Molecular pathogenesis of neuromyelitis optica

Macular microvascular and structural changes on optical coherence tomography angiography in atypical optic neuritis

BACKGROUND

Atypical optic neuritis, consisting of neuromyelitis optica spectrum disorders (NMOSD) or myelin oligodendrocyte glycoprotein antibody disease (MOGAD), has a very similar presentation but different prognostic implications and long-term management strategies. Vascular and metabolic factors are being thought to play a role in such autoimmune neuro-inflammatory disorders, apart from the obvious immune mediated damage. With the advent of optical coherence tomography angiography (OCTA), it is easy to pick up on these subclinical macular microvascular and structural changes.

AIM

To study the macular microvascular and structural changes on OCTA in atypical optic neuritis.

METHODS

This observational cross-sectional study involved 8 NMOSD and 17 MOGAD patients, diagnosed serologically, as well as 10 healthy controls. Macular vascular density (MVD) and ganglion cell + inner plexiform layer thickness (GCIPL) were studied using OCTA.

RESULTS

There was a significant reduction in MVD in NMOSD and MOGAD affected as well as unaffected eyes when compared with healthy controls. NMOSD and MOGAD affected eyes had significant GCIPL thinning compared with healthy controls. NMOSD unaffected eyes did not show significant GCIPL thinning compared to healthy controls in contrast to MOGAD unaffected eyes. On comparing NMOSD with MOGAD, there was no significant difference in terms of MVD or GCIPL in the affected or unaffected eyes.

CONCLUSION

Although significant microvascular and structural changes are present on OCTA between atypical optic neuritis and normal patients, they could not help in differentiating between NMOSD and MOGAD cases.

Indirect Immunofluorescence-Aided Detection of Antimyelin Oligodendrocyte Glycoprotein Antibodies in Neuromyelitis Optica Spectrum Disorder/Myelin Oligodendrocyte Glycoprotein-Associated Antibody Disorder: A Case Series Involving Five Patients

Autoantibodies are the cause of the chronic inflammatory diseases known as neuromyelitis optica spectrum disorders (NMOSD). Serum antibodies (Abs) that specifically target the aquaporin-4 (AQP-4) water channel are the cause of recurrent episodes of optic neuritis, myelitis, and/or brain stem disorders. In contrast to AQP-4 Abs, myelin oligodendrocyte glycoprotein (MOG) Abs are detected in some patients exhibiting nonmotor cognitive impairment. These days, the term "MOG-encephalomyelitis" (MOG-EM) is frequently used to describe these clinical syndromes. The diagnosis of these cases involves the use of magnetic resonance imaging, optical coherence tomography, antibody detection, and additional laboratory testing. By detecting the patient's Abs in their serum or cerebrospinal fluid (CSF), indirect immunofluorescence (IIF) aids in the proper diagnosis. We highlight five NMOSD cases where serum anti-MOG antibody positivity was found using IIF, but CSF was not. In none of the cases, anti-AQP Abs were found. Effective patient management strategies include the treatment of acute attacks and long-term immunosuppressive drugs such as rituximab, azathioprine, and immunoglobulins. IIF is a quick and easy tool to detect anti-MOG Abs in patients with NMOSD/myelin oligodendrocyte glycoprotein antibody-associated disorder. CSF testing for MOG or AQP-4 Abs is not usually advised. It does not offer additional benefits to help with MOG-EM or NMOSD diagnosis.

A rare case of systemic lupus erythematosus-associated neuromyelitis optica spectrum disorder with cystic lesions and dual seropositivity for anti-AQP4 and anti-MOG antibodies

Key Clinical Message

In patients with SLE, concurrent NMOSD can manifest with optic neuritis and transverse myelitis. AQP-4 antibody positivity confirms the diagnosis. Prompt treatment is critical to manage the acute symptoms and prevent relapses, as highlighted by a young patient's case with optic neuritis and extensive spinal cord lesions.

Abstract

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune disorder of the central nervous system that affects the optic nerve and spinal cord. It is associated with autoantibodies against aquaporin-4 (AQP-4) and/or myelin oligodendrocytes glycoproteins. It is diagnosed based on clinical, radiological, and serological criteria, and treated with immunosuppressants in the acute phase. Long-term immunosuppression is essential to prevent potential relapses. In this case report, we present the case of a 19-year-old female patient with systemic lupus erythematosus (SLE), who presented with blurriness and loss of vision in her left eye. Optical coherence tomography was normal, but a gadolinium-enhanced cervico-dorsal MRI showed multiple lesions extending from the brainstem to the C7-T1 junction suggestive of longitudinally extensive transverse myelitis (LETM), the largest of which was a cystic lesion at the cervico-spinal junction. A contrast injection also revealed left optic neuritis. Cerebrospinal fluid analysis showed elevated IgG and red blood cell count, but no oligoclonal bands. The patient tested positive for AQP-4 autoantibodies, confirming the diagnosis of NMOSD. Treatment with intravenous methylprednisolone led to partial improvement, but the patient experienced a relapse with severe neurological symptoms, including tetraplegia and bladder and bowel dysfunction. This case illustrates the importance of considering NMOSD in the differential diagnosis of patients with SLE who present with optic neuritis and/or myelitis, especially when MRI findings are suggestive of LETM. Early diagnosis and adherence to treatment are crucial to prevent further relapses and deleterious sequelae.

Emerging functions and therapeutic targets of IL-38 in central nervous system diseases

Interleukin (IL)-38 is a newly discovered cytokine of the IL-1 family, which binds various receptors (i.e., IL-36R, IL-1 receptor accessory protein-like 1, and IL-1R1) in the central nervous system (CNS). The hallmark physiological function of IL-38 is competitive binding to IL-36R, as does the IL-36R antagonist. Emerging research has shown that IL-38 is abnormally expressed in the serum and brain tissue of patients with ischemic stroke (IS) and autism spectrum disorder (ASD), suggesting that IL-38 may play an important role in neurological diseases. Important advances include that IL-38 alleviates neuromyelitis optica disorder (NMOD) by inhibiting Th17 expression, improves IS by protecting against atherosclerosis via regulating immune cells and inflammation, and reduces IL-1β and CXCL8 release through inhibiting human microglial activity post-ASD. In contrast, IL-38 mRNA is markedly increased and is mainly expressed in phagocytes in spinal cord injury (SCI). IL-38 ablation attenuated SCI by reducing immune cell infiltration. However, the effect and underlying mechanism of IL-38 in CNS diseases remain inadequately characterized. In this review, we summarize the biological characteristics, pathophysiological role, and potential mechanisms of IL-38 in CNS diseases (e.g., NMOD, Alzheimer's disease, ASD, IS, TBI, and SCI), aiming to explore the therapeutic potential of IL-38 in the prevention and treatment of CNS diseases.

Prevalence, Demographic, and Clinical Factors Associated With Cognitive Dysfunction in Patients With Neuromyelitis Optica Spectrum Disorder

BACKGROUND AND OBJECTIVES

Neuromyelitis optica spectrum disorder (NMOSD) is a chronic CNS demyelinating autoimmune disorder targeting the astrocyte antigen aquaporin-4 (AQP4), typically presenting with optic neuritis, transverse myelitis, and brain syndromes. Cognitive dysfunction (CD) in NMOSD is under-recognized and poorly understood. The purpose of this study was to evaluate the prevalence and clinical variables associated with CD in NMOSD.

METHODS

This observational retrospective study with longitudinal follow-up describes a clinical cohort seen in the Collaborative International Research in Clinical and Longitudinal Experience Study in NMOSD. Serial Montreal Cognitive Assessments (MoCAs) were performed upon enrollment and at 6-month intervals to evaluate longitudinal cognitive function relative to demographic and disease-related factors. We used 2-tailed t test, analysis of variance, the χ2 test, linear regression for univariable and adjusted analyses and simultaneous linear regression and mixed-effects model for multivariable analyses.

RESULTS

Thirty-four percent (75/219) of patients met criteria for CD (MoCA <26); 29% (64/219) showed mild dysfunction (MoCA 20-26/30), and 5% (11/219) showed moderate (MoCA <20/30) dysfunction. Patients with less neurologic disability and lower pain scores had higher MoCA scores (95% CI 0.24-0.65 and 95% CI 0.09-0.42, respectively). Patients with at least high school education scored higher on the MoCA (95% CI 2.2-5). When comparing patients dichotomized for CD, patients never on rituximab scored higher than patients only treated with rituximab (p < 0.029). There was no significant association between annualized relapse rate, age, sex, disease duration, AQP4 serostatus or brain lesions, and CD. CD was more pronounced among Black than White patients (95% CI -2.7 to -0.7). Multivariable analysis of serial MoCA did not indicate change (p = 0.715). Descriptive analysis of serial MoCA showed 30% (45/150) of patients with worsening MoCA performance had impaired language and verbal recall.

DISCUSSION

To our knowledge, this is the largest study of diverse cohort to investigate CD in patients with NMOSD. Our findings demonstrate 34% of patients with NMOSD experience mild-to-moderate CD, while 30% of patients demonstrated decline on serial testing. The substantial prevalence of CD in this pilot report highlights the need for improved and validated screening tools and comprehensive measures to investigate CD in NMOSD.

Fahr's syndrome as a manifestation of autoimmune polyendocrine syndrome-1 and its unusual association with neuromyelitis optica spectrum disorder

Fahr's syndrome, also known as bilateral striopallidodendate calcinosis, is a rare inherited neurodegenerative illness characterized by abnormal calcium deposition in several areas of the brain, resulting in a wide range of neuropsychological symptoms. Fahr's syndrome, secondary to autoimmune polyendocrine syndrome type 1, which includes adrenal insufficiency and mucocutaneous candidiasis in addition to hypoparathyroidism, is exceedingly rare. No case report has been documented to date to show the co-occurrence of Fahr's syndrome and neuromyelitis optica spectrum disorder. Here, we discuss the case of a 30-year-old man with a previous history of seizures and symptoms of ectodermal dystrophy presented with seizures, left-sided hemiparesis, dysarthria, and other characteristics indicative of severe hypocalcemia. The neuroimaging findings strongly suggested Fahr's syndrome, with radiographic evidence of Neuromyelitis optica spectrum disorder as longitudinal extensive transverse myelitis in the cervical spinal cord, high titers of serum aquaporin-4 antibodies, and demyelinating neuropathy on nerve conduction studies. This distinct neuropsychological presentation and neuroimaging findings led to the diagnosis of Fahr's syndrome as a result of hypoparathyroidism caused by autoimmune polyendocrine syndrome type 1 with cooccurrence of neuromyelitis optica spectrum disorder. The patient's clinical symptoms improved considerably after he was treated based on a provisional diagnosis. The clinical importance of our case is significant for both neuropsychiatrists and endocrinologists, as autoimmune polyendocrine syndrome should be considered as the etiology of Fahr's syndrome. This case report also aims to report this unusual association of Neuromyelitis optica spectrum disorder with Fahr's syndrome to give the future prospective to know whether this association is incidental or there is a missing link between these two different disorders.

An Update on the Laboratory Diagnosis of Neuromyelitis Optica Spectrum Disorders

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disorder of the central nervous system that is specifically associated with demyelination of spinal cord and optic nerves. The discovery of specific autoantibody markers such as aquaporin-4 IgG and myelin oligodendrocyte glycoprotein IgG has led to several methodologies being developed and validated. There have been numerous investigations of the clinical and radiological presentations used in the clinical diagnosis of NMOSD. However, although various laboratory diagnostic techniques have been standardized and validated, a gold-standard test has yet to be finalized due to uncertain sensitivities and specificities of the methodologies. For this review, the literature was surveyed to compile the standardized laboratory techniques utilized for the differential diagnosis of NMOSD. Enzyme-linked immunosorbent assays enable screening of NMOSD, but they are considered less sensitive than cell-based assays (CBAs), which were found to be highly sensitive and specific. However, CBAs are laborious and prone to batch variations in their results, since the expression levels of protein need to be maintained and monitored meticulously. Standardizing point-of-care devices and peptide-based assays would make it possible to improve the turnaround time and accessibility of the test, especially in resource-poor settings.

A Case of Neuromyelitis Optica: Puerto Rican Woman with an Increased Time Lag to Diagnosis and a High Response to Eculizumab Therapy

A link between intractable hiccups, as the initial symptom, and a possible neuromyelitis optica spectrum disorder (NMOSD) diagnosis is confusing but vital and may not be made by health care providers (HCPs) if they are not aware of the 2015 NMOSD criteria. Early diagnosis and adequate treatment are essential to prevent disease progression. We report the case of a 46-year-old Puerto Rican female who presented intractable hiccups when she was 31 (in 2004). Almost 15 years passed since the initial symptom, and after two severe relapses, she received a formal NMOSD diagnosis in March 2019. Treatment started with rituximab 1000 mg IV in April 2019. However, a lack of response to treatment led to a switch to eculizumab therapy in August 2019. The patient had cervical and brain magnetic resonance imaging (MRI) conducted in June 2020, which depicted a remarkable decrease in swelling and hyperintensity within the cervical spinal cord with no enhancing lesions when compared with the first MRI from February 2019. In addition, the patient suffered no new relapses, an improvement regarding disability, and a reduction of the cervical spinal cord lesion size. Nonetheless, this substantial decrease does not occur on all NMOSD patients, but more awareness of the disease is needed, especially in Puerto Rico. This case illustrates the efficacy of eculizumab therapy and the importance of differentiating the clinical, histopathological, and neuroimaging characteristics that separate demyelinating autoimmune inflammatory disorders, such as NMOSD and multiple sclerosis (MS).

The frequencies of peripheral blood CD5+CD19+ B cells, CD3-CD16+CD56+ NK, and CD3+CD56+ NKT cells and serum interleukin-10 in patients with multiple sclerosis and neuromyelitis optica spectrum disorder

BACKGROUND

Multiple sclerosis (MS) and neuromyelitis optica syndrome disease (NMOSD) are inflammatory diseases of the central nervous system. The pathogenesis and treatments for these two conditions are very different. Natural killer (NK) and natural killer T (NKT) cells are immune cells with an important role in shaping the immune response. B cells are involved in antigen presentation as well as antibody and cytokine production. There is conflicting evidence of the roles of NK, NKT, and B cells in the two conditions. We aimed to compare the frequency of CD3-CD16+CD56+NK, CD3+ CD56+ NKT, and CD5+CD19+ B cells in the peripheral blood and serum Interleukin-10 (IL-10) in patients with MS and NMOSD.

METHODS

CD19+CD5+ B, CD3- CD16+CD56+ NK, and CD3+CD56+ NKT cells were quantitated by flow cytometry in 15 individuals with Interferon-Beta (IFN-β) treated relapsing-remitting MS (RRMS), 15 untreated RRMS, and 15 NMOSD patients as well as 30 healthy controls (HC). Serum IL-10 was measured using an enzyme-linked immunosorbent assay (ELISA).

RESULTS

The percentage of CD3-CD56+CD16+ NK cells in the peripheral blood of IFN-treated MS (1.81 ± 0.87) was significantly lower than for untreated RRMS (4.74 ± 1.80), NMOSD (4.64 ± 1.26) and HC (5.83 ± 2.19) (p < 0.0001). There were also differences for the percentage of CD3-CD16+ and CD3-CD56+ cells (p < 0.001 and p < 0.0007; respectively). IFN-treated RRMS (2.89 ± 1.51) had the lowest proportion of CD3+CD56+ among the study groups (p < 0.002). Untreated RRMS (5.56 ± 3.04) and NMOSD (5.47 ± 1.24) had higher levels of CD3+CD56+ than the HC (3.16 ± 1.98). The mean percentage of CD19+CD5+ B cells in the peripheral blood of untreated RRMS patients (1.32 ± 0.67) was higher compared to the patients with NMOSD (0.30 ± 0.20), HC (0.5 ± 0.22) and IFN-treated RRMS (0.81 ± 0.17) (p < 0.0001). Serum interleukin-10 was significantly higher in the IFN-treated RRMS (8.06 ± 5.39) and in HC (8.38 ± 2.84) compared to untreated RRMS (5.07 ± 1.44) and the patients with NMOSD (5.33 ± 2.56) (p < 0.003).

CONCLUSIONS

The lower proportion of CD3-CD56+ CD16+ NK and CD3+CD56+ cells in peripheral blood of IFN-treated RRMS compared to other groups suggests the importance of immunomodulation in patients with RRMS disorder. Based on the differences in CD19+CD5+ B cells and serum IL-10 between patients and HC, supplementary assessments could be of value in clarifying their roles in autoimmunity.

Central Nervous System Systemic Lupus Erythematosus: Pathophysiologic, Clinical, and Imaging Features

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by multiple immunologic abnormalities and has the potential to involve the central nervous system (CNS). The prevalence of SLE seems to be growing, possibly because of earlier diagnosis and improved survival; however, the associated mortality is still high. The mortality is associated with disease-related risk factors such as lupus disease activity, young age, and organ damage or with antiphospholipid syndrome (APS). Neuropsychiatric SLE (NPSLE), which is caused by SLE-related CNS involvement, comprises a broad range of neurologic and psychiatric manifestations with varying severity, which can make this disease indistinguishable from other conditions that are unrelated to SLE. No unifying pathophysiology has been found in the etiology of NPSLE, suggesting that this condition has multiple contributors such as various immune effectors and the brain-intrinsic neuroimmune interfaces that are breached by the immune effectors. The postulated neuroimmune interfaces include the blood-brain barrier, blood-cerebrospinal fluid barrier, meningeal barrier, and glymphatic system. On the basis of the immunologic, pathologic, and imaging features of NPSLE, the underlying pathophysiology can be classified as vasculitis and vasculopathy, APS, demyelinating syndrome, or autoimmune antibody-mediated encephalitis. Each pathophysiology has different imaging characteristics, although the imaging and pathophysiologic features may overlap. Moreover, there are complications due to the immunocompromised status caused by SLE per se or by SLE treatment. Radiologists and clinicians should become familiar with the underlying mechanisms, radiologic findings, and complications of NPSLE, as this information may aid in the diagnosis and treatment of NPSLE. Online supplemental material is available for this article. ^©RSNA, 2022.

Safety and efficacy of interleukin-6-receptor inhibitors in the treatment of neuromyelitis optica spectrum disorders: a meta-analysis

BACKGROUND

Interleukin-6-receptor inhibitors like Tocilizumab and Satralizumab are showing promising results in the treatment of Neuromyelitis Optica spectrum disorder (NMOSD). We aimed to investigate the efficacy and safety of various Interleukin-6-receptor inhibitors in the management of NMO/NMOSD.

METHODS

PubMed, Embase, and The Cochrane Library were systematically searched for suitable studies. Change in Annualized Relapse Ratio (ARR), Change in Extended Disability Status Scale (EDSS) s, the proportion of relapse-free patients and proportion of patients with adverse events, including serious adverse events and mortality were the parameters considered for the meta-analysis for Tocilizumab. Mean difference (MD) with 95% CI was used to quantify the change in ARR and change in EDSS before and after treatment. A forest plot was prepared to indicate the efficacy and adverse effects outcomes. The results were compared with those of Satralizumab included in two trials.

RESULTS

A total of nine studies with 202 patients were included in our study. Tocilizumab found a good proportion (76.95% CI: 0.61-0.91; p < 0.001) of relapse free patients at follow up. It also significantly reduced mean ARR (mean difference: -2.6, 95% CI: - 2.71 to - 1.68; p < 0.001) and but did not show significant difference in change in EDSS score (mean difference = - 0.79, 95% CI: - 1.89 to - 0.31; p = 0.16). Also, the toxicity profile of Tocilizumab was acceptable considering the proportions of patients with adverse events 56% (95% C.I.;0.27-0.85, I2 = 88.95%, p < 0.001), proportions of patients with serious adverse events 11% (95% C.I.; 0.05 to 0.17, I2 = 0%, p < 0.001) and zero treatment related deaths. SAkura studies for Satralizumab showed similar relapse free patients (70% to 80%) and reduction of ARR and EDSS from baseline. Some studies of Tocilizumab have shown to reduce pain and fatigue while trials of Satralizumab had non-significant findings.

CONCLUSION

Interleukin-6-receptor inhibitors therapy showed a promising result with good efficacy and acceptable adverse events profile for treatment of NMOSD.

Monocyte to High-Density Lipoprotein Ratio: A Novel Predictive Marker of Disease Severity and Prognosis in Patients With Neuromyelitis Optica Spectrum Disorders

Background and Purpose: To investigate the association of monocyte to high-density lipoprotein ratio (MHR) with disease severity and prognosis in patients with neuromyelitis optica spectrum disorders (NMOSD).

Methods: This retrospective study included 125 patients with NMOSD. Demographic and clinical parameters, including the MHR, were assessed. The initial Expanded Disability Status Scale (EDSS) score and relapse rate were used to evaluate disease severity and prognosis, respectively. Correlations between MHR and disease severity and relapse rate were analyzed. The predictive value of MHR for prognosis was evaluated using receiver operating characteristic (ROC) curve analysis.

Results: Compared with the low MHR group, the initial EDSS score (median 4.5 vs. 5.5%, P = 0.025) and relapse rate (51.61 vs. 30.16%, P = 0.015) were significantly higher in the high MHR group. MHR was positively correlated with the initial EDSS score (r = 0.306, P = 0.001). Multivariate analysis showed that MHR was significantly associated with severity (odds ratio = 7.90, 95% confidence interval [CI] = 1.08–57.82, P = 0.041), and it was a significant predictor of disease prognosis (hazard ratio = 3.12, 95% CI = 1.02–9.53, P = 0.046). The median relapse interval of the high MHR group was 24.40 months. When the MHR was higher than 0.565, the risk of relapse was high [sensitivity, 33.3%; specificity, 91.9%; area under the ROC curve, 0.642 (95% CI = 0.54–0.74, P = 0.007)].

Conclusion: MHR is a novel predictive marker of disease severity and prognosis in patients with NMOSD. Early monitoring and reduction of MHR may allow earlier intervention and improved prognosis.

Neuromyelitis Optica in a Healthy Female After Severe Acute Respiratory Syndrome Coronavirus 2 mRNA-1273 Vaccine

Neuromyelitis optica spectrum disorder is an autoimmune demyelinating disease with high relative prevalence in the East Asian population. Clinical manifestations include optic neuritis, longitudinally extensive transverse myelitis, area postrema syndrome, brainstem syndromes, and diencephalic syndromes. In this case report, we present a case of neuromyelitis optica spectrum disorder that developed 10 days after the first dose of the severe acute respiratory syndrome coronavirus 2 mRNA-1273 vaccine. The patient was a previously healthy White female, completely independent and functional at baseline. She presented with bilateral lower-extremity numbness/tingling, weakness, and urinary retention. Although her neuromyelitis optica IgG was negative, the MRI was consistent with neuromyelitis optica involving and spanning longitudinally the C6-T2 vertebrae. She was treated with IV steroids and her symptoms improved. Given the novelty of the COVID-19 vaccines and the paucity of literature regarding their adverse effects, case reports such as ours provide unique information that aids healthcare providers in accurately diagnosing and treating patients, ultimately minimizing long-term neurologic deficits.

MRI Patterns Distinguish AQP4 Antibody Positive Neuromyelitis Optica Spectrum Disorder From Multiple Sclerosis

Neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS) are inflammatory diseases of the CNS. Overlap in the clinical and MRI features of NMOSD and MS means that distinguishing these conditions can be difficult. With the aim of evaluating the diagnostic utility of MRI features in distinguishing NMOSD from MS, we have conducted a cross-sectional analysis of imaging data and developed predictive models to distinguish the two conditions. NMOSD and MS MRI lesions were identified and defined through a literature search. Aquaporin-4 (AQP4) antibody positive NMOSD cases and age- and sex-matched MS cases were collected. MRI of orbits, brain and spine were reported by at least two blinded reviewers. MRI brain or spine was available for 166/168 (99%) of cases. Longitudinally extensive (OR = 203), "bright spotty" (OR = 93.8), whole (axial; OR = 57.8) or gadolinium (Gd) enhancing (OR = 28.6) spinal cord lesions, bilateral (OR = 31.3) or Gd-enhancing (OR = 15.4) optic nerve lesions, and nucleus tractus solitarius (OR = 19.2), periaqueductal (OR = 16.8) or hypothalamic (OR = 7.2) brain lesions were associated with NMOSD. Ovoid (OR = 0.029), Dawson's fingers (OR = 0.031), pyramidal corpus callosum (OR = 0.058), periventricular (OR = 0.136), temporal lobe (OR = 0.137) and T1 black holes (OR = 0.154) brain lesions were associated with MS. A score-based algorithm and a decision tree determined by machine learning accurately predicted more than 85% of both diagnoses using first available imaging alone. We have confirmed NMOSD and MS specific MRI features and combined these in predictive models that can accurately identify more than 85% of cases as either AQP4 seropositive NMOSD or MS.

Magnetic resonance imaging in neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory disease of the central nervous system (CNS) associated with antibodies to aquaporin-4 (AQP4), which has distinct clinical, radiological and pathological features, but also has some overlap with multiple sclerosis and myelin oligodendrocyte glycoprotein (MOG) antibody associated disease. Early recognition of NMOSD is important because of differing responses to both acute and preventive therapy. Magnetic resonance (MR) imaging has proved essential in this process. Key MR imaging clues to the diagnosis of NMOSD are longitudinally extensive lesions of the optic nerve (more than half the length) and spinal cord (three or more vertebral segments), bilateral optic nerve lesions and lesions of the optic chiasm, area postrema, floor of the IV ventricle, periaqueductal grey matter, hypothalamus and walls of the III ventricle. Other NMOSD-specific lesions are denoted by their unique morphology: heterogeneous lesions of the corpus callosum, 'cloud-like' gadolinium (Gd)-enhancing white matter lesions and 'bright spotty' lesions of the spinal cord. Other lesions described in NMOSD, including linear periventricular peri-ependymal lesions and patch subcortical white matter lesions, may be less specific. The use of advanced MR imaging techniques is yielding further useful information regarding focal degeneration of the thalamus and optic radiation in NMOSD and suggests that paramagnetic rim patterns and changes in normal appearing white matter are specific to MS. MR imaging is crucial in the early recognition of NMOSD and in directing testing for AQP4 antibodies and guiding immediate acute treatment decisions. Increasingly, MR imaging is playing a role in diagnosing seronegative cases of NMOSD.

Sera from Patients with NMOSD Reduce the Differentiation Capacity of Precursor Cells in the Central Nervous System

INTRODUCTION

AQP4 (aquaporin-4)-immunoglobulin G (IgG)-mediated neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory demyelinating disease that affects the central nervous system, particularly the spinal cord and optic nerve; remyelination capacity in neuromyelitis optica is yet to be determined, as is the role of AQP4-IgG in cell differentiation.

MATERIAL AND METHODS

We included three groups-a group of patients with AQP4-IgG-positive neuromyelitis optica, a healthy group, and a sham group. We analyzed differentiation capacity in cultures of neurospheres from the subventricular zone of mice by adding serum at two different times: early and advanced stages of differentiation. We also analyzed differentiation into different cell lines.

RESULTS AND CONCLUSIONS

The effect of sera from patients with NMOSD on precursor cells differs according to the degree of differentiation, and probably affects oligodendrocyte progenitor cells from NG2 cells to a lesser extent than cells from the subventricular zone; however, the resulting oligodendrocytes may be compromised in terms of maturation and possibly limited in their ability to generate myelin. Furthermore, these cells decrease in number with age. It is very unlikely that the use of drugs favoring the migration and differentiation of oligodendrocyte progenitor cells in multiple sclerosis would be effective in the context of neuromyelitis optica, but cell therapy with oligodendrocyte progenitor cells seems to be a potential alternative.

Eculizumab in the Treatment of Aquaporin-4 Seronegative Neuromyelitis Optica Spectrum Disorder: A Case Report

Objective: To report the case of a 35-year-old woman with treatment-resistant aquaporin-4 (AQP-4) immunoglobulin G (IgG) seronegative neuromyelitis optica spectrum disorder (NMOSD) successfully treated with eculizumab (a terminal complement inhibitor).

Methods: The investigational procedures and treatment regimens the patient received were documented over 8 years [2012 (first presentation) to 2020].

Results: The patient presented with subacute onset of lower-limb weakness and numbness, gait imbalance, and urinary incontinence. Magnetic resonance imaging (MRI) showed abnormalities in the thoracic spine from T7 to T10, but brain and cervical spine scans, visual evoked potential latencies, and IgG index were normal; cerebrospinal fluid pleocytosis and oligoclonal bands were both present. After treatment with intravenous methylprednisolone 1 g/day for 5 days, the patient was discharged without medication to acute rehabilitation but experienced relapses from 2012 to 2014. She was treated with oral prednisone (initiated at 40 mg/day in 2014; the dose was halved in 2015 due to weight gain) and mycophenolate mofetil (MMF) 1 g twice daily (from June 2015), but between 2014 and 2019 experienced 4–5 relapses/year, requiring treatment with intravenous methylprednisolone, with added maintenance plasma exchange from 2018 onwards. Although the patient tested negative for antibodies to AQP-4 and myelin oligodendrocyte glycoprotein, she was diagnosed with NMOSD in February 2017, based on recurrent episodes of longitudinal extensive transverse myelitis, MRI changes, and area postrema syndrome. By 2018 the patient needed a cane to walk. Prednisone and MMF were discontinued mid-2018, and rituximab was prescribed from July 2018 (maintenance regimen two 1 g doses 2 weeks apart every 6 months) but discontinued in July 2019 owing to lack of significant improvement. From July 2019 eculizumab was prescribed for 6 months (900 mg weekly for the first four doses, then 1200 mg every 2 weeks). The patient had no relapses or adverse events during and after eculizumab treatment (as of August 2020) and was able to walk unaided; her Expanded Disability Status Scale score improved from 4–5 during 2015–2018 to 2 in 2020 following eculizumab treatment.

Conclusion: Eculizumab shows promise as a treatment for AQP-4 IgG-seronegative NMOSD and further studies are warranted.

The Emerging Role of Microglia in Neuromyelitis Optica

Neuromyelitis optica (NMO) is an autoantibody-triggered neuro-inflammatory disease which preferentially attacks the spinal cord and optic nerve. Its defining autoantibody is specific for the water channel protein, aquaporin-4 (AQP4), which primarily is localized at the end-feet of astrocytes. Histopathology studies of early NMO lesions demonstrated prominent activation of microglia, the resident immune sentinels of the central nervous system (CNS). Significant microglial reactivity is also observed in NMO animal models induced by introducing AQP4-IgG into the CNS. Here we review the potential roles for microglial activation in human NMO patients as well as different animal models of NMO. We will focus primarily on the molecular mechanisms underlying microglial function and microglia-astrocyte interaction in NMO pathogenesis. Understanding the role of microglia in NMO pathology may yield novel therapeutic approaches for this disease.

"Hot Cord" Sign on 18F-FDG PET/CT in a Patient With Acute Myelitis Due to Neuromyelitis Optica Spectrum Disorder

A 44-year-old woman presented with prolonged low-grade fever, bilateral upper limb weakness, and hyperesthesia. MRI showed hyperintense T2 signal and enhancement of the cervicothoracic spinal cord. F-FDG PET/CT was requested to investigate pyrexia of unknown origin. It demonstrated diffusely increased FDG uptake along the entire spinal cord, suggestive of extensive acute myelitis. Initial blood work was positive for antinuclear antibodies and anti-Ro/SSA antibodies. Cerebrospinal fluid analysis revealed lymphocytosis and detected the presence of neuromyelitis optica aquaporin-4-immunoglobulin G antibodies, fulfilling the criteria for diagnosis of neuromyelitis optica spectrum disorder.

Different Targets of Monoclonal Antibodies in Neuromyelitis Optica Spectrum Disorders: A Meta-Analysis Evidenced From Randomized Controlled Trials

Background: Neuromyelitis optica spectrum disorder (NMOSD), an autoimmune inflammatory disorder of the central nervous system, often leads to vision loss or paralysis. This meta-analysis focused on the assessment of the monoclonal antibody therapy in NMOSD and compared different targets of monoclonal antibodies with each other in terms of efficacy and safety outcomes.

Method: We searched through the databases of MEDLINE, EMBASE, Central Register of Controlled Trials (CENTRAL), and clinicaltrials.gov for randomized controlled trials (RCTs) evaluating monoclonal antibody therapy in NMOSD up to April 2020.

Results: We identified seven randomized controlled trials (RCTs), including 775 patients (monoclonal antibody group, n = 485 and placebo group, n = 290). Monoclonal antibody therapy decreased relapse risk (RR 0.33, 95% CI 0.21–0.52, P < 0.00001), annualized relapse rate (ARR) (mean −0.28, 95% CI −0.35−0.20, P < 0.00001), expanded disability status scale score (EDSS) (mean −0.19, 95% CI −0.32−0.07, P = 0.002) and serious adverse events (RR 0.78, 95% CI 0.61–1.00, P = 0.05). However, we did not observe any significant difference in terms of adverse events or mortality. Further, the subgroup analysis demonstrated that the anti-complement protein C5 monoclonal antibody (eculizumab) might have a lower relapse risk (RR 0.07, 95% CI 0.02–0.23, P < 0.0001) in the AQP4 seropositive patients, and anti-interleukin-6 receptor monoclonal antibodies (satralizumab and tocilizumab) showed decreased EDSS score (mean −0.17, 95% CI −0.31−0.02, P = 0.02) more effectively than other monoclonal antibodies.

Conclusions: Monoclonal antibodies were effective and safe in NMOSD. Different targets of monoclonal antibodies might have their own advantages.

Could Galectin-3 be a key player in the etiology of neuromyelitis optica spectrum disorder?

Neuromyelitis Optica Spectrum Disorder (NMOSD) is a chronic, inflammatory, demyelinating disorder of the central nervous system (CNS) characterized primarily by transverse myelitis (TM) and optic neuritis (ON). Serum antibodies of the IgG class to the water channel protein aquaporin-4 (AQP4) are associated with NMOSD in most cases. These antibodies are thought to cause functional abnormality or changed expressional pattern of AQP4 channel proteins in the CNS lesions. Activation of microglia is one of the chief antibody-mediated effects in NMOSD and it has opposing detrimental and protective effects in NMOSD. On the one hand, it promotes neuroinflammation, demyelination and BBB breakdown. On the other, it aids in remyelination. What controls the switch between these effects is unknown. Recently, Galectin- 3, a lectin, has been identified as a key player in several neurodegenerative diseases. In transient focal brain ischemia, alzheimer's disease (AD), huntington disease (HD), and experimental autoimmune encephalitis (EAE), Galectin-3 promotes microglia-mediated inflammation. Conversely, in amyotrophic lateral sclerosis (ALS), Galectin-3 reduces inflammation. It also suppresses Th17 cytokines, which play a crucial role in NMOSD pathogenesis. Being devoid of a leader signal, Gal-3 localizes in different cellular compartments and is subject to various post-translational modifications. These reasons explain why Galectin-3 expression has opposing effects under different physiological conditions. Microglia-mediated inflammation in NMOSD has not been extensively studied. The factors that regulate microglia-mediated inflammation in NMOSD are unknown. Here, I hypothesize that Galectin-3 might be an etiological factor in NMOSD that regulates microglia-mediated inflammation. Analysing the role of Gal-3 in NMOSD could help in the development of novel therapies to treat NMOSD.

Factors Associated with Changes in Retinal Layers Following Acute Optic Neuritis: A Longitudinal Study Using Optical Coherence Tomography

This study aimed to analyze longitudinal changes in retinal microstructures following acute optic neuritis and to identify the factors that affect those changes using spectral-domain optical coherence tomography (OCT). Forty-eight eyes of 37 patients with a first episode of optic neuritis and 48 eyes of 48 healthy controls were enrolled. Patients underwent serial OCT and visual function testing for more than six months. Individual layers from macular OCT were segmented with an automated algorithm. The total retinal layer (TRL), nerve fiber layer (NFL), ganglion cell layer (GCL) and inner plexiform layer (IPL) of optic neuritis eyes showed significant thinning with time over 6–15 months (p < 0.001 for all). The outer nuclear layer (ONL) showed a later decrease in thickness (p = 0.007). The outer retinal layer (ORL) showed an increase (p = 0.007) in thickness at two to five months which was sustained over time. Low visual acuity and neuromyelitis optica (NMO) immunoglobulin (Ig) G were associated with changes in the thickness of the GCL, IPL, and ONL over time (p < 0.05 for all). Low visual acuity was also associated with changes in the thickness of the NFL over time (p = 0.033). Dynamic changes of retinal microstructures varied according to the retinal layer examined after an optic neuritis attack. Initial visual acuity and NMO-IgG were found to be significant factors affecting the changes in thickness of each retinal layer. These results will lead to a better understanding of the pathologic changes that occur in eyes with optic neuritis.

Concomitant abducens and facial nerve palsies: A rare presentation in anti-aquaporin-4 antibody-positive neuromyelitis optica

Over the past decade, the discovery of disease-specific aquaporin-4 antibodies has led to a better understanding of the diverse spectrum of disorders that are associated with neuromyelitis optica. Brainstem manifestations have been increasingly recognized in this disease. However, multiple cranial nerve palsies as an initial presentation of neuromyelitis optica are uncommon. We report a rare case of anti-aquaporin-4 antibody-positive neuromyelitis optica that presented with unilateral abducens and facial nerve palsies. Notably, this case did not involve the optic nerve or the spinal cord. Diagnosing neuromyelitis optica that presents as an isolated acute brainstem syndrome is challenging, but the outcome may be devastating if the diagnosis is delayed.

Serum albumin level is associated with the severity of neurological dysfunction of NMOSD patients

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory autoimmune disease of the central nervous system. Serum albumin (SA) has antioxidant, immunomodulatory and anti-inflammatory effects. However, the roles of SA in NMOSD have not been studied. The current study aimed to clarify the association of SA with disease severity and prognosis in NMOSD patients.

METHODS

Serum levels of albumin were measured by Bromcresol Green method. Serum level measurements of interleukins were performed using enzyme-linked immunoassay (ELISA) method.

RESULTS

Of all the 130 NMOSD patients, 96 patients were in the acute phase while 34 patients were in the remission phase of disease at the time of sampling. SA concentration was significantly correlated with EDSS score in patients in the acute phase but not in remission phase (r = - 0.388, p < 0.001 and r = - 0.467, p = 0.809, respectively). Logistic analysis revealed that SA was the only significant factor to predict severe NMOSD (EDSS 8.0-9.5) OR = 0.698, 95%CI 0.563-0.865, p = 0.001) after adjustment of other confounding factors. Furthermore, SA was negatively correlated with the serum level of IL-33 (r = -0.438, p = 0.016) in the acute phase of NMOSD patients.

CONCLUSION

The current study found that low level of SA was an independent indicator of more severe neurological deficit in patients in acute phase of NMOSD. SA concentration was negatively correlated with the serum level of IL-33 in the acute phase of the disease, which implies that SA might participate in the immunopathology of NMOSD partly through its interaction with IL-33.

Neuromyelitis Optica Spectrum Disorder: A Case Report of Effective Combination Immunosuppressant, Corticosteroids, and Therapeutic Plasma Exchange

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease that causes severe demyelination, especially in the optic nerve and spinal cord with typical clinical manifestations of acute optic neuritis and transverse myelitis. The symptoms can occur simultaneously or separated by a variable period. NMOSD is associated with serum aquaporin antibodies 4 immunoglobulin G (AQP4-IgG).

CASE PRESENTATION

We report a case of a 22-year-old male with complaints of weakness of all four limbs, impaired vision, urinary incontinence, and dyspnea. The Expanded Disability Status Scale (EDSS) was nine. Spinal magnetic resonance imaging (MRI) showed longitudinal extensive transversal myelitis. The brain MRI showed a normal impression, whereas the brain magnetic resonance spectroscopy (MRS) examination showed a description of the mild demyelination process. The serum antibody AQP4 (AQP4-IgG) results were seronegative, the cerebrospinal fluid examination was normal, and the oligoclonal band was negative. The ophthalmoscopic examination found bilateral papillary atrophy but optical coherence tomography (OCT) was still normal. Somatosensory evoked potential and visual evoked potential examinations were abnormal. The patient was diagnosed with NMOSD and was given combination immunosuppressant therapy, corticosteroids, and therapeutic plasma exchange. The patient experienced significant improvement with EDSS decreased to six.

CONCLUSION

In the case of relapsing NMOSD patient, combination therapy of immunosuppressant's, corticosteroids, and TPE was used. There were significant improvements from EDSS nine to six.

Neuromyelitis optic with positive Anti-AQP4 and Anti-SSA/Ro antibody

Neuromyelitis Optic (NMO) is an inflammatory disorder involving central nervous system which often co-exists with other autoimmune diseases such as Sjögren’s syndrome (SS). NMO manifestation could precede or follow SS, but the role of anti-SSA in the pathogenesis of NMO remains unclear. We present a case of NMO with anti-AQP4 anti-SSA antibody positive. A-44-year-old female presented with right side weakness. The symptoms began with numbness that improved spontaneously. She also complained pain and dry sensations on her eyes. Schirmer test on her left eye, antinuclear antibody (ANA) and anti-SSA antibody were positive. Cervical MRI revealed intramedullary lesion on T2-weighted-image at C2-C5 level. She was diagnosed as NMO with positive anti-AQP4 and probable SS. She received 1g methylprednisolone for 5 days proceeded with mycophenolic acid. One-year observation showed clinical improvement. Systemic autoantibodies must substansially be evaluated in NMO. Comprehensive diagnosis and providing appropriate immuno-suppressant might prevent further disability and relapse.

Effectiveness of rituximab in neuromyelitis optica: a meta-analysis

Background

Neuromyelitis optica (NMO) is a severe inflammatory autoimmune disorder of the central nervous system and often results in paralysis or blindness. Rituximab (RTX) is a mouse–human chimeric monoclonal antibody specific for the CD20 antigen on B lymphocytes and used to treat many autoimmune diseases. Disability and relapses were measured using the Expanded Disability Status Scale (EDSS) and annualized relapse rate (ARR) ratio to evaluate the effectiveness of RTX. This review performed a meta-analysis of the efficacy of RTX in NMO.

Methods

We searched through the databases of PubMed, Embase, and Cochrane Library. We compiled 26 studies, in which 18 used ARR ratio, 22 used EDSS score, and 14 used both variables. Differences in the ARR ratio and EDSS score before and after RTX therapy were used as the main efficacy measures. Publication bias was evaluated after the consistency test, and a sensitivity analysis was performed with mean difference (MD) of the efficacy of RTX.

Results

A meta-analysis of 26 studies with 577 participants was conducted. Antibodies against aquaporin-4 autoantibody were recorded in 435 of 577 (75.39%) patients with NMO. RTX therapy resulted in a mean (WMD) − 1.56 (95% CI, − 1.82 to − 1.29) reduction in the mean ARR ratio and a mean (WMD) − 1.16 (95% CI, − 1.36 to − 0.96) reduction in the mean EDSS score. A total of 330 of 528 patients (62.9%) reached the relapse-free state. A total of 95 of 577 (16.46%) patients had adverse reactions.

Conclusions

RTX has acceptable tolerance, reduces the relapse frequency, and improves disability in most patients with NMO. Future studies should focus on reducing the health-care costs, improving the functional outcomes, and reducing the adverse effects associated with RTX treatment.

Astrocytic degeneration in chronic traumatic encephalopathy

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease associated with repeated head traumas. Using immunohistochemistry for glial fibrillary acidic protein as a marker, plus automated quantitative analysis, we examined the characteristics and extent of astrogliosis present in stage III and IV CTE, along with Alzheimer's disease (AD), and frontotemporal dementia (FTD) cases. Astrogliosis in CTE patients was more diffuse compared to that of AD and FTD patients, which was concentrated in the sulcal depths. Of 14 patients with CTE, 10 exhibited signs of a degenerating astrocyte pathology, characterized by beaded, broken astrocytic processes. This astrocytic degeneration was typically found to be diffuse throughout the white matter, although two cases demonstrated astrocytic degeneration in the gray matter. The degeneration was also observed in 2 of 3 AD and 2 of 3 FTD brains, with overall similar characteristics across diseases. There was minimal to no astrocytic degeneration in six age-matched controls with no neurodegenerative disease. We found that the extent of the white matter astrocytic degeneration was strongly correlated with the level of overall astrogliosis in both the white and gray matter. However, astrocytic degeneration was not correlated with the overall extent of tau pathology. Specifically, there was no correlation between levels of p-tau in the sulcal depths and astrocytic degeneration in the white matter adjacent to the sulcal depths. Thus, astrocytic degeneration and overall astrogliosis appear to represent distinct pathological features of CTE. Further investigation into these astroglial pathologies could provide new insights into underlying disease mechanisms and represent a potential target for in vivo assessment of CTE as well as other neurodegenerative disorders.

Methyldopa blocks MHC class II binding to disease-specific antigens in autoimmune diabetes

Major histocompatibility (MHC) class II molecules are strongly associated with many autoimmune disorders. In type 1 diabetes (T1D), the DQ8 molecule is common, confers significant disease risk, and is involved in disease pathogenesis. We hypothesized that blocking DQ8 antigen presentation would provide therapeutic benefit by preventing recognition of self-peptides by pathogenic T cells. We used the crystal structure of DQ8 to select drug-like small molecules predicted to bind structural pockets in the MHC antigen-binding cleft. A limited number of the predicted compounds inhibited DQ8 antigen presentation in vitro, with 1 compound preventing insulin autoantibody production and delaying diabetes onset in an animal model of spontaneous autoimmune diabetes. An existing drug with a similar structure, methyldopa, specifically blocked DQ8 in patients with recent-onset T1D and reduced inflammatory T cell responses to insulin, highlighting the relevance of blocking disease-specific MHC class II antigen presentation to treat autoimmunity.

Combination Treatment of C16 Peptide and Angiopoietin-1 Alleviates Neuromyelitis Optica in an Experimental Model

Neuromyelitis optica (NMO) is an autoimmune inflammatory demyelinating disease that mainly affects the spinal cord and optic nerve, causing blindness and paralysis in some individuals. Moreover, NMO may cause secondary complement-dependent cytotoxicity (CDC), leading to oligodendrocyte and neuronal damage. In this study, a rodent NMO model, showing typical NMO pathogenesis, was induced with NMO-IgG from patient serum and human complement. We then tested whether the combination of C16, an αvβ3 integrin-binding peptide, and angiopoietin-1 (Ang1), a member of the endothelial growth factor family, could alleviate NMO in the model. Our results demonstrated that this combination therapy significantly decreased disease severity, inflammatory cell infiltration, secondary demyelination, and axonal loss, thus reducing neural death. In conclusion, our study suggests a possible treatment that can relieve progressive blindness and paralysis in an animal model of NMO through improvement of the inflammatory milieu.

Th2 axis-related cytokines in patients with neuromyelitis optica spectrum disorders

AIMS

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory autoimmune disease of the central nervous system. Increasing evidence indicates that NMOSD is a Th2- and Th17-dominant disease. IL-25, IL-31, and IL-33 are three newly found Th2-related cytokines, and their roles in the pathogenesis of NMOSD have not been studied. This study aimed to measure the serum levels of IL-25, IL-31, and IL-33 in patients with NMOSD and evaluate their clinical implications.

METHODS

Serum was collected from patients with NMOSD (n = 48) and healthy controls (HC, n = 28). Serum level measurements of IL-25, IL-31, IL-33, IL-17A, and IL-6 were performed using enzyme-linked immunoassay (ELISA) method.

RESULTS

The serum levels of IL-25, IL-31, and IL-33 were significantly higher in patients with NMOSD as compared to HC. The serum level of IL-31 was significantly correlated with IL-17A (r = 0.382,P = 0.009) in patients with NMOSD; the latter is a critical cytokine in the pathogenesis of NMOSD. The serum level of IL-33 was higher in patients with characteristic brain lesions than patients without (307 pg/mL vs 166 pg/mL, P = 0.028). Furthermore, the serum level of IL-33 in the acute phase of the disease was positively correlated with annualized relapse rate (r = 0.364, P = 0.04).

CONCLUSION

We found higher serum levels of IL-25, IL-31, and IL-33 in patient with NMOSD as compared to healthy controls. The serum level of IL-33 during acute phase was associated with more past attacks in patients with NMOSD.

Incidence and prevalence of NMOSD in Australia and New Zealand

OBJECTIVES

We have undertaken a clinic-based survey of neuromyelitis optica spectrum disorders (NMOSDs) in Australia and New Zealand to establish incidence and prevalence across the region and in populations of differing ancestry.

BACKGROUND

NMOSD is a recently defined demyelinating disease of the central nervous system (CNS). The incidence and prevalence of NMOSD in Australia and New Zealand has not been established.

METHODS

Centres managing patients with demyelinating disease of the CNS across Australia and New Zealand reported patients with clinical and laboratory features that were suspicious for NMOSD. Testing for aquaporin 4 antibodies was undertaken in all suspected cases. From this group, cases were identified who fulfilled the 2015 Wingerchuk diagnostic criteria for NMOSD. A capture-recapture methodology was used to estimate incidence and prevalence, based on additional laboratory identified cases.

RESULTS

NMOSD was confirmed in 81/170 (48%) cases referred. Capture-recapture analysis gave an adjusted incidence estimate of 0.37 (95% CI 0.35 to 0.39) per million per year and a prevalence estimate for NMOSD of 0.70 (95% CI 0.61 to 0.78) per 100 000. NMOSD was three times more common in the Asian population (1.57 (95% CI 1.15 to 1.98) per 100 000) compared with the remainder of the population (0.57 (95% CI 0.50 to 0.65) per 100 000). The latitudinal gradient evident in multiple sclerosis was not seen in NMOSD.

CONCLUSIONS

NMOSD incidence and prevalence in Australia and New Zealand are comparable with figures from other populations of largely European ancestry. We found NMOSD to be more common in the population with Asian ancestry.

Th17 Cells Pathways in Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorders: Pathophysiological and Therapeutic Implications

Several animal and human studies have implicated CD4+ T helper 17 (Th17) cells and their downstream pathways in the pathogenesis of central nervous system (CNS) autoimmunity in multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD), challenging the traditional Th1-Th2 paradigm. Th17 cells can efficiently cross the blood-brain barrier using alternate ways from Th1 cells, promote its disruption, and induce the activation of other inflammatory cells in the CNS. A number of environmental factors modulate the activity of Th17 pathways, so changes in the diet, exposure to infections, and other environmental factors can potentially change the risk of development of autoimmunity. Currently, new drugs targeting specific points of the Th17 pathways are already being tested in clinical trials and provide basis for the development of biomarkers to monitor disease activity. Herein, we review the key findings supporting the relevance of the Th17 pathways in the pathogenesis of MS and NMOSD, as well as their potential role as therapeutic targets in the treatment of immune-mediated CNS disorders.

Pain and spinal cord imaging measures in children with demyelinating disease

Pain is a significant problem in diseases affecting the spinal cord, including demyelinating disease. To date, studies have examined the reliability of clinical measures for assessing and classifying the severity of spinal cord injury (SCI) and also to evaluate SCI-related pain. Most of this research has focused on adult populations and patients with traumatic injuries. Little research exists regarding pediatric spinal cord demyelinating disease. One reason for this is the lack of reliable and useful approaches to measuring spinal cord changes since currently used diagnostic imaging has limited specificity for quantitative measures of demyelination. No single imaging technique demonstrates sufficiently high sensitivity or specificity to myelin, and strong correlation with clinical measures. However, recent advances in diffusion tensor imaging (DTI) and magnetization transfer imaging (MTI) measures are considered promising in providing increasingly useful and specific information on spinal cord damage. Findings from these quantitative imaging modalities correlate with the extent of demyelination and remyelination. These techniques may be of potential use for defining the evolution of the disease state, how it may affect specific spinal cord pathways, and contribute to the management of pediatric demyelination syndromes. Since pain is a major presenting symptom in patients with transverse myelitis, the disease is an ideal model to evaluate imaging methods to define these regional changes within the spinal cord. In this review we summarize (1) pediatric demyelinating conditions affecting the spinal cord; (2) their distinguishing features; and (3) current diagnostic and classification methods with particular focus on pain pathways. We also focus on concepts that are essential in developing strategies for the detection, monitoring, treatment and repair of pediatric myelitis.

•

Pain is a major presenting symptom in children with myelitis.

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Currently used imaging has limited sensitivity to myelin content.

•

We provide a summary on pediatric demyelinating conditions.

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We review pain involvement and pathways affected by demyelination.

•

We review imaging modalities for the diagnosis and monitoring of myelitis.

[Glial fibrillary acidic protein in patients with symptoms of acute stroke: diagnostic marker of cerebral hemorrhage]

Glial fibrillary acidic protein (GFAP) is a highly brain-specific protein that is expressed in large quantities in astrocytes and has important functions in terms of maintaining and stabilizing the cytoskeleton. Acute intracerebral hemorrhage leads to an immediate mechanical destruction of astroglial cells with the subsequent release of GFAP into the extracellular space and the bloodstream. On the other hand, necrosis, cytolysis and GFAP release does not occur before 6-12 h after symptom onset in ischemic stroke. Thus, in the early hours after stroke increased GFAP values could indicate intracerebral hemorrhage. This review article describes the underlying pathophysiology of the test and guides the reader through the available data. Potential implications regarding the prehospital triage of acute stroke patients are discussed, including the possibility to initiate hyperacute treatment, such as blood pressure reduction in patients with intracerebral hemorrhage. Other areas of interest for a potential GFAP test include traumatic brain injury and malignant gliomas.

Treating neuromyelitis optica with the interleukin-6 receptor antagonist tocilizumab

We present a 32-year-old female patient with fulminant neuromyelitis optica. After the initial treatment with the monoclonal antibody rituximab failed, therapy with the anti-IL-6 receptor antagonist tocilizumab was initiated. The patient experienced a clinically relevant improvement from severe tetraparesis to low-grade paresis, which is still maintained. On MRI of the spinal cord an almost complete restitution of a predescribed extensive myelopathy accompanied this clinical improvement. Meanwhile clinical stability was achieved for over 1 year without any side effects of the ongoing treatment with tocilizumab.

Distinct serum apolipoprotein A-I levels in neuromyelitis optica and acute transverse myelitis

OBJECTIVE

NMO and ATM are intertwined both clinically and pathologically. Apolipoprotein (apo) A-I, the main apolipoprotein of HDL, plays an important role in lipid metabolism in the cerebrospinal fluid and is known to suppress pro-inflammatory cytokines generated by activated T cells in some autoimmune diseases as an immune regulator. However, the differences in the levels of serum apoA-I between NMO and ATM patients are unclear.

METHODS

In the present study, serum apo A-I levels were measured in 53 NMO patients, 45 ATM patients and 49 healthy subjects. We tested serum apoA-I levels in all participants and investigated EDSS scores of patients with NMO and ATM. Statistical analyses were performed by using SPSS statistical software.

RESULT

We found that serum apoA-I levels in patients with NMO were significantly lower in comparison to those with ATM. We also found that serum levels of apoA-I was lower in male subjects in comparison to the female subjects in all groups although these differences were not statistically significant in patients with NMO or ATM. It is also shown in our study that serum apoA-I levels in patients with NMO were significantly elevated after receiving a high dosage of intravenous corticosteroids over a period of one week. However, we did not find any correlation between the apoA-I levels and disease disability.

CONCLUSION

From this study, we concluded that serum levels of apoA-I were lower in NMO patients compared to patients with ATM. Serum apoA-I studies might provide some useful clues to differentiate NMO cases from ATM cases.

Astrocytes differentially respond to inflammatory autoimmune insults and imbalances of neural activity

BACKGROUND

Neuronal activity intimately communicates with blood flow through the blood-brain barrier (BBB) in the central nervous system (CNS). Astrocyte endfeet cover more than 90% of brain capillaries and interact with synapses and nodes of Ranvier. The roles of astrocytes in neurovascular coupling in the CNS remain poorly understood.

RESULTS

Here we show that astrocytes that are intrinsically different are activated by inflammatory autoimmune insults and alterations of neuronal activity. In the progression of experimental autoimmune encephalomyelitis (EAE), both fibrous and protoplasmic astrocytes were broadly and reversibly activated in the brain and spinal cord, indicated by marked upregulation of glial fibrillary acidic protein (GFAP) and other astrocytic proteins. In early and remitting EAE, upregulated GFAP and astrocytic endfoot water channel aquaporin 4 (AQP4) enclosed white matter lesions in spinal cord, whereas they markedly increased and formed bundles in exacerbated lesions in late EAE. In cerebellar cortex, upregulation of astrocytic proteins correlated with EAE severity. On the other hand, protoplasmic astrocytes were also markedly activated in the brains of ankyrin-G (AnkG) and Kv3.1 KO mice, where neuronal activities are altered. Massive astrocytes replaced degenerated Purkinje neurons in AnkG KO mice. In Kv3.1 KO mice, GFAP staining significantly increased in cerebellar cortex, where Kv3.1 is normally highly expressed, but displayed in a patchy pattern in parts of the hippocampus.

CONCLUSIONS

Thus, astrocytes can detect changes in both blood and neurons, which supports their central role in neurovascular coupling. These studies contribute to the development of new strategies of neuroprotection and repair for various diseases, through activity-dependent regulation of neurovascular coupling.

[Neuromyelitis optica]

BACKGROUND

Neuromyelitis optica (NMO) is a rare autoimmune inflammatory disease of the central nervous system that is characterized mainly by recurrent optic neuritis and longitudinally extensive transverse myelitis. The aim of this article is to present current knowledge on the clinical features, diagnosis, pathogenesis and treatment of the condition.

METHOD

The article is based on a discretionary selection of English-language original articles, meta-analyses and review articles found in PubMed, and on the authors' own experience with the patient group.

RESULTS

Neuromyelitis optica was previously assumed to be a variant of multiple sclerosis (MS), but the discovery of aquaporin-4 antibodies in patients with neuromyelitis optica has led to this view being revised. The cause of the condition is still unknown, but it has been shown that the antibodies bind selectively to a water channel expressed mainly on astrocytes at the blood-brain-barrier, which has an important role in the regulation of brain volume and ion homeostasis. Clinically, the condition presents as optic neuritis and/or transverse myelitis. A diagnosis is made on the basis of case history, clinical examination, MRI of the brain and spinal cord, analysis of cerebrospinal fluid, visual evoked potentials and a blood test with analysis of aquaporin-4 antibodies. Once a diagnosis has been made, rapid treatment is important. In the acute phase, intravenous methylprednisolone is recommended. There are several options for preventative treatment, but the primary recommendations are oral prednisolone and azathioprine or intravenous infusion of rituximab. Treatment is distinct from the treatment of MS and some of the immunomodulatory drugs commonly used in MS can lead to worsening of neuromyelitis optica.

INTERPRETATION

The condition is an important differential diagnosis of MS, but differs from MS in terms of clinical features, prognosis and treatment. Patients have a high risk of sequelae following relapses, and therefore early diagnosis and treatment is important.

The major brain endocannabinoid 2-AG controls neuropathic pain and mechanical hyperalgesia in patients with neuromyelitis optica

Recurrent myelitis is one of the predominant characteristics in patients with neuromyelitis optica (NMO). While paresis, visual loss, sensory deficits, and bladder dysfunction are well known symptoms in NMO patients, pain has been recognized only recently as another key symptom of the disease. Although spinal cord inflammation is a defining aspect of neuromyelitis, there is an almost complete lack of data on altered somatosensory function, including pain. Therefore, eleven consecutive patients with NMO were investigated regarding the presence and clinical characteristics of pain. All patients were examined clinically as well as by Quantitative Sensory Testing (QST) following the protocol of the German Research Network on Neuropathic Pain (DFNS). Additionally, plasma endocannabinoid levels and signs of chronic stress and depression were determined. Almost all patients (10/11) suffered from NMO-associated neuropathic pain for the last three months, and 8 out of 11 patients indicated relevant pain at the time of examination. Symptoms of neuropathic pain were reported in the vast majority of patients with NMO. Psychological testing revealed signs of marked depression. Compared to age and gender-matched healthy controls, QST revealed pronounced mechanical and thermal sensory loss, strongly correlated to ongoing pain suggesting the presence of deafferentation-induced neuropathic pain. Thermal hyperalgesia correlated to MRI-verified signs of spinal cord lesion. Heat hyperalgesia was highly correlated to the time since last relapse of NMO. Patients with NMO exhibited significant mechanical and thermal dysesthesia, namely dynamic mechanical allodynia and paradoxical heat sensation. Moreover, they presented frequently with either abnormal mechanical hypoalgesia or hyperalgesia, which depended significantly on plasma levels of the endogenous cannabinoid 2-arachidonoylglycerole (2-AG). These data emphasize the high prevalence of neuropathic pain and hyperalgesia in patients with NMO. The degree of mechanical hyperalgesia reflecting central sensitization of nociceptive pathways seems to be controlled by the major brain endocannabinoid 2-AG.

Neuromyelitis optica in a Ugandan woman: a case report

Introduction

Few cases of neuromyelitis optica have been reported in Africa. This is the first case report of neuromyelitis optica in Uganda. It highlights the need to have a high index of suspicion to promptly identify and appropriately treat these patients.

Case presentation

We present the case of a 24-year-old woman of Bantu origin who presented initially with bilateral loss of vision and weakness of the lower limbs in 2010 that resolved completely after a few days. Eight months later, she presented with bilateral lower limb weakness and urinary incontinence that improved completely following steroid use. This was followed four months later with an episode of quadriparesis that was treated with steroids and azathioprine with some improvement currently using a walking aide.

Conclusions

The patient described here represents a phenotypic expression of a recurrent (multiphasic), steroid-sensitive, inflammatory demyelinating disorder of the central nervous system occurring in a black Ugandan woman. This case highlights the occurrence of Devic’s disease within our setting and the need to properly diagnose this condition even in a resource-limited setting to prevent disability.