Neuromyelitis Optica Immunoglobulin G Research Articles

Electrochemical Biosensing Strategy for Ultrasensitive Detection of Aquaporin-4 Antibody as Neuromyelitis Optica Autoimmune Disease Biomarker Using Aquaporin-4 Extracellular Loop

Neuromyelitis optica (NMO) is a severe and disabling neurodegenerative disorder of the central nervous system (CNS). Neuromyelitis optica-Immunoglobulin G (NMO-IgG) is a serum IgG autoantibody almost exclusively present in NMO patients, which helps to differentiate NMO from other CNS disorders. Developing standardized and user-friendly assays remains a significant challenge in making NMO-IgG testing widely available. Label-free methods are simpler and faster, without additional reagents and procedures. Here, we present a peptide-based label-free electrochemical biosensor for detecting aquaporin-4 antibodies (AQP4-Abs) using extracellular AQP4 to diagnose NMO disease via the DPV electrochemical method. We have developed a novel approach in which the E loop of extracellular AQP4 is bemployed to detect NMO. 3 phenylalanines (Phe) were annexed to the C terminal, and because phenylalanine has a benzene ring, it can have π-π interaction with the benzene ring of carbon nanotube (CNT). In the designated platform, instead of using functional groups with complex and multi-step processes for immobilizing on the electrode surface, we used Nickel-Metal−organic framework /CNT as a novel modifier for measuring AQP4 antibodies with a simple, cheap, and accessible synthesis method. The developed sensor can detect antibodies with detection limit and quantification of 6.2 and 10.0 pg ml−1, respectively (S/N = 3). Also, superb sensitivity of the biosensor was attained as 28.8 μA mL ng−1 cm−2, confirming that the sensor has great potential for clinical application as a diagnostic test.

Inhibition of Neuromyelitis Optica Immunoglobulin G Binding to Aquaporin-4 by the Small Molecule Blocker Melanthioidine.

Neuromyelitis optica (NMO) is a severe neurological demyelinating autoimmune disease affecting the optic nerves and spinal cord. The binding of neuromyelitis optica immunoglobulin G (NMO-IgG) and aquaporin-4 (AQP4) on the surface of astrocytes in the serum and cerebrospinal fluid is the main pathogenesis of NMO. Currently, therapeutic strategies for NMO include a reduction of the secondary inflammation response and the number of NMO-IgG, which can only alleviate clinical symptoms rather than fundamentally preventing a series of pathological processes caused by NMO-IgG binding to AQP4. The purpose of this study was to investigate the blocking effect of melanthioidine on the binding of NMO-IgG to AQP4 and its potential cytotoxicity. The current study developed a cell-based high-throughput screening approach to identify a molecular blocker of NMO-IgG binding to AQP4 using the Chinese hamster lung fibroblast (V79) cells expressing M23-AQP4. By screening ~400 small molecules, we identified melanthioidine with blocking effects without affecting AQP4 expression or its water permeability. Melanthioidine effectively blocked the binding of NMO-IgG to AQP4 in immunofluorescence assays and reduced complement-dependent cytotoxicity against both NMO-IgG/complement-treated Fischer rat thyroid-AQP4 cells and primary astrocytes. The docking computations identified the putative sites of blocker binding at the extracellular surface of AQP4. This study serves as proof of a potential NMO therapy by using a small-molecule blocker to target NMO pathogenesis.

The association between body mass index, demographic and clinical characteristics with cognitive performance in patients with neuromyelitis optica spectrum disorder.

Background: Cognitive dysfunction is one of the problems that patients with neuromyelitis optica spectrum disorder (NMOSD) suffer from. We aimed to assess the association between demographic and clinical features as well as body mass index (BMI) and cognitive function in patients with NMOSD. Methods: A cross-sectional study was performed on 41 patients with definite diagnosis of NMOSD. Serum status of neuromyelitis optica immunoglobulin G (NMO-IgG) was determined using enzyme-linked immunosorbent assay (ELISA) method. Cognitive function was assessed by Minimal Assessment of Cognitive Function in Multiple Sclerosis (MACFIMS) battery which is validated for Persian people before and North American Adult Reading Test (NAART). Results: The mean score of NAART test was higher in participants with normal weight compared with overweight patients (40.47 ± 3.51 vs. 36.00 ± 5.74, P = 0.02). Current age was negatively correlated with Delis-Kaplan Executive Function System (D-KEFS)-Sorting (P = 0.05, r = -0.30). The correlation of duration of disease and cognitive performance was not significant (P > 0.05). Higher physical disability based on Expanded Disability Status Scale (EDSS) was correlated with lower results in Brief Visuospatial Memory Test-Revised (BVMT-R) (P < 0.01, r = -0.50), California Verbal Learning Test-second edition (CVLT-II)-Delayed Recall (P = 0.02, r = -0.35), and Symbol Digit Modalities Test (SDMT) (P = 0.03, r = -0.33) subtests of MACFIMS. Annual relapse rate was indirectly correlated with CVLT-II (P = 0.03, r = -0.34) and CVLT-II-Delayed Recall (P = 0.01, r = -0.38). Male participants obtained better scores in Paced Auditory Serial Addition Test (PASAT) subtest (P = 0.05). NMO-IgG seropositive patients had poorer performance in terms of CVLT-II-Delayed Recall, Controlled Oral Word Association Test (COWAT), and D-KEFS-Descriptive (P < 0.05). Participants with bachelor and master education degrees showed significantly better results compared to those with high school degree (P < 0.05). Conclusion: Investigating the clinical and demographic factors affecting cognitive impairment can increase the awareness of health care providers for early diagnosis of cognitive impairment in patients with NMOSD and increase the quality of health services.

Atypical presentation of multiple sclerosis – A few points to ponder

The article by Dr. Aishwarya Angadi has brilliantly highlighted how multiple sclerosis can present as unilateral internuclear ophthalmoplegia. The author has meticulously examined the patient and presented it along with the detailed neurological findings. Early detection of multiple sclerosis can go a long way in reducing the morbidity of the disease through timely treatment and intervention. From an academic point of view, there are a few points that I would like to contribute. Since the patient complained of visual blurring, subclinical optic neuritis should have been ruled out with a visually evoked potential test.[1] In the cerebrospinal fluid study, the number of oligoclonal bands is significant for the prognosis of multiple sclerosis.[2] In a case of multiple sclerosis, NeuroMyelitis Optica Immunoglobulin G (NMOIgG) and anti-Myelin Oligodendrocyte Glycoprotein (anti-MOG) antibody should be tested.[345] Lesions on Magnetic Resonance Imaging (MRI) should fulfil McDonald's criteria to qualify as those of multiple sclerosis. MRI orbit is relevant in this case. Also, MRI brainstem should show lesions in the medial longitudinal fasciculus to explain the internuclear ophthalmoplegia. As this patient was positive for Anti Neutrophil Cytoplasmic Antibodies (ANCA), autoimmune vasculitis should also be ruled out. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

New BBB Model Reveals That IL-6 Blockade Suppressed the BBB Disorder, Preventing Onset of NMOSD.

Background and ObjectivesTo evaluate the pathophysiology of neuromyelitis optica spectrum disorder (NMOSD) and the therapeutic mechanism and levels of interleukin-6 (IL-6) blockade (satralizumab), especially with respect to blood-brain barrier (BBB) disruption with the new in vitro and ex vivo human BBB models and in vivo model.MethodsWe constructed new static in vitro and flow-based ex vivo models for evaluating continued barrier function, leukocyte transmigration, and intracerebral transferability of neuromyelitis optica-immunoglobulin G (NMO-IgG) and satralizumab across the BBB using the newly established triple coculture system that are specialized to closely mimic endothelial cell contact of pericytes and endfeet of astrocytes. In the in vivo study, we assessed the effects of an anti–IL-6 receptor antibody for mice (MR16-1) on in vivo BBB disruption in mice with experimental autoimmune encephalomyelitis in which IL-6 concentration in the spinal cord dramatically increases.ResultsIn vitro and ex vivo experiments demonstrated that NMO-IgG increased intracerebral transferability of satralizumab and NMO-IgG and that satralizumab suppressed the NMO-IgG–induced transmigration of T cells and barrier dysfunction. In the in vivo study, the blockade of IL-6 signaling suppressed the migration of T cells into the spinal cord and prevented the increased BBB permeability.DiscussionThese results suggest that (1) our triple-cultured in vitro and in ex vivo BBB models are ideal for evaluating barrier function, leukocyte transmigration, and intracerebral transferability; (2) NMO-IgG increased the intracerebral transferability of NMO-IgG via decreasing barrier function and induced secretion of IL-6 from astrocytes causing more dysfunction of the barrier and disrupting controlled cellular infiltration; and (3) satralizumab, which can pass through the BBB in the presence of NMO-IgG, suppresses the BBB dysfunction and the infiltration of inflammatory cells, leading to prevention of onset of NMOSD.

Inhibition of RGMa alleviates symptoms in a rat model of neuromyelitis optica

Neuromyelitis optica (NMO) is an autoimmune disease associated with NMO immunoglobulin G (NMO-IgG), an antibody that selectively binds to the aquaporin-4. Here, we established a localized NMO model by injecting NMO-IgG into the spinal cord, and assessed the efficacy of treating its NMO-like symptoms by blocking repulsive guidance molecule-a (RGMa), an axon growth inhibitor. The model showed pathological features consistent with NMO. Systemic administration of humanized monoclonal anti-RGMa antibody delayed the onset and attenuated the severity of clinical symptoms. Further, it preserved astrocytes and reduced inflammatory-cell infiltration and axonal damage, suggesting that targeting RGMa is effective in treating NMO.

Effects of neuromyelitis optica-IgG at the blood-brain barrier in vitro.

Objective:To address the hypothesis that physiologic interactions between astrocytes and endothelial cells (EC) at the blood–brain barrier (BBB) are afflicted by pathogenic inflammatory signaling when astrocytes are exposed to aquaporin-4 (AQP4) antibodies present in the immunoglobulin G (IgG) fraction of serum from patients with neuromyelitis optica (NMO), referred to as NMO-IgG.Methods:We established static and flow-based in vitro BBB models incorporating co-cultures of conditionally immortalized human brain microvascular endothelial cells and human astrocyte cell lines with or without AQP4 expression.Results:In astrocyte–EC co-cultures, exposure of astrocytes to NMO-IgG decreased barrier function, induced CCL2 and CXCL8 expression by EC, and promoted leukocyte migration under flow, contingent on astrocyte expression of AQP4. NMO-IgG selectively induced interleukin (IL)-6 production by AQP4-positive astrocytes. When EC were exposed to IL-6, we observed decreased barrier function, increased CCL2 and CXCL8 expression, and enhanced leukocyte transmigration under flow. These effects were reversed after application of IL–6 neutralizing antibody.Conclusions:Our results indicate that NMO-IgG induces IL-6 production by AQP4-positive astrocytes and that IL-6 signaling to EC decreases barrier function, increases chemokine production, and enhances leukocyte transmigration under flow.

Mutagenesis of the Aquaporin 4 Extracellular Domains Defines Restricted Binding Patterns of Pathogenic Neuromyelitis Optica IgG

Neuromyelitis optica-immunoglobulin G (NMO-IgG) binds to aquaporin-4 (AQP4) water channels in the central nervous system leading to immune-mediated injury. We have previously demonstrated that a high proportion of CSF plasma cells of NMO patients produce antibody to the extracellular domains of the AQP4 protein and that recombinant IgG (rAb) derived from these cells recapitulate pathogenic features of disease. We performed a comprehensive mutational analysis of the three extracellular loops of the M23 isoform of human AQP4 using both serial and single point mutations, and we evaluated the effects on binding of NMO AQP4-reactive rAbs by quantitative immunofluorescence. Whereas all NMO rAbs required conserved loop C ((137)TP(138) and Val(150)) and loop E ((230)HW(231)) amino acids for binding, two broad patterns of NMO-IgG recognition could be distinguished based on differential sensitivity to loop A amino acid changes. Pattern 1 NMO rAbs were insensitive to loop A mutations and could be further discriminated by differential sensitivity to amino acid changes in loop C ((148)TM(149) and His(151)) and loop E (Asn(226) and Glu(228)). Alternatively, pattern 2 NMO rAbs showed significantly reduced binding following amino acid changes in loop A ((63)EKP(65) and Asp(69)) and loop C (Val(141), His(151), and Leu(154)). Amino acid substitutions at (137)TP(138) altered loop C conformation and abolished the binding of all NMO rAbs and NMO-IgG, indicating the global importance of loop C conformation to the recognition of AQP4 by pathogenic NMO Abs. The generation of human NMO rAbs has allowed the first high resolution mapping of extracellular loop amino acids critical for NMO-IgG binding and identified regions of AQP4 extracellular structure that may represent prime targets for drug therapy.

Diagnostic value of aquaporin 4 antibody in assessing idiopathic inflammatory demyelinating central nervous system diseases in Egyptian patients

Neuromyelitis optica immunoglobulin G (NMO-IgG) binds selectively to aquaporin 4 (AQP4). We aimed to evaluate the frequency of AQP4 antibody in Egyptian patients. We retrospectively evaluated 39 consecutive Egyptian patients with suspected idiopathic inflammatory demyelinating central nervous system disease (IIDCD) who visited the multiple sclerosis clinic at Kaser Al-Aini Hospital. The patients were diagnosed with NMO, other NMO spectrum disorders, or multiple sclerosis using the respective current diagnostic criteria. For the anti-AQP4 antibody assays, serum samples from all patients and 16 healthy matched controls were evaluated. The coded sera were tested for AQP4 antibody using an enzyme-linked immunosorbent assay kit. The relations between the clinical diagnosis and the AQP4 antibody serologic status were studied. Among the 39 patients, 21 (53.85%) were AQP4 antibody-positive. NMO spectrum disorders patients had a significantly higher level of AQP4 antibody compared with MS patients and controls (p<0.001). Only eight patients (36.36%) met the Wingerchuk 2006 criteria for NMO diagnosis excluding AQP4 antibody-seropositive status. AQP4 antibody was highly prevalent (almost 54%) in Egyptian IIDCD patients. Our research revealed that we must maintain a high index of suspicion for NMO spectrum disorders.

The intrinsic pathogenic role of autoantibodies to aquaporin 4 mediating spinal cord disease in a rat passive-transfer model

Neuromyelitis optica (NMO) is causally linked to autoantibodies (ABs) against aquaporin 4 (AQP4). Here, we focused on the pathogenic effects exclusively mediated by human ABs to AQP4 in vivo. We performed cell-free intrathecal (i.th.) passive transfer experiments in Lewis rats using purified patient NMO immunoglobulin G (IgG) and various recombinant human anti-AQP4 IgG-ABs via implanted i.th. catheters. Repetitive application of patient NMO IgG fractions and of recombinant human anti-AQP4 ABs induced signs of spinal cord disease. Magnetic resonance imaging (MRI) revealed longitudinal spinal cord lesions at the site of application of anti-AQP4 IgG. Somatosensory evoked potential amplitudes were reduced in symptomatic animals corroborating the observed functional impairment. Spinal cord histology showed specific IgG deposition in the grey and white matter in the affected areas. We did not find inflammatory cell infiltration nor activation of complement in spinal cord areas of immunoglobulin deposition. Moreover, destructive lesions showing axon or myelin damage and loss of astrocytes and oligodendrocytes were all absent. Immunoreactivity to AQP4 and to the excitatory amino acid transporter 2 (EAAT2) was markedly reduced whereas immunoreactivity to the astrocytic marker glial fibrillary acid protein (GFAP) was preserved. The expression of the NMDA-receptor NR1 subunit was downregulated in areas of IgG deposition possibly induced by sustained glutamatergic overexcitation. Disease signs and histopathology were reversible within weeks after stopping injections. We conclude that in vivo application of ABs directed at AQP 4 can induce a reversible spinal cord disease in recipient rats by inducing distinct histopathological abnormalities. These findings may be the experimental correlate of “penumbra-like” lesions recently reported in NMO patients adjacent to effector-mediated tissue damage.

Variants of autophagy-related gene 5 are associated with neuromyelitis optica in the Southern Han Chinese population

Neuromyelitis optica (NMO) and multiple sclerosis (MS) are autoimmune demyelinating diseases of the central nervous system. The discovery of NMO immunoglobulin G (NMO-IgG) antibody has improved the clinical definition of NMO. Recently, the autophagy-related genes (ATGs) have been proved to be associated with several autoimmune and inflammation diseases. Increased T cell expression of ATG5 may be correlated with the pathogenesis of inflammatory demyelination in MS. However, the association of ATG5 variants with MS and NMO patients has not been well studied. In this study, five ATG5 variants were genotyped in 144 MS patients, 109 NMO patients and 288 controls in the Han Chinese population. In the cohort of NMO patients, we observed that the CC genotype of rs548234 increased susceptibility to NMO (p = 0.016), while the allele T of rs548234 (p = 0.003) and the allele A of rs6937876 (p = 0.009) acted as protective factors for NMO-IgG positive NMO patients. However, no association was found between ATG5 variants and MS patients. These results indicated that ATG5 variants are associated with NMO but not MS patients, which may provide a clue for further clarifying the autoimmune mechanisms of autophagy-related pathogenesis in NMO.

Case Report: A young woman with weakness of the legs

A previously well 22-year-old woman presented with progressive weakness of her legs and urinary incontinence over 7 days. Clinically she was healthy, with no skin rashes. On neurological examination she had profound bilateral weakness of the lower limbs, hypertonia, hyperreflexia, a positive Babinski sign and a T6 sensory level. Tests for syphilis and HIV and screening for auto-immune conditions were negative. Magnetic resonance imaging of the brain and spinal cord revealed extensive cord swelling between the craniocervical junction and T11, a high signal in the right optic nerve and a normal brain. Aquaporin 4 antibodies (neuromyelitis optica immunoglobulin G (NMO-IgG)) were positive with a titre of 1:1 000. These findings confirmed a diagnosis of NMO or Devic’s disease.

Relapsing optic neuritis: a multicentre study of 62 patients

Background: Optic neuritis (ON) may be the first symptom of a central nervous system demyelinating, systemic or infectious disease but few patients experience recurrent episodes and have a negative workup. Objective: This disorder, named relapsing optic neuritis (RON), is poorly described in the literature and still presents a particular challenge in diagnosis and management. Methods: We describe the clinical, laboratory, magnetic resonance imaging (MRI) and disability course of RON in a French cohort of 62 patients, based on a multicentre, retrospective, observational study. Results: In our cohort, we identified two distinct groups of RON patients. The first is characterised by relapsing inflammatory optic neuritis (RION, 68%), which is non-progressive, whereas the second presented as a chronic relapsing inflammatory optic neuritis (CRION, 32%), which is progressive. We have noted more cases with steroid dependence in the CRION group than the RION group (42% vs 10%). The long-term visual prognosis was more severe in CRION patients and neuromyelitis optica-immunoglobulin G (NMO-IgG)-positive patients. Conclusion: RON is likely a separate entity corresponding to an autoimmune disease that differs from multiple sclerosis (MS), NMO and vasculitis. We provide a new classification system based on a better understanding of RON which could allow an improved management by early treatment of poor prognosis forms.

Seropositive Neuromyelitis Optica: A Pediatric Case Report and 6-Year Follow-Up

Neuromyelitis optica is an autoimmune demyelinating disorder of the central nervous system. Although it has some features in common with multiple sclerosis, it has different clinical features, prognosis, and treatment. We describe a boy with seropositive neuromyelitis optica and his 6-year follow-up. A boy aged 5 years 8 months presented with relapsing optic neuritis, short segment transverse myelitis, and brain involvement. He met the diagnostic criteria for multiple sclerosis fulfilling the McDonald 2010 criteria; however, neuromyelitis optica immunoglobulin-G was detected, and the patient was diagnosed with neuromyelitis optica. He had frequent relapses until immunosuppressive treatment with azathioprine and low-dose prednisone was started. After he was asymptomatic for 2.5 years, prednisone was withdrawn, but he had a new attack soon after withdrawal of the steroid. It is important to differentiate neuromyelitis optica from multiple sclerosis because early immunosuppressive treatment prevents further disability, and longer periods of immunosuppressive treatment should be planned to prevent relapses.

Severe optic neuritis in a patient with combined neuromyelitis optica spectrum disease and primary Sjögren’s syndrome: a case report

IntroductionOptic neuritis, although uncommon, can be the initial presentation of Sjögren’s syndrome. Coexisting Sjögren’s syndrome has also been reported with neuromyelitis optica spectrum disorder. This case report highlights the association between the two diseases and the importance of rheumatological and neurological evaluations in patients with such diagnoses. Distinction of neuromyelitis optica with coexisting connective tissue disease has both prognostic and therapeutic significance for the patient.Case presentationWe report a case of a 56-year-old Chinese woman who presented with bilateral asymmetric visual loss secondary to optic neuritis. She was subsequently found to be seropositive for neuromyelitis optica immunoglobulin G (NMO-IgG) (anti-aquaporin-4 antibody) and was diagnosed with neuromyelitis optica spectrum disorder. She also fulfilled the international criteria for Sjögren’s syndrome. Despite initial high dose immunosuppressive therapy, she failed to regain vision in one eye.ConclusionPatients presenting with optic neuritis and severe visual loss should be screened for neuromyelitis optica and treated appropriately. Neuromyelitis optica has been associated with systemic autoimmune diseases, in particular Sjögren’s syndrome, and current evidence indicates that they are two distinct entities. We recommend that both diagnoses be considered in cases of optic neuritis with severe visual loss.

Neuromyelitis Optica Immunoglobulin G in Chinese Patients Detected by Immunofluorescence Assay on a Monkey Brain Substrate

Background: Serum neuromyelitis optica immunoglobulin G (NMO-IgG) is used as a biomarker to differentiate between neuromyelitis optica (NMO) and multiple sclerosis (MS). However, the original assay is expensive and complex and shows low sensitivity. Here, we investigated the potential of NMO-IgG detection using an indirect immunofluorescence (IIF) assay on monkey brains. Methods: NMO-IgG seroprevalence was determined in 168 samples by an IIF assay on a monkey brain substrate. The data were compared with those from a standard mouse brain IIF assay using McNemar and kappa tests. Results: Thirty-one of 50 (62%) NMO patients, 7 of 18 (38.9%) longitudinally extensive transverse myelitis patients, 6 of 57 (10.5%) MS patients, and 5 of 10 (50%) optic neuritis patients were seropositive for NMO-IgG. None of the acute partial transverse myelitis patients (n = 3) or healthy controls (n = 20) was positive. Thus, the sensitivity of the test was 62% for the patients with clinically definite NMO. The specificity was 89.5%, considering the 57 MS patients as the control group. The modified IIF assay on monkey brains and the standard IIF assay based on mouse brains were not significantly different (McNemar test; p = 1.000). The two assays were concordant in 39 seropositive samples and 100 seronegative samples (kappa test; kappa = 0.592, p < 0.0001). Conclusions: Although the modified IIF monkey brain assay was no better than the standard mouse brain IIF assay, we affirmed that NMO-IgG is a sensitive and specific biomarker to differentiate between NMO and MS.

Clinical features of ultra longitudinally extensive transverse myelitis

To analyze the clinical features of ultra longitudinally extensive transverse myelitis (uLETM). Four first-onset uLETM patients hospitalized during September 2009 and March 2011 were recruited and retrospectively analyzed for clinical and MRI (magnetic resonance imaging) features, as well as therapeutic profiles and prognoses. The male-to-female ratio was 1:3 and the age-of-onset 29 - 33 years old. Extremity paralysis and intrinsic sphincter disorders were initially observed. The clinical manifestations include visual, motor, sense and intrinsic sphincter disorders caused by optic nerve and spinal cord lesions. Uric acid decreased in 3 cases. Seropositivity for autoimmune antibody spectrum and NMO-IgG (neuromyelitis optica-immunoglobulin G) was found in some patients. Spinal MRI showed overall hypointense T1 and hyperintense T2 lesions in spinal cord with partial swelling and negative in brain MRI. Sjogren's syndrome associated with uLETM was diagnosed in 2 patients. Three cases improved after treatment with high-dose corticosteroids, intravenous immunoglobulin and other immunosuppressive agents. One patient died. uLETM is commonly found in young women. Spinal cord is frequently affected. And it may occur concurrently with optical abnormalities and other autoimmune diseases. Intracranial parenchyma is rarely affected. The therapy of corticosteroids is recommended.

Multiple organ injury associated with neuromyelitis optica spectrum disorder in a low-grade B-cell lymphoma suspected of being follicular lymphoma

A 57-year-old woman was admitted to our hospital because she developed progressive paresthesia in the chest, lower limb weakness, and pain and swelling of the femoral region. Magnetic resonance imaging (MRI) of the spinal cord showed longitudinally extended transverse myelitis and a T2-hyperintense lesion extending from C5 to T4 (Fig. 1a). Brain MRI showed T2-hyperintense lesions predominantly in periventricular white matter, and corona radiata (Fig. 1b). MRI of the thighs showed T2-hyperintense lesions with hematomas in the rectus femoris muscles bilaterally associated with severe edema (Fig. 1c). Computed tomography showed no lymphadenopathy. The results of blood analysis were as follows: white blood cell count, 15.25 9 10/l (38.5% abnormal small cleaved lymphoid cells with inconspicuous nucleoli); creatine kinase, 2156 U/l; and C-reactive protein, 2.10 mg/dl. Serum NMO immunoglobulin G (NMO-IgG) (often called anti-aquaporin-4 [AQP4] antibody [AQP4-Ab]) was 3.8 U/ ml (normal \1.0 U/ml). A bone marrow aspirate showed an abnormal lymphoid infiltration of 32.6%. Immunohistochemical analysis showed that the cells were positive for CD10, CD20, and bcl-2. Southern-blot analysis showed clonal rearrangement of the immunoglobulin heavy-chain gene. We diagnosed her as a case of neuromyelitis optica (NMO) spectrum disorder [1] and AQP4-Ab–associated hematoma in rectus femoris bilaterally. We suspected follicular lymphoma but could not locate the primary site. Therefore, we also diagnosed low-grade B-cell lymphoma that was highly suspected of being follicular lymphoma. Methylprednisolone (1,000 mg/day) was administered intravenously, and was followed by a reduced dose of betamethasone (2 mg/day). However, a few days later, progressive paresthesia and leg weakness reappeared and she was diagnosed as a case of NMO spectrum disorder. Moreover, the patient’s serum sodium level had decreased to 127 mEq/l (normal 135–148 mEq/l), plasma osmolarity was 265 mOsm/kg/H2O (normal 285–295 mOsm/kg/H2O), while the urine osmolarity was 906 mOsm/kg/H2O. Plasma antidiuretic hormone (ADH) concentration was 8.3 pg/ml (normal 1.3–4.1 pg/ml). The patient was diagnosed with AQP4-Ab–associated syndrome of inappropriate secretion of ADH (SIADH). The NMO spectrum disorder was controlled by increasing the methylprednisolone dose to 125 mg/day followed by reducing the dose to 60 mg/day. Two weeks later, cough and dyspnea developed and the blood gas values showed a deteriorated condition. Chest radiograph revealed marked infiltrative shadows in bilateral lung fields (Fig. 1d). The clinical course and findings led to the diagnosis of AQP4-Ab-associated adult respiratory distress syndrome (ARDS). Methylprednisolone (1,000 mg/day) was administered, after which methylprednisolone was tapered off. Four days later, improvement of infiltrative shadows was observed on chest radiographs S. Nakayama-Ichiyama (&) T. Yokote N. Hiraoka K. Iwaki A. Takayama K. Kobayashi T. Akioka S. Oka T. Miyoshi S. Ishida T. Hanafusa Department of Internal Medicine (I), Osaka Medical College, 2-7 Daigakumachi, Takatsuki City, Osaka 569-0801, Japan e-mail: 1304@poh.osaka-med.ac.jp

Pearls: Myelopathy

Both general neurologists and neurologists with a broad spectrum of subspecialty interests are often asked to evaluate patients with disorders of the spinal cord. Over the past decade, there have been significant advances in our understanding of a wide spectrum of immune-mediated, infectious, metabolic, hereditary, paraneoplastic, and compressive myelopathies. Advances have been made in the classification and management of spinal vascular malformations. Aortic reconstruction surgery has led to an increased incidence of spinal cord stroke. It is important to recognize a dural arteriovenous fistula as a cause of progressive myelopathy. In the past, noninfectious inflammatory myelopathies have frequently been categorized as idiopathic transverse myelitis. Advances in neuroimaging and discovery of a serum antibody marker, neuromyelitis optica-immunoglobulin G (NMO-IgG), have allowed more specific diagnoses, such as multiple sclerosis and neuromyelitis optica. Abnormalities suggestive of demyelinating disease on brain magnetic resonance imaging (MRI) are known to be highly predictive of conversion to multiple sclerosis in a patient who presents with a transverse myelitis ("clinically isolated syndrome"). Acquired copper deficiency can cause a clinical picture that mimics the subacute combined degeneration seen with vitamin B (12) deficiency. A history of bariatric surgery is commonly noted in patients with copper deficiency myelopathy. Genetics has advanced our understanding of the complex field of hereditary myelopathies. Three hereditary myelopathy phenotypes are recognized: predominantly cerebellar (e.g., Friedreich's ataxia), predominantly motor (e.g., hereditary spastic paraparesis), and a leukodystrophy phenotype (e.g., adrenomyeloneuropathy). Evaluation of myelopathies when no abnormalities are seen on spinal cord imaging is a commonly encountered diagnostic challenge. This article presents some "clinical pearls" in the evaluation and management of spinal cord diseases in context of these recent developments.

Neuromyelitis Serostatus in Fulminant CNS Demyelinating Disease

The presence of the autoantibody neuromyelitis optica immunoglobulin G (NMO-IgG) has been found to distinguish NMO — typically, a fulminant disease —