Neuromyelitis Optica Spectrum Disorders

The association between dietary inflammatory index and risk of neuromyelitis optica spectrum disorder: a case-control study

BACKGROUND AND AIM

Neuromyelitis optica spectrum disorder (NMOSD) is a severe and rare inflammatory disease affecting the central nervous system through optic neuritis and transverse myelitis. Present study aimed to investigate the association between dietary inflammatory index (DII) and risk of NMOSD.

METHODS

In this case-control study, 30 NMOSD cases and 90 aged matched healthy individuals were recruited. Habitual dietary intakes were assessed by a validated 168-item food frequency questionnaire to calculate the DII score. A multiple adjusted regression was used to determine the odd ratio (OR) of NMOSD across DII tertiles. The Residual method was applied to adjust the energy intake.

RESULTS

Participants in the top of DII tertile were more likely to have NMOSD in the crude model compared to those with the lowest one (OR: 4.18; 95%CI: 1.43-12.21). It was the case when multivariable confounders were considered in adjustment model I (OR: 3.98; 95%CI: 1.34-11.82) and II (OR: 4.43; 95%CI: 1.36-14.38), such that, individuals with a greater DII score had 3.98 and 4.43-time higher risk of NMOSD in model I and II, respectively.

CONCLUSION

The Present study suggests that greater adherence to a pro-inflammatory diet may be associated with an increased risk of NMOSD.

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.

It Looks Like a Spinal Cord Tumor but It Is Not

Differentiating neoplastic from non-neoplastic spinal cord pathologies may be challenging due to overlapping clinical and radiological features. Spinal cord tumors, which comprise only 2-4% of central nervous system tumors, are rarer than non-tumoral myelopathies of inflammatory, vascular, or infectious origins. The risk of neurological deterioration and the high rate of false negatives or misdiagnoses associated with spinal cord biopsies require a cautious approach. Facing a spinal cord lesion, prioritizing more common non-surgical myelopathies in differential diagnoses is essential. A comprehensive radiological diagnostic approach is mandatory to identify spinal cord tumor mimics. The diagnostic process involves a multi-step approach: detecting lesions primarily using MRI techniques, precise localization of lesions, assessing lesion signal intensity characteristics, and searching for potentially associated anomalies at spinal cord and cerebral MRI. This review aims to delineate the radiological diagnostic approach for spinal cord lesions that may mimic tumors and briefly highlight the primary pathologies behind these lesions.

ACT001 Relieves NMOSD Symptoms by Reducing Astrocyte Damage with an Autoimmune Antibody

Neuromyelitis optica spectrum disorder (NMOSD) is a central nervous system inflammatory demyelinating disease, the pathogenesis of which involves autoantibodies targeting the extracellular epitopes of aquaporin-4 on astrocytes. We neutralized the AQP4-IgG from NMOSD patient sera using synthesized AQP4 extracellular epitope peptides and found that the severe cytotoxicity produced by aquaporin-4 immunoglobin (AQP4-IgG) could be blocked by AQP4 extracellular mimotope peptides of Loop A and Loop C in astrocyte protection and animal models. ACT001, a natural compound derivative, has shown anti-tumor activity in various cancers. In our study, the central nervous system anti-inflammatory effect of ACT001 was investigated. The results demonstrated the superior astrocyte protection activity of ACT001 at 10 µM. Furthermore, ACT001 decreases the behavioral score in the mouse NMOSD model, which was not inferior to Methylprednisolone Sodium Succinate, the first-line therapy of NMOSD in clinical practice. In summary, our study showed that astrocytes are protected by specific peptides, or small molecular drugs, which is a new strategy for the treatment of NMOSD. It is possible for ACT001 to be a promising therapy for NMOSD.

Neuroimaging features in inflammatory myelopathies: A review

Spinal cord involvement can be observed in the course of immune-mediated disorders. Although multiple sclerosis (MS) represents the leading cause of inflammatory myelopathy, an increasing number of alternative etiologies must be now considered in the diagnostic work-up of patients presenting with myelitis. These include antibody-mediated disorders and cytotoxic T cell-mediated diseases targeting central nervous system (CNS) antigens, and systemic autoimmune conditions with secondary CNS involvement. Even though clinical features are helpful to orient the diagnostic suspicion (e.g., timing and severity of myelopathy symptoms), the differential diagnosis of inflammatory myelopathies is often challenging due to overlapping features. Moreover, noninflammatory etiologies can sometimes mimic an inflammatory process. In this setting, magnetic resonance imaging (MRI) is becoming a fundamental tool for the characterization of spinal cord damage, revealing a pictorial scenario which is wider than the clinical manifestations. The characterization of spinal cord lesions in terms of longitudinal extension, location on axial plane, involvement of the white matter and/or gray matter, and specific patterns of contrast enhancement, often allows a proper differentiation of these diseases. For instance, besides classical features, such as the presence of longitudinally extensive spinal cord lesions in patients with aquaporin-4-IgG positive neuromyelitis optica spectrum disorder (AQP4+NMOSD), novel radiological signs (e.g., H sign, trident sign) have been recently proposed and successfully applied for the differential diagnosis of inflammatory myelopathies. In this review article, we will discuss the radiological features of spinal cord involvement in autoimmune disorders such as MS, AQP4+NMOSD, myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), and other recently characterized immune-mediated diseases. The identification of imaging pitfalls and mimics that can lead to misdiagnosis will also be examined. Since spinal cord damage is a major cause of irreversible clinical disability, the recognition of these radiological aspects will help clinicians achieve a correct and prompt diagnosis, treat early with disease-specific treatment and improve patient outcomes.

Post COVID-19 vaccination neuromyelitis optica spectrum disorder: Case report & MRI findings

There are rising concerns among the medical community and the public regarding the side effects of different vaccines developed throughout the world and their short and long-term effects, particularly COVID19 vaccines. Most notably, post-vaccination demyelinating diseases such as acute disseminated encephalomyelitis, transverse myelitis, and multiple sclerosis relapses have been reported. We present a case of a 32-year-old male who presented with a 2 weeks history of acute confusional state and imbalance 1 week after receiving the second dose of COVID19 vaccination. MRI findings showed typical distribution of neuromyelitis optica spectrum disorder and the patient was positive for AQP4 IgG. The pathogenesis behind developing neuromyelitis optica and vaccines is still unknown. Few case reports have been reported of post-vaccination neuromyelitis optica spectrum disorder but to our knowledge, this would be the first case published of neuromyelitis optica following exposure to COVID19 vaccine.

Neuromyelitis optica spectrum disorders: A nationwide Portuguese clinical epidemiological study

INTRODUCTION

Neuromyelitis optica spectrum disorder (NMOSD) is a rare disorder in which astrocyte damage and/or demyelination often cause severe neurological deficits.

OBJECTIVE

To identify Portuguese patients with NMOSD and assess their epidemiological/clinical characteristics.

METHODS

This was a nationwide multicenter study. Twenty-four Portuguese adult and 3 neuropediatric centers following NMOSD patients were included.

RESULTS

A total of 180 patients met the 2015 Wingerchuk NMOSD criteria, 77 were AQP4-antibody positive (Abs+), 67 MOG-Abs+, and 36 seronegative. Point prevalence on December 31, 2018 was 1.71/100,000 for NMOSD, 0.71/100,000 for AQP4-Abs+, 0.65/100,000 for MOG-Abs+, and 0.35/100,000 for seronegative NMOSD. A total of 44 new NMOSD cases were identified during the two-year study period (11 AQP4-Abs+, 27 MOG-Abs+, and 6 seronegative). The annual incidence rate in that period was 0.21/100,000 person-years for NMOSD, 0.05/100,000 for AQP4-Abs+, 0.13/100,000 for MOG-Abs+, and 0.03/100,000 for seronegative NMOSD. AQP4-Abs+ predominated in females and was associated with autoimmune disorders. Frequently presented with myelitis. Area postrema syndrome was exclusive of this subtype, and associated with higher morbidity/mortality than other forms of NMOSD. MOG-Ab+ more often presented with optic neuritis, required less immunosuppression, and had better outcome.

CONCLUSION

Epidemiological/clinical NMOSD profiles in the Portuguese population are similar to other European countries.

The Potential Immunoregulatory Roles of Vitamin D in Neuromyelitis Optica Spectrum Disorder

Neuromyelitis optica spectrum disorder (NMOSD) is an autoantibody-mediated disease affecting the central nervous system (CNS). Its pathogenesis involves both innate and acquired immune reactions; specific antibody (Aquaporin-4 antibody) and inflammatory cells cause direct damage on lesion sites, while B cell-T cell interactions facilitate the demyelination. However, its etiology is still not fully understood. Vitamin D deficiency is present in numerous autoimmune diseases, including NMOSD. Evidence suggests that low vitamin D levels mayassociate with disease activity and relapse rate in NMOSD, indicating the participation in the pathogenesis of NMOSD. The immunoregulatory roles of vitamin D in both numerous autoimmune diseases and experimental autoimmune encephalomyelitis (EAE) models are increasingly recognized. Recent studies have revealed vitamin D modulation in cytokine production, immune cell development and differentiation, as well as antibody production. By enhancing an anti-inflammatory environment and suppressing the overactivated autoimmune process, vitamin D shows its potential immunoregulatory roles in NMOSD, which could possibly introduce a new therapy for NMOSD patients.

Neuromyelitis Optica Spectrum Disorder and Other Non-Multiple Sclerosis Central Nervous System Inflammatory Diseases

PURPOSE OF REVIEW

This article reviews the clinical features, diagnostic approach, treatment, and prognosis of central nervous system inflammatory diseases that mimic multiple sclerosis (MS), including those defined by recently discovered autoantibody biomarkers.

RECENT FINDINGS

The discovery of autoantibody biomarkers of inflammatory demyelinating diseases of the central nervous system (aquaporin-4 IgG and myelin oligodendrocyte glycoprotein IgG) and the recognition that, despite some overlap, their clinical phenotypes are distinct from MS have revolutionized this field of neurology. These autoantibody biomarkers assist in diagnosis and have improved our understanding of the underlying disease pathogenesis. This has allowed targeted treatments to be translated into clinical trials, three of which are now under way in aquaporin-4 IgG-seropositive neuromyelitis optica (NMO) spectrum disorder.

SUMMARY

Knowledge of the clinical attributes, MRI findings, CSF parameters, and accompanying autoantibody biomarkers can help neurologists distinguish MS from its inflammatory mimics. These antibody biomarkers provide critical diagnostic and prognostic information and guide treatment decisions. Better recognition of the clinical, radiologic, and laboratory features of other inflammatory MS mimics that lack autoantibody biomarkers has allowed us to diagnose these disorders faster and initiate disease-specific treatments more expeditiously.

Neuromyelitis optica spectrum disorders in Arabian Gulf (NMOAG); establishment and initial characterization of a patient registry

OBJECTIVE

To describe the clinical and radiological characteristics of neuromyelitis optica spectrum disorders (NMOSD) patients from the Arabian Gulf relative to anti-aquaporin 4 antibody serostatus.

METHODS

Retrospective multicentre study of hospital records of patients diagnosed with NMOSD based on 2015 International Panel on NMOSD Diagnosis (IPND) consensus criteria.

RESULTS

One hundred forty four patients were evaluated, 64.3% were anti-AQP4 antibody positive. Mean age at onset and disease duration were 31±12 and 7 ± 6 years respectively. Patients were predominantly female (4.7:1). Overall; relapsing course (80%) was more common than monophasic (20%). Optic neuritis was the most frequent presentation (48.6%), regardless of serostatus. The proportion of patients (54.3%) with visual acuity of ≤ 0.1 was higher in the seropositive group (p = 0.018). Primary presenting symptoms of transverse myelitis (TM) were observed in 29% of patients, and were the most significant correlate of hospitalization (p<0.001). Relative to anti-APQ4 serostatus, there were no significant differences in terms of age of onset, course, relapse rates or efficacy outcomes except for oligoclonal bands (OCB), which were more often present in seronegative patients (40% vs.22.5%; p = 0.054). Irrespective of serostatus, several disease modifying therapies were instituted including steroids or immunosuppressives, mostly, rituximab and azathioprine in the cohort irrespective of serostatus. The use of rituximab resulted in reduction in disease activity.

CONCLUSION

This is the first descriptive NMOSD cohort in the Arabian Gulf region. Seropositive patients were more prevalent with female predominance. Relapsing course was more common than monophasic. However, anti-AQP4 serostatus did not impact disease duration, relapse rate or therapeutic effectiveness. These findings offer new insights into natural history of NMOSD in patients of the Arabian Gulf and allow comparison with patient populations in different World regions.

Dietary total antioxidant capacity and neuromyelitis optica spectrum disorder susceptibility

Purpose

Neuromyelitis Optica Spectrum Disorder (NMOSD) is a rare disease with unknown risk factors. The role of oxidative stress and nutritional factors is imprecise in NMOSD development. Therefore, this paper aims to evaluate the effects of dietary total antioxidant capacity (TAC) on the odds of NMOSD.

Design/methodology/approach

Dietary TAC was determined in 70 definite NMOSD cases and 164 healthy controls in term of Ferric Reducing Antioxidant Power (FRAP) method. A validated 168-item semi-quantitative food frequency questionnaire (FFQ) was used for dietary assessment. Three multivariate regression models were applied to analyze the odds of NMOSD across the TAC quartiles.

Findings

A significant inverse association was found between dietary TAC and odds of being assigned to the NMOSD group in all three regression models. In the fully adjusted model ORs (95% CI) in the second, third and fourth quartiles of TAC vs the first quartile were as follows: 0.11 (0.04-0.29), 0.05 (0.01-0.16) and 0.01 (0.00-0.05), respectively. Odds of NMOSD also indicated a significant decreasing trend across the quartiles of dietary TAC (p-trend: <0.01). Total energy (p < 0.01) as well as consumption of vegetables (p < 0.01), whole grains (p < 0.01), tea and coffee (p < 0.01), legumes (p < 0.01) and poultry (p < 0.01) significantly increased through the TAC quartiles.

Originality/value

In the present study, a new hypothesis was proposed concerning the influence of dietary TAC on the odds of NMOSD. A diet rich in foods with high TAC can be effective in the modification of the NMOSD odds.

Epidemiology of neuromyelitis optica spectrum disorder in Denmark (1998-2008, 2007-2014)

Epidemiological studies of the uncommon disorder neuromyelitis optica spectrum disorder (NMOSD) may be difficult to interpret because of the evolving nature of diagnostic criteria, differences in the definition and accuracy of NMOSD diagnosis, the completeness of case ascertainment, and variability in assays for the disease-specific biomarker aquaporin-4 (AQP4)-IgG. A sub-group of patients with the clinical syndrome NMOSD lack detectable AQP4-IgG and in these cases an accurate diagnosis requires precise diagnostic algorithms and longitudinal follow-up. Consecutive sets of criteria for NMO/NMOSD have been introduced during the two last decades. Such criteria need validation in different populations. Detection of other autoantibodies, such as IgG specific for myelin oligodendrocyte glycoprotein or for glial fibrillary acidic protein in a sub-group of AQP4-IgG-negative NMOSD patients, has improved over the past decade and may lead to overlap of the clinical syndromes/phenotypes. This review begins by summarizing current knowledge on the widening clinical spectrum of NMOSD. Subsequently, we describe two epidemiological studies from Denmark carried out in two different decades (1998-2008 and 2007-2014) and comment on the differences in study design, patient ascertainment, and interpretation of results. These factors may explain some of the observed differences, reflecting the complexity and providing a clear example of this development.

Infectious encephalitis: mimics and chameleons

Click here to listen to the Podcast 'Query encephalitis' is a common neurological consultation in hospitalised patients. Identifying the syndrome is only part of the puzzle. Although historically encephalitis has been almost synonymous with infection, we increasingly recognise parainfectious or postinfectious as well as other immune-mediated causes. We must also distinguish encephalitis from other causes of encephalopathy, including systemic infection, metabolic derangements, toxins, inherited metabolic disorders, hypoxia, trauma and vasculopathies. Here, we review the most important differential diagnoses (mimics) of patients presenting with an encephalitic syndrome and highlight some unusual presentations (chameleons) of infectious encephalitis.

NEUROMYELITIS OPTICA SPECTRUM DISORDERS: DIAGNOSIS AND TREATMENT, THE EXPERIENCE OF CLINICAL OBSERVATIONS

Neuromyelitis optica spectrum disorder (NMOSD) is an aggregate of inflammatory and autoimmune disorders of the central nervous system characterized by recurrent, disabling clinical course and damages predominantly targeting optic nerves, brain stem and spinal cord. NMOSD is stratified into two types: seropositive for aquaporin-4 antibodies (AQP4-IgG) and seronegative, which is reported in 25 % of cases. This article presents modern conceptualizations of NMOSD and describes authors’ own experience of clinical observation of patients.

Neuromyelitis Optica Spectrum Disorders: Spectrum of MR Imaging Findings and Their Differential Diagnosis

Neuromyelitis optica (NMO) is an autoimmune demyelinating disorder for which the aquaporin-4 (AQP4) water channels are the major target antigens. Advances in the understanding of NMO have clarified several points of its pathogenesis, clinical manifestations, and imaging patterns. A major advance was the discovery of the AQP4 antibody, which is highly specific for this disorder. Descriptions of new clinical and radiologic features in seropositive patients have expanded the spectrum of NMO, and the term NMO spectrum disorder (NMOSD) has been adopted. NMOSD is now included in a widening list of differential diagnoses. Acknowledgment of NMOSD imaging patterns and their mimicry of disorders has been crucial in supporting early NMOSD diagnosis, especially for unusual clinical manifestations of this demyelinating disease. This pictorial review summarizes the wide imaging spectrum of NMOSD and its differential diagnosis, as well as its historical evolution, pathophysiology, and clinical manifestations. ^©RSNA, 2018.

Importance of Regular and Maintenance Therapy Adherence in Neuromyelitis Optica (NMO): Lessons from a Repeating Relapse Case

Patient: Female, 58

Final Diagnosis: NMO

Symptoms: New-onset right leg weakness and pain

Medication: —

Clinical Procedure: Progressive and recurring

Specialty: Neurology

Evaluation of idiopathic transverse myelitis revealing specific myelopathy diagnoses

Objective

To evaluate specific myelopathy diagnoses made in patients with suspected idiopathic transverse myelitis (ITM).

Methods

A total of 226 patients 18 years and older were referred to Mayo Clinic Neurology for suspected ITM from December 1, 2010, to December 31, 2015. Electronic medical records were reviewed for detailed clinical presentation and course, laboratory and electrophysiologic investigations, and neuroimaging to determine the etiology. Current diagnostic criteria for ITM and alternative myelopathy diagnoses were applied. All cases where any discrepancy was suspected from the final reported clinical diagnosis were reviewed by each author and a consensus final diagnosis was made.

Results

The diagnostic criteria for ITM were met in 41 of 226 patients (18.1%). In 158 patients (69.9%), an alternative specific myelopathy diagnosis was made: multiple sclerosis or clinically isolated syndrome, 75; vascular myelopathy, 41; neurosarcoidosis, 12; neuromyelitis optica spectrum disorder, 12; myelin oligodendrocyte glycoprotein myelopathy, 5; neoplastic, 4; compressive, 3; nutritional, 3; infectious, 2; and other, 2. A myelopathy was not confirmed in 27 patients. Time from symptom onset to final clinical diagnosis in patients without ITM was a median of 9 months (range 0–288). Fifty-five patients (24%) required treatment changes according to their final clinical diagnosis.

Conclusions

The majority of patients with suspected ITM have an alternative specific myelopathy diagnosis. A presumptive diagnosis of ITM can lead to premature diagnostic conclusions affecting patient treatment.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice-Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Seventh Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating, and categorizing indications for the evidence-based use of therapeutic apheresis in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the Committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Seventh Edition of the JCA Special Issue continues to maintain this methodology and rigor to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Seventh Edition, like its predecessor, has consistently applied the category and grading system definitions in the fact sheets. The general layout and concept of a fact sheet that was used since the fourth edition has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis in a specific disease entity. The Seventh Edition discusses 87 fact sheets (14 new fact sheets since the Sixth Edition) for therapeutic apheresis diseases and medical conditions, with 179 indications, which are separately graded and categorized within the listed fact sheets. Several diseases that are Category IV which have been described in detail in previous editions and do not have significant new evidence since the last publication are summarized in a separate table. The Seventh Edition of the JCA Special Issue serves as a key resource that guides the utilization of therapeutic apheresis in the treatment of human disease. J. Clin. Apheresis 31:149-162, 2016. © 2016 Wiley Periodicals, Inc.

Ring-enhancing spinal cord lesions in neuromyelitis optica spectrum disorders

OBJECTIVE

We assessed the frequency and characteristics of ring-enhancing spinal cord lesions in neuromyelitis optica spectrum disorder (NMOSD) myelitis and myelitis of other cause.

METHODS

We reviewed spinal cord MRIs for ring-enhancing lesions from 284 aquaporin-4 (AQP4)-IgG seropositive patients at Mayo Clinic from 1996 to 2014. Inclusion criteria were as follows: (1) AQP4-IgG seropositivity, (2) myelitis attack and (3) MRI spinal cord demonstrating ring-enhancement. We identified two groups of control patients with: (1) longitudinally extensive myelopathy of other cause (n=66) and (2) myelitis in the context of a concurrent or subsequent diagnosis of multiple sclerosis (MS) from a population-based cohort (n=30).

RESULTS

Ring-enhancement was detected in 50 of 156 (32%) myelitis episodes in 41 patients (83% single; 17% multiple attacks). Ring-enhancement was noted on sagittal and axial images in 36 of 43 (84%) ring enhancing myelitis episodes and extended a median of two vertebral segments (range, 1-12); in 21 of 48 (44%) ring enhancing myelitis episodes, the ring extended greater than or equal to three vertebrae. Ring-enhancement was accompanied by longitudinally extensive (greater than or equal to three vertebral segments) T2-hyperintensity in 44 of 50 (88%) ring enhancing myelitis episodes. One case of a spinal cord biopsy during ring-enhancing myelitis revealed tissue vacuolation and loss of AQP4 immunoreactivity with preserved axons. The clinical characteristics of ring-enhancing myelitis episodes did not differ from non-ring-enhancing episodes. Ring-enhancing spinal cord lesions were more common in NMOSD than other causes of longitudinally extensive myelopathy (50/156 (32%) vs 0/66 (0%); p≤0.001) but did not differ between NMOSD and MS (50/156 (32%) vs 6/30 (20%); p=0.20).

CONCLUSIONS

Spinal cord ring-enhancement accompanies one-third of NMOSD myelitis episodes and distinguishes NMOSD from other causes of longitudinally extensive myelopathies but not from MS.

Diagnosis and management of spinal cord emergencies

Most spinal cord injury is seen with trauma. Nontraumatic spinal cord emergencies are discussed in this chapter. These myelopathies are rare but potentially devastating neurologic disorders. In some situations prior comorbidity (e.g., advanced cancer) provides a clue, but in others (e.g., autoimmune myelopathies) it may come with little warning. Neurologic examination helps distinguish spinal cord emergencies from peripheral nervous system emergencies (e.g., Guillain-Barré), although some features overlap. Neurologic deficits are often severe and may quickly become irreversible, highlighting the importance of early diagnosis and treatment. Emergent magnetic resonance imaging (MRI) of the entire spine is the imaging modality of choice for nontraumatic spinal cord emergencies and helps differentiate extramedullary compressive causes (e.g., epidural abscess, metastatic compression, epidural hematoma) from intramedullary etiologies (e.g., transverse myelitis, infectious myelitis, or spinal cord infarct). The MRI characteristics may give a clue to the diagnosis (e.g., flow voids dorsal to the cord in dural arteriovenous fistula). However, additional investigations (e.g., aquaporin-4-IgG) are often necessary to diagnose intramedullary etiologies and guide treatment. Emergency decompressive surgery is necessary for many extramedullary compressive causes, either alone or in combination with other treatments (e.g., radiation) and preoperative neurologic deficit is the best predictor of outcome.

An update on the evidence for the efficacy and safety of rituximab in the management of neuromyelitis optica

Neuromyelitis optica spectrum disorders (NMOSDs) is a new concept which includes classical neuromyelitis optica (NMO) and partial forms of NMO such as recurrent optic neuritis with positive aquaporin-4 antibodies (AQP4) or brainstem symptoms (intractable hiccups or vomiting). This disease is clearly distinguished from multiple sclerosis (MS) and the therapeutic approach is clearly different. Rituximab is actually considered to be one of the most efficient treatments of NMOSD, even if class I studies are clearly lacking. In the present review, we describe the state of the art about rituximab treatment in NMOSD, including adults and children, plus its efficacy and tolerance and we also underline the questions that should be addressed in the near future.

Epidemiology of aquaporin-4 autoimmunity and neuromyelitis optica spectrum

OBJECTIVE

Neuromyelitis optica (NMO) and its spectrum disorders (NMOSD) are inflammatory demyelinating diseases (IDDs) with a specific biomarker, aquaporin-4-immunoglobulin G (AQP4-IgG). Prior NMO/NMOSD epidemiological studies have been limited by lack of AQP4-IgG seroprevalence assessment, absence of population-based USA studies, and under-representation of blacks. To overcome these limitations, we sought to compare NMO/NMOSD seroepidemiology across 2 ethnically divergent populations.

METHODS

We performed a population-based comparative study of the incidence (2003-2011) and prevalence (on December 31, 2011) of NMO/NMOSD and AQP4-IgG seroincidence and seroprevalence (sera collected in 80-84% of IDD cases) among patients with IDD diagnosis in Olmsted County, Minnesota (82% white [Caucasian]) and Martinique (90% black [Afro-Caribbean]). AQP4-IgG was measured by M1 isoform fluorescence-activated cell-sorting assays.

RESULTS

The age- and sex-adjusted incidence (7.3 vs 0.7/1,000,000 person-years [p < 0.01]) and prevalence (10 vs 3.9/100,000 [p = 0.01]) in Martinique exceeded that in Olmsted County. The AQP4-IgG age- and sex-adjusted seroincidence (6.5 vs 0.7/1,000,000 person-years [p < 0.01]) and seroprevalence (7.9 vs 3.3/100,000 [p = 0.04]) were also higher in Martinique than Olmsted County. The ethnicity-specific prevalence was similar in Martinique and Olmsted County: 11.5 and 13/100,000 in blacks, and 6.1 and 4.0/100,000 in whites, respectively. NMO/NMOSD represented a higher proportion of IDD cases in Martinique than Olmsted County (16% vs 1.4%; p < 0.01). The onset age (median = 35-37 years) and female:male distribution (5-9:1) were similar across both populations; 60% of prevalent cases were either blind in 1 eye, dependent on a gait aid, or both.

INTERPRETATION

This study reports the highest prevalence of NMO/NMOSD in any population (10/100,000 in Martinique), estimates it affects 16,000 to 17,000 in the USA (higher than previous predictions), and demonstrates it disproportionately affects blacks. Ann Neurol 2016;79:775-783.

Circulating Memory T Follicular Helper Cells in Patients with Neuromyelitis Optica/Neuromyelitis Optica Spectrum Disorders

OBJECTIVE

This study aimed to examine the potential role of memory T follicular helper (Tfh) cells in patients with neuromyelitis optica/neuromyelitis optica spectrum disorders (NMO/NMOSD).

METHODS

The percentages of different subsets of circulating memory Tfh cells in 25 NMO/NMOSD patients before and after treatment as well as in 17 healthy controls were examined by flow cytometry. The levels of IL-21 and AQP4 Ab in plasma and CSF were measured by ELISA.

RESULTS

The percentages and numbers of circulating memory Tfh cells, ICOS(+), CCR7(-), CCR7(-)ICOS(+), CCR7(+), CCR7(+)ICOS(+) memory Tfh cells, and the levels of IL-21 in plasma and CSF were significantly increased in NMO/NMOSD patients. The percentages of CCR7(-) and CCR7(-)ICOS(+) memory Tfh cells were positively correlated with ARR, plasma IL-21, and AQP4 Ab levels. The percentages of CCR7(+) and CCR7(+)ICOS(+) memory Tfh cells were positively correlated with CSF white blood cell counts, proteins, and IL-21 levels. Treatment with corticosteroids significantly reduced the numbers of CCR7(-)ICOS(+) and CCR7(+)ICOS(+) memory Tfh cells as well as plasma IL-21 levels in patients with partial remission.

CONCLUSIONS

Our findings indicate that circulating memory Tfh cells may participate in the relapse and development of NMO/NMOSD and may serve as a new therapeutic target.

Discriminating long myelitis of neuromyelitis optica from sarcoidosis

OBJECTIVE

To compare longitudinally extensive myelitis in neuromyelitis optica spectrum disorders (NMOSD) and spinal cord sarcoidosis (SCS).

METHODS

We identified adult patients evaluated between 1996 and 2015 with SCS or NMOSD whose first myelitis episode was accompanied by a spinal cord lesion spanning ≥3 vertebral segments. All NMOSD patients were positive for aquaporin-4-immunoglobulin G, and all sarcoidosis cases were pathologically confirmed. Clinical characteristics were evaluated. Spine magnetic resonance imaging was reviewed by 2 neuroradiologists.

RESULTS

We studied 71 patients (NMOSD, 37; SCS, 34). Sixteen (47%) SCS cases were initially diagnosed as NMOSD or idiopathic transverse myelitis. Median delay to diagnosis was longer for SCS than NMOSD (5 vs 1.5 months, p < 0.01). NMOSD myelitis patients were more commonly women, had concurrent or prior optic neuritis or intractable vomiting episodes more frequently, had shorter time to maximum deficit, and had systemic autoimmunity more often than SCS (p < 0.05). SCS patients had constitutional symptoms, cerebrospinal fluid (CSF) pleocytosis, and hilar adenopathy more frequently than NMOSD (p < 0.05); CSF hypoglycorrhachia (11%, p = 0.25) and elevated angiotensin-converting enzyme (18%, p = 0.30) were exclusive to SCS. Dorsal cord subpial gadolinium enhancement extending ≥2 vertebral segments and persistent enhancement >2 months favored SCS, and ringlike enhancement favored NMOSD (p < 0.05). Maximum disability was similar in both disorders.

INTERPRETATION

SCS is an under-recognized cause of longitudinally extensive myelitis that commonly mimics NMOSD. We identified clinical, laboratory, systemic, and radiologic features that, taken together, help discriminate SCS from NMOSD.

Autoimmune myelopathies

Autoimmune myelopathies are a heterogeneous group of immune-mediated spinal cord disorders with a broad differential diagnosis. They encompass myelopathies with an immune attack on the spinal cord (e.g., aquaporin-4-IgG (AQP4-IgG) seropositive neuromyelitis optica (NMO) and its spectrum disorders (NMOSD)), myelopathies occurring with systemic autoimmune disorders (which may also be due to coexisting NMO/NMOSD), paraneoplastic autoimmune myelopathies, postinfectious autoimmune myelopathies (e.g., acute disseminated encephalomyelitis), and myelopathies thought to be immune-related (e.g., multiple sclerosis and spinal cord sarcoidosis). Spine magnetic resonance imaging is extremely useful in the evaluation of autoimmune myelopathies as the location of signal change, length of the lesion, gadolinium enhancement pattern, and evolution over time narrow the differential diagnosis considerably. The recent discovery of multiple novel neural-specific autoantibodies accompanying autoimmune myelopathies has improved their classification. These autoantibodies may be pathogenic (e.g., AQP4-IgG) or nonpathogenic and more reflective of a cytotoxic T-cell-mediated autoimmune response (collapsin response mediator protein-5(CRMP5)-IgG). The presence of an autoantibody may help guide cancer search, assist treatment decisions, and predict outcome/relapse. With paraneoplastic myelopathies the initial goal is detection and treatment of the underlying cancer. The aim of immunotherapy in all autoimmune myelopathies is to maximize reversibility, maintain benefits (while preventing relapse), and minimize side effects.

Neuromyelitis optica shorter lesion can cause important pyramidal deficits

OBJECTIVE

Evaluate the correlation between spinal cord lesion length and pyramidal function system score in a cohort of patients with NMO.

METHODOLOGY

Retrospective retrieval of all exams performed in our center from January 2004 to December 2012 for patients with NMO. The exams were evaluated for lesion length, contrast enhancement and T1 hypointensity; these variables were correlated with the functional system score from the EDSS, performed no more than three months from the scan.

RESULTS

41 patients were included. Although patients with lesion extension ≥2 vertebral segments did not present worse pyramidal scores in a direct comparison, the influence of lesion length was not so strong when patients were separated in 3 groups (≥2, ≥3 or ≥4 vertebral segments) and evaluated with a receiving operating characteristics (ROC) curves. Gadolinium enhancement also contributed to more severe pyramidal system scores, but T1 hypointensity did not.

CONCLUSION

Although patients with spinal cord lesion extending ≥3 vertebral segments had more pyramidal disability, its difference was not so strong when compared to patients with ≥2 or ≥4 vertebral segments. This suggests that lesion extension might not be the most important factor in favoring a worse prognosis in spinal cord lesions in NMO.

Seronegative Neuromyelitis Optica Spectrum Disorder following Exposure to Hepatitis B Vaccination

Controversy exists regarding a potential link between exposure to recombinant hepatitis B vaccine (HBV) and central nervous system demyelinating diseases. Here, we present a case of seronegative neuromyelitis optica spectrum disorder (NMOSD) following exposure to HBV. A 28-year-old man developed painful eye movements 11 days after exposure to HBV. Within 24 h, he experienced vision loss, ascending numbness, and ataxia. T-spine MRI showed a cord lesion spanning T6–T9. Brain MRI showed bilateral optic nerve contrast enhancement and a right-sided internal capsule lesion. Cerebrospinal fluid analysis was normal, including negative oligoclonal bands and normal IgG index. AQP4-IgG serology was negative. The patient's visual symptoms improved after treatment with steroids and plasma exchange. He received plasma exchange weekly for 4 weeks with decreased numbness and tingling as well as improved coordination. Treatment with mycophenolate mofetil was started, and the patient remains clinically stable with near resolution of his prior symptoms. Neuromyelitis optica is characterized by optic neuritis and/or longitudinally extensive transverse myelitis. While our patient tested seronegative for AQP4-IgG (which remains negative in 10–50% of NMOSD cases, despite testing with the most sensitive assays available), he did meet NMOSD diagnostic criteria. In a literature review, we found 7 cases of NMOSD onset or relapse associated with exposure to various vaccines, but to our knowledge this represents the first published report of NMOSD onset following exposure to HBV. While causality between vaccination and CNS demyelinating disease remains elusive, it is important to report these cases to help develop safer vaccinations and provoke further inquiry into the pathogenesis of NMOSD.

Follicular Helper CD4+ T Cells in Human Neuroautoimmune Diseases and Their Animal Models

Follicular helper CD4+ T (TFH) cells play a fundamental role in humoral immunity deriving from their ability to provide help for germinal center (GC) formation, B cell differentiation into plasma cells and memory cells, and antibody production in secondary lymphoid tissues. TFH cells can be identified by a combination of markers, including the chemokine receptor CXCR5, costimulatory molecules ICOS and PD-1, transcription repressor Bcl-6, and cytokine IL-21. It is difficult and impossible to get access to secondary lymphoid tissues in humans, so studies are usually performed with human peripheral blood samples as circulating counterparts of tissue TFH cells. A balance of TFH cell generation and function is critical for protective antibody response, whereas overactivation of TFH cells or overexpression of TFH-associated molecules may result in autoimmune diseases. Emerging data have shown that TFH cells and TFH-associated molecules may be involved in the pathogenesis of neuroautoimmune diseases including multiple sclerosis (MS), neuromyelitis optica (NMO)/neuromyelitis optica spectrum disorders (NMOSD), and myasthenia gravis (MG). This review summarizes the features of TFH cells, including their development, function, and roles as well as TFH-associated molecules in neuroautoimmune diseases and their animal models.