKGROUND: Neuromyelitis Optica spectrum disorder (NMOSD) is an antibody-mediated autoimmune disease of the CNS, which especially affects the optic nerves and spinal cord. There is little known in Latin America (LATAM) about NMOSD, and few reports have been published in the literature so far. We aimed to describe an NMOSD study in a single center from Argentina. METHODS: A retrospective cross sectional study was carried out in a single reference center in the city of Buenos Aires, Argentina. Data were collected from January 2000 through December 2021 using medical records from patients attending Ramos Mejia Hospital in Buenos Aires, Argentina. Here we describe the clinical, laboratory, MRI, disability course, and treatment of 92 NMOSD patients. RESULTS: Mean age at the onset of symptoms was 31 years (range 2-68) with a female/male ratio of 4.8:1. 71.7 % had an early onset before the age of 50 years old, 8.7 % had a late onset of the disease and 19.6 % had an onset at pediatric age. The first symptom of NMOSD was optic neuritis in 47.8 % of the patients, followed by transverse myelitis, 33.7 % and area postrema syndrome, 5.4 %. 96.7 % of patients relapsed at least once during the follow-up period. The mean of the expanded disability status scale (EDSS) was 4.0 (range 2-8). 34,8 % had one or more associated autoimmune diseases. 78,6 % had a positive result for AQP4-IgG. The ratio of male to female was 1:8.4 vs.1:1.2 in the seropositive group vs. the seronegative. CSF results showed OCB type 2 in 6.3 %. The brain MRI did not show brain lesions in 71,7 % of the patients. 17 % presented spinal cord lesions with less than 3 vertebral segments. All patients received treatment with immunosuppressive drugs. Rituximab and azathioprine were the most used. CONCLUSIONS: This is the largest hospital-based study in an Argentina cross-sectional study of patients with NMOSD. Recurrent disease, early age at onset, female prevalence in AQP4-IgG+ patients, and the difficulty to assess new treatments, are the highlight features in our study of patients. Further Argentinian and LATAM studies will provide more information.

Sleep in multiple sclerosis and neuromyelitis optica spectrum disorder-the SEMN study.

PURPOSE: This study aimed to (1) evaluate in patients with multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) the presence of sleep disorders such as hypersomnia, fatigue, risk of apnea, and the presence of restless legs syndrome/Willis-Ekbom disease (RLS/WED); (2) evaluate quality of sleep in patients with MS and NMOSD; and (3) correlate them with clinical and imaging data. METHODS: The study was cross-sectional and was carried out in the sector of demyelinating diseases of the neurology service of HUGV-UFAM, Manaus, Brazil, from January 2017 to December 2020. RESULTS: Our sample consisted of 60 patients, 41 with MS and 19 with NMOSD. We found that patients with MS and NMOSD have poor sleep quality (65%) and hypersomnia (53% in MS; 47% in NMOSD), but low risk of apnea by STOP-BANG. The frequency of RLS/WE found was 14% in MS, and 5% in NMOSD. No correlation existed between sleep quality, number of relapses, and sleep quality for the Expanded Disability Status Scale (EDSS), i.e., fatigue/illness duration. CONCLUSION: Patients with MS and NMOSD have poor sleep quality, excessive sleepiness, and are at low risk for OSA, yet the frequency of RLS/WED is like that of the general population. There does not seem to be a significant difference between these sleep disorders in these demyelinating diseases of the CNS.

Estimated prevalence of AQP4 positive neuromyelitis optica spectrum disorder and MOG antibody associated disease in São Paulo, Brazil.

BACKGROUND: Numerous studies addressed the prevalence of multiple sclerosis, but prevalence studies of NMOSD and, particularly, MOGAD are scarce. We aimed to estimate the prevalence of NMOSD and MOGAD in the city of São Paulo, based on the known prevalence of MS. METHODS: In this observational study, we determined the total number of patients with central nervous system demyelinating disease on regular follow-up in a university referral center in São Paulo, from May 2019 to May 2021 according to the diagnosis of multiple sclerosis (MS), NMOSD and MOGAD using the current diagnostic criteria for these diseases. We used the MS: NMOSD and MS: MOGAD ratios to estimate the ratio of these diseases in São Paulo, Brazil. RESULTS: We identified 968 patients with MS, 133 patients with AQP4 positive NMOSD, and 28 patients with MOGAD. We found the MS: NMOSD ratio of 7,28 and the MS: MOGAD ratio of 34,57. We estimated a prevalence of 2,1 per 100,000 inhabitants for NMOSD and of 0,4 per 100,000 inhabitants for MOGAD. CONCLUSION: The prevalence of NMOSD is high in São Paulo, but the prevalence of MOGAD is low when compared with the prevalence found in most of the studies reported to date.

Barriers to access and unmet needs to neuromyelitis optica spectrum disorders care in an Argentinean cohort.

INTRODUCTION: Neuromyelitis optica spectrum disorder (NMOSD) is a rare but severe neuroimmunological condition associated with a significant financial burden. NMOSD is also associated with increased health care utilization, including neurology outpatient visits, magnetic resonance imaging (MRI) use, long-term medication, among others. We aimed to evaluate real-world patient experiences in access to care and NMOSD burden in an Argentinean cohort. METHODS: This cross-sectional study used a self-administered survey and was conducted in Argentina (2022). Patients with NMOSD were divided into three groups: private health insurance (PHI), social health insurance (SHI), and public health insurance (PHI, Ministry of Public Health). Differences in access and health care barriers were assessed. RESULTS: One hundred patients with NMOSD (74 women) with a mean age at diagnosis of 38.7 years were included. Their EDSS was 2.8 and they were followed for 5.2 years. Of them, 51%, 11%, and 13% were employed (full-time: 57.5%), currently unemployed and retired by NMOSD, respectively. 55% of them visited between 2-3 specialists before NMOSD diagnosis. Aquaporin-4-antibody and/or myelin oligodendrocyte glycoprotein-antibody testing was requested in 91% (health insurance covered this partially in 15.3% and 32.9% of the time the test was entirely paid by patient/family). Patients with NMOSD receiving private medical care reported greater access to MRI, outpatient visits, and fewer issues to obtain NMOSD medications compared to those treated at public institutions. A longer mean time to MRI and neurology visit was found in the PHI group when compared with the other two subgroups. Regression analysis showed that private insurance (OR=3.84, p=0.01) was the only independent factor associated with appropriate access to NMOSD medications in Argentina. CONCLUSION: These findings suggest that barriers to access and utilization of NMOSD care services in Argentina are common. NMOSD patients experienced problems to receive NMOSD medication properly, especially those from the public sector.

Neuromyelitis optica spectrum disorders with and without associated autoimmune diseases.

OBJECTIVES: We aimed to determinate the frequency of this association and compare the features of neuromyelitis optica spectrum disorder (NMOSD) with and without associated autoimmune diseases (AD) in a Latin American (LATAM) population in clinical practice. METHODS: We retrospectively reviewed the medical records of patients with NMOSD according to the 2015 diagnostic criteria. Patients from Argentina (n=77), Brazil (n=46), and Venezuela (n=17) were enrolled and classified into two groups as follows: with AD or without AD. Clinical, paraclinical (including aquaporin-4 antibodies (AQP4-ab) status), magnetic resonance imaging (MRI), and prognosis data were analyzed and compared. Kaplan-Meier (KM) and the Nelson-Aalen estimator analyses were performed to estimate both time and the cumulative hazard risk of disability reaching an EDSS≥4; and time for the first recurrence. RESULTS: Out of 140 patients, 33 (23.5%) patients had associated an AD at presentation. The most frequent associated AD was Hashimoto disease (n=10) followed by lupus (n=7) and Sjogren's syndrome (n=6). However, rituximab use (42.4% vs. 21.5%, p=0.02), female gender (82.2% vs. 100%, p=0.006), corticospinal lesions on MRI (0% vs. 12.5%, p=0.01) at onset, and positivity for antinuclear antibodies (21.2% vs. 48.4%, p=0.03) were significantly associated with NMOSD patients with AD in comparison to NMOSD patients without AD. No differences were found in other clinical and paraclinical aspects between groups. KM and Nelson-Aalen estimator analyses did not show differences between groups. CONCLUSION: NMOSD patients associated with AD were observed in 23.5%. In addition, NMOSD patients with and without associated AD were similar in most evaluated features.

Frequency of NMOSD misdiagnosis in a cohort from Latin America: Impact and evaluation of different contributors.

BACKGROUND: Neuromyelitis optica spectrum disorder (NMOSD) misdiagnosis (i.e. the incorrect diagnosis of patients who truly have NMOSD) remains an issue in clinical practice. We determined the frequency and factors associated with NMOSD misdiagnosis in patients evaluated in a cohort from Latin America. METHODS: We retrospectively reviewed the medical records of patients with NMOSD, according to the 2015 diagnostic criteria, from referral clinics in six Latin American countries (Argentina, Chile, Paraguay, Colombia, Ecuador, and Venezuela). Diagnoses prior to NMOSD and ultimate diagnoses, demographic, clinical and paraclinical data, and treatment schemes were evaluated. RESULTS: A total of 469 patients presented with an established diagnosis of NMOSD (73.2% seropositive) and after evaluation, we determined that 56 (12%) patients had been initially misdiagnosed with a disease other than NMOSD. The most frequent alternative diagnoses were multiple sclerosis (MS; 66.1%), clinically isolated syndrome (17.9%), and cerebrovascular disease (3.6%). NMOSD misdiagnosis was determined by MS/NMOSD specialists in 33.9% of cases. An atypical MS syndrome was found in 86% of misdiagnosed patients, 50% had NMOSD red flags in brain and/or spinal magnetic resonance imaging (MRI), and 71.5% were prescribed disease-modifying drugs. CONCLUSIONS: NMOSD misdiagnosis is relatively frequent in Latin America (12%). Misapplication and misinterpretation of clinical and neuroradiological findings are relevant factors associated with misdiagnosis.

Disability outcomes in NMOSD and MOGAD patients: data from a nationwide registry in Argentina.

The objective was to evaluate time to reach an EDSS of 4, 6, and 7 in NMOSD and MOGAD patients included in the Argentinean MS and NMOSD registry (RelevarEM, NCT 03,375,177). METHODS: NMOSD patients diagnosed according to 2015 criteria and with MOGAD were identified. Patients with at least 3 years of follow-up and periodic clinical evaluations with EDSS outcomes were included. AQP4-antibody and MOG-antibody status was recorded, and patients were stratified as seropositive and seronegative for AQP4-antibody. EDSS of 4, 6, and 7 were defined as dependent variables. Log rank test was used to identify differences between groups. RESULTS: Registry data was provided for a total of 137 patients. Of these, seventy-five presented AQP4-ab-positive NMOSD, 45 AQP4-ab-negative NMOSD, and 11 MOGAD. AQP4-ab status was determined by cell-based assay (CBA) in 72% of NMOSD patients. MOG-ab status was tested by CBA in all cases. Mean time to EDSS of 4 was 53.6 ± 24.5 vs. 63.1 ± 32.2 vs. 44.7 ± 32 months in seropositive, seronegative NMOSD, and MOGAD, respectively (p = 0.76). Mean time to EDSS of 6 was 79.2 ± 44.3 vs. 75.7 ± 48.6 vs. 54.7 ± 50 months in seropositive, seronegative NMOSD, and MOGAD (p = 0.23), while mean time to EDSS of 7 was 86.8 ± 54 vs. 80.4 ± 51 vs. 58.5 ± 47 months in seropositive, seronegative NMOSD, and MOGAD (p = 0.39). CONCLUSION: No differences were observed between NMOSD (seropositive and seronegative) and MOGAD in survival curves.

Clinical and paraclinical profile of neuromyelitis optic spectrum disorder in a peruvian cohort.

BACKGROUND: Neuromyelitis Optica Spectrum Disorders (NMOSD) is an autoimmune, inflammatory disorder of the Central Nervous System that typically involves the spinal cord and the optic nerves. Recently, the clinical and radiological spectrum of NMOSD has been increasing in Latin America. In Peru, there have only been a few clinical reports on NMOSD published. For this reason, we aimed to assess the clinical and paraclinical characteristics of patients with NMOSD from a tertiary-level neurological center in Lima-Peru. METHODS: This is a descriptive study. We assessed medical reports of patients with NMOSD based on the 2015 diagnostic criteria attended in a goverment institute (Instituto Nacional de Ciencias Neurologicas) from Peru between 2013-2019. Those patients who met diagnostic criteria were selected and analyzed. We analyzed continuous data among groups (AQP4-IgG seropositive and AQP4-IgG seronegative/unknow). RESULTS: We identified 58 clinical records that met the selection criteria and were included in the study. The highest percentage of patients (53%) were born in the north of Peru (from parallel 0°01'48''S - 6°56'38''S). NMOSD were more prevalent in women (86%), the male:female ratio was 1:6, the mean age at diagnosis was 50 years. AQP4-IgG antibodies were tested in (63.8%), 62% of whom were seropositive and 38% seronegative. The frequency of EO-NMO and LO-NMO was 34.8% and 65.2% in AQP4-IgG seropositive patients, respectively. Unknown AQP4-IgG was found 21 patients. In LO-NMOSD group, AQP4-IgG seropositive was found in a higher percentage. Optic neuritis was the first clinical event at 40% . In the patients who presented myelitis as the first clinical event, 18.2% were AQP4-IgG seropositive, while only 4.8% was found in the rest of the patients. 17% had other associated autoimmune diseases and 16% had anti-nuclear antibodies. 79% of patients had low vitamin D-25(OH) levels (<30ng/ml). Orbit MRI showed unilateral optic neuritis in 46.6%. Spinal cord MRIs showed extensive longitudinal myelitis in 52% of patients and the thoracic segment was the most frequently affected (47%). CONCLUSIONS: In the present study of a peruvian NMOSD cohort, we found a higher frequency of unilateral optic neuritis cases, and a higher percentage of AQP4-IgG seropositive patients among those older than 50.

[Predictors of disability in a cohort with neuromyelitis optica spectrum]. / Predictores de discapacidad en una cohorte con espectro de neuromielitis óptica.

INTRODUCTION: Disability in neuromyelitis optica spectrum disorder (NMOSD) is common and can be severe. AIM: To determine factors associated with increased disability in NMOSD. PATIENTS AND METHODS: Observational, analytical, ambispective study in a cohort of patients with NMOSD between January 2015 and July 2021, using a secondary source to review variables and the expanded disability status scale (EDSS) after onset and a primary source, with a telephone survey for the final EDSS and missing data. Major disability was defined as occurring when the EDSS score was = 6. The analysis was performed by means of logistic regression with SPSS 25®. RESULTS: A total of 125 patients were analysed. The average age at onset was 41 (standard deviation: 14) years, with a female-to-male ratio of 8:1. Of the total sample, 87% (109) were positive for anti-aquaporin antibodies. Optic neuritis (44.8%) and transverse myelitis (39.2%) were the most frequent clinical manifestations at onset. Altogether 71.2% of patients received acute treatment at their first relapse. Mean chronic treatment initiation was 12 months (interquartile range: 3-60) and 44% had difficulties with immunosuppression compliance. Of the total number of patients, 80.8% had relapses and 44% had a final EDSS score = 6. The median baseline-to-final EDSS score was 1 (interquartile range: 0-3), often towards disability accumulation. An association was found between a relapsing course (odds ratio = 3.73; p = 0.011) and a high baseline EDSS (odds ratio = 1.54; p = 0.0001) with increased disability. In the multivariate analysis, with a higher baseline EDSS and a relapsing course disability was 1.6 and 5.3 times more likely to occur, respectively. CONCLUSIONS: Disease relapses and high EDSS after the first episode are predictors of disability in NMOSD.

TITLE: Predictores de discapacidad en una cohorte con espectro de neuromielitis óptica.Introducción. La discapacidad en el espectro de neuromielitis óptica (NMOSD) es frecuente y puede ser grave. Objetivo. Determinar factores asociados a mayor discapacidad en el NMOSD. Pacientes y métodos. Estudio observacional, analítico, ambispectivo, en una cohorte de pacientes con NMOSD entre enero de 2015 y julio de 2021, utilizando una fuente secundaria para la revisión de variables y la escala extendida de discapacidad (EDSS) después del inicio y una fuente primaria, con una encuesta telefónica para la EDSS final y los datos faltantes. Se definió la discapacidad mayor cuando la puntuación de la EDSS era = 6. El análisis se realizó por medio de regresión logística con SPSS 25®. Resultados. Se analizó a 125 pacientes. La edad promedio de inicio fue 41 (desviación estándar: 14) años, con una relación mujer:hombre de 8:1. El 87% (109) era positivo para anticuerpos antiacuaporinas. La neuritis óptica (44,8%) y la mielitis transversa (39,2%) fueron las manifestaciones clínicas más frecuentes en el inicio. El 71,2% de los pacientes recibió tratamiento agudo en la primera recaída. La mediana de inicio del tratamiento crónico fue de 12 meses (rango intercuartílico: 3-60) y el 44% tuvo dificultades en el cumplimiento de la inmunosupresión. El 80,8% presentó recaídas y el 44% tenía una puntuación en la EDSS final = 6. La mediana de EDSS basal-final fue de 1 (rango intercuartílico, 0-3), con frecuencia hacia la acumulación de discapacidad. Se encontró asociación entre el curso con recaídas (odds ratio = 3,73; p = 0,011) y la EDSS basal alta (odds ratio = 1,54; p = 0,001) con una mayor discapacidad. En el análisis multivariado, una mayor EDSS basal y un curso con recaídas presentaron una probabilidad de discapacidad 1,6 y 5,3 veces mayor, respectivamente. Conclusiones. Las recaídas de la enfermedad y la EDSS alta después del primer episodio son predictores de discapacidad en el NMOSD.

Sociodemographic and clinical characteristics of people with multiple sclerosis and neuro-myelitis optica spectrum disorder in a central northern region of Chile: A prevalence study.

BACKGROUND: There is a scarcity of information on the prevalence of demyelinating diseases in Chile and other Latin American countries. The aim of this study was to determine the prevalence of multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) in a region of central-northern Chile. METHODS: A cross-sectional study was performed. All patients in the region with a confirmed diagnosis of MS or NMOSD under control of the program by the end of 2020 and were included in the study, totalling sixty patients with a diagnosis of MS and eight patients with NMOSD. Sociodemographic and clinical variables for these patients were recorded by the neurologists in charge of the MS programs at each public and private facility in the Coquimbo region between January and March of 2021. RESULTS: The prevalence of MS was 7.18 per 100,000 inhabitants (95% CI: 5.36‒8.99) and NMOSD, 0.95 per 100,000 population (95% CI: 0.9‒1.62). Both diseases were several times more prevalent in women than in men (female/male ratio: MS, 5:1 and NMOSD, 7:1). The mean age at diagnosis was 32.2 for MS and 32.2 years for NMOSD. No relevant risk factors were identified. In terms of the type of MS, 86.6% patients had a diagnosis of relapsing-remitting MS, 6.7% had primary progressive MS, and 6.7% had secondary progressive MS. Overall, 20% of patients with MS and 12.5% with NMOSD presented score over 5 in the Expanded Disability Status Scale, and 87.5% of the NMOSD patients were receiving rituximab. CONCLUSION: The prevalence of demyelinating diseases in a central-northern region of Chile corresponds to the reported rates for other Latin American countries. This is an important contribution, given the scarcity of evidence on the prevalence of demyelinating diseases in Chile. These illnesses mainly affect young adult women and are a cause of disability among productive adults.

Neuromyelitis optica spectrum disorder in Western Mexico.

BACKGROUND: Neuromyelitis Optica Spectrum Disorders (NMOSD) are a group of inflammatory diseases of the Central Nervous System (CNS) that primarily affect the optic nerve and spinal cord, usually with a severe and relapsing course. Due to the scarce information in non-Caucasian populations, we aimed to describe incidence, prevalence, and main clinical characteristics of NMOSD in a defined region in Mexico. MATERIALS AND METHODS: Descriptive, retrospective analysis of all reported cases of NMOSD attended in the neurology department of the UMAE-HE, CMNO, IMSS, the biggest third level hospital in Western Mexico. We searched the electronic medical records of the hospital for patients with a diagnosis of NMO, and reviewed all cases to confirm if they fulfilled NMOSD 2015 diagnostic criteria. Data were collected through a structured form. We described adjusted incidence and prevalence according to the WHO method, for the IMSS affiliated total population in Jalisco state in 2019. RESULTS: 67 NMOSD patients were included in the analysis of clinical data, with a mean age at onset of symptoms of 36 years ((Rivera et al., 2008-65). Most patients were female (74.6%). 53 patients living in Jalisco by the end of 2019 were included in the analysis of prevalence and incidence. Adjusted prevalence was 0.71/100,000 (95% CI 0.55-0.92), while adjusted incidence was 1.87/1,000,000 person-years (95% CI 1.11-3.16). In the full cohort, the first symptom of NMOSD was optic neuritis in 49.3% of the patients, followed by transverse myelitis (23.9%) and area postrema syndrome (10.4%). 62 patients relapsed in a mean follow-up of 2 years (0-7). 5 patients with less than 6 months of follow up had not relapsed. 55.2% of the patients were AQP4-IgG +, 14.9% AQP4-IgG -, and 29.9% unknown status. CONCLUSIONS: Although NMOSD prevalence is similar to other reports around the world, incidence is higher than in Caucasian populations. We believe that this high incidence is related to an increased awareness of the disease in the era of new NMOSD treatments. Recurrent disease is very frequent in our cohort.

Clinical and prognostic aspects of patients with the Neuromyelitis Optica Spectrum Disorder (NMOSD) from a cohort in Northeast Brazil.

INTRODUCTION: Neuromyelitis optica spectrum disorders (NMOSD) is a rare inflammatory and demyelinating disease of the central nervous system (CNS) more frequent in women and Afro-descendants. No previous epidemiological or prognostic study has been conducted in the region of the state of Bahia, Brazilian Northeast. OBJECTIVE: To evaluate clinical and prognostic aspects in patients with NMOSD from a cohort in northeastern Brazil. MATERIAL AND METHODS: A single-center retrospective study was conducted with consecutive patients diagnosed with NMOSD. Clinical and epidemiological characteristics were described. The degree of disability was expressed by the Expanded Disability Status Scale (EDSS). Worsening disability were analyzed through negative binomial regression adjusted for disease duration. RESULTS: Ninety-one patients were included, 72 (79.1%) female and 67 (73.6%) afro descendants. Mean age at onset was 36 (± 14) years and 73.3% were anti-aquaporin-4 antibody positive. Isolated transverse myelitis (32.9%) and isolated optic neuritis (22.4%) were the most frequent initial clinical syndromes. After multivariate analysis, optic neuritis (RR = 0.45; 95% CI = 0.23 - 0.88; p = 0.020) and dyslipidemia (RR = 0.40; 95% CI = 0.20 - 0.83; p = 0.014) were associated with slower disease progression. Area postrema involvement (RR = 6.70; 95% CI = 3.31 - 13.54; p < 0.001) and age at onset (RR = 1.03; 95% CI = 1.01 - 1.05; p = 0.003) were associated with faster disease progression. CONCLUSIONS: In the first clinical and prognostic study in northeastern Brazil, we identified area postrema involvement, age at onset, optic neuritis at fist syndrome and dyslipidemia as the main prognostic factors associated with disease progression.

Prevalence of neuromyelitis optica spectrum disorder in antioquia between 2016 and 2018.

BACKGROUND: There are few epidemiological studies published in the world evaluating the prevalence of Neuromyelitis Optica Spectrum Disorder (NMOSD). The true prevalence of the disease is not known and the studies carried out are based on the diagnostic criteria used prior to 2015. OBJECTIVE: To determine the prevalence of NMOSD in Antioquia, from January 2016 to December 2018. METHODS: The prevalence of NMOSD in Antioquia was determined using the Capture-Recapture Method. Eight centers in the Department of Antioquia for the care of patients with neurological diseases were included. The data was collected between 2016 and 2018. RESULTS: A total of 221 consultation histories, 169 patients with a diagnosis of NMOSD were identified. The prevalence was 4.03 cases/100,000 inhabitants (95% confidence interval (CI) 3.3-4.8) of whom (87.5%), were women and the predominant race was Mestizo (81.6%). The most frequent initial presentation was optic neuritis (ON) (50.9%). Most of the patients had motor or visual disability (86.4%) and the treatment most used was Rituximab (47.9%). CONCLUSION: The prevalence of NMOSD in Antioquia is one of the highest reported in the world, except for the French Antilles. More studies are required to know the prevalence of this disease in the Colombian population.

Health-related quality of life in neuromyelitis optica spectrum disorder patients in an Argentinean cohort.

BACKGROUND: We aimed to describe the health-related quality of life (HRQoL) in patients with neuromyelitis optica spectrum disorders (NMOSD), to compare HRQoL between NMOSD patients, multiple sclerosis (MS), and healthy controls (HC) and to study the associations between HRQoL and the clinical variables of the disease. METHODS: A cross-sectional study was carried out. Patients with NMOSD seropositive, MS, and HC were enrolled and age-matched. The HRQoL was studied using the Argentinean validation of the SF-36 health questionnaire. Demographic and clinical characteristics were analyzed, as well as the EDSS and the total scores and subscales of the SF-36. RESULTS: 243 individuals were included (NMOSD= 53, MS =100, and HC =90). The mean EDSS was 3.06 ± 2.01 in NMOSD and 2.67 ± 1.83 in MS with a mean of disease duration of 6.2 ± 4.4 and 6.3 ± 5.3 years, respectively. Significant statistical differences were observed in the total SF-36 score between both NMOSD and MS vs. HC (p < 0.01), but no differences were found when the total SF-36 score was compared between NMOSD vs. MS. Overall, NMOSD patients scored significantly lower in the total SF-36 and subscale scores compared to HC (p< 0.05). NMOSD patients also showed significant differences in bodily pain (58.8 ± 29.8 vs 75.1 ± 25.1, p < 0.01) and general health (44.4 ± 20.9 vs.31.9 ± 23.1, p < 0.01) when compared with MS, but no differences were found after comparing the rest of the subscales. We found that higher EDSS scores (ß -1.28 p = 0.03) and disease duration (ß 0.8, p = 0.02) were significantly associated to lower (worse) general health (dependent variable) score in NMOSD patients after having applied multiple linear regression analysis. Additionally, we observed that higher EDSS scores (ß -10.2 p = 0.008) and the presence of relapses in the previous year (ß -28.9, p = 0.02) were significantly associated to lower (worse) physical functioning (dependent variable) score. CONCLUSION: Pain seems to be a significant undertreated symptom in NMOSD patients that strongly impact on HRQoL. Patient-reported HRQoL scales scores provide comprehensive additional prognostic information beyond physical disability score.

Seasonal variation in attacks of neuromyelitis optica spectrum disorders and multiple sclerosis: Evaluation of 794 attacks from a nationwide registry in Argentina.

BACKGROUND: Identification of triggers that potentially instigate attacks in neuromyelitis optica spectrum disorders (NMOSD) and multiple sclerosis (MS) has remained challenging. We aimed to analyze the seasonality of NMOSD and MS attacks in an Argentinean cohort seeking differences between the two disorders. METHODS: A retrospective study was conducted in a cohort of NMOSD and MS patients followed in specialized centers from Argentina and enrolled in RelevarEM, a nationwide, longitudinal, observational, non-mandatory registry of MS/NMOSD patients. Patients with complete relapse data (date, month and year) at onset and during follow-up were included. Attack counts were analyzed by month using a Poisson regression model with the median monthly attack count used as reference. RESULTS: A total of 551 patients (431 MS and 120 NMOSD), experiencing 236 NMOSD-related attacks and 558 MS-related attacks were enrolled. The mean age at disease onset in NMOSD was 39.5 ± 5.8 vs. 31.2 ± 9.6 years in MS (p < 0.01). Mean follow-up time was 6.1 ± 3.0 vs. 7.4 ± 2.4 years (p < 0.01), respectively. Most of the included patients were female in both groups (79% vs. 60%, p < 0.01). We found a peak of number of attacks in June (NMOSD: 28 attacks (11.8%) vs MS: 33 attacks (5.9%), incidence rate ratio 1.82, 95%CI 1.15-2.12, p = 0.03), but no differences were found across the months in both disorders when evaluated separately. Strikingly, we observed a significant difference in the incidence rate ratio of attacks during the winter season when comparing NMOSD vs. MS (NMOSD: 75 attacks (31.7%) vs MS: 96 attacks (17.2%), incidence rate ratio 1.82, 95%CI 1.21-2.01, p = 0.02) after applying Poisson regression model. Similar results were observed when comparing the seropositive NMOSD (n = 75) subgroup vs. MS. CONCLUSIONS: Lack of seasonal variation in MS and NMOSD attacks was observed when evaluated separately. Future epidemiological studies about the effect of different environmental factors on MS and NMOSD attacks should be evaluated prospectively in Latin America population.

Clinical Features of COVID-19 on Patients With Neuromyelitis Optica Spectrum Disorders.

BACKGROUND AND OBJECTIVES: To describe the clinical features and disease outcomes of coronavirus disease 2019 (COVID-19) in patients with neuromyelitis optica spectrum disorder (NMOSD). METHODS: The Neuroimmunology Brazilian Study Group has set up the report of severe acute respiratory syndrome (SARS-CoV2) cases in patients with NMOSD (pwNMOSD) using a designed web-based case report form. All neuroimmunology outpatient centers and individual neurologists were invited to register their patients across the country. Data collected between March 19 and July 25, 2020, were uploaded at the REDONE.br platform. Inclusion criteria were as follows: (1) NMOSD diagnosis according to the 2015 International Panel Criteria and (2) confirmed SARS-CoV2 infection (reverse transcription-polymerase chain reaction or serology) or clinical suspicion of COVID-19, diagnosed according to Center for Disease Control / Council of State and Territorial Epidemiologists (CDC/CSTE) case definition. Demographic and NMOSD-related clinical data, comorbidities, disease-modifying therapy (DMT), COVID-19 clinical features, and severity were described. RESULTS: Among the 2,061 pwNMOSD followed up by Brazilian neurologists involved on the registry of COVID-19 in pwNMOSD at the REDONE.br platform, 34 patients (29 women) aged 37 years (range 8-77), with disease onset at 31 years (range 4-69) and disease duration of 6 years (range 0.2-20.5), developed COVID-19 (18 confirmed and 16 probable cases). Most patients exhibited mild disease, being treated at home (77%); 4 patients required admission at intensive care units (severe cases); and 1 patient died. Five of 34 (15%) presented neurologic manifestations (relapse or pseudoexacerbation) during or after SARS-CoV2 infection. DISCUSSION: Most NMOSD patients with COVID-19 presented mild disease forms. However, pwNMOSD had much higher odds of hospitalization and intensive care unit admission comparing with the general Brazilian population. The frequency of death was not clearly different. NMOSD disability, DMT type, and comorbidities were not associated with COVID-19 outcome. SARS-CoV2 infection was demonstrated as a risk factor for NMOSD relapses. Collaborative studies using shared NMOSD data are needed to suitably define factors related to COVID-19 severity and neurologic manifestations.