Pediatric Neuromyelitis Optica Spectrum Disorders

Leptomeningeal Enhancement in Pediatric Anti-Myelin Oligodendrocyte Glycoprotein Antibody Disease, Multiple Sclerosis, and Neuromyelitis Optica Spectrum Disorder

BACKGROUND

Anti-myelin oligodendrocyte glycoprotein (MOG) antibody disease (MOGAD) is a type of acquired demyelinating disease that is distinct from multiple sclerosis (MS) and aquaporin-4 antibody neuromyelitis optica spectrum disorder (AQP4-NMOSD). Leptomeningeal enhancement (LME) has been reported in children and adults with MOGAD, and in adults with MS and AQP4-NMOSD, but less is known about LME in pediatric-onset MS (POMS) and pediatric AQP4-NMOSD. Here we compare the rates of LME in children with MOGAD, POMS, and AQP4-NMOSD.

METHODS

A retrospective chart review was performed in patients with MOGAD, POMS, and AQP4-NMOSD who presented to our institution. Clinical characteristics, imaging features, and relapsing data were included. Descriptive statistics were used, including chi-square or Fischer exact test, to compare proportions. The Benjamini-Hochberg procedure was used to correct for multiple comparisons.

RESULTS

A total of 42 children were included: 16 with POMS, six with AQP4-NMOSD, and 20 with MOGAD. Brain LME was only observed in the MOGAD group (six of 20 = 30%) when compared with zero (0%) POMS and AQP4-NMOSD (P = 0.012). Relapsing disease occurred in nine of 20 (45%), but LME did not associate with relapse.

CONCLUSIONS

LME is only observed in pediatric MOGAD and not in POMS or pediatric AQP4-NMOSD. LME did not predict relapses in MOGAD. Further work is needed to determine the clinical significance of LME in pediatric MOGAD.

Monophasic Acquired Demyelinating Syndromes of the Central Nervous System in Children

Acquired demyelinating syndromes of the central nervous system are immune-mediated demyelinating disorders that can affect the brain, optic nerves, and spinal cord. These disorders have become increasingly recognized in children due to advances in imaging techniques, improvements in diagnostic testing, extensive research into understanding the pathophysiology underlying these disorders, and collaborative multi-institutional efforts to raise awareness of these disorders in children. Moreover, developments in the field of neuroimmunology have allowed us to identify autoantibodies that have presumed causal roles in acquired demyelinating syndromes. Identification of these autoantibodies helps determine clinical course (ie, monophasic vs relapsing course), prognosis, and treatment approach. Acquired demyelinating disorders can affect both children and adults. However, the clinical features, disease course, and treatments are often unique in the pediatric population. Thus, it is important to understand the spectrum of these disorders in children to help provide a timely diagnosis and prompt treatment to achieve optimal outcomes. In this article, the epidemiology, clinical features, diagnosis, treatment, and outcomes of the most common monophasic acquired demyelinating syndromes in children will be reviewed.

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.

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.

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.

Clinical predictive factors for diagnosis of MOG-IgG and AQP4-IgG related paediatric optic neuritis: a Chinese cohort study

BACKGROUND

Different glial-autoantibodies-related paediatric optic neuritis (ON) are associated with different clinical characteristics and prognosis that require different treatments. Because glial autoantibody detection is not available in some parts of the world and there is often a delay in obtaining results, clinical factors that can be used to predict the subtype of paediatric ON are needed.

METHODS

This was a single-centre retrospective cohort study. Children who presented with their first ON attack and with complete clinical data were included in the analysis. Single and multiple parameters for predicting paediatric myelin oligodendrocyte glycoprotein immunoglobin-associated ON (MOG-ON) and aquaporin-4 immunoglobin-related ON (AQP4-ON) were calculated.

RESULTS

78 paediatric patients had their first ON attack from January 2016 to December 2019, of whom 69 were included in the final analysis, including 33 MOG-ON cases, 17 AQP4-ON cases and 19 Seronegative-ON cases. For predicting paediatric MOG-ON, the most sensitive predictors were 'male or optic disc swelling (ODS) or bilateral' (sensitivity 0.97 (95% CI 0.82 to 1.00)) and 'follow-up visual acuity (VA) ≤0.1 logMAR or ODS' (sensitivity 0.97 (95% CI 0.82 to 1.00)), and the most specific factor was 'Age ≤11 y and simultaneous CNS involvement' (specificity 0.97 (95% CI 0.84 to 1.00)). For predicting paediatric AQP4-ON, the most sensitive predictor was 'Female or without ODS' (sensitivity 1.00 (95% CI 0.77 to 1.00)), and the most specific factors were Neurological history (sensitivity 0.94 (95% CI 0.83 to 0.98)) and follow-up VA >1.0 logMAR (sensitivity 0.96 (95% CI 0.86 to 0.99)).

CONCLUSION

According to our data from a Chinese paediatric cohort, using multiple parameters increases the sensitivity and specificity of diagnosing paediatric MOG-ON and AQP4-ON. These can assist clinicians in diagnosing and treating paediatric ON when glial autoantibody status is not available.

Can Immune Tolerance Be Re-established in Neuromyelitis Optica?

Neuromyelitis optica (NMO) is a chronic inflammatory disease of the central nervous system that primarily affects the optic nerves and spinal cord of patients, and in some instances their brainstem, diencephalon or cerebrum as spectrum disorders (NMOSD). Clinical and basic science knowledge of NMO has dramatically increased over the last two decades and it has changed the perception of the disease as being inevitably disabling or fatal. Nonetheless, there is still no cure for NMO and all the disease-modifying therapies (DMTs) are only partially effective. Furthermore, DMTs are not disease- or antigen-specific and alter all immune responses including those protective against infections and cancer and are often associated with significant adverse reactions. In this review, we discuss the pathogenic mechanisms of NMO as they pertain to its DMTs and immune tolerance. We also examine novel research therapeutic strategies focused on induction of antigen-specific immune tolerance by administrating tolerogenic immune-modifying nanoparticles (TIMP). Development and implementation of immune tolerance-based therapies in NMO is likely to be an important step toward improving the treatment outcomes of the disease. The antigen-specificity of these therapies will likely ameliorate the disease safely and effectively, and will also eliminate the clinical challenges associated with chronic immunosuppressive therapies.

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.

Aseptic meningitis and leptomeningeal enhancement associated with anti-MOG antibodies: A review

BACKGROUND

Aseptic meningitis can be caused by autoimmune diseases, such as lupus and sarcoidosis. Aseptic meningitis with leptomeningeal enhancement can be the initial presentation of a neuroinflammatory syndrome associated with antibodies to myelin oligodendrocyte glycoprotein (MOG-abs). MOG-abs is a serum biomarker for MOG-associated disorder (MOG-AD), an acquired demyelinating syndrome that includes features of neuromyelitis optica, multiple sclerosis, optic neuritis, and acute disseminated encephalomyelitis. The purpose of this study is to review cases of aseptic meningitis and leptomeningeal enhancement associated with MOG-abs.

METHODS

Systematic review using PubMed, Embase, Ovid MEDLINE, Web of Science Core Collection, and Google Scholar up to December 2020 was performed. Cases of MOG-AD were included if they met the following criteria: 1) Initial clinical presentation of aseptic meningitis; 2) positive leptomeningeal enhancement and 3) MOG-Ab seropositivity. Descriptive statistics were used. This analysis was limited to the cases available in the literature.

RESULTS

11 total cases of aseptic meningitis and leptomeningeal enhancement in setting of MOG-ab were identified. Demyelinating type T2 lesions were also present at time of presentation in 6/11; however, 5/11 of patients had leptomeningeal enhancement alone without demyelinating lesions. All 5 patients required immunotherapy for improvement, including one patient with symptoms for 28 days, with 4/5 receiving steroids and 1/5 receiving intravenous immunoglobulin (IVIG).

CONCLUSIONS

Aseptic meningitis with leptomeningeal enhancement can be the initial presenting symptom of MOG-AD. MOG-ab testing should be considered in a patient presenting with aseptic meningitis and leptomeningeal enhancement of unknown etiology.

Inflammatory Diseases of the Central Nervous System

Pediatric neuroinflammatory conditions are a complex group of disorders with a wide range of clinical presentations. Patients can present with a combination of focal neurologic deficits, encephalopathy, seizures, movement disorders, or psychiatric manifestations. There are several ways that pediatric neuroinflammatory conditions can be classified, including clinical presentation, pathophysiologic mechanism, and imaging and laboratory findings. In this article, we group these conditions into acquired demyelinating diseases, immune-mediated epilepsies/encephalopathies, primary rheumatologic conditions with central nervous system (CNS) manifestations, CNS vasculitis, and neurodegenerative/genetic conditions with immune-mediated pathophysiology and discuss epidemiology, pathophysiology, clinical presentation, treatment, and prognosis of each disorder.

[From neuromyelitis optica to neuromyelitis optica spectrum disorder: from clinical syndrome to diagnistic classification]

Neuromyelitis optica spectrum disorder (NMOSD), derived from NMO or Devic's disease, is considered as a distinct disease since the discovery of a novel and pathogenic serum autoantibody targeting aquaporin‑4 (AQP4-IgG) and is distinguished from classical multiple sclerosis (MS). With the continuous extension of knowledge on the clinical manifestations, the previously narrow diagnostic term NMO became NMOSD, which has also been used in the diagnostic criteria since 2015. The current diagnostic criteria enable the early diagnosis of NMOSD in patients with and without AQP4-IgG. Typical clinical manifestations include involvement of the spinal cord, optic nerve and brainstem. Typically patients with the disease also present with neuropathic pain, painful tonic spasms and also other unusual manifestations in NMOSD. Especially in AQP4-IgG positive NMOSD patients, the coexistence with other autoimmune diseases is frequently observed. In most cases NMOSD follows a relapsing course with exacerbation-free periods sometimes lasting years and can be manifested first in advanced adulthood. A subset of AQP4-IgG negative NMOSD patients have been found to harbor autoantibodies targeting myelin oligodendrocyte glycoprotein (MOG), which is considered as a distinct disease entity: these MOG antibody-associated disorders (MOGAD) can present with clinical syndromes resembling both NMOSD and MS and are currently the subject of intensive research.

Autologous hematopoietic stem cell transplantation in a pediatric patient with aquaporin-4 neuromyelitis optica spectrum disorder

We report on a child with an early and severe manifestation of an Aquaporin-4 (AQP-4) positive Neuromyelitis Optica Spectrum Disorder (NMOSD) who had a refractory disease course despite aggressive immunotherapy and underwent autologous hematopoietic stem cell transplant (AHSCT).

Assessment and Management of Acute Disseminated Encephalomyelitis (ADEM) in the Pediatric Patient

Acute disseminated encephalomyelitis (ADEM) is an inflammatory demyelinating disease of the central nervous system that typically presents in childhood and is associated with encephalopathy and multifocal brain lesions. Although ADEM is thought to be a post-infectious disorder, the etiology is still poorly understood. ADEM is often a monophasic disorder, in contrast to other demyelinating disorders such as multiple sclerosis and neuromyelitis optica spectrum disorder. With increasing awareness, understanding, and testing for myelin oligodendrocyte glycoprotein antibodies, this disease is now known to be a cause of pediatric ADEM and also has the potential to be relapsing. Diagnostic evaluation for ADEM involves neuroimaging and laboratory studies to exclude potential infectious, inflammatory, neoplastic, and genetic mimics of ADEM. Acute treatment modalities include high-dose intravenous corticosteroids, therapeutic plasma exchange, and intravenous immunoglobulin. Long-term outcomes for ADEM are generally favorable, but some children have significant morbidity related to the severity of acute illness and/or manifest ongoing neurocognitive sequelae. Further research related to the optimal management of pediatric ADEM and its impact on prognosis is needed. This review summarizes the current knowledge of the pathogenesis, epidemiology, clinical features, diagnostic evaluation, treatment approaches, and outcomes in pediatric ADEM.

Understanding Pediatric Neuroimmune Disorder Conflicts: A Neuroradiologic Approach in the Molecular Era

Neuroimmune disorders in children are a complex group of inflammatory conditions of the central nervous system with diverse pathophysiologic mechanisms and clinical manifestations. Improvements in antibody analysis, genetics, neuroradiology, and different clinical phenotyping have expanded knowledge of the different neuroimmune disorders. The authors focus on pediatric-onset myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease, which is a new entity in the spectrum of inflammatory demyelinating diseases, distinct from both multiple sclerosis (MS) and anti-aquaporin-4 (AQP4) antibody neuromyelitis optica spectrum disorders (NMOSDs). The authors review the importance of an optimized antibody-detection assay, the frequency of MOG antibodies in children with acquired demyelinating syndrome (ADS), the disease course, the clinical spectrum, proposed diagnostic criteria, and neuroimaging of MOG antibody-associated disease. Also, they outline differential diagnosis from other neuroimmune disorders in children according to the putative primary immune mechanism. Finally, they recommend a diagnostic algorithm for the first manifestation of ADS or relapsing ADS that leads to four demyelinating syndromes: MOG antibody-associated disease, AQP4 antibody NMOSDs, MS, and seronegative relapsing ADS. This diagnostic approach provides a framework for the strategic role of neuroradiology in diagnosis of ADS and decision making, to optimize patient care and treatment outcome in concert with clinicians. Online supplemental material is available for this article. ^©RSNA, 2020.

Identification of TNFAIP3 as relapse biomarker and potential therapeutic target for MOG antibody associated diseases

MOG-antibody associated disease (MOG-AAD) is a recently recognized demyelinating disorder predominantly affecting children but also occurs in adults, with a relapsing course in approximately 50% of patients. We evaluated peripheral blood mononuclear cells from MOG-AAD patients by flow cytometry and found a strong antigen specific central memory cell (CMC) response with increased Th1 and Th17 cells at the time of a relapse. Transcriptomic analysis of CMCs by three independent sequencing platforms revealed TNFAIP3 as a relapse biomarker, whose expression was down regulated at a relapse compared to remission in MOG-AAD patients. Serum in an additional cohort of patients showed decreased TNFAIP3 levels at relapse compared to remission state in MOG-AAD patients. Our studies suggest that alterations in TNFAIP3 levels are associated with relapses in MOG-AAD patients, which may have clinical utility as a disease course biomarker and therapeutic target.

Epidemiology of Pediatric NMOSD in Germany and Austria

Background: Neuromyelitis optica spectrum disorders (NMOSD) are severe inflammatory demyelinating disorders of the central nervous system mainly characterized by recurrent episodes of uni- or bilateral optic neuritis (ON), transverse myelitis (TM) and brainstem syndromes (BS). The majority of adult patients has serum antibodies directed against the water channel protein aquaporin 4 (AQP4-abs). In pediatric patients, AQP4-abs are less, while antibodies against myelin oligodendrocyte glycoprotein (MOG-abs) are more frequently detectable than in adults. Some children with NMOSD have neither AQP4- nor MOG-ab (double-seronegative).

Objective: Evaluation of epidemiological data regarding incidence and prevalence of pediatric NMOSD in Germany and Austria.

Methods: We recruited pediatric NMOSD patients between 1 March 2017 and 28 February 2019 with five different tools: (1) ESPED (Surveillance Unit for Rare Pediatric Disorders in Germany), (2) ESNEK (Surveillance for Rare Neurological Disorders during Childhood), (3) pediatric neurology working group within the Austrian Society of Pediatrics and Adolescent Medicine, (4) BIOMARKER Study and (5) NEMOS (Neuromyelitis optica Study Group). We requested data regarding clinical symptoms, antibody status, therapy regimen and response via a standardized questionnaire.

Results: During the 2-year recruitment period, 46 (both incidental and prevalent) patients with a suspected diagnosis of NMOSD were brought to our attention. Twenty-two of these patients did not fulfill the inclusion criteria. Of the remaining 24 children, 22 had a median age at onset of 11 (range 3–17) years and 16/22 were female (72.7%) (no data in two patients). Sixteen of 24 patients were AQP4-ab positive (67%), 4/24 MOG-ab positive (16.7%), three children were double-seronegative and in one patient no antibody testing was done. We calculated an incidence rate of 0.022 per 100,000 person-years for Germany, while there was no incidental case in Austria during the recruitment period. The prevalence rate was 0.147 and 0.267 per 100,000 persons in Germany and Austria, respectively.

Conclusion: Pediatric NMOSD, with and without associated antibodies, are very rare even considering the different limitations of our study. An unexpected finding was that a considerable proportion of patients was tested neither for AQP4- nor MOG-abs during diagnostic work-up, which should prompt to establish and disseminate appropriate guidelines.

Aquaporin-4 neuromyelitis optica spectrum disorder in a 2-year-old girl: Diagnostic and treatment considerations

We describe a case of an unusually early and severe manifestation of Aquaporin-4 (AQP-4) positive Neuromyelitis Optica Spectrum Disorder (NMOSD) in a two-year-old girl. We discuss learning points from her clinical presentation and highlight differences between pediatric and adult presentations of the disease. We argue that AQP-4 NMOSD should always be considered in the differential diagnosis for any child presenting with an acute neuroimmunological process given the morbidity associated with the condition and the importance of early diagnosis and treatment.

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

Neuromyelitis Optica Spectrum Disorder (NMOSD) is an inflammatory demyelinating disease of the central nervous system (CNS) primarily affecting the optic nerves and spinal cord, but also involving other regions of the CNS including the area postrema, periaqueductal gray matter, and hypothalamus. Knowledge related to pediatric manifestations of NMOSD has grown in recent years, particularly in light of newer information regarding the importance of not only antibodies to aquaporin 4 (AQP4-IgG) but also myelin oligodendrocyte glycoprotein (MOG-IgG) in children manifesting clinically with this syndrome. In this review, we describe the current state of the knowledge related to clinical manifestations, diagnosis, and chronic therapies for children with NMOSD, with emphasis on literature that has been published in the last 5 years. Following the review, we propose recommendations for the assessment/follow up clinical care, and treatment of this population.

Acute Transverse and Flaccid Myelitis in Children

PURPOSE OF REVIEW

The etiologies of myelitis in children are broad, and our understanding of inflammatory myelopathies in the pediatric population continues to evolve. Acute flaccid myelitis (AFM), increasingly linked to enterovirus infections, has risen in incidence over recent years. As with other infectious myelopathies, AFM can be challenging to distinguish from inflammatory causes of acute transverse myelitis (ATM) at initial presentation. This review outlines an approach to the treatment of children presenting with myelopathy of suspected inflammatory etiology, with attention to how management may differ in the specific case of acute flaccid myelitis.

RECENT FINDINGS

Although high-quality evidence is limited, intravenous corticosteroids, intravenous immunoglobulin, and plasma exchange have important roles in the acute management of ATM. Spinal cord injury in AFM, though similar to ATM in clinical presentation, is largely mediated by direct infection as opposed to a primary inflammatory process, and treatment with corticosteroids may worsen outcomes. Awareness of the distinguishing clinical features of AFM and the underlying inflammatory conditions that commonly manifest with ATM is essential to judicious selection of appropriate acute (and potentially chronic) therapies in children presenting with myelitis.

Update on pediatric optic neuritis

PURPOSE OF REVIEW

To summarize recent developments in the classification, investigation and management of pediatric optic neuritis (PON).

RECENT FINDINGS

A recent surge in interest surrounding antibodies to myelin oligodendrocyte glycoprotein antibody (MOG-Ab) has instigated a paradigm shift in our assessment of children with PON. This serological marker is associated with a broad spectrum of demyelinating syndromes that are clinically and radiologically distinct from multiple sclerosis (MS) and aquaporin-4 antibody positive neuromyelitis optica spectrum disorder (AQP4+NMOSD). Optic neuritis is the most common presenting phenotype of MOG-Ab positive-associated disease (MOG+AD). MOG-Ab seropositivity is much more common in the pediatric population and it predicts a better prognosis than MS or AQP4+NMOSD, except in the subset that exhibit a recurrent phenotype.

SUMMARY

A better grasp of MOG+AD features and its natural history has facilitated more accurate risk stratification of children after a presenting episode of PON. Consequently, the initial investigation of PON has broadened to include serology, along with neuroimaging and cerebrospinal fluid analysis. Acute treatment of PON and chronic immunotherapy is also becoming better tailored to the suspected or confirmed diagnoses of MS, AQP4+NMOSD and MOG+AD.

Neuromyelitis optica spectrum disorder in pediatrics. Case report

Introduction: Neuromyelitis optica is an inflammatory disorder of the central nervous system that accounts for 5% of demyelinating diseases in pediatrics. Its clinical presentation is variable and associated to the involved area of the central nervous system.Case presentation: This is the case of a 15-year-old patient who consulted several times for nonspecific neurological symptoms. During his last visit to the Clínica Universitaria Colombia in Bogotá, he presented with bilateral optic neuritis, associated with frontal and parietal headache. Immunophenotyping studies were carried out, reporting positive IgG anti-aquaporin 4 antibodies (anti-AQP4 antibody), thus leading to a diagnosis of seropositive neuromyelitis optica spectrum disorder (NMOSD). Management with methylprednisolone pulses was initiated with subsequent outpatient management with rituximab that allowed stabilizing the disease.Discussion: This is an interesting case due to its insidious and uncertain onset in a pediatric patient. It was possible to evaluate clinical and diagnostic differences in relation to its presentation in adults. NMOSD mediated by anti-AQP4 is rare; brain and bone marrow MRI are essential for diagnosis. The treatment of choice for acute conditions consists of high doses of methylprednisolone.Conclusion: This disorder may result in irreversible neurological damage; for this reason, high suspicion is required for early diagnosis and timely treatment.

Mycophenolate mofetil, azathioprine and methotrexate usage in paediatric anti-NMDAR encephalitis: A systematic literature review

BACKGROUND

Available data on mycophenolate mofetil (MMF), azathioprine (AZA) and methotrexate (MTX) for paediatric-onset anti-N-methyl-d-aspartate receptor encephalitis (anti-NMDARE) is limited.

METHODS

Systematic literature review on patients treated with MMF/AZA/MTX for paediatric-onset anti-NMDARE, with focus on modes of use, efficacy and safety.

RESULTS

87 patients were included (age at onset median 11 years, range 0.8-18 years; 69% females). 46% had a relapsing course. 52% received MMF, 27% AZA, 15% MTX, and 6% a combination of MMF/AZA/MTX (7 patients received intrathecal MTX). Before MMF/AZA/MTX, 100% patients received steroids, 83% intravenous immunoglobulin and 45% plasma exchange, and 50% received second-line treatments (rituximab/cyclophosphamide). MMF/AZA/MTX were administered >6 months from onset in 51%, and only after relapse in 40%. Worst mRS before MMF/AZA/MTX was median 4.5 (range 3-5). At last follow-up (median 2 years, range 0.2-8.6), median mRS was 1 (range 0-6). Median annualised relapse rate was 0.4 (range 0-6.7) pre-MMF/AZA/MTX (excluding first events), and 0 on MMF/AZA/MTX (mean 0.03, range 0-0.8). 7% patients relapsed on MMF/AZA/MTX. These relapsing patients had low rate of second-line treatments before MMF/AZA/MTX (25%), long median time between onset and MMF/AZA/MTX usage (18 months), and frequently they were started on MMF/AZA/MTX only after relapse (75%). Relapse rate was lower among patients who received first immune therapy ≤30 days (25%) than later (64%), who received second-line treatments at first event (14%) rather than not (64%), who were started on MMF/AZA/MTX after the first (12%) rather than subsequent events (17%), and who were started on MMF/AZA/MTX ≤3 months from onset (33%) rather than later (53%). Adverse reactions to MMF/AZA/MTX occurred in 2 cases (cytomegalovirus colitis and respiratory infection), of grade 3 Common Terminology Criteria for Adverse Events v4.0.

DISCUSSION

Our literature review disclosed heterogeneity in the use of MMF/AZA/MTX in paediatric-onset anti-NMDARE. MMF/AZA/MTX usage is mostly restricted to retrospective cohort descriptions. These agents may reduce risk of relapse, and have a reasonable safety profile, however data on larger cohorts are required to definitively determine effect.

Antibodies to myelin oligodendrocyte glycoprotein in chronic relapsing inflammatory optic neuropathy

BACKGROUND/AIMS

To evaluate the status of myelin oligodendrocyte glycoprotein antibodies (MOG-IgG) in chronic relapsing inflammatory optic neuropathy (CRION) and investigate its different clinical characteristics and prognosis.

METHODS

Patients diagnosed with CRION were recruited by the Neuro-ophthalmology Department of the Chinese People's Liberation Army General Hospital from December 2015 to April 2017. Based on antibody status, they were assigned to either the MOG-CRION or seronegative-CRION groups.

RESULTS

A total of 33 patients (38 eyes) were assessed and divided into the following groups: 22 (66.7%) MOG-CRION and 11 (33.3%) seronegative-CRION. The ratio of female to male was 1:1, and 81.8% of total CRION patients were adults (≥18 years). A total of 29 eyes (76.3%) showed severe visual loss (<20/200) during the first optic neuritis episode, and 37 eyes (72.5%) demonstrated good visual recovery (>20/40) during the final follow-up. The mean onset age of MOG-CRION patients was 28 ± 16 years (range 6-62), which was significantly younger than that of seronegative-CRION (45 ± 12 years, range 22-59) (p=0.029). The intraorbital and canalicular segments were highly involved in the orbital MRI of CRION patients. During the final follow-up, MOG-CRION patients had more bilateral involvement (p=0.008) and higher annualised relapse rates compared with the seronegative-CRION patients (p=0.019).

CONCLUSION

CRION was predominantly found in adults with unilateral ON and exhibited a higher rate of seropositive MOG-IgG. MOG-CRION, which may be a disparate subtype of MOG-IgG-induced demyelinating disease that needs further investigation, was found in younger patients at onset, with more bilateral involvement and more relapse tendency.