Pediatric NMOSD: A Review and Position Statement on Approach to Work-Up and Diagnosis

Predictors of relapse risk and treatment response in AQP4-IgG positive and seronegative NMOSD: A multicentre study

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) can be categorised into aquaporin-4 antibody (AQP4-IgG) NMOSD or seronegative NMOSD. While our knowledge of AQP4-IgG NMOSD has evolved significantly in the past decade, seronegative NMOSD remains less understood. This study aimed to evaluate the predictors of relapses and treatment responses in AQP4-IgG NMOSD and seronegative NMOSD.

METHODS

This was a multicentre, international, retrospective cohort study using the MSBase registry. Recurrent relapse risk was assessed using an Andersen-Gill model and risk of first relapse was evaluated using a Cox proportional hazards model. Covariates that putatively influence relapse risk included demographic factors, clinical characteristics and immunosuppressive therapies; the latter was assessed as a time-varying covariate.

RESULTS

A total of 398 patients (246 AQP4-IgG NMOSD and 152 seronegative NMOSD) were included. The AQP4-IgG NMOSD and seronegative NMOSD patients did not significantly differ by age at disease onset, ethnicity or annualised relapse rate. Both low-efficacy and high-efficacy immunosuppressive therapies were associated with significant reductions in recurrent relapse risk, with notably greater protection conferred by high-efficacy therapies in both AQP4-IgG NMOSD (HR 0.27, 95% CI 0.15 to 0.49, p<0.001) and seronegative NMOSD (HR 0.21, 95% CI 0.08 to 0.51, p<0.001). Longer disease duration (HR 0.97, 95% CI 0.95 to 0.99, p<0.001) and male sex (HR 0.52, 95% CI 0.34 to 0.84, p=0.007) were additional protective variables in reducing the recurrent relapse risk for the AQP4-IgG NMOSD group.

CONCLUSION

Although further studies are needed to improve our understanding of seronegative NMOSD, our findings underscore the importance of aggressive treatment with high-efficacy immunotherapies in both NMOSD subtypes, regardless of serostatus.

Predictors of a relapsing course in myelin oligodendrocyte glycoprotein antibody-associated disease

BACKGROUND

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a recently described demyelinating disorder, and children represent about 50% of all cases. Almost half of the patients experience relapses, but very few studies have evaluated predictors of relapse risk, challenging clinical management. The study aimed to identify predictors at MOGAD onset that are associated with a relapsing course.

METHODS

Prospectively collected data from paediatric patients with MOGAD seen by the US Network of Paediatric MS Centres were leveraged. Univariable and adjusted multivariable models were used to predict recurrent disease.

RESULTS

We identified 326 MOGAD cases (mean age at first event 8.9 years [SD 4.3], 57% female, 77% white and 74% non-Hispanic) and 46% relapsed during a mean follow-up of 3.9 years (SD 4.1). In the adjusted multivariable model, female sex (HR 1.66, 95% CI 1.17 to 2.36, p=0.004) and Hispanic/Latino ethnicity (HR 1.77, 95% CI 1.19 to 2.64, p=0.005) were associated with a higher risk of relapsing MOGAD. Maintenance treatment initiated before a second event with rituximab (HR 0.25, 95% CI 0.07 to 0.92, p=0.037) or intravenous immunoglobulin (IVIG) (HR 0.35, 95% CI 0.14 to 0.88, p=0.026) was associated with lower risk of a second event in multivariable analyses. Conversely, maintenance steroids were associated with a higher estimated relapse risk (HR 1.76, 95% CI 0.90 to 3.45, p=0.097).

CONCLUSION

Sex and ethnicity are associated with relapsing MOGAD. Use of rituximab or IVIG therapy shortly after onset is associated with a lower risk of the second event. Preventive treatment after a first event could be considered for those with a higher relapse risk.

Case Report: Contiguous presentation of anti-MDA5 juvenile dermatomyositis and anti-AQP4 neuromyelitis optica spectrum disorder in an adolescent patient

Neuromyelitis optica spectrum disorder (NMOSD) is a rare inflammatory disorder of the central nervous system (CNS) that is known to be associated with other neurologic and organ-specific autoimmune conditions. There has been increasing recognition of the association between NMOSD and systemic autoimmune disease, most commonly systemic lupus erythematosus and Sjogren's syndrome. We report a case of an adolescent presenting with anti-melanoma differentiation-associated protein 5 juvenile dermatomyositis (anti-MDA5 JDM) and NMOSD, exhibiting clinical features of myelitis, polyarthritis, myositis, and skin involvement. Currently, only two other published cases have described NMOSD associated with anti-MDA5 dermatomyositis, both in adults. To the best of our knowledge, this is the first reported case in an adolescent patient.

Advances in the long-term treatment of neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune neuroinflammatory disorder with a prevalence of 1-5/100,000 globally, characterized by attacks of the central nervous system including but not limited to optic neuritis, transverse myelitis and brainstem lesions, including area postrema lesions. These autoimmune attacks can lead to irreversible damage if left untreated, therefore strategies have been developed to prevent relapses. Initial off-label treatments have achieved variable levels of success in relapse prevention, but improved relapse prevention and quality of life remain a goal in the field. A better understanding of the underlying pathophysiology of NMOSD over the last 10 years has led to newer, more specific approaches in treatment, culminating in the first FDA approved treatments in the disease. In this review, we will discuss the seminal trials of PREVENT or Eculizumab in the treatment of aquaporin-4 (AQP4)-IgG positive NMOSD, N-Momentum or Inebilizumab in the study of NMOSD (both AQP4-IgG positive and negative) and SAkura Sky and SAkuraStar which studied satralizumab in AQP4-IgG seropositive and seronegative NMOSD patients. We will also discuss the extension trials of each of these medications and what lead to their approval in AQP4-IgG seropositive NMOSD patients. We will then examine treatments in the pipeline for adult and pediatric NMOSD patients and conclude with discussions on treatment considerations in pregnant patients and how to approach treatment of NMOSD patients during COVID.

Monoclonal antibody therapies for aquaporin-4-immunoglobulin G-positive neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein antibody-associated disease

Monoclonal antibody therapies mark the new era of targeted treatment for relapse prevention in aquaporin-4 (AQP4)-immunoglobulin G (IgG)-positive neuromyelitis optica spectrum disorder (AQP4-IgG+NMOSD). For over a decade, rituximab, an anti-CD20 B-cell-depleting agent, had been the most effectiveness treatment for AQP4-IgG+NMOSD. Tocilizumab, an anti-interleukin-6 receptor, was also observed to be effective. In 2019, several randomized, placebo-controlled trials were completed that demonstrated the remarkable efficacy of eculizumab (anti-C5 complement inhibitor), inebilizumab (anti-CD19 B-cell-depleting agent), and satralizumab (anti-interleukin-6 receptor), leading to the Food and Drug Administration (FDA) approval of specific treatments for AQP4-IgG+NMOSD for the first time. Most recently, ravulizumab (anti-C5 complement inhibitor) was also shown to be highly efficacious in an open-label, external-controlled trial. Although only some patients with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) warrant immunotherapy, there is currently no FDA-approved treatment for relapse prevention in MOGAD. Observational studies showed that tocilizumab was associated with a decrease in relapses, whereas rituximab seemed to have less robust effectiveness in MOGAD compared to AQP4-IgG+NMOSD. Herein, we review the evidence on the efficacy and safety of each monoclonal antibody therapy used in AQP4-IgG+NMOSD and MOGAD, including special considerations in children and women of childbearing potential.

Update on the diagnosis and treatment of neuromyelitis optica spectrum disorders (NMOSD) - revised recommendations of the Neuromyelitis Optica Study Group (NEMOS). Part II: Attack therapy and long-term management

This manuscript presents practical recommendations for managing acute attacks and implementing preventive immunotherapies for neuromyelitis optica spectrum disorders (NMOSD), a rare autoimmune disease that causes severe inflammation in the central nervous system (CNS), primarily affecting the optic nerves, spinal cord, and brainstem. The pillars of NMOSD therapy are attack treatment and attack prevention to minimize the accrual of neurological disability. Aquaporin-4 immunoglobulin G antibodies (AQP4-IgG) are a diagnostic marker of the disease and play a significant role in its pathogenicity. Recent advances in understanding NMOSD have led to the development of new therapies and the completion of randomized controlled trials. Four preventive immunotherapies have now been approved for AQP4-IgG-positive NMOSD in many regions of the world: eculizumab, ravulizumab - most recently-, inebilizumab, and satralizumab. These new drugs may potentially substitute rituximab and classical immunosuppressive therapies, which were as yet the mainstay of treatment for both, AQP4-IgG-positive and -negative NMOSD. Here, the Neuromyelitis Optica Study Group (NEMOS) provides an overview of the current state of knowledge on NMOSD treatments and offers statements and practical recommendations on the therapy management and use of all available immunotherapies for this disease. Unmet needs and AQP4-IgG-negative NMOSD are also discussed. The recommendations were developed using a Delphi-based consensus method among the core author group and at expert discussions at NEMOS meetings.

Acquired Demyelinating Syndromes

Acquired demyelinating syndromes (ADS) are a heterogenous group of inflammatory demyelinating conditions that include presentations of optic neuritis, transverse myelitis, and acute demyelinating encephalomyelitis. They can be monophasic or can develop into relapsing episodes of the initial demyelinating event or evolve to include other types of demyelination. Significant progress has been made in differentiating subtypes of ADS that differ in their tendency to relapse and in which anti-inflammatory therapies are effective. Differentiating between these subtypes is important for the optimal management of these patients. Clinical features, labs (especially autoantibodies), and MRI findings can help to differentiate between the different ADS.

Pediatric anti-NMDAR encephalitis with demyelination on brain MRI: A single center study

OBJECTIVE

To explore the clinical characteristics, immunotherapy response, and prognosis of pediatric anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis associated with demyelination on brain magnetic resonance (MRI).

METHODS

We retrospectively reviewed the medical records of children diagnosed with anti-NMDAR encephalitis in our hospital between January 2016 and December 2021. All children with evidence of demyelination on brain MRI were included.

RESULTS

A total of 183 anti-NMDAR encephalitis children were included; 8.7 % (16/183) of them had demyelination on brain MRI. Nine were positive for myelin oligodendrocyte glycoprotein (MOG)-IgG, while two were positive for both MOG-IgG and glial fibrillary acidic protein (GFAP)-IgG. Four patients had a history of acquired demyelinating syndromes and encephalitis, respectively, while nine (56.3 %) had atypical symptoms of anti-NMDAR encephalitis. All children had supratentorial demyelination on brain MRI; four of them had additional infratentorial lesions. All children received first-line immunotherapy; four were administered repeated first-line immunotherapy and/or rituximab because of poor initial response. During the follow-up, 37.5 % (6/16) of the children relapsed, but all responded well to immunotherapy. There were no significant differences in mRS score before immunotherapy, response to first-line immunotherapy, and long-term prognosis between anti-NMDAR encephalitis children with and without demyelination. However, patients with demyelination were more likely to have a history of acquired demyelinating syndromes or unexplained cortical encephalitis and to relapse.

CONCLUSION

Pediatric anti-NMDAR encephalitis can co-occur with demyelination and has a high rate of MOG-IgG positivity. A history of acquired demyelinating syndromes or unexplained cortical encephalitis and atypical symptoms may indicate demyelination in children with anti-NMDAR encephalitis. Pediatric anti-NMDAR encephalitis with demyelination is more likely to relapse and needs a closer follow-up. However, it remains unknown whether more intensive immunotherapy is required in these patients.

Population Pharmacodynamic Modelling of the CD19+ Suppression Effects of Rituximab in Paediatric Patients with Neurological and Autoimmune Diseases

BACKGROUND

Limited pharmacotherapy and the failure of conventional treatments in complex pathologies in children lead to increased off-label use of rituximab. We aimed to characterize the time course of CD19+ B lymphocytes (CD19+) under treatment with intravenous rituximab in children with neurologic and autoimmune diseases and to evaluate the impact of covariates (i.e., demographics, diagnosis and substitution between innovator and biosimilar product) on rituximab pharmacodynamics and disease activity.

METHODS

Pre- and post-drug infusion CD19+ in peripheral blood were prospectively registered. A population pharmacodynamic model describing the time course of CD19+ was developed with NONMEM v7.4. Simulations of three different rituximab regimens were performed to assess the impact on CD19+. Logistic regression analysis was performed to identify predictors of clinical response recorded through disease activity scores.

RESULTS

281 measurements of CD19+ lymphocyte counts obtained from 63 children with neurologic (n = 36) and autoimmune (n = 27) diseases were available. The time course of CD19+ was described with a turn-over model in which the balance between synthesis and degradation rates is disrupted by rituximab, increasing the latter process. The model predicts half-lives (percent coefficient of variation, CV(%)) of rituximab and CD19+ of 11.6 days (17%) and 173.3 days (22%), respectively. No statistically significant effect was found between any of the studied covariates and model parameters (p > 0.05). Simulations of different regimens showed no clinically significant differences in terms of CD19+ repopulation times. A trend towards a lack of clinical response was observed in patients with lower CD19+ repopulation times and higher areas under the CD19+ versus time curve.

CONCLUSIONS

Rituximab pharmacodynamics was described in a real-world setting in children suffering from autoimmune and neurologic diseases. Diagnosis, substitution between innovator rituximab and its biosimilars or type of regimen did not affect rituximab-induced depletion of CD19+ nor the clinical response in this cohort of patients. According to this study, rituximab frequency and dosage may be chosen based on clinical convenience or safety reasons without affecting CD19+ repopulation times. Further studies in larger populations are required to confirm these results.

Pediatric Neuromyelitis Optica Spectrum Disorder

Neuromyelitis Optica Spectrum Disorder (NMOSD) is a demyelinating disease with a high relapse rate and risk of disability accrual. The condition is an astrocytopathy, with antibodies to the aquaporin-4 (AQP4) water channel being detected in AQP4-IgG seropositive disease. Presentation is uncommon in the pediatric age range, accounting for about 3%-5% of cases. NMOSD is more prevalent in populations of Black or East Asian ancestry. Core clinical syndromes include optic neuritis, acute myelitis, area postrema syndrome, acute brainstem syndrome, acute diencephalic syndrome, and symptomatic cerebral syndrome. First-line treatment options in pediatrics include rituximab, azathioprine, and mycophenolate mofetil. Over half of children with AQP4-IgG seropositive NMOSD develop permanent disability, particularly in visual and motor domains. Novel therapeutic targets in the adult population have been developed and are changing the treatment landscape for this disorder.

Can early-onset acquired demyelinating syndrome (ADS) hide pediatric Behcet's disease? A case report

Behcet's disease (BD) is a rare vasculitis characterized by multisystemic inflammation. Central nervous system (CNS) involvement is rare and heterogeneous, particularly in the pediatric population. A diagnosis of neuro-Behcet could be highly challenging, especially if neurological manifestations precede other systemic features; however, its timely definition is crucial to prevent long-term sequelae. In this study, we describe the case of a girl who, at 13 months of age, presented with a first episode of encephalopathy compatible with acute disseminated encephalomyelitis, followed, after 6 months, by a neurological relapse characterized by ophthalmoparesis and gait ataxia, in association with new inflammatory lesions in the brain and spinal cord, suggesting a neuromyelitis optica spectrum disorder. The neurological manifestations were successfully treated with high-dose steroids and intravenous immunoglobulins. In the following months, the patient developed a multisystemic involvement suggestive of Behcet's disease, characterized by polyarthritis and uveitis, associated with HLA-B51 positivity. The challenge presented by this unique case required a multidisciplinary approach involving pediatric neurologists, neuro-radiologists, and pediatric rheumatologists, with all of these specialists creating awareness about early-onset acquired demyelinating syndromes (ADSs). Given the rarity of this presentation, we performed a review of the literature focusing on neurological manifestations in BD and differential diagnosis of patients with early-onset ADS.

The Neutrophil-to-Lymphocyte Ratio and the Monocyte-to-Lymphocyte Ratio Predict Expanded Disability Status Scale Score at One Year in Pediatric Neuromyelitis Optica Spectrum Disorder but not in Multiple Sclerosis

BACKGROUND

The neutrophil-to-lymphocyte ratio (NLR) and monocyte-to-lymphocyte ratio (MLR) are inflammatory biomarkers that may predict disease course in neuroinflammatory diseases. We examine whether NLR or MLR at the time of the first attack predicts longitudinal disease outcomes in pediatric neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS).

METHODS

Clinical data were collected retrospectively at a single institution. NLR (ratio of percent neutrophils to percent lymphocytes) and MLR (ratio of percent monocytes to percent lymphocytes) were calculated in the complete blood cell count at the time of presentation before treatments. Expanded Disability Status Scale (EDSS) score and time to next relapse were used as the outcome assessments.

RESULTS

Twenty-eight patients with MS and eight patients with aquaporin-4-positive NMOSD were included. For NMOSD, NLR at presentation associated with EDSS at six months (P = 0.003) and one year (P = 0.032) even when adjusting for age at presentation. MLR associated with EDSS at six months (P = 0.0203) and EDSS at one year (P = 0.0079). However, NLR and MLR did not predict EDSS scores in MS. MLR and NLR did not predict time to next relapse or did not associate with magnetic resonance imaging activity in MS and NMOSD. Changes in MLR and NLR were observed with disease-modifying therapies but did not predict disease activity.

CONCLUSIONS

NLR and MLR associated with six-month and one-year EDSS in children with NMOSD but not in MS. Future studies should explore whether changes in NLR and MLR could predict disease activity or treatment efficacy.

Pediatric acute flaccid myelitis: Evaluation of diagnostic criteria and differentiation from other causes of acute flaccid paralysis

BACKGROUND

Acute flaccid paralysis (AFP) is characterized by rapidly progressive limb weakness with low muscle tone. It has a broad differential diagnosis, which includes acute flaccid myelitis (AFM), a rare polio-like condition that mainly affects young children. Differentiation between AFM and other causes of AFP may be difficult, particularly at onset of disease. Here, we evaluate the diagnostic criteria for AFM and compare AFM to other causes of acute weakness in children, aiming to identify differentiating clinical and diagnostic features.

METHODS

The diagnostic criteria for AFM were applied to a cohort of children with acute onset of limb weakness. An initial classification based on positive diagnostic criteria was compared to the final classification, based on application of features suggestive for an alternative diagnosis and discussion with expert neurologists. Cases classified as definite, probable, or possible AFM or uncertain, were compared to cases with an alternative diagnosis.

RESULTS

Of 141 patients, seven out of nine patients initially classified as definite AFM, retained this label after further classification. For probable AFM, this was 3/11, for possible AFM 3/14 and for uncertain 11/43. Patients initially classified as probable or possible AFM were most commonly diagnosed with transverse myelitis (16/25). If the initial classification was uncertain, Guillain-Barré syndrome was the most common diagnosis (31/43). Clinical and diagnostic features not included in the diagnostic criteria, were often used for the final classification.

CONCLUSION

The current diagnostic criteria for AFM usually perform well, but additional features are sometimes required to distinguish AFM from other conditions.

Long-lasting pain and somatosensory disturbances in children with myelin oligodendrocyte glycoprotein antibody-associated disease

Myelin oligodendrocyte glycoprotein antibody (MOG-Ab) is an autoantibody associated with acquired demyelinating syndrome (ADS) in childhood and adults. The pathogenic roles of MOG-Ab and long-term outcomes of children with MOG-Ab-associated disease (MOGAD) remain elusive. We investigated the clinical features of children with ADS during follow-up in our institute. Clinical data were retrospectively analyzed using medical charts of patients managed in Kyushu University Hospital from January 1st, 2001, to March 31st, 2022. Participants were children of < 18 years of age when they received a diagnosis of ADS in our hospital. Cell-based assays were used to detect MOG-Ab in serum or cerebrospinal fluid at the onset or recurrence of ADS. The clinical and neuroimaging data of MOG-Ab-positive and MOG-Ab-negative patients were statistically analyzed. Among 31 patients enrolled in this study, 22 (13 females, 59%) received tests for MOG antibodies. Thirteen cases (59%) were MOG-Ab-positive and were therefore defined as MOGAD; 9 (41%) were MOG-Ab-negative. There were no differences between MOGAD and MOG-Ab-negative patients in age at onset, sex, diagnostic subcategories, or duration of follow-up. MOGAD patients experienced headache and/or somatosensory symptoms more frequently than MOG-Ab-negative patients (12/13 (92%) vs. 3/9 (22%); p = 0.0066). Somatosensory problems included persistent pain with hyperesthesia in the left toe, perineal dysesthesia, and facial hypesthesia. No specific neuroimaging findings were associated with MOGAD or the presence of somatosensory symptoms.

CONCLUSIONS

Long-lasting somatosensory disturbances are prominent comorbidities in children with MOGAD. Prospective cohorts are required to identify molecular and immunogenetic profiles associated with somatosensory problems in MOGAD.

WHAT IS KNOWN

• Recurrence of demyelinating events occurs in a group of children with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD).

WHAT IS NEW

• Long-lasting headache and somatosensory problems are frequent comorbidities with pediatric MOGAD. Pain and somatosensory problems may persist for more than 5 years. • Neuroimaging data do not indicate specific findings in children with somatic disturbances.

Framework for Patient Experience Value Elements in Rare Disease: A Case Study Demonstrating the Applicability of Combined Qualitative and Quantitative Methods

BACKGROUND AND OBJECTIVE

Several novel methods have been suggested to extend a conventional value assessment to capture a more comprehensive perspective of value from a patient perspective. The objective of this research was to demonstrate a framework for implementing a combined qualitative and quantitative method to elicit and prioritize patient experience value elements in rare diseases. Neuromyelitis optica spectrum disorder was used as a case study.

METHODS

The method for eliciting and prioritizing patient experience value elements involved a three-step process: (1) collecting potential patient experience value elements from existing literature sources followed by deliberation by a multi-stakeholder research team; (2) a pre-workshop webinar and survey to identify additional patient-reported value elements; and (3) a workshop to discuss, prioritize the value elements using a swing weighting method. Outcomes were prioritized value elements with normalized weights for patients considering a treatment for neuromyelitis optica spectrum disorder.

RESULTS

A literature review and deliberation resulted in the following initial value elements: ability to reach important personal milestones, patient's financial burden, value of hope/balance or timing of risks and benefits, Uncertainty about long-term benefits and safety of the treatment, Patient empowerment through therapeutic advancement and technology, Caregiver/family's financial burden, patient experience related to treatment regimen, Therapeutic options, and Caregiver/family's quality of life. Eight patients with neuromyelitis optica spectrum disorder participated in the case study. In the online survey, participants found the nine proposed patient experience value elements both understandable and important with no additions. During the workshop, 'Uncertainty about long-term benefits and safety,' 'Patient experience related to treatment regimen,' and 'Patient's financial burden' were found to be the most important patient experience value elements, with a respective weight of 25%, 19.2%, and 14.4% (out of total 100%).

CONCLUSIONS

This case study provides a framework for eliciting and prioritizing patient experience value elements using direct patient input. Although elements/weights may differ by disease, and even in neuromyelitis optica spectrum disorder, additional research is needed, value frameworks, researchers, and manufacturers can use this practical method to generate patient experience value elements and evaluate their impact on treatment selection.

Neuromyelitis optica spectrum disorders: a review with a focus on children and adolescents

Neuromyelitis optica spectrum disorder (NMOSD) is a rare and severe inflammatory disorder of the central nervous system (CNS). It is strongly associated with anti-aquaporin 4 antibodies (AQP4-IgG), and it mainly affects young women from non-white ethnicities. However, ∼ 5 to 10% of all cases have onset during childhood. Children and adolescents share the same clinical, radiologic, and laboratory presentation as adults. Thus, the same NMOSD diagnostic criteria are also applied to pediatric-onset patients, but data on NMOSD in this population is still scarce. In seronegative pediatric patients, there is a high frequency of the antibody against myelin oligodendrocyte glycoprotein (MOG-IgG) indicating another disease group, but the clinical distinction between these two diseases may be challenging. Three drugs (eculizumab, satralizumab, and inebilizumab) have been recently approved for the treatment of adult patients with AQP4-IgG-positive NMOSD. Only satralizumab has recruited adolescents in one of the two pivotal clinical trials. Additional clinical trials in pediatric NMOSD are urgently required to evaluate the safety and efficacy of these drugs in this population.

Safety and efficacy of plasma exchange treatment in children with AQP4-IgG positive neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD), a severe demyelinating disease, is rare among children. Plasma exchange (PE) is widely used as a salvage therapy for severe and corticosteroid-unresponsive patients with NMOSD. Presently, there are limited studies on the safety and efficacy of PE in children with NMOSD. Herein, we report the case of six children with NMOSD who received PE along with the outcomes and adverse events. All six children (female, age at onset 4 years 9 months-13 years 2 months) were AQP4-IgG positive and received standard PE using the COM.TEC Cell Separator. The interval between NMOSD onset and PE was 29 days (range 10-98). Only one patient (P3) who received PE 10 days after acute exacerbations exhibited clinical improvement. Her left visual acuity increased from 0.06 to 0.6 (spectacle-corrected visual acuity was 1.0) and her EDSS score decreased from 4 to 3 points. The other five patients had no clinical improvement and no EDSS scores changes after PE. Adverse events included rashes (P1, P3), acute non-occlusive thrombosis of the internal jugular vein (P1), and thrombocytopenia (P2). In conclusion, the timing of PE initiation as a rescue therapy for severe and corticosteroid-unresponsive pediatric AQP4-IgG positive NMOSD may be crucial to treatment efficacy, and early initiation of PE may be associated with a better outcome. Furthermore, PE has the potential risk for clinically significant adverse effects that should be considered before initiating the therapy and should be weighed against potential benefits.

An update on biologic treatments for neuromyelitis optica spectrum disorder

INTRODUCTION

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease of the central nervous system mediated by antibodies targeting the aquaporin-4 (AQP4) water channel expressed on astrocytes. The binding of specific antibodies to AQP4 causes complement-dependent cytotoxicity, leading to inflammation and demyelination. Several recent phase 2 and 3 randomized placebo-controlled trials showed the efficacy and safety of monoclonal antibody therapies targeting B-cells, interleukin-6 receptor, and complement.

AREAS COVERED

Current biologic treatments for NMOSD and developments therein, and unresolved issues in NMOSD treatment.

EXPERT OPINION

New biologic treatments demonstrate high efficacy and good safety for patients with AQP4-IgG-positive NMOSD. The optimal therapeutics for seronegative NMOSD, pediatric patients, and female patients who are pregnant or wish to be are unclear, and further research is needed. Also, real-world studies of new biological agents and the data on the durability of their beneficial effects and their long-term safety are required. Effective rescue therapy for an acute attack is critical given permanent disability in NMOSD is attack-related, and biologic agents that treat acute attack are emerging. If such treatments are to become widely applied, studies on the most cost-effective treatment strategies are needed.

Asymptomatic MRI lesions in pediatric-onset AQP4-IgG positive NMOSD

BACKGROUND AND PURPOSE

Around 5% of all Neuromyelitis Optica Spectrum Disorders (NMOSD) cases start before 18 years of age. Clinical and radiological manifestations of AQP4-IgG positive NMOSD were revised in 2015, and the importance of neuroimaging in the diagnosis is well recognized. Neuroimaging findings in pediatric-onset NMOSD were scarcely described, and longitudinal evaluation of NMOSD lesions was only accessed in a few adult-onset cohorts.

METHODS

This study evaluated brain, spinal cord, and optic nerve MRI of sixteen pediatric-onset AQP4-IgG positive NMOSD through a qualitative evaluation of lesion evolution. Lesions were classified as symptomatic or asymptomatic in acute or chronic phase (> 30 days from last attack) MRI.

RESULTS

Seventy MRI scans and 54 subsequent exams were evaluated. Most NMOSD lesions (74.5%) reduced, remained stable, or developed atrophy/cavitation. New brain lesions or enlargement of existing brain lesions were found in two patients (12.5%) without any clinical symptom and in five patients (31.2%) in the course of an attack from other topography (optic neuritis or acute myelitis). One patient (6.3%) presented an asymptomatic spinal cord lesion irrespective of clinical manifestation. No asymptomatic lesion was described in optic nerve MRI. In acute phase exams, longitudinally extensive transverse myelitis (13/19 vs 8/24; p = 0.033), cervical myelitis (15/19 vs 10/24, p = 0.028), lumbar myelitis (5/19 vs 0/24; p = 0.012), and a higher number of segments [median 8 (range 4-17) vs 3.5 (range 1-14); p = 0.003] were affected.

CONCLUSIONS

Asymptomatic brain and spinal cord lesions can occur in pediatric-onset NMOSD, especially in the course of acute optic neuritis or myelitis. More longitudinal studies are necessary to guide recommendations on neuroimaging frequency in pediatric patients with AQP4-IgG NMOSD.

The patient journey with NMOSD: From initial diagnosis to chronic condition

Objective

To better understand the patient experience with neuromyelitis optica spectrum disorder (NMOSD) through the course of the illness.

Background

NMOSD is a rare autoimmune disorder that causes recurrent inflammatory attacks of the optic nerve, spinal cord, and brain. Knowledge and awareness of NMOSD in the general medical community are often limited, resulting in potential delays in diagnosis and treatment.

Design/methods

We developed a comprehensive 101-question survey to understand the patient's perspective on their journey from initial presentation to present condition. The survey covered basic demographics, symptoms, medical tests used to reach a diagnosis, and the patient's psychosocial responses to their diagnosis. The survey included questions to determine internal consistency in responses. We shared the survey with members of the Neuromyelitis Optica (NMO) Clinic Facebook group and received responses from 151 patients. All data collected were self-reported and presented as summary statistics.

Results

The majority of survey responses were from patients who were female (83%) and White (76%), Asian (7%), or African American (7%). Initial symptoms of disease included fatigue, pain, stiffness/spasticity, bladder and bowel dysfunction, cognitive/emotional symptoms, and visual disturbances. Initial reactions to NMOSD diagnosis were frequently fear, anxiety, and/or depression. Mean (SD) time to diagnosis was 2.2 (3.2) years. First contact with a medical professional was felt to be not helpful or somewhat helpful for many patients (71%), in part due to uncertain diagnosis and/or treatment. However, once referred to specialists (primarily neurologists), the majority of patients (87%) reported finding a professional who could help. Tests leading to diagnosis included magnetic resonance imaging, lumbar puncture, and blood tests for autoantibodies including aquaporin-4 (AQP4) and myelin oligodendrocyte glycoprotein (MOG). While approximately 30% of patients still felt challenged for a variety of reasons, most patients reported that having a diagnosis and being under the care of a specialist contributed to a comprehensive plan with hope for their future.

Conclusions

The NMOSD patient journey frequently begins with anxiety, fear, and frustration. Finding the right specialist and identifying appropriate screening tests can lead to earlier diagnosis and progression toward better patient outcomes.

Neuromyelitis Optica Spectrum Disorders

PURPOSE OF REVIEW

This article reviews the cardinal clinical features, distinct immunopathology, current diagnostic criteria, relapse-related risk factors, emerging biomarkers, and evolving treatment strategies pertaining to neuromyelitis optica spectrum disorders (NMOSD).

RECENT FINDINGS

The discovery of the pathogenic aquaporin-4 (AQP4)-IgG autoantibody and characterization of NMOSD as an autoimmune astrocytopathy have spearheaded the identification of key immunologic therapeutic targets in this disease, including but not limited to the complement system, the interleukin 6 (IL-6) receptor, and B cells. Accordingly, four recent randomized controlled trials have demonstrated the efficacy of three new NMOSD therapies, namely eculizumab, satralizumab, and inebilizumab.

SUMMARY

Currently, NMOSD poses both diagnostic and treatment challenges. It is debated whether individuals who are seropositive for myelin oligodendrocyte glycoprotein (MOG)-IgG belong within the neuromyelitis optica spectrum. This discussion is fueled by disparities in treatment responses between patients who are AQP4-IgG seropositive and seronegative, suggesting different immunopathologic mechanisms may govern these conditions. As our understanding regarding the immune pathophysiology of NMOSD expands, emerging biomarkers, including serum neurofilament light chain and glial fibrillary acidic protein (GFAP), may facilitate earlier relapse detection and inform long-term treatment decisions. Future research focal points should include strategies to optimize relapse management, restorative treatments that augment neurologic recovery, and practical solutions that promote equitable access to approved therapies for all patients with NMOSD.

Saudi consensus recommendations on the management of multiple sclerosis: MS management in children and adolescents

Multiple sclerosis (MS) most commonly presents in young adults, although 3-5% of patients develop MS prior to the age of 18 years. The new and comprehensive consensus for the management of MS in Saudi Arabia includes recommendations for the management of MS and other CNS inflammatory demyelinating disorders in pediatric and adolescent patients. This article summarizes the key recommendations for the diagnosis and management of these disorders in young patients. Pediatric and adult populations with MS differ in their presentation and clinical course. Careful differential diagnosis is important to exclude alternative diagnoses such as acute disseminated encephalomyelitis (ADEM) or neuromyelitis optica spectrum disorders (NMOSD). The diagnosis of MS in a pediatric/adolescent patient is based on the 2017 McDonald diagnostic criteria, as in adults, once the possibility of ADEM or NMOSD has been ruled out. Few data are available from randomized trials to support the use of a specific disease-modifying therapy (DMT) in this population. Interferons and glatiramer acetate are preferred initial choices for DMTs based on observational evidence, with the requirement of a switch to a more effective DMT if breakthrough MS activity occurs.

The First Case Report of Preschool-Onset SS/SLE Coexisting With NMOSD of Chinese Origin

Systemic lupus erythematosus (SLE) is an autoimmune connective tissue disease (CTD), the main features of which are multiple serum autoantibodies and extensive involvement of multiple systems. The onset age of patients varies from childhood to middle age, with nearly 1/5 in childhood. Sjogren’s syndrome (SS) is also an autoimmune disease characterized by high-degree lymphocytic infiltration of exocrine glands, usually occurring in middle-aged and older women, and rarely in childhood. Neuromyelitis optica spectrum disorder (NMOSD) is an immune-mediated inflammatory demyelinating disease of the central nervous system (CNS) mainly involving the optic nerve and spinal cord. The coexistence of NMOSD and SLE and/or SS is well recognized by both neurologists and rheumatologists, but cases in children have been rarely reported. In this paper, we reported a case of a girl with onset at age 5 clinically featured by recurrent parotid gland enlargement, pancytopenia, hypocomplementemia, multiple positive serum antibodies, and cirrhosis. She was initially diagnosed with SS/SLE overlap syndrome at age 5. Four years later, the patient suffered a sudden vision loss and was examined to have positive AQP4 antibodies in serum and cerebrospinal fluid (CSF), and long segmental spinal swelling, in line with the diagnostic criteria for NMOSD. Up to now, the current patient is of the youngest onset age to develop SS/SLE coexisting with NMOSD, also with cirrhosis. It is important for clinicians to be aware of the possibility of CTDs coexisting with NMOSD in children, especially in those with positive anti-multiple autoantibodies, and to decrease the rate of missed diagnosis.

Diagnosis and management of multiple sclerosis and other relapsing demyelinating disease in childhood

There are several important relapsing demyelinating syndromes (RDS) that may present in childhood, of which paediatric-onset multiple sclerosis is the most common. These are rare conditions, so recognising presentations and referring early to specialist services is important to enable prompt diagnosis and effective treatment. Understanding of RDS is rapidly evolving, with many new and effective treatments that aim to reduce relapses and disability accumulation. A holistic and child-focused approach to management is key to supporting patients and families, with thought given to early detection of cognitive and psychological issues to provide appropriate support.

Risk Factors and Nomogram for Predicting Relapse Risk in Pediatric Neuromyelitis Optica Spectrum Disorders

Background

Neuromyelitis optica spectrum disorders (NMOSDs) are attack-relapsing autoimmune inflammatory diseases of the central nervous system, which are characterized by the presence of serological aquaporin-4 (AQP4) antibody. However, this disorder is uncommon in children, and AQP4 antibody was often found to be seronegative. However, some pediatric patients diagnosed with NMOSDs were tested to be positive for myelin oligodendrocyte glycoprotein (MOG) antibody. The previous investigations of pediatric NMOSDs were usually focused on the clinical presentation, treatment responses, and long-term prognoses, but little is known about the risk factors predicting NMOSD relapse attacks in a shorter time, especially, for Chinese children.

Methods

We retrospectively identified 64 Chinese pediatric patients, including 39 positive for AQP4 antibody, 12 positive for MOG antibody, and the rest negative for AQP4 and MOG antibodies. Independent risk factors predicting relapse in 1-year follow-up were extracted by multivariate regression analysis to establish a risk score model, its performance evaluation was analyzed using receiver operating characteristic (ROC) curve, and the independent risk factors related to relapse manifestation were also explored through multivariate logistic analysis. A nomogram was generated to assess relapse attacks in 1-year follow-up. Thirty-five patients from 3 other centers formed an external cohort to validate this nomogram.

Results

Four independent relapsed factors included discharge Expanded Disability Status Scale (EDSS) (p = 0.017), mixed-lesion onset (p = 0.010), counts (≧1) of concomitant autoantibodies (p = 0.015), and maintenance therapy (tapering steroid with mycophenolate mofetil (MMF), p = 0.009; tapering steroid with acetazolamide (AZA), p = 0.045; and tapering steroid only, p = 0.025). The risk score modeled with these four factors was correlated with the likelihood of relapse in the primary cohort (AUC of 0.912) and the validation cohort (AUC of 0.846). Also, our nomogram exhibited accurate relapse estimate in the primary cohort, the validation cohort, and the whole cohort, but also in the cohorts with positive/negative AQP4 antibody, and noticeably, it performed predictive risk improvement better than other factors in the concordance index (C-index), net reclassification improvement (NRI), and integrated discrimination improvement (IDI).

Conclusions

The risk score and nomogram could facilitate accurate prognosis of relapse risk in 1-year follow-up for pediatric NMOSDs and help clinicians provide personalized treatment to decrease the chance of relapse.

Intensive Safety Monitoring of Rituximab (Biosimilar Novex® and the Innovator) in Pediatric Patients With Complex Diseases

Although rituximab is widely used off-label for complex pediatric diseases, safety reports are limited. We aimed to report evidence of its use in clinical practice, to describe the incidence of adverse drug reactions (ADR) to rituximab biosimilar Novex^® and innovator, and to identify risk factors for the development of ADR in a real-life follow-up cohort of pediatric patients with complex diseases. We conducted a prospective, longitudinal, observational, single-centre study in patients that received rituximab for any complex disease, and as part of an intensive pharmacovigilance program. Demographic, pharmacological, clinical, and drug-related data were collected for all patients. ADR-free survival, including infusion-related reactions (IRR) and delayed ADR (dADR), was estimated using Kaplan-Meier curves. Risk factors were evaluated by multivariable Cox regression models. In total, 77 patients (<19 y.o.) received 187 infusions of rituximab Novex^® (n = 155) or innovator rituximab (n = 32) for neurologic (Neu), immune-hematologic-rheumatic (IHR), oncologic (O) diseases, and hematopoietic stem-cell transplantation (HSCT) or solid-organ transplantation (SOT). We recorded 29 IRR and 58 dADR that occurred in 27 (35.1%) and 29 (37.7%) patients, respectively. The respiratory tract was the most affected during IRR (29.6%) and hypogammaglobulinemia (37.9 %) was the most frequent dADR. First versus subsequent infusions (HR 5.4, CI95% 2.4-12.1, p<0.05), sex (boys vs. girls, HR 0.3, CI95% 0.1-0.8, and p<0.05), and diagnosis (Neu-IHR diseases vs. O-HSCT-SOT, HR 2.3, CI95% 1.02-5.4, and p < 0.05) were significantly associated with the development of IRR. For dADR, risk factors were diagnosis (Neu-IHR diseases vs. O-HSCT-SOT, HR 0.4, CI95% 0.2-0.9, and p < 0.05) and cumulative body surface area-normalized dosage (HR 1.0003, CI95% 1.0001-1.0006, and p < 0.05). The present is the largest real-world safety assessment of rituximab in Latin-American children with complex diseases supporting its use based on the overall acceptable safety. Identification of risk factors may contribute to optimization of off-label rituximab treatment in pediatrics.

Early predictors of disability of paediatric-onset AQP4-IgG-seropositive neuromyelitis optica spectrum disorders

OBJECTIVE

To describe onset clinical features predicting time to first relapse and time to long-term visual, motor and cognitive disabilities in paediatric-onset aquaporin-4 antibody (AQP4-IgG) neuromyelitis optica spectrum disorders (NMOSDs).

METHODS

In this retrospective UK multicentre cohort study, we recorded clinical data of paediatric-onset AQP4-IgG NMOSD. Univariate and exploratory multivariable Cox proportional hazard models were used to identify long-term predictors of permanent visual disability, Expanded Disability Status Scale (EDSS) score of 4 and cognitive impairment.

RESULTS

We included 49 paediatric-onset AQP4-IgG patients (38.8% white, 34.7% black, 20.4% Asians and 6.1% mixed), mean onset age of 12±4.1 years, and 87.7% were female. Multifocal onset presentation occurred in 26.5% of patients, and optic nerve (47%), area postrema/brainstem (48.9%) and encephalon (28.6%) were the most involved areas. Overall, 52.3% of children had their first relapse within 1 year from disease onset. Children with onset age <12 years were more likely to have an earlier first relapse (p=0.030), despite showing no difference in time to immunosuppression compared with those aged 12-18 years at onset. At the cohort median disease duration of 79 months, 34.3% had developed permanent visual disability, 20.7% EDSS score 4 and 25.8% cognitive impairment. Visual disability was associated with white race (p=0.032) and optic neuritis presentations (p=0.002). Cognitive impairment was predicted by cerebral syndrome presentations (p=0.048), particularly if resistant to steroids (p=0.034).

CONCLUSIONS

Age at onset, race, onset symptoms and resistance to acute therapy at onset attack predict first relapse and long-term disabilities. The recognition of these predictors may help to power future paediatric clinical trials and to direct early therapeutic decisions in AQP4-IgG NMOSD.

Utility of paramagnetic rim lesions on 1.5-T susceptibility phase imaging for the diagnosis of pediatric multiple sclerosis

BACKGROUND

Studies have suggested that paramagnetic rim lesions on 7-tesla (T) and 3-T susceptibility-based brain MRI are specific features of multiple sclerosis (MS) lesions in adults.

OBJECTIVE

The aim of this study was to investigate whether the presence of paramagnetic rim lesions on 1.5-T phase images can help discriminate pediatric patients with MS from those with other demyelinating diseases.

MATERIALS AND METHODS

In this retrospective study we reviewed brain MRIs performed on 1.5-T scanners that included susceptibility-weighted imaging (SWI) sequences with phase images in children younger than 18 years diagnosed with MS and other acquired demyelinating syndromes. In each case, five white matter lesions were selected using T2/fluid-attenuated inversion recovery images for further paramagnetic rim evaluation on SWI. Two researchers performed independent assessments of the presence of paramagnetic rim lesions. Discrepancies between them were settled by consensus, with input from a senior neuroradiologist.

RESULTS

We included 13 children diagnosed with MS and 16 children diagnosed with non-MS demyelinating diseases and analyzed a total of 132 focal white matter lesions. Seventy-one percent of the lesions in the MS group had paramagnetic rims, while none of the lesions in the non-MS group had rims. All but one of the children with MS had at least one lesion with a paramagnetic rim. The presence of one lesion with a paramagnetic rim on 1.5-T phase-contrast images resulted in 70% sensitivity and 100% specificity for MS.

CONCLUSION

Paramagnetic rim lesions detected on 1.5-T phase-contrast MR images can help discriminate MS from other acquired demyelinating syndromes in the pediatric population.

Pediatric Neuromyelitis Optica Spectrum Disorder: Case Series and Literature Review

Neuromyelitis Optica Spectrum Disorder (NMOSD) is a central nervous system (CNS) inflammatory demyelinating disease characterized by recurrent inflammatory events that primarily involve optic nerves and the spinal cord, but also affect other regions of the CNS, including hypothalamus, area postrema and periaqueductal gray matter. The aquaporin-4 antibody (AQP4-IgG) is specific for NMOSD. Recently, myelin oligodendrocyte glycoprotein antibodies (MOG-IgG) have been found in a group of AQP4-IgG negative patients. NMOSD is rare among children and adolescents, but early diagnosis is important to start adequate therapy. In this report, we present cases of seven pediatric patients with NMOSD and we review the clinical and neuroimaging characteristics, diagnosis, and treatment of NMOSD in children.

Pathogenic antibodies to AQP4: Neuromyelitis optica spectrum disorder (NMOSD)

NMOSD is a rare but severe relapsing remitting demyelinating disease that affects both adults and children. Most patients have pathogenic antibodies that target the central nervous system AQP4 protein. This review provides an update on our current understanding of the disease pathophysiology and describes the clinical, paraclinical features and therapeutic management of the disease.

The Role of Pediatric Rheumatologists in Autoimmune Brain Disease

The spectrum of autoimmune and inflammatory brain diseases continues to evolve with medical advances facilitating both the detection of inflammation of the central nervous system and the discovery of novel disease mechanisms. The clinical overlap of these disorders with primary rheumatic diseases and the efficacy of immunotherapy have led to strong partnerships between pediatric rheumatologists, neurologists, psychiatrists, and other providers in the care of children with these conditions. Early diagnosis and initiation of targeted therapy improve clinical outcomes, highlighting the importance of interdisciplinary collaborative care.

Reduced quality of life in a pediatric-onset Neuromyelitis optica spectrum disorders cohort

BACKGROUND

Neuromyelitis optica spectrum disorders (NMOSD) is a severe condition associated with high disability and low quality of life (QoL) in adults. Since this evaluation had been rarely perfomed in children, this study aimed to describe QoL in pediatric-onset NMOSD with positive aquaporin4 antibody (AQP4-IgG) patients.

METHODS

This was a cross-section evaluation of patients and parents' proxy QoL from individuals enrolled in a longitudinal cohort of AQP4-IgG positive NMOSD with onset ≤ 18 years of age.

RESULTS

Eighteen patients were included, sixteen girls. The mean (SD) age at disease onset was 11.5 (3.6) years. Eleven of patients experienced disability during a mean (SD) of 8.3 (5.3) years of follow-up. NMOSD had impact in QoL in 10 patients, being associated with higher EDSS and poor academic performance at last follow-up. Results from the PedsQL inventory for 13 patients and 10 parents disclosed low QoL specially in emotional functioning.

CONCLUSION

This study indicates impaired quality of life, high disability and high impact of the disease in daily life of adolescents and young adults with pediatric onset NMOSD.

Identification of the clinical and neuroimaging characteristics in children with neuromyelitis optica spectrum disorders: a case series

BACKGROUND

Childhood neuromyelitis optica spectrum disorders (NMOSDs) may cause visual impairment and brain or spinal cord damage, and the effects may be permanent if left untreated. Since the incidence of NMOSD cases in children is relatively low, the understanding of NMOSD among children is inadequate.

METHODS

This investigation examined the clinical and neuroimaging characteristics of childhood NMOSD. We retrospectively analyzed the clinical information of 11 NMOSD patients admitted to our centre from 2012 to 2021. The disease status was assessed by the Expanded Disability Status Scale (EDSS) score.

RESULTS

The two major symptoms observed in the study cohort were optic neuritis (ON) (9/11) and encephalopathy (7/11). Antibody tests were performed on 8 children, 2 of whom showed serum aquaporin 4 (AQP4) antibody positivity, and another 2 presented with serum myelin oligodendrocyte glycoprotein (MOG) antibody positivity. All patients showed white matter hyperintensity on magnetic resonance imaging (MRI) scans. Interestingly, a rare radiological sign, enlarged perivascular space (PVS), which is more commonly observed in the elderly or adults, was found in 4 participants with more severe clinical manifestations.

CONCLUSIONS

While NMOSD in children is less commonly diagnosed through clinical evaluations, the symptoms of ON and encephalopathy should raise the possibility of the disease. As the diagnosis of NMOSD in children is relatively difficult, enlarged PVS may represent a promising biomarker for the diagnosis and evaluation of NMOSD.

Neuromyelitis optica spectrum disorders: from pathophysiology to therapeutic strategies

Neuromyelitis optica (NMO) is a chronic inflammatory autoimmune disease of the central nervous system (CNS) characterized by acute optic neuritis (ON) and transverse myelitis (TM). NMO is caused by a pathogenic serum IgG antibody against the water channel aquoporin 4 (AQP4) in the majority of patients. AQP4-antibody (AQP4-ab) presence is highly specific, and differentiates NMO from multiple sclerosis. It binds to AQP4 channels on astrocytes, triggering activation of the classical complement cascade, causing granulocyte, eosinophil, and lymphocyte infiltration, culminating in injury first to astrocyte, then oligodendrocytes followed by demyelination and neuronal loss. NMO spectrum disorder (NMOSD) has recently been defined and stratified based on AQP4-ab serology status. Most NMOSD patients experience severe relapses leading to permanent neurologic disability, making suppression of relapse frequency and severity, the primary objective in disease management. The most common treatments used for relapses are steroids and plasma exchange.Currently, long-term NMOSD relapse prevention includes off-label use of immunosuppressants, particularly rituximab. In the last 2 years however, three pivotal clinical trials have expanded the spectrum of drugs available for NMOSD patients. Phase III studies have shown significant relapse reduction compared to placebo in AQP4-ab-positive patients treated with satralizumab, an interleukin-6 receptor (IL-6R) inhibitor, inebilizumab, an antibody against CD19⁺ B cells; and eculizumab, an antibody blocking the C5 component of complement. In light of the new evidence on NMOSD pathophysiology and of preliminary results from ongoing trials with new drugs, we present this descriptive review, highlighting promising treatment modalities as well as auspicious preclinical and clinical studies.

Juvenile progressive optic atrophy as the presenting feature of biotinidase deficiency, a treatable metabolic disorder

A 10-year-old girl initially diagnosed with functional visual loss was later diagnosed with progressive optic atrophy. Directed questioning at 13 years of age revealed difficulty hearing that had not been noted by the parents. Whole exome sequencing and subsequent metabolic testing confirmed biotinidase deficiency. Although biotinidase deficiency classically manifests in early childhood with multiple manifestations, such as seizures and failure to thrive, a delayed-onset form can present primarily as juvenile progressive optic atrophy. Early diagnosis is critical because biotin supplementation prevents disease and deterioration.

A window into the future? MRI for evaluation of neuromyelitis optica spectrum disorder throughout the disease course

Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing, inflammatory disease of the central nervous system marked by relapses often associated with poor recovery and long-term disability. Magnetic resonance imaging (MRI) is recognized as an important tool for timely diagnosis of NMOSD as, in combination with serologic testing, it aids in distinguishing NMOSD from possible mimics. Although the role of MRI for disease monitoring after diagnosis is not as well established, MRI may provide important prognostic information and help differentiate between relapses and pseudorelapses. Increasing evidence of subclinical disease activity and the emergence of newly approved, highly effective immunotherapies for NMOSD adjure us to re-evaluate MRI as a tool to guide optimal treatment selection and escalation throughout the disease course. In this article we review the role of MRI in NMOSD diagnosis, prognostication, disease monitoring, and treatment selection.

Paediatric multiple sclerosis and antibody-associated demyelination: clinical, imaging, and biological considerations for diagnosis and care

The field of acquired CNS neuroimmune demyelination in children is transforming. Progress in assay development, refinement of diagnostic criteria, increased biological insights provided by advanced neuroimaging techniques, and high-level evidence for the therapeutic efficacy of biological agents are redefining diagnosis and care. Three distinct neuroimmune conditions-multiple sclerosis, myelin-oligodendrocyte glycoprotein antibody-associated disease (MOGAD), and aquaporin-4 antibody-associated neuromyelitis optica spectrum disorder (AQP4-NMOSD)-can now be distinguished, with evidence from humans and animal models supporting distinct pathobiological disease mechanisms. The development of highly effective therapies for adult-onset multiple sclerosis and AQP4-NMOSD that suppress relapse rate by more than 90% has motivated advocacy for trials in children. However, doing clinical trials is challenging because of the rarity of these conditions in the paediatric age group, necessitating new approaches to trial design, including age-based trajectory modelling based on phase 3 studies in adults. Despite these limitations, the future for children and adolescents living with multiple sclerosis, MOGAD, or AQP4-NMOSD is far brighter than in years past, and will be brighter still if successful therapies to promote remyelination, enhance neuroprotection, and remediate cognitive deficits can be further accelerated.