The Role of Glial Fibrillary Acidic Protein as a Biomarker in Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorder: A Systematic Review and Meta-Analysis.

There is debate on the role of glial fibrillary acidic protein (GFAP) as a reliable biomarker in multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD), and its potential to reflect disease progression. This review aimed to investigate the role of GFAP in MS and NMOSD. A systematic search of electronic databases, including PubMed, Embase, Scopus, and Web of Sciences, was conducted up to 20 December 2023 to identify studies that measured GFAP levels in people with MS (PwMS) and people with NMOSD (PwNMOSD). R software version 4.3.3. with the random-effect model was used to pool the effect size with its 95% confidence interval (CI). Of 4109 studies, 49 studies met our inclusion criteria encompassing 3491 PwMS, 849 PwNMOSD, and 1046 healthy controls (HCs). The analyses indicated that the cerebrospinal fluid level of GFAP (cGFAP) and serum level of GFAP (sGFAP) were significantly higher in PwMS than HCs (SMD = 0.7, 95% CI: 0.54 to 0.86, p < 0.001, I2 = 29%, and SMD = 0.54, 95% CI: 0.1 to 0.99, p = 0.02, I2 = 90%, respectively). The sGFAP was significantly higher in PwNMOSD than in HCs (SMD = 0.9, 95% CI: 0.73 to 1.07, p < 0.001, I2 = 10%). Among PwMS, the Expanded Disability Status Scale (EDSS) exhibited significant correlations with cGFAP (r = 0.43, 95% CI: 0.26 to 0.59, p < 0.001, I2 = 91%) and sGFAP (r = 0.36, 95% CI: 0.23 to 0.49, p < 0.001, I2 = 78%). Regarding that GFAP is increased in MS and NMOSD and has correlations with disease features, it can be a potential biomarker in MS and NMOSD and indicate the disease progression and disability in these disorders.

Digital symbol-digit modalities test with modified flexible protocols in patients with CNS demyelinating diseases.

Cognitive impairment (CI) is prevalent in central nervous system demyelinating diseases, such as multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD). We developed a novel tablet-based modified digital Symbol Digit Modalities Test (MD-SDMT) with adjustable protocols that feature alternating symbol-digit combinations in each trial, lasting one or two minutes. We assessed 144 patients (99 with MS and 45 with NMOSD) using both MD-SDMT protocols and the traditional paper-based SDMT. We also gathered participants' feedback through a questionnaire regarding their preferences and perceived reliability. The results showed strong correlations between MD-SDMT and paper-based SDMT scores (Pearsons correlation: 0.88 for 2 min; 0.85 for 1 min, both p < 0.001). Among the 120 respondents, the majority preferred the digitalized SDMT (55% for the 2 min, 39% for the 1 min) over the paper-based version (6%), with the 2 min MD-SDMT reported as the most reliable test. Notably, patients with NMOSD and older individuals exhibited a preference for the paper-based test, as compared to those with MS and younger patients. In summary, even with short test durations, the digitalized SDMT effectively evaluates cognitive function in MS and NMOSD patients, and is generally preferred over the paper-based method, although preferences may vary with patient characteristics.

Dysphagia in neuromyelitis optica spectrum disorder and multiple sclerosis: A comparison of frequency, severity, and effects on quality of life.

OVERVIEW: Dysphagia has been previously discussed as a potential life-threatening condition secondary to chronic neurological diseases such as multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD). However, its impact on the quality of life (QoL) of patients with NMOSD has never been studied before. This study aims to determine the frequency of dysphagia and its impact on QoL in NMOSD patients in comparison with MS people and healthy individuals. METHODS: Seventy-five MS and sixty-five NMOSD patients with an expanded disability status scale (EDSS) score ≥ 3.5 in addition to 106 healthy controls were enrolled in this cross-sectional study. All the participants completed the self-report dysphagia in MS (DYMUS) and 36-item short-form health survey (SF-36) questionnaires. In case of positive answers to at least one of the questions in DYMUS, they were asked to fill out the dysphagia handicap index (DHI) questionnaire. RESULTS: The frequency of dysphagia in NMOSD, MS, and control groups was 61.54 %, 72.97 %, and 27 %, respectively. Patients with swallowing problems had reduced scores across different swallowing-related QoL domains compared to non-dysphagic patients (p < 0.05). NMOSD (1, IQR [0-3.5]) and MS patients (2, IQR [0-4]) had a significantly higher median total DYMUS score than control (0, IQR [0-1]) (p < 0.01). However, there was no discernible difference between the two patient groups. NMOSD had the highest mean total DHI score (21.22 ± 21), followed by MS (15.25 ± 18.94) and control (7.08 ± 5.12). A significant correlation was seen in the NMOSD group between the DHI total score and the SF-36 total score (r = 0.62, p < 0.05). The DHI and SF-36 subscales showed a strong association as well. The overall SF-36 scores in both the control and MS groups was not significantly correlated with DHI. The generalized linear model analysis showed that the NMOSD group's age (p-value = 0.005), EDSS (p-value < 0.001), and total DYMUS score (p-value = 0.018) significantly affected overall health status. CONCLUSION: The presence of dysphagia significantly impacts the QoL in NMOSD patients, particularly in aspects related to swallowing. These findings underscore the critical need for diligent dysphagia screening and emphasize the importance of educating both caregivers and NMOSD patients about managing this challenging symptom.

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.

Cognitive impairment and its association with clinical variables in Mexican persons with neuromyelitis optica spectrum disorder.

INTRODUCTION: Cognitive impairment has a substantial impact on the daily function of people living with demyelinating diseases. However, the study of cognitive failures and their association with clinical variables in people suffering from neuromyelitis optica spectrum disorder (NMOSD) has been scarce, especially in the latin american (Mexican) population at early and middle stages of the disease. METHOD: We applied the Rao's Brief Repeatable Battery of Neuropsychological tests and obtained data of lesion burden through magnetic resonance imaging (MRI), expression of AQPQ4-IgG antibodies, and degree of disability in 30 patients with NMOSD and 30 healthy participants as a control group. RESULTS: About half of the NMOSD patients (47%) showed some degree of cognitive impairment, especially in the executive domain compared to the control group. Executive function scores were positively associated with the degree of physical disability. We found no associations between cognitive dysfunction and disease duration, AQPQ4-IgG antibodies, lesion burden, nor depression. CONCLUSIONS: Executive functioning impairment is present in NMOSD and may predict the degree of functional disability in patients. Cognitive failures were not associated with immunological or radiological data, which emphasizes the relevance of applying systematic neuropsychological assessments in this clinical population.

Abnormal functional connectivity of white-matter networks and gray-white matter functional networks in patients with NMOSD.

Cognitive impairment (CI) has been reported in 29-70% of patients with neuromyelitis optica spectrum disorder (NMOSD). Abnormal white matter (WM) functional networks that correlate with cognitive functions have not been studied well in patients with NMOSD. The aim of the current study was to investigate functional connectivity (FC), spontaneous activity, and functional covariance connectivity (FCC) abnormalities of WM functional networks in patients with NMOSD and their correlation with cognitive performance. Twenty-four patients with NMOSD and 24 healthy controls (HCs) were included in the study. Participants underwent brain resting-state functional magnetic resonance imaging (fMRI) and the Montreal Cognitive Assessment (MoCA). Eight WM networks and nine gray matter (GM) networks were created. In patients, WM networks, including WM1-4, WM1-8, WM2-6, WM2-7, WM2-8, WM4-8, WM5-8 showed reduced FC (P < 0.05). All WM networks except WM1 showed decreased spontaneous activity (P < 0.05). The major GM networks demonstrated increased/decreased FC (P < 0.05), whereas GM7-WM7, GM8-WM4, GM8-WM6 and GM8-WM8 displayed decreased FC (P < 0.05). The MoCA results showed that two-thirds (16/24) of the patients had CI. FC and FCC in WM networks were correlated negatively with the MoCA scores (P < 0.05). WM functional networks are multi-layered. Abnormal FC of WM functional networks and GM functional networks may be responsible for CI.

Seizures in inflammatory demyelinating disorders of the central nervous system.

BACKGROUND: Multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) may be associated with acute symptomatic seizures and chronic epilepsy as well. The clinical features of the seizures and/or accompanying epilepsy seen in each disease group may vary. In this study, we aimed to contribute to the existing literature by describing the clinical features of seizures and epilepsy in our demyelinating patient population. METHODS: We retrospectively analyzed patients who were followed up in our tertiary referral center neurology demyelinating diseases outpatient clinic between 2019 and 2024. Patients who had at least one seizure before, simultaneously, or after the diagnosis of demyelinating disease were included in the study. RESULTS: Among 1735 patients with MS, 40 had experienced at least one epileptic seizure (2.3 %). Thirty patients (1.7 %) had seizures that could not be explained by another factor than MS. When secondary progressive MS (SPMS) and relapsing-remitting MS (RRMS) were compared, the interval between MS-epilepsy diagnosis was longer and seizure recurrence was more in SPMS. However, the prognosis of epilepsy was good in both subtypes. There were 21 patients followed up with antibody-positive neuromyelitis optica spectrum disorder. No patient had a seizure during the follow-up. We identified 56 patients who fulfilled the criteria for MOGAD with high antibody titers. Seizures were observed in three of them (5.4 %). All of them had status epilepticus either at the onset or during the course of the disease. CONCLUSION: Even rare, seizures constitute one of the important clinical features of the inflammatory demyelinating disorders of the central nervous system. The pathophysiologic mechanism underlying seizures in MS is still not clear. Seizures may occur through different mechanisms in patients where seizures are the initial symptom or a sign of relapse and those that occur spontaneously during the progressive course of the disease. Prevalence of status epilepticus was common in MOGAD patients. Given the rarity of the seizures in CNS demyelinating disorders, it is difficult the define clinical and pathophysiological characteristics of accompanying seizures and epilepsy. Future studies conducted on large patient groups will contribute to the existing literature.

Espectro de neuromielitis óptica: ¿seropositivo para la anticuaporina es una entidad diferente de los pacientes que son seronegativos? Una perspectiva de Colombia / Neuromyelitis optica spectrum disorder: Do patients positive and negative for anti–aquaporin-4 antibodies present distinct entities? A Colombian perspective

Introducción: La neuromielitis óptica es una enfermedad inflamatoria del sistema nervioso central, caracterizada por ataques de neuritis óptica y mielitis transversa longitudinalmente extensa. El descubrimiento del biomarcador diagnóstico anticuerpo anti-acuaporina-4 y los hallazgos imagenológicos en resonancia magnética cerebral han permitido el reconocimiento de un fenotipo clínico más amplio y detallado denominado espectro neuromielitis óptica. Objetivo: Determinar las características demográficas y clínicas de los pacientes diagnosticados con NMO/NMOSD, de acuerdo con la seropositividad del anticuerpo, en dos instituciones de cuarto nivel de complejidad en Bogotá. Métodos: Se realizó un estudio tipo serie de casos. Fueron incluidos aquellos pacientes > 18 años con diagnóstico de NMO/NMOSD, valorados en el Servicio de Neurología de dos hospitales de alta complejidad entre los años 2013 y 2017, con disponibilidad de estudios imagenológicos y resultados de serología. Se evaluaron variables demográficas, clínicas e imagenológicas, y se realizó un análisis de estas variables, según seropositividad del Ac-AQP4. Resultados: Se incluyeron 35 pacientes con NMO/NMOSD, la mediana de edad de inicio fue de 46,5 años (P25-P75 = 34,2-54,0), la mayoría de los pacientes tuvo manifestaciones clínicas a nivel sensitivo (n = 25) y motor (n = 26), en seis (n = 6) pacientes se identificó una enfermedad autoinmune concomitante. Se encontró seropositividad en 20 pacientes. Encontramos algunas diferencias en las características clínicas e imagenológicas, pero solo la edad y el compromiso de nervio óptico mostraron diferencia estadísticamente significativa (p = 0,03). Conclusiones: No se encontraron grandes diferencias clínicas, imagenológicas y de laboratorio, según la seropositividad del Ac-AQP4, excepto en la edad de inicio y el compromiso de nervio óptico (uni o bilateral), pero deben ser estudiadas de manera más detallada en poblaciones más amplias.(AU)

Introduction: Neuromyelitis optica (NMO) is an inflammatory disease of the central nervous system characterised by attacks of optic neuritis and longitudinally extensive transverse myelitis. The discovery of anti–aquaporin-4 (anti-AQP4) antibodies and specific brain MRI findings as diagnostic biomarkers have enabled the recognition of a broader and more detailed clinical phenotype, known as neuromyelitis optica spectrum disorder (NMOSD). Objective: This study aimed to determine the demographic and clinical characteristics of patients with NMO/NMOSD with and without seropositivity for anti-AQP4 antibodies, in 2 quaternary-level hospitals in Bogotá. Methods: Our study included patients > 18 years of age and diagnosed with NMO/NMOSD and for whom imaging and serology results were available, assessed between 2013 and 2017 at the neurology departments of hospitals providing highly complex care. Demographic, clinical, and imaging data were gathered and compared in patients with and without seropositivity for anti-AQP4 antibodies. Results: The sample included 35 patients with NMO/NMOSD; the median age of onset was 46.5 years (P25-P75, 34.2-54.0); most patients had sensory (n = 25) and motor manifestations (n = 26), and a concomitant autoimmune disease was identified in 6. Twenty patients were seropositive for anti-AQP4 antibodies. Only age and presence of optic nerve involvement showed statistically significant differences between groups (p = .03). Conclusions: Clinical, imaging, and laboratory variables showed no major differences between patients with and without anti-AQP4 antibodies, with the exception of age of onset and presence of optic nerve involvement (uni- or bilateral); these factors should be studied in greater detail in larger populations.(AU)

Astrocytic outer retinal layer thinning is not a feature in AQP4-IgG seropositive neuromyelitis optica spectrum disorders.

BACKGROUND: Patients with anti-aquaporin-4 antibody seropositive (AQP4-IgG+) neuromyelitis optica spectrum disorders (NMOSDs) frequently suffer from optic neuritis (ON) leading to severe retinal neuroaxonal damage. Further, the relationship of this retinal damage to a primary astrocytopathy in NMOSD is uncertain. Primary astrocytopathy has been suggested to cause ON-independent retinal damage and contribute to changes particularly in the outer plexiform layer (OPL) and outer nuclear layer (ONL), as reported in some earlier studies. However, these were limited in their sample size and contradictory as to the localisation. This study assesses outer retinal layer changes using optical coherence tomography (OCT) in a multicentre cross-sectional cohort. METHOD: 197 patients who were AQP4-IgG+ and 32 myelin-oligodendrocyte-glycoprotein antibody seropositive (MOG-IgG+) patients were enrolled in this study along with 75 healthy controls. Participants underwent neurological examination and OCT with central postprocessing conducted at a single site. RESULTS: No significant thinning of OPL (25.02±2.03 µm) or ONL (61.63±7.04 µm) were observed in patients who were AQP4-IgG+ compared with patients who were MOG-IgG+ with comparable neuroaxonal damage (OPL: 25.10±2.00 µm; ONL: 64.71±7.87 µm) or healthy controls (OPL: 24.58±1.64 µm; ONL: 63.59±5.78 µm). Eyes of patients who were AQP4-IgG+ (19.84±5.09 µm, p=0.027) and MOG-IgG+ (19.82±4.78 µm, p=0.004) with a history of ON showed parafoveal OPL thinning compared with healthy controls (20.99±5.14 µm); this was not observed elsewhere. CONCLUSION: The results suggest that outer retinal layer loss is not a consistent component of retinal astrocytic damage in AQP4-IgG+ NMOSD. Longitudinal studies are necessary to determine if OPL and ONL are damaged in late disease due to retrograde trans-synaptic axonal degeneration and whether outer retinal dysfunction occurs despite any measurable structural correlates.

Frequency of New Silent MRI Lesions in Myelin Oligodendrocyte Glycoprotein Antibody Disease and Aquaporin-4 Antibody Neuromyelitis Optica Spectrum Disorder.

Importance: In multiple sclerosis, magnetic resonance imaging (MRI) new silent lesions contribute to the diagnostic criteria, have prognostic value, and are used in treatment monitoring; but in aquaporin-4 antibody neuromyelitis optica spectrum disorder (AQP4-NMOSD), they are rare between attacks. Their frequency and their association with relapses in adults with myelin oligodendrocyte glycoprotein antibody disease (MOGAD) are still unclear. Objective: To examine the frequency and characteristics of MRI new silent lesions in MOGAD and AQP4-NMOSD. Design, Setting, and Participants: This retrospective cohort study analyzed clinical and MRI data of 404 patients with MOGAD or AQP4-NMOSD between February 1, 1994, and April 1, 2021; data were prospectively recorded on the Oxford NMOSD clinical database under follow-up. The study was conducted at the Oxford National Referral Center for NMOSD. Participants included patients with MOGAD and AQP4-NMOSD who were treated within the Oxford National NMO Specialist Service. Exposures: Seropositive MOGAD and AQP4-NMOSD patients who had MRIs during attacks and the remission phase of their disease. Main Outcomes and Measures: Frequency of new silent lesions detected by either attack MRIs (during the acute clinical event) or remission MRIs (performed outside of a relapse and at least 3 months from last attack). Median time to next relapse in the presence of definite (reference MRI performed at least 4 weeks from last attack onset), probable (reference MRI performed during last attack), and no new silent lesions on remission MRIs was also evaluated. Results: One hundred eighty-two MOGAD patients and 222 AQP4-NMOSD patients were included. Of the MOGAD patients, 113 (62%) were female, median age at onset was 28 years (range, 2-72), and median follow-up was 52 months (range, 11-253). Of the AQP4-NMOSD patients, 189 (85%) were female, median age at onset was 43 years (range, 2-82), and median follow-up was 87.5 months (range, 11-260). MOGAD patients had 296 attack MRI sessions and 167 remission MRI sessions. New attack silent lesions were found in 97 of 296 (33%) attack MRI sessions, whereas new remission silent lesions were found in 5 of 167 (3.0%) remission MRI sessions. Median time from remission scan to the next relapse in the presence of definite or probable new remission lesions was 2 months (IQR, 1-6), whereas in the absence of any new remission lesions it was 73 months (IQR, 20-104; hazard ratio, 23.86; 95% CI, 7.51-75.79; P < .001). AQP4-NMOSD patients had 470 attack MRI sessions and 269 remission MRI sessions. New attack silent lesions were detected in 88 of 470 (18.7%) attack MRI sessions, whereas new remission silent lesions were found in 7 of 269 (2.6%) remission MRI sessions. Median time from remission scan to the next relapse in the presence of definite or probable new remission lesions was 5 months (IQR, 2-6), whereas in the absence of any new remission lesions it was 85 months (IQR, 29-167; hazard ratio, 21.23; 95% CI, 8.05-53.65; P < .001). Conclusions and Relevance: In contrast to that reported in multiple sclerosis, results of this cohort study suggest that new remission silent lesions are rare on follow-up scans in MOGAD and AQP4-NMOSD and appear to indicate a high risk of imminent relapse.

Early Initiation of Tocilizumab Treatment Against Moderate-to-Severe Myelitis in Neuromyelitis Optica Spectrum Disorder.

Background: Interleukin-6 receptor blockade is effective in reducing the risk of relapses in neuromyelitis optica spectrum disorder (NMOSD). However, its efficacy during acute attacks of NMOSD remains elusive. Objective: We investigated the effects of tocilizumab on disability during acute attacks, as well as its maintenance, in patients with moderate-to-severe myelitis. Methods: Nineteen patients with NMOSD received tocilizumab treatment as add-on to high-dose methylprednisolone (HDMP) in acute myelitis and twenty-two patients who only received HDMP were compared. Disease disability was assessed using a multi-level scaling system that included the expanded disability status scale (EDSS), Hauser ambulation index (HAI), modified Rankin scale (mRS), pain numerical rating scale (NRS), functional assessment of chronic illness therapy-fatigue scale (FACIT-F), activity of daily living (ADL), EuroQol five-dimensions-three-level questionnaire (EQ-5D-3L), and sensory function score and bowel and bladder function score in Kurtzke functional systems scores (FSS). Results: Improved EDSS, HAI, and mRS, as well as increased ADL and EQ-5D-3L were significant in patients on tocilizumab compared with those on steroids as monotherapy at 3 months (p < 0.05). Both groups of patients showed improved pain, fatigue, sensory function, and autonomic function at follow-ups, compared with baseline respectively. The changes in NRS, FACIT-F, and sensory and autonomic FSS showed no significant differences between the two groups. Tocilizumab significantly lowered the risk of relapses (HR = 0.21, 95% CI 0.06-0.76, p = 0.017) and reduced the annualized relapse rate compared with those by steroids (0.1 ± 0.2 vs 0.5 ± 0.6, p = 0.013). Conclusion: Early initiation of tocilizumab provided a safe and effective add-on alternative during attacks, and its maintenance contributed to a significant reduction of relapse rate in NMOSD.

Neuromyelitis Optica Spectrum Disorders in Africa: A Systematic Review.

BACKGROUND AND OBJECTIVES: Neuromyelitis optica (NMO) is a CNS inflammatory disease that predominantly affects the optic nerves and the spinal cord. It is more frequent in Asian and African populations than in European ones. Data on epidemiology, clinical presentation, additional investigations, and treatment in the African continent are scarce. We aim to (1) collect and analyze published data on neuromyelitis optica spectrum disorder (NMOSD), (2) indicate challenges in the diagnosis and management, and (3) discuss opportunities for future research, education, and policy making, specifically on the African continent. METHODS: A systematic review was performed in January 2021 with the search terms "Neuromyelitis optica and Africa," "Devic Disease and Africa," and "NMOSD and Africa." We included all study types except case reports, correspondence, or conference abstracts on NMO or NMOSD. Extracted data included study design, country, study period, demographic and clinical characteristics, results of paraclinical investigations, and outcome. Data analysis was performed with descriptive statistics. RESULTS: We retrieved a total of 79 records, of which 19 were included. Ten of 54 African countries reported a total of 410 cases. Almost half of them were from North African countries. The mean age at diagnosis was 33 years (range 7-88 years), and 75% were female. Transverse myelitis followed by optic neuritis were the most frequent symptoms at the time of presentation. One hundred nineteen patients experienced at least 1 previous relapse, and 106 had a relapsing course after diagnosis. Relapses were treated with IV methylprednisolone. Azathioprine and steroids were used most often as maintenance treatments. Outcomes were rarely described. DISCUSSION: The majority of studies on NMOSD from the African continent are retrospective, and most countries do not report any data. Our systemic review shows that data derived from patients living in Africa correspond well to what has been previously published in meta-analyses on patients of African ancestry with NMOSD who live outside of Africa, except for a younger age at onset and a lower proportion of females. We advocate for systematic data collection to adequately capture and monitor the burden of NMOSD, for expansion of research efforts and facilities to perform fundamental and clinical research, and for improved access to health care including diagnostics, treatments, and rehabilitation services for people affected by NMOSD in the African continent.

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.

Sarcoidosis and neuromyelitis optica in a patient with optic neuritis - a case report.

We present a case of atypical recurrent optic neuritis. A man in his 50s presented with right optic neuritis and profound visual loss, associated with elevated inflammatory markers. Lymph-node biopsy was consistent with sarcoidosis. Aquaporin-4 antibodies were also present. Three months following corticosteroid treatment, his right optic neuritis relapsed, again with raised inflammatory markers. He was started on azathioprine and prednisolone with good effect. A dual diagnosis of sarcoidosis and neuromyelitis optica with aquaporin-4 antibodies is very rare. Long-term immunosuppression is required. The case highlights the importance of identifying the features and cause of atypical optic neuritis.

Pain, Depression, and Quality of Life in Neuromyelitis Optica Spectrum Disorder: A Cross-Sectional Study of 166 AQP4 Antibody-Seropositive Patients.

OBJECTIVES: To evaluate prevalence, clinical characteristics, and predictors of pain, depression, and their impact on the quality of life (QoL) in a large neuromyelitis optica spectrum disorder (NMOSD) cohort. METHODS: We included 166 patients with aquaporin-4-seropositive NMOSD from 13 tertiary referral centers. Patients received questionnaires on demographic and clinical characteristics, PainDetect, short form of Brief Pain Inventory, Beck Depression Inventory-II, and Short Form 36 Health Survey. RESULTS: One hundred twenty-five (75.3%) patients suffered from chronic NMOSD-associated pain. Of these, 65.9% had neuropathic pain, 68.8% reported spasticity-associated pain and 26.4% painful tonic spasms. Number of previous myelitis attacks (OR = 1.27, p = 0.018) and involved upper thoracic segments (OR = 1.31, p = 0.018) were the only predictive factors for chronic pain. The latter was specifically associated with spasticity-associated pain (OR = 1.36, p = 0.002). More than a third (39.8%) suffered from depression, which was moderate to severe in 51.5%. Pain severity (OR = 1.81, p < 0.001) and especially neuropathic character (OR = 3.44, p < 0.001) were associated with depression. Pain severity and walking impairment explained 53.9% of the physical QoL variability, while depression and walking impairment 39.7% of the mental QoL variability. No specific medication was given to 70.6% of patients with moderate or severe depression and 42.5% of those with neuropathic pain. Two-thirds (64.2%) of patients with symptomatic treatment still reported moderate to severe pain. CONCLUSIONS: Myelitis episodes involving upper thoracic segments are main drivers of pain in NMOSD. Although pain intensity was lower than in previous studies, pain and depression remain undertreated and strongly affect QoL. Interventional studies on targeted treatment strategies for pain are urgently needed in NMOSD.

Autoantibodies Against the Complement Regulator Factor H in the Serum of Patients With Neuromyelitis Optica Spectrum Disorder.

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory disease of the central nervous system (CNS), characterized by pathogenic, complement-activating autoantibodies against the main water channel in the CNS, aquaporin 4 (AQP4). NMOSD is frequently associated with additional autoantibodies and antibody-mediated diseases. Because the alternative pathway amplifies complement activation, our aim was to evaluate the presence of autoantibodies against the alternative pathway C3 convertase, its components C3b and factor B, and the complement regulator factor H (FH) in NMOSD. Four out of 45 AQP4-seropositive NMOSD patients (~9%) had FH autoantibodies in serum and none had antibodies to C3b, factor B and C3bBb. The FH autoantibody titers were low in three and high in one of the patients, and the avidity indexes were low. FH-IgG complexes were detected in the purified IgG fractions by Western blot. The autoantibodies bound to FH domains 19-20, and also recognized the homologous FH-related protein 1 (FHR-1), similar to FH autoantibodies associated with atypical hemolytic uremic syndrome (aHUS). However, in contrast to the majority of autoantibody-positive aHUS patients, these four NMOSD patients did not lack FHR-1. Analysis of autoantibody binding to FH19-20 mutants and linear synthetic peptides of the C-terminal FH and FHR-1 domains, as well as reduced FH, revealed differences in the exact binding sites of the autoantibodies. Importantly, all four autoantibodies inhibited C3b binding to FH. In conclusion, our results demonstrate that FH autoantibodies are not uncommon in NMOSD and suggest that generation of antibodies against complement regulating factors among other autoantibodies may contribute to the complement-mediated damage in NMOSD.

Autoantibodies in neurological disease.

The realization that autoantibodies can contribute to dysfunction of the brain has brought about a paradigm shift in neurological diseases over the past decade, offering up important novel diagnostic and therapeutic opportunities. Detection of specific autoantibodies to neuronal or glial targets has resulted in a better understanding of central nervous system autoimmunity and in the reclassification of some diseases previously thought to result from infectious, 'idiopathic' or psychogenic causes. The most prominent examples, such as aquaporin 4 autoantibodies in neuromyelitis optica or NMDAR autoantibodies in encephalitis, have stimulated an entire field of clinical and experimental studies on disease mechanisms and immunological abnormalities. Also, these findings inspired the search for additional autoantibodies, which has been very successful to date and has not yet reached its peak. This Review summarizes this rapid development at a point in time where preclinical studies have started delivering fundamental new data for mechanistic understanding, where new technologies are being introduced into this field, and - most importantly - where the first specifically tailored immunotherapeutic approaches are emerging.

The possible role of Interleukin-6 as a regulator of insulin sensitivity in patients with neuromyelitis optica spectrum disorder.

BACKGROUND: Neuromyelitis optica spectrum disorder (NMOSD) is associated with inflammatory mediators that may also trigger downstream signaling pathways leading to reduce insulin sensitivity. METHODS: We aimed to determine the risk association of hyperinsulinemia in NMOSD patients with seropositive AQP4-IgG and the serum levels of interleukin (IL)-6 and IL-17A compared with the control group. Serum levels of metabolic (Insulin, Fasting Blood Sugar (FBS), lipid profile) and inflammatory (IL-6 and IL-17) markers were assessed in 56 NMOSD patients and 100 controls. RESULTS: Hyperinsulinemia was more prevalent in NMOSD patients independent of age, sex and body mass index (BMI) (48.2% vs. 26%, p = 0.005) compared to control group. After adjusting age, sex and BMI, there was significant association between lower insulin sensitivity (IS) and NMOSD risk (95% CI: Beta = 0.73, 0.62 to 0.86, p = 0.0001). Circulating levels of IL-6 and IL-17 were higher in NMOSD patients, and only IL-6 had an effect modifier for the association between lower insulin sensitivity and NMOSD risk. CONCLUSIONS: Our data suggests that inflammatory pathogenesis of NMOSD leads to hyperinsulinemia and increases the risk of insulin resistance.

Investigating the Presence of Interattack Astrocyte Damage in Neuromyelitis Optica Spectrum Disorder: Longitudinal Analysis of Serum Glial Fibrillary Acidic Protein.

OBJECTIVES: Information on subclinical astrocyte damage can provide further insight into neuromyelitis optica spectrum disorder (NMOSD) pathophysiology and disease-monitoring strategies. To investigate whether astrocyte and neuroaxonal damage occurs during interattack periods in individuals with NMOSD through longitudinal measurement of serum glial fibrillary acidic protein (sGFAP) and neurofilament light chain (sNfL) at multiple time points. METHODS: sGFAP and sNfL levels were measured in 187 serum samples from 20 participants with NMOSD treated with rituximab (median follow-up: 24 months) and 19 age-/sex-matched healthy controls using a highly sensitive single-molecule array assay. From the NMOSD cohort of National Cancer Center, Korea, 14 clinically stable participants were randomly selected for focused investigation of interattack periods, and 6 participants with clinical attacks despite treatment were enrolled for attack-related measurements. RESULTS: Significant elevations of sGFAP levels were observed in all clinical attacks, and 95% (19/20) of patients showed reduction of sGFAP levels below the cutoff value (3 SDs above mean levels in age-/sex-matched healthy controls) within 3 months of their clinical attacks. The sGFAP levels were consistently low during interattack periods in 90% (17/19) of patients whose sGFAP levels returned to below the cutoff value. Changes in sNfL levels were similar to but slower than those in sGFAP levels. CONCLUSIONS: Subclinical astrocyte damage represented by increasing sGFAP levels rarely occurred during interattack periods in individuals with NMOSD; however, a certain degree of astrocyte damage did occur at the time of clinical attacks without exception, but it was not evident within 3 months of the attack.