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

Sex ratio and age of onset in AQP4 antibody-associated NMOSD: a review and meta-analysis

BACKGROUND

Aquaporin-4 (AQP4) antibody-associated neuromyelitis optica spectrum disorder (NMOSD) is an antibody-mediated inflammatory disease of the central nervous system. We have undertaken a systematic review and meta-analysis to ascertain the sex ratio and mean age of onset for AQP4 antibody associated NMOSD. We have also explored factors that impact on these demographic data.

METHODS

A systematic search of databases was conducted according to the PRISMA guidelines. Articles reporting sex distribution and age of onset for AQP4 antibody-associated NMSOD were reviewed. An initially inclusive approach involving exploration with regression meta-analysis was followed by an analysis of just AQP4 antibody positive cases.

RESULTS

A total of 528 articles were screened to yield 89 articles covering 19,415 individuals from 88 population samples. The female:male sex ratio was significantly influenced by the proportion of AQP4 antibody positive cases in the samples studied (p < 0.001). For AQP4 antibody-positive cases the overall estimate of the sex ratio was 8.89 (95% CI 7.78-10.15). For paediatric populations the estimate was 5.68 (95% CI 4.01-8.03) and for late-onset cases, it was 5.48 (95% CI 4.10-7.33). The mean age of onset was significantly associated with the mean life expectancy of the population sampled (p < 0.001). The mean age of onset for AQP4 antibody-positive cases in long-lived populations was 41.7 years versus 33.3 years in the remainder.

CONCLUSIONS

The female:male sex ratio and the mean age of onset of AQP4 antibody-associated NMOSD are significantly higher than MS. The sex ratio increases with the proportion of cases that are positive for AQP4 antibodies and the mean age of onset increases with population life expectancy.

Cognitive and psychopathological features of neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein antibody-associated disease: A narrative review

Clinicians are becoming increasingly aware of the cognitive and psychopathological consequences of neurological diseases, which were once thought to manifest with motor and sensory impairments only. The cognitive profile of multiple sclerosis, in particular, is now well-characterised. Similar efforts are being made to better characterise the cognitive profile of other central nervous system inflammatory demyelinating autoimmune disorders. This review discusses the current understanding of the cognitive and psychological features of neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). Detailed analysis of the cognitive sequelae of the above conditions can not only assist with understanding disease pathogenesis but also can guide appropriate management of the symptoms and consequently, improve the quality of life and long-term outcomes for these patients. This narrative review will also identify research gaps and provide recommendations for future directions in the field.

Clinical features and prognosis of Tibetan patients with neuromyelitis optica spectrum disorder are different from those of Han Chinese patients

We compared the prognosis of Tibetan and Han Chinese patients with neuromyelitis optica spectrum disorder (NMOSD). The Expanded Disability Status Scale (EDSS) score at each attack, response to immunosuppressive therapy, risk of first relapse, severe attack, visual disability, motor disability, and total risk of disability were compared between Tibetan and Han Chinese patients. Tibetan patients showed higher EDSS during acute attacks. Annualized relapse rate did not differ between groups. Risk of severe attack, visual disability, and total risk of disability were higher in Tibetan patients. Tibetan patients with NMOSD have a higher risk of poor prognosis than Han Chinese patients.

Predicting time to serologic diagnosis of AQP4+ NMOSD based on clinical factors and social determinants of health

BACKGROUND

Early serologic diagnosis and initiation of targeted therapy are associated with better outcomes in aquaporin-4 IgG positive (AQP4+) neuromyelitis optica spectrum disorder (NMOSD).

OBJECTIVE

To determine predictors of time to serologic diagnosis of AQP4+ NMOSD.

METHODS

In CANOPTICS, a multi-centre, Canadian cohort study of NMOSD, we retrospectively evaluated time from the first clinical attack to first positive AQP4-IgG serology. We used a multivariable negative binomial regression model to evaluate possible predictors of time to diagnosis.

RESULTS

We identified 129 participants with AQP4+ NMOSD from 7 centres. Diagnostic delay of >1 month was observed in 82 (63.6 %). Asian compared to European (White) ethnicity (IRR:0.40, 95 % CI:0.21-0.78), female sex (IRR:0.56, 95 % CI:0.32-0.99), later calendar year (IRR:0.84, 95 % CI:0.81-0.86), and hospitalization for the first attack (IRR:0.35, 95 % CI:0.20-0.62) were associated with shorter times to serologic diagnosis. We did not observe any overall effect of Afro-Caribbean ethnicity, but in exploratory analyses, Afro-Caribbean individuals with low income had longer times to diagnosis.

CONCLUSION

More than 60 % of patients with NMOSD experienced delays to AQP4-IgG serologic diagnosis in this cohort. Given evidence of more adverse long-term outcomes in Afro-Caribbean individuals with NMOSD, intersectional effects of ethnicity and social determinants of health merit further study.

Patterns of neuromyelitis optica spectrum disorder attacks in different age groups and sexes depending on the status of immunosuppressive therapy: A retrospective cohort study

BACKGROUND AND PURPOSE

The association between onset age and sex with relapse risk in neuromyelitis optica spectrum disorder (NMOSD) remains inconclusive. We aimed to describe the clinical features of patients with NMOSD in different age groups and sexes and to analyse relapse characteristics pre- and post-immunosuppressive therapy (IST).

METHODS

Patients with NMOSD were retrospectively reviewed from our clinical centre's database. Demographic and clinical data, attack presentation, and disease course pre- and post-IST were investigated. We also analysed the effect of onset age on the annualized relapse rate and relapse risk according to sex and IST status. Interactions on the additive scale between onset age and sex were analysed. A restricted cubic spline was used to analyse potential nonlinear correlations. Longitudinal changes in the Expanded Disability Status Scale score across NMOSD attacks were analysed using linear mixed-effect models.

RESULTS

In total, 533 patients experienced 1394 attacks pre-IST and 753 relapses post-IST. Older age at onset was correlated with more myelitis attacks but fewer optic neuritis attacks, with no sex-related differences in attack presentation. Pre-IST, relapse risk increased with age at onset in women, while a U-shaped correlation between onset age and relapse risk was found in men. Post-IST, an inverted U-shaped association between the predicted relapse risk and onset age was observed in women. Conversely, a negative correlation between the predicted relapse risk and onset age was found in men. Overall, a higher ratio of myelitis attacks was found post-IST.

CONCLUSIONS

Patients of different onset ages and sexes had different relapse patterns before and after IST.

The Etiology and Outcome of Area Postrema Syndrome in Childhood: Two Cases and a Literature Review

BACKGROUND

Area postrema syndrome (APS), a rare childhood condition, manifests as intractable nausea and hiccups. APS has high diagnostic significance in neuromyelitis optica syndrome spectrum disorders (NMOSD) and can be the initial presentation of other critical diseases, including brainstem glioma.

METHODS

We described two representative cases of unrelated Japanese patients with APS. An etiologic evaluation, including a detailed intracranial neuroradiological examination and autoantibodies assessment, was performed. We also reviewed the literature focusing on the prognosis of pediatric APS symptoms.

RESULTS

A 14-year-old girl with aquaporin-4 antibody-positive NMOSD showed a good prognosis with immunotherapy, whereas another nine-year-old girl with irresectable medullary low-grade glioma had persistent symptoms for more than 10 years. All reported children aged >12 years were diagnosed with NMOSD, and patients aged <13 years showed heterogeneous etiologies.

CONCLUSIONS

Distinctive time courses and neuroimaging features were key clinical findings for the diagnostic and therapeutic processes in these patients. This literature review highlights the wide spectrum and prognosis of pediatric-onset APS.

The Impact of Neuroimmunologic Disease and Developing Nervous System

Over the last two decades, neuroimmunologic disorders of childhood have been increasingly described, phenotyped, and treated. These disorders remain rare in the general population and while sharing common therapeutic interventions due to their immune pathophysiology, are heterogeneous with regard to presentation and risk of recurrence. As such, the impact of these disorders on the developing brain has come into the forefront of emerging research in pediatric neuroimmunology. Investigations into the singular impact of monophasic disease on long-term development and the impact of early and aggressive disease-modifying therapy in relapsing conditions are quickly becoming areas of ripe investigation as the field's most optimal way to treat and monitor these conditions over time. Although critically important in evaluating the developing brain, research has been heterogeneous among these diseases and limited by small cohort size. This narrative review details the role of common neuroimmunologic disorders in long-term neurological and cognitive outcomes in children as they develop.

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.

Visual disability in neuromyelitis optica spectrum disorders: prognostic prediction models

Background and objectives

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory disease of the central nervous system characterized by simultaneous or consecutive episodes of acute optic neuritis and transverse myelitis. Attacks of NMOSD can result in the accrual of severe visual disability over time. This study aimed to develop and validate prognostic models for visual disability risk within 1, 3, and 5 years.

Methods

Medical records of NMOSD patients were retrospectively analyzed. The least absolute shrinkage and selection operator (LASSO) regression algorithm and univariate and multivariate Cox regression analyses were performed to select predictors of visual disability. Two models predicting the probability of visual disability in 1, 3, and 5 years were developed based on different selections and displayed as nomograms. Risk scores were calculated for every patient, and a cut-off point was obtained to recognize patients at high risk.

Results

In total, 161 (25.2%) patients developed visual disabilities during the follow-up period. Four visual disability-related factors were selected using LASSO regression: optic neuritis (ON) onset, higher annual relapse rate (ARR) before maintenance therapy, no maintenance immune suppression therapy (IST), and initial severe attack. Three additional predictors were determined using multivariate Cox regression: male sex, age at first onset, and positive AQP4-IgG serology. Discrimination and calibration were satisfied, with concordance indexes (C-index) close to 0.9 in both models. Decision curve analysis showed good clinical usefulness in both models, and Kaplan-Meier curves showed satisfactory discrimination between patients with high risk and low risk by the cut-off points.

Conclusion

This study reported predictors of visual disability and generated nomograms. High-risk patients need more active treatment and management to avoid unfavorable outcomes.

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.

Non-immune system comorbidity in neuromyelitis optica spectrum disorders

Comorbidities may influence the clinical features, prognosis, and treatment outcomes of neuromyelitis optica spectrum disorders (NMOSD). The aim of this study was to determine the status of non-immune system comorbidities in patients with NMOSD and the effect on treatment response and prognosis. We retrospectively collected data from all patients who met the 2015 NMOSD diagnostic criteria from the NMOSD database established by our center. Patients were divided into positive and negative groups based on the presence of non-immune disease comorbidities. Patient data, clinical characteristics, treatment response, prognosis, and mortality were compared between the two groups. A total of 138 patients with NMOSD plus comorbidities were included, and 404 patients without comorbidities were selected as controls. The average age at onset was older (45 years vs 38 years, P < 0.001), the mean body mass index was higher (23.12 vs 22.04, P = 0.042) and more patients experienced relapse after immunotherapy (68.5 % vs 54.5 %, P = 0.020) in the comorbidity group than in the non-comorbidity group. Multifocal central nervous system lesions as an initial symptom was more common in the comorbidity group than in the non-comorbidity group (30.4 % vs 18.32 %, P = 0.003). Further, more patients experienced severe vision attacks (28.3 % vs 15.8 %, P = 0.003) and severe motor attacks (30.4 % vs 11.9 %, P < 0.001) in the comorbidity group than in the non-comorbidity group. In conclusion, patients with NMOSD with comorbidities tended to be older, less responsive to treatment, and at a higher risk of vision loss and paralysis.

Altered functional connectivity associated with cognitive impairment in neuromyelitis optica spectrum disorder

BACKGROUND

Cognitive impairment is one of the common symptoms in patients with neuromyelitis optica spectrum disorder (NMOSD). However, the underlying mechanism remains unclear. Resting-state functional magnetic resonance imaging (rs-fMRI) offers the opportunity to reveal the patterns of brain activity in patients with different cognitive states. Accordingly, this study investigated functional connectivity (FC) abnormalities within and between the main cognitive networks in cognitively impaired (CI) patients with NMOSD and their correlations with cognitive performance.

METHODS

Thirty-four patients with NMOSD and 39 healthy controls (HC) were included. Neuropsychological evaluations and rs-fMRI scanning were performed. Patients were classified as CI (n = 16) or cognitively preserved (CP; n = 18) according to neuropsychological evaluations. Seven components representing six main cognitive networks were selected by group independent component analysis. The differences in inter- and intranetwork FC among CI, CP, and HC groups were assessed. The correlation between FC values and neuropsychological data in NMOSD was calculated.

RESULTS

The CI group showed decreased intranetwork connectivity in the posterior default mode network (pDMN) compared with the HC group (P < 0.05, GRF corrected), and decreased internetwork connectivity between the salience network (SN) and pDMN, and between the SN and right frontoparietal network (rFPN) compared with CP and HC groups. The altered FC values were significantly correlated with cognitive performance in the whole NMOSD group.

CONCLUSION

The disconnection within the pDMN and between the SN and pDMN or rFPN might suggest the neural substrates underlying cognitive impairment in NMOSD.

Myelitis features and outcomes in CNS demyelinating disorders: Comparison between multiple sclerosis, MOGAD, and AQP4-IgG-positive NMOSD

Inflammatory myelopathies can manifest with a combination of motor, sensory and autonomic dysfunction of variable severity. Depending on the underlying etiology, the episodes of myelitis can recur, often leading to irreversible spinal cord damage and major long-term disability. Three main demyelinating disorders of the central nervous system, namely multiple sclerosis (MS), aquaporin-4-IgG-positive neuromyelitis optica spectrum disorders (AQP4+NMOSD) and myelin oligodendrocyte glycoprotein-IgG associated disease (MOGAD), can induce spinal cord inflammation through different pathogenic mechanisms, resulting in a more or less profound disruption of spinal cord integrity. This ultimately translates into distinctive clinical-MRI features, as well as distinct patterns of disability accrual, with a step-wise worsening of neurological function in MOGAD and AQP4+NMOSD, and progressive disability accrual in MS. Early recognition of the specific etiologies of demyelinating myelitis and initiation of the appropriate treatment is crucial to improve outcome. In this review article we summarize and compare the clinical and imaging features of spinal cord involvement in these three demyelinating disorders, both during the acute phase and over time, and outline the current knowledge on the expected patterns of disability accrual and outcomes. We also discuss the potential implications of these observations for patient management and counseling.

Identifying different cognitive phenotypes and their relationship with disability in neuromyelitis optica spectrum disorder

Background

The existence, frequency, and features of cognitive impairment (CI) in patients with neuromyelitis optica spectrum disorder (NMOSD) are still debated. A precise classification and characterization of cognitive phenotypes in patients with NMOSD are lacking.

Methods

A total of 66 patients with NMOSD and 22 healthy controls (HCs) underwent a neuropsychological assessment. Latent profile analysis (LPA) on cognitive test z scores was used to identify cognitive phenotypes, and ANOVA was used to define the clinical features of each phenotype. Univariate and multivariate analyses were used to explore the predictors of severe CI, and a corresponding nomogram was created to visualize the predictive model.

Results

LPA results suggested four distinct meaningful cognitive phenotypes in NMOSD: preserved cognition (n = 20, 30.3%), mild-attention (n = 21, 31.8%), mild-multidomain (n = 18, 27.3%), and severe-multidomain (n = 7, 10.6%). Patients with the last three phenotypes were perceived to have CI, which accounts for 67.6% of patients with NMOSD. Patients with NMOSD and worse cognitive function were older (p < 0.001) and had lower educational levels (p < 0.001), later clinical onset (p = 0.01), worse Expanded Disability Status Scale scores (p = 0.001), and poorer lower-limb motor function (Timed 25-Foot Walk, p = 0.029; 12-item Multiple Sclerosis Walking Scale [MSWS-12], p < 0.001). Deterioration of Nine-Hole Peg Test (odds ratio, OR: 1.115 [1, 1.243], p = 0.05) and MSWS-12 (OR: 1.069 [1.003, 1.139], p = 0.04) were the independent risk factors for severe cognitive dysfunction. Finally, a nomogram was built based on the entire cohort and the above factors to serve as a useful tool for clinicians to evaluate the risk of severe cognitive dysfunction.

Conclusions

We introduced a classification scheme for CI and highlighted that the deterioration of upper- and lower-limb motor disability potentially predicts cognitive phenotypes in NMOSD.

Sex bias in multiple sclerosis and neuromyelitis optica spectrum disorders: How it influences clinical course, MRI parameters and prognosis

This review is a condensed summary of representative articles addressing the sex/gender bias in multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD). The strong effects of sex on the incidence and possibly also the activity and progression of these disorders should be implemented in the evaluation of any phase of clinical research and also in treatment choice consideration in clinical practice and evaluation of MRI parameters. Some relationships between clinical variables and gender still remain elusive but with further understanding of sex/gender-related differences, we should be able to provide appropriate patient-centered care and research.

Chronic Cognitive Impairment in AQP4+ NMOSD With Improvement in Cognition on Eculizumab: A Report of Two Cases

Cognitive impairment may be associated with aquaporin-4 antibody positive (AQP4+) NMOSD, particularly where there is prominent cerebral, corpus callosum, or thalamic involvement. It is unclear to what extent this phenomenon may be treatable after months to years. We describe two cases of AQP4+ NMOSD with cognitive impairment persisting over more than 6 months, where cognition improved after eculizumab was initiated. In the first case, a 51-year-old woman presented with a 2-month history of cognitive decline and ataxia, and diffuse involvement of the corpus callosum on MRI. AQP4 antibody testing returned positive. Cognitive impairment persisted on therapy with mycophenolate, then rituximab. She was switched to eculizumab from rituximab 18 months after disease onset because of breakthrough optic neuritis; memory and cognitive function improved on eculizumab. In the second case, a 26-year-old woman initially presented with visual, auditory and tactile hallucinations, and impairment in activities of daily living, and was given a diagnosis of schizophrenia. Nine months later she was hospitalized for increasing confusion. MRI showed leukoencephalopathy and diffuse involvement of the corpus callosum with multiple enhancing callosal lesions. AQP4 antibody testing was positive and CSF testing for other antibodies of autoimmune encephalitis was negative. She had some improvement in cognition with high dose corticosteroids but remained significantly impaired. On follow-up, her repeat MRI showed a small new right inferomedial frontal enhancing lesion although she did not complain of any new cognitive issues, her MOCA score was 21/30, and she was started on eculizumab. Two months after eculizumab initiation she and her family reported cognitive improvement and MOCA score was 25/30. Common features of these two cases included extensive callosal involvement and an element of ongoing gadolinium enhancement on MRI. Our experience suggests the possibility that cognitive impairment may be amenable to immunotherapy in certain cases of NMOSD.

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.