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Introduction: While monophasic and relapsing forms of myelin oligodendrocyte glycoprotein antibody associated disorders (MOGAD) are increasingly diagnosed world-wide, consensus on management is yet to be developed., Objective: To survey the current global clinical practice of clinicians treating MOGAD., Method: Neurologists worldwide with expertise in treating MOGAD participated in an online survey (February-April 2019)., Results: Fifty-two responses were received (response rate 60.5%) from 86 invited experts, comprising adult (78.8%, 41/52) and paediatric (21.2%, 11/52) neurologists in 22 countries. All treat acute attacks with high dose corticosteroids. If recovery is incomplete, 71.2% (37/52) proceed next to plasma exchange (PE). 45.5% (5/11) of paediatric neurologists use IV immunoglobulin (IVIg) in preference to PE. Following an acute attack, 55.8% (29/52) of respondents typically continue corticosteroids for ≥ 3 months; though less commonly when treating children. After an index event, 60% (31/51) usually start steroid-sparing maintenance therapy (MT); after ≥ 2 attacks 92.3% (48/52) would start MT. Repeat MOG antibody status is used by 52.9% (27/51) to help decide on MT initiation. Commonly used first line MTs in adults are azathioprine (30.8%, 16/52), mycophenolate mofetil (25.0%, 13/52) and rituximab (17.3%, 9/52). In children, IVIg is the preferred first line MT (54.5%; 6/11). Treatment response is monitored by MRI (53.8%; 28/52), optical coherence tomography (23.1%; 12/52) and MOG antibody titres (36.5%; 19/52). Regardless of monitoring results, 25.0% (13/52) would not stop MT., Conclusion: Current treatment of MOGAD is highly variable, indicating a need for consensus-based treatment guidelines, while awaiting definitive clinical trials.

Background: Neurological disorders with IgG antibodies against myelin-oligodendrocyte glycoprotein (MOG-IgG) have been increasingly recognised as a new type of neuroinflammatory disorder., Objective: The study aimed to identify regional and ethnic differences in clinical profiles of MOG-IgG-associated disorders between East Asian (Japanese) and Caucasian (German) patients., Methods: Demographic, clinical and therapeutic data from 68 MOG-IgG-positive adults were collected (Japanese, n=44; German, n=24)., Results: Age and sex were similar between cohorts, with optic neuritis occurring most frequently at onset (Japanese: 61%; German: 58%). However, Japanese patients had a lower annualised relapse rate (0.4 vs 0.8, p=0.019; no relapse, 64% vs 25%, p=0.002) and lower Expanded Disability Status Scale score at the last visit (1.0 vs 2.0; p = 0.008), despite similar follow-up periods (mean, 73.9 months vs 73.4 months), than those of German patients, respectively. Cerebral syndromes were more common (27% vs 4%; p=0.021) and myelitis less common (21% vs 50%; p=0.012) in Japanese than in German patients, respectively. Japanese patients were more commonly treated with long-term corticosteroids (73%), whereas German patients were more commonly treated with rituximab or other immunosuppressants (63%)., Conclusions: Among patients with MOG-IgG, Japanese tended to have a monophasic milder disease, whereas the majority of German patients had a relapsing course and more frequent myelitis, findings compatible with neuromyelitis optica spectrum disorder. Although the attack-prevention treatment regimens were considerably different, genetic and environmental factors may be important to determine clinical phenotypes and disease activity., Competing Interests: Competing interests: HZ received research grants from Novartis and speaking honoraria from Bayer Healthcare. JH is reviewing editor in the Frontiers in Neurology/Frontiers in Immunology. JH reports grants for neurovisual research from the Friedrich-Baur-Stiftung and Merck, personal fees and non-financial support from Celgene, Merck, Alexion, Novartis, Roche, Santhera, Biogen, Heidelberg Engineering, Sanofi Genzyme and non-financial support of the Guthy-Jackson Charitable Foundation, all outside the submitted work. SA received travel grant from Celgene and speaker’s honorary from Roche and Bayer, unrelated to this project. GC received speaker honoraria from Merck Serono and Bayer Healthcare, unrelated to this project. EM is reviewing editor in the Journal of Biological Chemistry, editor in the Journal of Pathology, associate editor in Frontiers in Neurology and Frontiers in Immunology, editor in PLOS-One, received honorarium from Roche, Novartis, Sanofi, Biogen and Bioeq and grant support from Novartis, Sanofi and Merck. SJ was indirectly supported by research grants from the Dietmar Hopp Foundation and from Merck Serono to the Department of Neurology, University Hospital Heidelberg, Heidelberg, Germany. TK has received speaker honoraria including advisory boards from Bayer Healthcare, Teva Pharma, Merck, Novartis Pharma, Sanofi-Aventis/Genzyme, Roche Pharma and Biogen as well as grant support from Novartis and Chugai Pharma in the past. FP serves as an Associate Editor for Neurology: Neuroimmunology & Neuroinflammation, reports research grants and speaker honoraria from Bayer, Teva, Genzyme, Merck, Novartis, MedImmune and is member of the steering committee of the OCTIMS study (Novartis). SK serves as the Deputy Editor of the Journal of Neurology, Neurosurgery, and Psychiatry and is an Editorial Board member of the Journal of the Neurological Sciences., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Optic neuritis (ON) is a frequent manifestation of aquaporin-4 (AQP4) antibody-mediated neuromyelitis optica spectrum disorders (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated encephalomyelitis (MOG-EM; also termed MOG antibody-associated disorders, MOGAD). The past few years have seen major advances in the diagnosis and treatment of these two relatively new entities: international diagnostic criteria for NMOSD and MOG-EM have been proposed, improved antibody assays developed, and consensus recommendations on the indications and methodology of serological testing published. Very recently, the results of four phase III trials assessing new treatment options for NMOSD have been presented. With eculizumab, a monoclonal antibody inhibiting complement factor C5, for the first time a relapse-preventing long-term treatment for NMOSD - which has so far mostly been treated off-label with rituximab, azathioprine, and other immunosuppressants - has been approved. Data from recent retrospective studies evaluating treatment responses in MOG-ON suggest that rituximab and other immunosuppressants are effective also in this entity. By contrast, many drugs approved for the treatment of multiple sclerosis (MS) have been found to be either ineffective or to cause disease exacerbation (e.g., interferon-β). Recent studies have shown that not only NMOSD-ON but also MOG-ON usually follows a relapsing course. If left untreated, both disorders can result in severe visual deficiency or blindness, though MOG-ON seems to have a better prognosis overall. Acute attacks are treated with high-dose intravenous methylprednisolone and, in many cases, plasma exchange (PEX) or immunoadsorption (IA). Early use of PEX/IA may prevent persisting visual loss and improve the long-term outcome. Especially MOG-ON has been found to be frequently associated with flare-ups, if steroids are not tapered, and to underlie many cases of "chronic relapsing inflammatory optic neuropathy" (CRION). Both NMOSD-ON and MOG-ON are often associated with simultaneous or consecutive attacks of myelitis and brainstem encephalitis; in contrast to earlier assumptions, supratentorial MRI brain lesions are a common finding and do not preclude the diagnosis. In this article, we review the current knowledge on the clinical presentation, epidemiology, diagnosis, and treatment of these two rare yet important differential diagnoses of both MS-associated ON und idiopathic autoimmune ON., Competing Interests: B. Wildemann erhielt Forschungsunterstützung durch das Bundesministerium für Bildung und Forschung (Klinisches Kompetenznetz Multiple Sklerose), die Dietmar-Hopp-Stiftung und Merck Serono; außerdem Forschungsunterstützung durch die Deutsche Forschungsgemeinschaft und die Klaus-Tschira-Stiftung; Forschungsunterstützung und Honorare für Vortragstätigkeiten und Reiseunterstützung von Merck Serono, Sanofi Genzyme, Novartis; und Honorare für Vortragstätigkeiten und/oder Reiseunterstützung von Alexion, Bayer, Biogen, Teva. S. Horstmann, S. Jarius, M. Korporal-Kuhnke und A. Viehöver geben keine Interessenkonflikte an., (Thieme. All rights reserved.)

Neuromyelitis optica (NMO; also known as Devic syndrome) is a clinical syndrome characterized by attacks of acute optic neuritis and transverse myelitis. In most patients, NMO is caused by pathogenetic serum IgG autoantibodies to aquaporin 4 (AQP4), the most abundant water-channel protein in the central nervous system. In a subset of patients negative for AQP4-IgG, pathogenetic serum IgG antibodies to myelin oligodendrocyte glycoprotein, an antigen in the outer myelin sheath of central nervous system neurons, are present. Other causes of NMO (such as paraneoplastic disorders and neurosarcoidosis) are rare. NMO was previously associated with a poor prognosis; however, treatment with steroids and plasma exchange for acute attacks and with immunosuppressants (in particular, B cell-depleting agents) for attack prevention has greatly improved the long-term outcomes. Recently, a number of randomized controlled trials have been completed and the first drugs, all therapeutic monoclonal antibodies, have been approved for the treatment of AQP4-IgG-positive NMO and its formes frustes.

Aims: To explore differences in advanced brain magnetic resonance imaging (MRI) characteristics between myelin oligodendrocyte (MOG) immunoglobulin (IgG) and aquaporin-4 (AQP4) IgG seropositive (+) neuromyelitis optica spectrum disorders (NMOSD). Methods: 33 AQP4-IgG and 18 MOG-IgG seropositive NMOSD patients and 61 healthy control (HC) subjects were included. All 112 participants were scanned with the same standardized MRI-protocol on a 3-Tesla MRI-scanner. Brain volume and diffusion tensor imaging (DTI) parameters were assessed. Results: MOG-IgG+ patients showed reduced parallel diffusivity within white matter tracts compared to HC whereas AQP4-IgG+ showed no significant brain parenchymal damage in DTI analysis. AQP4-IgG+ patients showed reduced whole brain volumes and reduced volumes of several deep gray matter structures compared to HC whereas MOG-IgG+ patients did not show reduced brain or deep gray matter volumes compared to HC. Conclusions: Microstructural brain parenchymal damage in MOG-IgG+ patients was more pronounced than in AQP4-IgG+ patients, compared with HC, whereas normalized brain volume reduction was more severe in AQP4-IgG+ patients. Longitudinal imaging studies are warranted to further investigate this trend in NMOSD. Our results suggest that MOG-IgG+ and AQP4-IgG+ NMOSD patients differ in cerebral MRI characteristics. Advanced MRI analysis did not help to differentiate between MOG-IgG+ and AQP4-IgG+ patients in our study., (Copyright © 2020 Schmidt, Chien, Kuchling, Bellmann-Strobl, Ruprecht, Siebert, Asseyer, Jarius, Brandt, Scheel and Paul.)

Background: New-generation, cell-based assays have demonstrated a robust association of serum autoantibodies to full-length human myelin oligodendrocyte glycoprotein (MOG-IgG) with (mostly recurrent) optic neuritis, myelitis, and brainstem encephalitis, as well as with neuromyelitis optica (NMO)-like or acute-disseminated encephalomyelitis (ADEM)-like presentations. However, only limited data are yet available on cerebrospinal fluid (CSF) findings in MOG-IgG-associated encephalomyelitis (MOG-EM; also termed MOG antibody-associated disease, MOGAD)., Objective: To describe systematically the CSF profile in children with MOG-EM., Material and Methods: Cytological and biochemical findings (including white cell counts [WCC] and differentiation; frequency and patterns of oligoclonal bands; IgG/IgM/IgA and albumin concentrations and CSF/serum ratios; intrathecal IgG/IgM/IgA fractions; locally produced IgG/IgM/IgA concentrations; immunoglobulin class patterns; IgG/IgA/IgM reibergrams; Link index; measles/rubella/zoster [MRZ] reaction; other anti-viral and anti-bacterial antibody indices; CSF total protein; CSF L-lactate) from 108 lumbar punctures in 80 pediatric patients of mainly Caucasian descent with MOG-EM were analyzed retrospectively., Results: Most strikingly, CSF-restricted oligoclonal IgG bands, a hallmark of multiple sclerosis (MS), were absent in 89% of samples (N = 96), and the MRZ reaction, the most specific laboratory marker of MS known so far, in 100% (N = 29). If present at all, intrathecal IgG synthesis was low, often transient and mostly restricted to acute attacks. Intrathecal IgM synthesis was present in 21% and exclusively detectable during acute attacks. CSF WCC were elevated in 54% of samples (median 40 cells/μl; range 6-256; mostly lymphocytes and monocytes; > 100/μl in 11%). Neutrophils were present in 71% of samples; eosinophils, activated lymphocytes, and plasma cells were seen only rarely (all < 7%). Blood-CSF barrier dysfunction (as indicated by an elevated albumin CSF/serum ratio) was present in 46% of all samples (N = 79) and at least once in 48% of all patients (N = 67) tested. CSF alterations were significantly more frequent and/or more pronounced in patients with acute spinal cord or brain disease than in patients with acute ON and varied strongly depending on attack severity. CSF L-lactate levels correlated significantly with the spinal cord lesions load (measured in vertebral segments) in patients with acute myelitis (p = 0.0099). An analysis of pooled data from the pediatric and the adult cohort showed a significant relationship of QAlb (p < 0.0005), CST TP (p < 0.0001), and CSF L-lactate (p < 0.0003) during acute attacks with age., Conclusion: MOG-IgG-associated EM in children is characterized by CSF features that are distinct from those in MS. With regard to most parameters, no marked differences between the pediatric cohort and the adult cohort analyzed in Part 1 were noted. Our findings are important for the differential diagnosis of pediatric MS and MOG-EM and add to the understanding of the immunopathogenesis of this newly described autoimmune disease.

Background: New-generation cell-based assays have demonstrated a robust association of serum autoantibodies to full-length human myelin oligodendrocyte glycoprotein (MOG-IgG) with (mostly recurrent) optic neuritis, myelitis, and brainstem encephalitis, as well as with neuromyelitis optica (NMO)-like or acute-disseminated encephalomyelitis (ADEM)-like presentations. However, only limited data are yet available on cerebrospinal fluid (CSF) findings in MOG-IgG-associated encephalomyelitis (MOG-EM; also termed MOG antibody-associated disease, MOGAD)., Objective: To describe systematically the CSF profile in MOG-EM., Material and Methods: Cytological and biochemical findings (including white cell counts and differentiation; frequency and patterns of oligoclonal bands; IgG/IgM/IgA and albumin concentrations and CSF/serum ratios; intrathecal IgG/IgA/IgM fractions; locally produced IgG/IgM/IgA concentrations; immunoglobulin class patterns; IgG/IgA/IgM reibergrams; Link index; measles/rubella/zoster (MRZ) reaction; other anti-viral and anti-bacterial antibody indices; CSF total protein; CSF L-lactate) from 163 lumbar punctures in 100 adult patients of mainly Caucasian descent with MOG-EM were analyzed retrospectively., Results: Most strikingly, CSF-restricted oligoclonal IgG bands, a hallmark of multiple sclerosis (MS), were absent in almost 90% of samples (N = 151), and the MRZ reaction, the most specific laboratory marker of MS known so far, in 100% (N = 62). If present, intrathecal IgG (and, more rarely, IgM) synthesis was low, often transient and mostly restricted to acute attacks. CSF WCC was elevated in > 50% of samples (median 31 cells/μl; mostly lymphocytes and monocytes; > 100/μl in 12%). Neutrophils were present in > 40% of samples; activated lymphocytes were found less frequently and eosinophils and/or plasma cells only very rarely (< 4%). Blood-CSF barrier dysfunction (as indicated by an elevated albumin CSF/serum ratio) was present in 48% of all samples and at least once in 55% of all patients (N = 88) tested. The frequency and degree of CSF alterations were significantly higher in patients with acute myelitis than in patients with acute ON and varied strongly depending on attack severity. CSF L-lactate levels correlated significantly with the spinal cord lesion load in patients with acute myelitis (p < 0.0001). Like pleocytosis, blood-CSF barrier dysfunction was present also during remission in a substantial number of patients., Conclusion: MOG-IgG-positive EM is characterized by CSF features that are distinct from those in MS. Our findings are important for the differential diagnosis of MS and MOG-EM and add to the understanding of the immunopathogenesis of this newly described autoimmune disease.

Objective: To assess the effect of anti-CD20 B-cell depletion with rituximab (RTX) on relapse rates in myelin oligodendrocyte glycoprotein antibody-associated disorder (MOGAD)., Methods: Retrospective review of RTX-treated MOGAD patients from 29 centres in 13 countries. The primary outcome measure was change in relapse rate after starting rituximab (Poisson regression model)., Results: Data on 121 patients were analysed, including 30 (24.8%) children. Twenty/121 (16.5%) were treated after one attack, of whom 14/20 (70.0%) remained relapse-free after median (IQR) 11.2 (6.3-14.1) months. The remainder (101/121, 83.5%) were treated after two or more attacks, of whom 53/101 (52.5%) remained relapse-free after median 12.1 (6.3-24.9) months. In this 'relapsing group', relapse rate declined by 37% (95%CI=19-52%, p<0.001) overall, 63% (95%CI=35-79%, p = 0.001) when RTX was used first line (n = 47), and 26% (95%CI=2-44%, p = 0.038) when used after other steroid-sparing immunotherapies (n = 54). Predicted 1-year and 2-year relapse-free survival was 79% and 55% for first-line RTX therapy, and 38% and 18% for second-/third-line therapy. Circulating CD19 + B-cells were suppressed to <1% of total circulating lymphocyte population at the time of 45/57 (78.9%) relapses., Conclusion: RTX reduced relapse rates in MOGAD. However, many patients continued to relapse despite apparent B-cell depletion. Prospective controlled studies are needed to validate these results., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objectives: We aimed to evaluate optic chiasm (OC) measures as potential imaging marker for anterior optic pathway damage assessment in the context of neuromyelitis optica spectrum disorders (NMOSD)., Materials and Method: This cross-sectional study included 39 patients exclusively with aquaporin 4-IgG seropositive NMOSD of which 25 patients had a history of optic neuritis (NMOSD-ON) and 37 age- and sex-matched healthy controls (HC). OC heights, width, and area were measured using standard 3D T1-weighted MRI. Sensitivity of these measures to detect neurodegeneration in the anterior optic pathway was assessed in receiver operating characteristics analyses. Correlation coefficients were used to assess associations with structural measures of the anterior optic pathway (optic nerve dimensions, retinal ganglion cell loss) and clinical measures (visual function and disease duration)., Results: OC heights and area were significantly smaller in NMOSD-ON compared to HC (NMOSD-ON vs. HC p < 0.0001). An OC area smaller than 22.5 mm 2 yielded a sensitivity of 0.92 and a specificity of 0.92 in separating chiasms of NMOSD-ON from HC. OC area correlated well with structural and clinical measures in NMOSD-ON: optic nerve diameter (r = 0.4, p = 0.047), peripapillary retinal nerve fiber layer thickness (r = 0.59, p = 0.003), global visual acuity (r = - 0.57, p = 0.013), and diseases duration (r = - 0.5, p = 0.012)., Conclusion: Our results suggest that OC measures are promising and easily accessible imaging markers for the assessment of anterior optic pathway damage., Key Points: • Optic chiasm dimensions were smaller in neuromyelitis optica spectrum disorder patients compared to healthy controls. • Optic chiasm dimensions are associated with retinal measures and visual dysfunction. • The optic chiasm might be used as an easily accessible imaging marker of neurodegeneration in the anterior optic pathway with potential functional relevance.

Aside from well-characterized immune-mediated ataxias with a clear trigger and/or association with specific neuronal antibodies, a large number of idiopathic ataxias are suspected to be immune mediated but remain undiagnosed due to lack of diagnostic biomarkers. Primary autoimmune cerebellar ataxia (PACA) is the term used to describe this later group. An International Task Force comprising experts in the field of immune ataxias was commissioned by the Society for Research on the Cerebellum and Ataxias (SRCA) in order to devise diagnostic criteria aiming to improve the diagnosis of PACA. The proposed diagnostic criteria for PACA are based on clinical (mode of onset, pattern of cerebellar involvement, presence of other autoimmune diseases), imaging findings (MRI and if available MR spectroscopy showing preferential, but not exclusive involvement of vermis) and laboratory investigations (CSF pleocytosis and/or CSF-restricted IgG oligoclonal bands) parameters. The aim is to enable clinicians to consider PACA when encountering a patient with progressive ataxia and no other diagnosis given that such consideration might have important therapeutic implications.

Background: Myelin oligodendrocyte glycoprotein antibody (MOG-Ab) disease is an inflammatory autoimmune condition of the central nervous system, defined by antibodies (Abs) against MOG. Of the various clinical phenotypes optic neuritis (ON) is the commonest. We have observed that some patients with MOG-Ab ON present with a severe associated headache., Objective: To highlight the importance of headache in MOG-Ab related optic neuritis., Methods: Clinical and MRI data from MOG-Ab patients with ON (n = 129) were obtained from observational cohort studies and clinical notes at the NeuroCure Clinical Research Center, Charité Berlin and at the Diagnostic and Advisory Service for Neuromyelitis Optica, John Radcliffe Hospital, Oxford., Results: Sixty-four of 129 MOG-Ab patients (49.6%) reported ≥1 headache-related ON. Headache usually started a few days prior to visual loss and extended from the ocular region to the periorbital and fronto-temporal area, sometimes mimicking migraine. Of those, thirty-two patients (50%) reported severe headache. Two patients did not have headache. No headache history was recorded for 63 patients. MRIs performed acutely during headache-related MOG-Ab ON (n = 15) showed anterior ON with extensive swelling and edema of the optic nerve/s in all patients, either unilaterally (n = 5) or bilaterally (n = 10). Peri-optic cerebro-spinal fluid (CSF) was undetectable due to the inflammatory extension in 12 out of 15 patients., Conclusion: Our findings indicate that acute MOG-Ab ON shows florid intra-orbital and peri‑optic inflammation, likely to involve meninges and nociceptive fibers around the optic nerve. This may explain the frequent and often severe headache that precedes the visual deficit, sometimes misdiagnosed as migraine., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020. Published by Elsevier B.V.)

Neuromyelitis optica spectrum disorders (NMOSD) are a type of neurological autoimmune disease characterized by attacks of CNS inflammation that are often severe and predominantly affect the spinal cord and optic nerve. The majority of individuals with NMOSD are women, many of whom are of childbearing age. Although NMOSD are rare, several small retrospective studies and case reports have indicated that pregnancy can worsen disease activity and might contribute to disease onset. NMOSD disease activity seems to negatively affect pregnancy outcomes. Moreover, some of the current NMOSD treatments are known to pose risks to the developing fetus and only limited safety data are available for others. Here, we review published studies regarding the relationship between pregnancy outcomes and NMOSD disease activity. We also assess the risks associated with using disease-modifying therapies for NMOSD during the course of pregnancy and breastfeeding. On the basis of the available evidence, we offer recommendations regarding the use of these therapies in the course of pregnancy planning in individuals with NMOSD.

Background: Therapy of autoimmune diseases of the central and peripheral nervous system with intravenous IgG immunoglobulin (IVIg) is well established. Since IVIg is produced from pooled human plasma, autoantibodies can be found in IVIg products and, accordingly, in patient sera after transfusion. The de novo evidence or disappearance of anti-neural autoantibodies after IVIg treatment has so far not been systematically examined., Methods: We screened 50 neurological patients before and after IVIg treatment for classical onconeural and the most common neurological surface autoantibodies as well as for ganglioside autoantibodies and 23 different antinuclear autoantibodies using immunoblot or cell-based indirect immunofluorescence assays. Furthermore, we screened 31 neurological patients with previously known seropositivity for disappearance of the corresponding antibody after treatment., Results: After IVIg treatment, 90% of all sera were de novo positive for antinuclear antibodies, especially for Ro-52. In contrast, 94% of all sera did not show any de novo-positive anti-neural antibodies. In the remaining three cases, titers were very low. Importantly, 12.9% of all tested sera of patients with known antibody positivity turned false negative after IVIg treatment and titers were falsely low in 37% of the remaining sera., Conclusions: Here, we present for the first time results of a broad screening for clinically relevant autoantibodies before and after IVIg treatment in neurological patients. We identified a high specificity but reduced sensitivity for anti-neural antibody testing after IVIg transfusion. In contrast, antinuclear antibody testing is not reliable after IVIg treatment. These results are of high practical importance for diagnostic of neuroimmunological diseases.

Objective: To investigate if patients with neuromyelitis optica spectrum disorder (NMOSD) develop subclinical visual pathway impairment independent of acute attacks., Methods: A total of 548 longitudinally assessed full-field visual evoked potentials (VEP) of 167 patients with NMOSD from 16 centers were retrospectively evaluated for changes of P100 latencies and P100-N140 amplitudes. Rates of change in latencies (RCL) and amplitudes (RCA) over time were analyzed for each individual eye using linear regression and compared using generalized estimating equation models., Results: The rates of change in the absence of optic neuritis (ON) for minimal VEP intervals of ≥3 months between baseline and last follow-up were +1.951 ms/y (n = 101 eyes; SD = 6.274; p = 0.012) for the P100 latencies and -2.149 µV/y (n = 64 eyes; SD = 5.013; p = 0.005) for the P100-N140 amplitudes. For minimal VEP intervals of ≥12 months, the RCL was +1.768 ms/y (n = 59 eyes; SD = 4.558; p = 0.024) and the RCA was -0.527 µV/y (n = 44 eyes; SD = 2.123; p = 0.111). The history of a previous ON >6 months before baseline VEP had no influence on RCL and RCA. ONs during the observational period led to mean RCL and RCA of +11.689 ms/y (n = 16 eyes; SD = 17.593; p = 0.003) and -1.238 µV/y (n = 11 eyes; SD = 3.708; p = 0.308), respectively., Conclusion: This first longitudinal VEP study of patients with NMOSD provides evidence of progressive VEP latency delay occurring independently of acute ON. Prospective longitudinal studies are needed to corroborate these findings and help to interpret the clinical relevance., (© 2019 American Academy of Neurology.)

Neuromyelitis optica (NMO) was long considered a clinical variant of multiple sclerosis (MS). However, the discovery of a novel and pathogenic anti-astrocytic serum autoantibody targeting aquaporin-4 (termed NMO-IgG or AQP4-Ab), the most abundant water channel protein in the central nervous system, led to the recognition of NMO as a distinct disease entity in its own right and generated strong and persisting interest in the condition. NMO is now studied as a prototypic autoimmune disorder, which differs from MS in terms of immunopathogenesis, clinicoradiological presentation, optimum treatment, and prognosis. While the history of classic MS has been extensively studied, relatively little is known about the history of NMO. In Part 1 of this series we focused on the late 19th century, when the term 'neuromyelitis optica' was first coined, traced the term's origins and followed its meandering evolution throughout the 20th and into the 21st century. Here, in Part 2, we demonstrate that the peculiar concurrence of acute optic nerve and spinal cord affliction characteristic for NMO caught the attention of physicians much earlier than previously thought by re-presenting a number of very early cases of possible NMO that date back to the late 18th and early 19th century. In addition, we comprehensively discuss the pioneering concept of 'spinal amaurosis', which was introduced into the medical literature by ophthalmologists in the first half of the 19th century.

In 1894, Eugène Devic (1858-1930) and his doctoral student Fernand Gault (1873-1936) reported on a patient with optic neuritis (ON) and myelitis and proposed the name "neuro-myélite optique" for this syndrome. Subsequently, Devic became the eponym of neuromyelitis optica (NMO), which was then referred to as "Devic's syndrome", "Devic's disease" or "Morbus Devic". Thereby, the case became a historical index case of NMO. For many decades little attention was paid to NMO, which most authors considered a clinical variant of multiple sclerosis. However, the discovery of pathogenic antibodies to aquaporin-4 at the beginning of the 21st century revived interest in the syndrome, and AQP4-IgG-positive NMO spectrum disorders (NMOSD) are now studied as prototypical autoimmune diseases. More recently, antibodies to full-length myelin oligodendrocyte glycoprotein (MOG) have been detected in patients with ON as well as in patients with myelitis, some of whom exhibit a clinical phenotype very similar to that described by Devic. This raises the question of whether Devic's patient might have suffered from MOG encephalomyelitis rather than classic NMOSD. In this article, we summarise and discuss the available evidence for and against that hypothesis. We also discuss differential diagnoses and the question whether Devic's patient, who worked as a hatter and had initially been admitted for nervous hyperexcitability and tremor, might have suffered from co-existing erethism ('mad hatter disease'), which is caused by chronic occupational exposure to mercury., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Serum antibodies against myelin-oligodendrocyte-glycoprotein (MOG-IgG) are detectable in a proportion of patients with acute or relapsing neuroinflammation. It is unclear, if neuro-axonal damage occurs only in an attack-dependent manner or also progressively. Therefore, this study aimed to investigate longitudinally intra-retinal layer changes in eyes without new optic neuritis (ON) in MOG-IgG-seropositive patients., Methods: We included 38 eyes of 24 patients without ON during follow-up (F/U) [median years (IQR)] 1.9 (1.0-2.2) and 56 eyes of 28 age- and sex-matched healthy controls (HC). The patient group's eyes included 18 eyes without (Eye ON- ) and 20 eyes with history of ON (Eye ON+ ). Using spectral domain optical coherence tomography (OCT), we acquired peripapillary retinal nerve fiber layer thickness (pRNFL) and volumes of combined ganglion cell and inner plexiform layer (GCIP), inner nuclear layer (INL), and macular volume (MV). High-contrast visual acuity (VA) was assessed at baseline., Results: At baseline in Eye ON- , pRNFL (94.3 ± 15.9 μm, p = 0.36), INL (0.26 ± 0.03 mm 3 , p = 0.11), and MV (2.34 ± 0.11 mm 3 , p = 0.29) were not reduced compared to HC; GCIP showed thinning (0.57 ± 0.07 mm 3 ; p = 0.008), and VA was reduced (logMAR 0.05 ± 0.15 vs. - 0.09 ± 0.14, p = 0.008) in comparison to HC. Longitudinally, we observed pRNFL thinning in models including all patient eyes (annual reduction - 2.20 ± 4.29 μm vs. - 0.35 ± 1.17 μm, p = 0.009) in comparison to HC. Twelve Eye ON- with other than ipsilateral ON attacks ≤ 6 months before baseline showed thicker pRNFL at baseline and more severe pRNFL thinning in comparison to 6 Eye ON- without other clinical relapses., Conclusions: We observed pRNFL thinning in patients with MOG-IgG during F/U, which was not accompanied by progressive GCIP reduction. This effect could be caused by a small number of Eye ON- with other than ipsilateral ON attacks within 6 months before baseline. One possible interpretation could be a reduction of the swelling, which could mean that MOG-IgG patients show immune-related swelling in the CNS also outside of an attack's target area.

Treatment with alemtuzumab is followed by an early increase in Treg frequencies. Whether naïve and memory subsets are differentially affected and how depletion influences dysfunctional MS-Treg is unclear. In this study, we analyzed the effect of alemtuzumab on regulatory T-cells (Treg) in patients with multiple sclerosis (MS). For this purpose 182 blood samples from 25 MS patients were taken shortly before treatment and serially for up to 24 months after two alemtuzumab cycles. We studied Treg by flow cytometry (quantitation, phenotypical characterization), real-time polymerase chain reaction (T-cell receptor (TCR) excision circles [TREC] content), CDR3-spectratyping (clonal distribution), and proliferation assays (suppressive function). CD52-mediated cytolysis of Treg and conventional T-cells was determined by a complement-dependent cytolysis assay. Our studies revealed that 1 week post-alemtuzumab, Treg were depicted at constant frequencies among CD4 + T-cells. In contrast, Treg frequencies were massively increased at month 1. Post-depletional Treg exhibited a CD45RO + memory phenotype, a skewed TCR repertoire, and contained minimum TREC numbers. Naïve Treg, thymic markers, and TCR-variability commenced to rise after 6 months but did not attain baseline levels. In vitro , Treg exhibited higher susceptibility to lysis than Tcon. Treg suppressive function constantly increased within 1 year when co-cultured with syngeneic T-cells, but remained stable against allogeneic T-cells from normal donors. Our findings suggest that (1) Treg are not spared from alemtuzumab-mediated depletion and thymopoiesis does not considerably contribute to long-term recovery, (2) either homeostatic proliferation and/or conversion from residual Tcon contributes to Treg expansion during the early post-treatment phase (3) the enhanced inhibitory effect of Treg following alemtuzumab is due to altered composition and reactivity of post-depletional Tcon.

Background: Myelinoclastic diffuse sclerosis (MDS; also termed Schilder's disease) is a rare inflammatory demyelinating disorder of the central nervous system characterised by demyelination of vast areas of the white matter. It is unclear whether MDS is a variant of multiple sclerosis (MS) or a disease entity in its own right., Objective: To compare the cerebrospinal fluid (CSF) features of MDS with those of MS., Methods: Retrospective analysis of the CSF profile of all patients with MDS reported in the medical literature between 1960 and 2018., Results: The most striking finding was a substantial lack of oligoclonal bands (OCBs) in MDS, which were absent in at least 77% (30/39) of all lumbar punctures (LP) in the total cohort and in 86% in the subgroup of patients with normal very long-chain fatty acid serum ratios (VLCFA). Almost all cases published in the past 15 years were negative for OCBs. These findings are in contrast to MS, in which OCBs are present in up to 98% of cases (p < 0.00001 when compared with reference works in MS; both in adult and in pediatric patients). CSF pleocytosis was absent in at least 79% (46/58) of all LP (p < 0.0001 vs. MS) and in 92% (24/26) of LPs in the VLCFA-tested subgroup. CSF total protein levels were elevated in 56% of all LPs (p < 0.0001 vs. MS) and in 63% of LPs in the VLCFA-tested subgroup and were often higher than in typical MS (> 100 mg/dL in 13/22; up to 220 mg/dL). EBV serum antibodies, which are present in virtually all patients with MS, and the so-called MRZ (measles/rubella/zoster) reaction, a highly specific marker of MS, were absent in all of the few patients tested. In addition, we discuss further differences between MS and MDS, taking into account also Schilder's original comprehensive case description from 1912., Conclusion: In the majority of patients diagnosed with MDS, CSF features differ significantly from those typically found in MS and are more similar to those previously reported in patients with myelin oligodendrocyte glycoprotein-immunoglobulin G (IgG)-positive encephalomyelitis, aquaporin-4-IgG-positive neuromyelitis optica spectrum disorders or Baló's concentric sclerosis. Our data suggest that MDS and MS are immunopathologically distinct entities in the majority of cases.

Objectives: Neuromyelitis optica spectrum disorders (NMOSD) are inflammatory conditions of the central nervous system and an important differential diagnosis of multiple sclerosis (MS). Unlike MS, the course is usually relapsing, and it is unclear, if progressive neurodegeneration contributes to disability. Therefore, we aimed to investigate if progressive retinal neuroaxonal damage occurs in aquaporin4-antibody-seropositive NMOSD., Methods: Out of 157 patients with NMOSD screened, 94 eyes of 51 patients without optic neuritis (ON) during follow-up (F/U) and 56 eyes of 28 age-matched and sex-matched healthy controls (HC) were included (median F/U 2.3 years). The NMOSD cohort included 60 eyes without (Eye ON - ) and 34 eyes with a history of ON prior to enrolment (Eye ON+ ). Peripapillary retinal nerve fibre layer thickness (pRNFL), fovea thickness (FT), volumes of the combined ganglion cell and inner plexiform layer (GCIP) and the inner nuclear layer (INL) and total macular volume (TMV) were acquired by optical coherence tomography (OCT)., Results: At baseline, GCIP, FT and TMV were reduced in Eye ON+ (GCIP p<2e -16 ; FT p=3.7e -4 ; TMV p=3.7e -12 ) and in Eye ON -  (GCIP p=0.002; FT p=0.040; TMV p=6.1e -6 ) compared with HC. Longitudinally, we observed GCIP thinning in Eye ON- (p=0.044) but not in Eye ON+ . Seven patients had attacks during F/U; they presented pRNFL thickening compared with patients without attacks (p=0.003)., Conclusion: This study clearly shows GCIP loss independent of ON attacks in aquaporin4-antibody-seropositive NMOSD. Potential explanations for progressive GCIP thinning include primary retinopathy, drug-induced neurodegeneration and retrograde neuroaxonal degeneration from lesions or optic neuropathy. pRNFL thickening in the patients presenting with attacks during F/U might be indicative of pRNFL susceptibility to inflammation., Competing Interests: Competing interests: FCO has nothing to disclose. JH reports personal fees and non-financial support from Merck, grants, personal fees and non-financial support from Novartis, personal fees from Roche, non-financial support from Bayer Healthcare, personal fees from Santhera, personal fees and non-financial support from Biogen, personal fees and non-financial support from Sanofi Genzyme, all outside the submitted work. ARF is sponsored by Abide Therapeutic outside of the submitted work and reports no potential conflicts of interest. NL has nothing to disclose. HZ reports grants from Novartis, during the conduct of the study. SM has nothing to disclose; he is named as inventor on a patent application describing OCT image analysis. NB has nothing to disclose. JBS received speaking fees and travel grants from Bayer Healthcare, Sanofi-Aventis/Genzyme, Biogen and Teva Pharmaceuticals, unrelated to the present scientific work. PA reports grants, personal fees and non-financial support from Allergan, personal fees and non-financial support from Bayer Healthcare, grants, personal fees and non-financial support from Biogen, grants, personal fees and non-financial support from Ipsen, grants, personal fees and non-financial support from Merz Pharmaceuticals, personal fees and non-financial support from Merck, grants, personal fees and non-financial support from Novartis, non-financial support from Sanofi-Aventis/Genzyme, personal fees and non-financial support from Teva Pharmaceuticals, grants, personal fees and non-financial support from Roche, outside the submitted work. KR reports research support from Novartis and Merck Serono as well as speaking fees or travel grants from Bayer Healthcare, Biogen Idec, Merck Serono, Sanofi-Aventis/Genzyme, Teva Pharmaceuticals, Roche, Novartis and the Guthy-Jackson Charitable Foundation, all unrelated to this work. TK received travel expenses and personal compensations from Bayer Healthcare, Teva Pharmaceuticals, Merck, Novartis Pharma, Sanofi-Aventis/Genzyme, Roche and Biogen as well as grant support from Bayer-Schering AG, Novartis and Chugai Pharma, unrelated to this work. OW has nothing to disclose. SJ has nothing to disclose. MIL reports personal fees from Biogen Idec and grants from Novartis, outside the submitted work. JP reports grants Journal of Neurology, Neurosurgery and Psychiatry and personal fees from Merck Serono, grants and personal fees from Biogen Idec, personal fees from Teva Pharmaceuticals, grants from Chugai, grants and personal fees from MedImmun, grants and personal fees from Alexion, grants and personal fees from Novartis, personal fees from Roche, grants from Genzyme, grants and personal fees from ABIDE, personal fees from TG Therapeutics, outside the submitted work. In addition, JP has a patent Isis: Diagnosing Multiple Sclerosis. FP reports research grants and speaker honoraria from Bayer, Teva, Genzyme, Merck, Novartis, MedImmune and is member of the steering committee of the OCTIMS study (Novartis), all unrelated to this work. AUB is cofounder and holds shares of commercial entities Motognosis and Nocturne. He is named as inventor on several patent applications describing serum biomarkers for MS, perceptive visual computing for tracking of motor dysfunction and OCT image analysis., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Over the past few years, new-generation cell-based assays have demonstrated a robust association of autoantibodies to full-length human myelin oligodendrocyte glycoprotein (MOG-IgG) with (mostly recurrent) optic neuritis, myelitis and brainstem encephalitis, as well as with acute disseminated encephalomyelitis (ADEM)-like presentations. Most experts now consider MOG-IgG-associated encephalomyelitis (MOG-EM) a disease entity in its own right, immunopathogenetically distinct from both classic multiple sclerosis (MS) and aquaporin-4 (AQP4)-IgG-positive neuromyelitis optica spectrum disorders (NMOSD). Owing to a substantial overlap in clinicoradiological presentation, MOG-EM was often unwittingly misdiagnosed as MS in the past. Accordingly, increasing numbers of patients with suspected or established MS are currently being tested for MOG-IgG. However, screening of large unselected cohorts for rare biomarkers can significantly reduce the positive predictive value of a test. To lessen the hazard of overdiagnosing MOG-EM, which may lead to inappropriate treatment, more selective criteria for MOG-IgG testing are urgently needed. In this paper, we propose indications for MOG-IgG testing based on expert consensus. In addition, we give a list of conditions atypical for MOG-EM ("red flags") that should prompt physicians to challenge a positive MOG-IgG test result. Finally, we provide recommendations regarding assay methodology, specimen sampling and data interpretation, and propose for the first time diagnostic criteria for MOG-EM.

Objective: To analyze whether 1 of the 2 apheresis techniques, therapeutic plasma exchange (PE) or immunoadsorption (IA), is superior in treating neuromyelitis optica spectrum disorder (NMOSD) attacks and to identify predictive factors for complete remission (CR)., Methods: This retrospective cohort study was based on the registry of the German Neuromyelitis Optica Study Group, a nationwide network established in 2008. It recruited patients with neuromyelitis optica diagnosed according to the 2006 Wingerchuk criteria or with aquaporin-4 (AQP4-ab)-antibody-seropositive NMOSD treated at 6 regional hospitals and 16 tertiary referral centers until March 2013. Besides descriptive data analysis of patient and attack characteristics, generalized estimation equation (GEE) analyses were applied to compare the effectiveness of the 2 apheresis techniques. A GEE model was generated to assess predictors of outcome., Results: Two hundred and seven attacks in 105 patients (87% AQP4-ab-antibody seropositive) were treated with at least 1 apheresis therapy. Neither PE nor IA was proven superior in the therapy of NMOSD attacks. CR was only achieved with early apheresis therapy. Strong predictors for CR were the use of apheresis therapy as first-line therapy (OR 12.27, 95% CI: 1.04-144.91, p = 0.047), time from onset of attack to start of therapy in days (OR 0.94, 95% CI: 0.89-0.99, p = 0.014), the presence of AQP4-ab-antibodies (OR 33.34, 95% CI: 1.76-631.17, p = 0.019), and monofocal attack manifestation (OR 4.71, 95% CI: 1.03-21.62, p = 0.046)., Conclusions: Our findings suggest early use of an apheresis therapy in NMOSD attacks, particularly in AQP4-ab-seropositive patients. No superiority was shown for one of the 2 apheresis techniques., Classification of Evidence: This study provides Class IV evidence that for patients with NMOSD, neither PE nor IA is superior in the treatment of attacks.

Background: Baló's concentric sclerosis (BCS) is a rare condition characterized by concentrically layered white matter lesions. While its pathogenesis is unknown, hypoxia-induced tissue injury and chemotactic stimuli have been proposed as potential causes of BCS lesion formation. BCS has been suggested to be a variant of multiple sclerosis (MS). Here, we aimed to elucidate similarities and differences between BCS and MS by describing lesion morphology and localization in high-resolution 7 Tesla (7 T) magnetic resonance imaging (MRI) scans., Methods: Ten patients with Baló-type lesions underwent 7 T MRI, and 10 relapsing remitting MS patients served as controls. The 7 T MR imaging protocol included 3D T 1 -weighted (T 1 w) magnetization-prepared rapid gradient echo, 2D high spatial resolution T 2 *-weighted (T 2 *w) fast low-angle shot and susceptibility-weighted imaging., Results: Intralesional veins were visible in the center of all but one Baló-type lesion. Four Baló-type lesions displayed inhomogeneous intralesional T 2 *w signal intensities, which are suggestive of microhemorrhages or small ectatic venules. Eight of 10 BCS patients presented with 97 additional lesions, 36 of which (37%) had a central vein. Lesions involving the cortical gray matter and the U-fibers were not detected in BCS patients., Conclusion: Our findings support the hypothesis that BCS and MS share common pathogenetic mechanisms but patients present with different lesion phenotypes.

Background: Optic neuritis (ON) is an inflammatory optic neuropathy, where the genetic and autoimmune dependency remains poorly characterized., Objective: To investigate autoimmune and immunogenetic aspects of ON., Method: In a prospective population-based cohort 51 patients with ON were included. At follow up 20 patients had progressed to multiple sclerosis (MS-ON). All patients were screened for neuronal and systemic autoantibodies. HLA genotypes and allele and genotype frequencies of the PTPN22 C1858T and the PD-1.3 single-nucleotide polymorphisms (SNPs) were determined and compared to a cohort of Danish blood donors, acting as healthy controls., Results: Median follow-up was 366 days (301-430) for MS-ON patients and 375 (range 50-436) for isolated ON (ION). Autoantibodies against myelin oligodendrocyte glycoprotein (MOG-IgG), were positive in two patients, no patients had anti-aquaporin-4 antibodies. Coexisting neural autoantibodies were detected in two patients and in 12 patients other systemic autoantibodies were found. Four (8%) had other autoimmune disorders. A family history of autoimmunity was observed in 12 (24%) and of demyelinating disease in six patients (12%). In MS-ON patients the frequencies of HLA-DQB1*06:02 and HLA-DRB1*15:01 tended to be higher compared to controls (p = 0.08). Stratification of patients with presence of oligoclonal bands (OCB) showed an association to the HLA-DQB1*06:02-HLA-DRB1*15:01 haplotype in ION (HLA-DQB1*06:02 and HLA-DRB1*15:01 (p = 0.03)), and in MS-ON patients (HLA-DQB1*06:02 and HLA-DRB1*15:01 (p = 0.03)). No significant associations to PTPN22 1858C/T or PD-1.3 G/A were found in any group comparison., Conclusions: ON patients had a general susceptibility to autoimmunity and two were MOG-IgG positive. HLA-DQB1*06:02 and HLA-DRB1*15:01 were associated with the presence of OCB in ON patients., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Antibodies to human full-length myelin oligodendrocyte glycoprotein (MOG-IgG) as detected by new-generation cell-based assays have recently been described in patients presenting with acute demyelinating disease of the central nervous system, including patients previously diagnosed with multiple sclerosis (MS). However, only limited data are available on the relevance of MOG-IgG testing in patients with chronic progressive demyelinating disease. It is unclear if patients with primary progressive MS (PPMS) or secondary progressive MS (SPMS) should routinely be tested for MOG-IgG., Objective: To evaluate the frequency of MOG-IgG among patients classified as having PPMS or SPMS based on current diagnostic criteria., Methods: For this purpose, we retrospectively tested serum samples of 200 patients with PPMS or SPMS for MOG-IgG using cell-based assays. In addition, we performed a review of the entire English language literature on MOG-IgG published between 2011 and 2017., Results: None of 139 PPMS and 61 SPMS patients tested was positive for MOG-IgG. Based on a review of the literature, we identified 35 further MOG-IgG tests in patients with PPMS and 55 in patients with SPMS; the only reportedly positive sample was positive just at threshold level and was tested in a non-IgG-specific assay. In total, a single borderline positive result was observed among 290 tests., Conclusion: Our data suggest that MOG-IgG is absent or extremely rare among patients with PPMS or SPMS. Routine screening of patients with typical PPMS/SPMS for MOG-IgG seems not to be justified.

Background: Serum immunoglobulin G targeting the astrocyte water channel aquaporin-4 (AQP4) in the central nervous system (CNS) is a biomarker for neuromyelitis optica spectrum disease (NMOSD). Co-existence of NMOSD with systemic lupus erythematosus (SLE) putatively suggests susceptibility to antibody-mediated autoimmune disease., Objective: To estimate the prevalence of NMOSD in SLE and investigate the immunogenetic background for an association of NMOSD and SLE., Methods: The study included a predominantly population-based cohort with clinical and serological investigations of 208 patients with SLE, followed prospectively since 1995. All patients received immunosuppressive treatment. NMOSD was evaluated retrospectively based on the 2015 International Panel for NMOSD Diagnosis (IPND) criteria. Polymorphisms in programmed cell death protein 1 (PDCD-1) PD-1.3 G/A were genotyped. AGP4-IgG and other autoantibodies, including myelin oligodendrocyte glycoprotein (MOG), was determined blinded to clinical diagnosis., Results: Of 208 patients with SLE, 45(22%) had neuropsychiatric (NP) SLE, and CNS involvement predominated in 30 of 45 (67%) patients. Serum AQP4-IgG was detected in 2 of 30 (6.7%) neuropsychiatric SLE (NPSLE) patients both of whom had myelitis and antiphospholipid syndrome; one patient also had myasthenia gravis. None had MOG-IgG. PD-1.3A allele was not associated with SLE nor with NPSLE., Conclusion: AQP4-IgG autoimmune syndrome may rarely co-exist with SLE, and such patients have other NMOSD-typical syndromes such as myelitis.

Background: Optic neuritis (ON) is a focal demyelinating event, which may evolve into multiple sclerosis (MS)., Objective: To study MRI characteristics in the acute phase of the first ON episode., Methods: A prospective population-based study was performed on 31 patients with a first episode of acute ON with a one year follow-up. MRI, clinical evaluation, and detection of aquaporin-4 (AQP4)-IgG and myelin oligodendrocyte glycoprotein (MOG)-IgG was undertaken. For lesion characterization on MRI the optic nerves were divided into three segments: intra-orbital (IO), canalicular (CAN) and chiasmal (CHI)., Results: Lesions of the optic nerve were observed in 80.6%(25/31), with IO location in 48%(12/25), CAN in 8% (2/25) and both IO and CAN in 44%(11/25). Patients who converted to MS had lesions located at IO in 77%(10/13), whereas the group with isolated ON had IO and CAN in 73% (8/11), p = 0.003. Brain lesions were observed in 84% (21/25) at onset of ON; 62%(13/25) progressed to MS with more frequent location in brainstem (p = 0.030) and lesions in periventricular areas (p = 0.015). Spinal cord lesions were detected only in patients who progressed to MS (p = 0.002). MOG-IgG was detected in one patient with an optic nerve lesion located at IO and CAN. Serum AQP4-IgG was detected in none. Follow-up MRI showed progression in optic nerve lesions in 55% (11/20) patients., Conclusions: Specific location of optic nerve and brain lesions and the presence of spinal cord lesions in the acute phase of the first ON episode facilitated an MS diagnosis. The extension of optic nerve lesions following ON suggests a long-term progressive degeneration as an important element of ON pathology., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: Patients with multiple sclerosis (MS) frequently have an intrathecal production of antibodies to different common viruses, which can be detected by elevated antiviral antibody indices (AIs). There is a strong and consistent association of MS and Epstein-Barr virus (EBV) infection., Objective: To systematically compare the frequencies of intrathecal antibody production to EBV, measles virus, rubella virus, varicella zoster virus (VZV) and herpes simplex virus (HSV) in patients with MS., Methods: Review of the English and German literature on the frequencies of intrathecal immunoglobulin (Ig)G antibody production, as defined by an elevated AI, to EBV, measles virus, rubella virus, VZV and HSV in adult and pediatric patients with MS., Results: In nine original studies identified, the frequencies of an intrathecal production of antibodies to Epstein-Barr nuclear antigen-1 (33/340, 9.7%), EBV viral capsid antigen (12/279, 4.3%) and antigens from EBV-infected cell lines (14/90, 15.6%) in adult patients with MS were clearly lower (p ≤ 0.03 for all pairwise comparisons) than the frequencies of an intrathecal production of antibodies to measles virus (612/922, 66.4%), rubella virus (521/922, 56.5%), VZV (470/922, 51%; data from 17 original studies) and HSV (78/291, 26.8%; data from 6 original studies). Though based on a lower number of original studies and patients, findings in children with MS were essentially similar. As in adults and children with MS the seroprevalence of EBV is higher than the seroprevalences of the other investigated viruses, the lower frequency of elevated EBV AIs became even more pronounced after correction of the frequencies of elevated antiviral AIs for the seroprevalences of the respective viruses., Conclusions: Given the very high seroprevalence of EBV in MS, the frequency of intrathecally produced antibodies to EBV in patients with MS is paradoxically low compared to that of other common viruses. These findings are compatible with the recently proposed hypothesis that in individuals going on to develop MS antiviral antibody-producing cells may invade the brain predominantly at the time of and triggered by acute primary EBV infection, before anti-EBV IgG producing cells have yet occurred.

Background: Optic neuritis (ON) is often associated with multiple sclerosis (MS). Early diagnosis is critical to optimal patient management., Objective: To estimate the incidence of acute ON and the rates of conversion to MS and antibody-mediated ON., Method: Population-based prospective study was performed in patients with ON from three ophthalmological departments and 44 practicing ophthalmologists from 2014 to 2016. Ophthalmological and neurological examination, magnetic resonance imaging (MRI), determination of aquaporin-4(AQP4)-IgG and myelin-oligodendrocyte glycoprotein (MOG)-IgG were investigated blindly., Results: In all, 63 patients were evaluated and 51 fulfilled the criteria for ON. All were Caucasian, with female:male ratio of 2.2:1 and a median age of 38 years (16-66); 44 (86%) had a single episode of ON (four bilateral), while 7/51 (14%) had recurrent ON. The overall age-specific incidence was 3.28 (2.44-4.31) per 100,000 person years, 2.02 for men and 4.57 for women. At follow-up, 20 patients met the diagnostic criteria for MS, MRI lesions disseminated in space and time in 17/20 patients. AQP4-IgG was detected in none, MOG-IgG was detected in two patients., Conclusion: The prospective incidence of ON was estimated. MRI enabled a diagnosis of MS in a subgroup of patients. Antibody-mediated ON with specificity for MOG was detected in 4% of cases.

Objective: To study the prevalence of autoantibodies to synapsin in patients with psychiatric and neurological disorders and to describe clinical findings in synapsin antibody positive patients., Methods: Sera of 375 patients with different psychiatric and neurological disorders and sera of 97 healthy controls were screened (dilution 1:320) for anti-synapsin IgG using HEK293 cells transfected with rat synapsin Ia. Positive sera were further analyzed by immunoblots with brain tissue from wild type and synapsin knock out mice and with HEK293 cells transfected with human synapsin Ia and Ib. Binding of synapsin IgG positive sera to primary neurons was studied using murine hippocampal neurons., Results: IgG in serum from 23 (6.1%) of 375 patients, but from none of the 97 healthy controls (p=0.007), bound to rat synapsin Ia transfected cells with a median (range) titer of 1:1000 (1:320-1:100,000). Twelve of the 23 positive sera reacted with a protein of the molecular size of synapsin I in immunoblots of wild type but not of synapsin knock out mouse brain tissue. Out of 19/23 positive sera available for testing, 13 bound to human synapsin Ia and 16 to human synapsin Ib transfected cells. Synapsin IgG positive sera stained fixed and permeabilized murine hippocampal neurons. Synapsin IgG positive patients had various psychiatric and neurological disorders. Tumors were documented in 2 patients (melanoma, small cell lung carcinoma); concomitant anti-neuronal or other autoantibodies were present in 8 patients., Conclusions: Autoantibodies to human synapsin Ia and Ib are detectable in a proportion of sera from patients with different psychiatric and neurological disorders, warranting further investigation into the potential pathophysiological relevance of these antibodies., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Neuromyelitis optica (NMO) is a severe autoimmune inflammatory disorder of the central nervous system. NMO and its abortive forms are referred to as NMO spectrum disorders (NMOSD). NMOSD are mostly associated with antibodies to aquaporin-4 (AQP4-IgG). However, recent studies have demonstrated antibodies to myelin oligodendrocyte glycoprotein (MOG-IgG) in a subset of patients. Data on NMOSD in North Africa are sparse., Objective: To describe the frequency of MOG-IgG and AQP4-IgG among patients with optic neuritis (ON) and/or myelitis in Algeria as well as the clinical and paraclinical features associated with these antibodies., Methods: Retrospective testing of 42 patients with optic neuritis and/or myelitis treated at the teaching hospital of TiziOuzou for MOG-IgG and AQP4-IgG, and retrospective evaluation of the patients' medical records., Results: Six of 42 (14.3%) patients were positive for AQP4-IgG and 3/42 (7.1%) were positive for MOG-IgG. No patient was positive for both AQP4-IgG and MOG-IgG. All antibody-positive patients were women. MOG-IgG was associated with severe episodes of ON in all MOG-IgG-positive patients. Steroid treatment was followed by complete remission in two patients. AQP4-IgG was associated with ON and/or longitudinally extensive transverse myelitis (LETM), often with severe onset. While all six of the AQP4-IgG-positive patients met the 2015 IPND criteria for NMOSD, only one of the three MOG-IgG-positive patients did so. Interestingly, clinically silent extensive spinal cord or brain lesions were present in two of the three MOG-IgG-positive patients, and altered visual evoked potentials without clinical evidence of ON were found in three of the six AQP4-IgG-positive patients., Conclusion: MOG-IgG and AQP4-IgG are found in a substantial subset of Algerian patients with ON and/or myelitis, are present predominantly in women, and may be associated with differences in clinical presentation and, possibly, outcome. Only a subset of MOG-IgG positive patients meets the current diagnostic criteria for NMOSD., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In 2010, a novel anti-neuronal autoantibody, termed anti-Ca, was described in a patient with subacute cerebellar ataxia, and Rho GTPase-activating protein 26 (ARHGAP26) was identified as the target antigen. Recently, three additional cases of anti-Ca-positive cerebellar ataxia have been published. In addition to ataxia, cognitive decline and depression have been observed in some patients. Here, we report two new cases of anti-Ca-associated autoimmune cerebellar ataxia. Patient 1 presented with dizziness and acute yet mild limb and gait ataxia. Symptoms stabilized with long-term oral corticosteroid therapy but transiently worsened when steroids were tapered. Interestingly, both initial occurrence and worsening of the patient's neurological symptoms after steroid withdrawal were accompanied by spontaneous cutaneous hematomas. Patient 2 initially presented with an increased startle response and myoclonic jerks, and subsequently developed severe limb and gait ataxia, dysarthria, oculomotor disturbances, head and voice tremor, dysphagia, cognitive symptoms and depression. Steroid treatment was started five years after disease onset. The symptoms then responded only poorly to corticosteroids. At most recent follow-up, 19 years after disease onset, the patient was wheelchair-bound. These cases extend the clinical spectrum associated with anti-ARHGAP26 autoimmunity and suggest that early treatment may be important in patients with this rare syndrome., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Objective: To analyse predictors for relapses and number of attacks under different immunotherapies in patients with neuromyelitis optica spectrum disorder (NMOSD)., Design: This is a retrospective cohort study conducted in neurology departments at 21 regional and university hospitals in Germany. Eligible participants were patients with aquaporin-4-antibody-positive or aquaporin-4-antibody-negative NMOSD. Main outcome measures were HRs from Cox proportional hazard regression models adjusted for centre effects, important prognostic factors and repeated treatment episodes., Results: 265 treatment episodes with a mean duration of 442 days (total of 321 treatment years) in 144 patients (mean age at first attack: 40.9 years, 82.6% female, 86.1% aquaporin-4-antibody-positive) were analysed. 191 attacks occurred during any of the treatments (annual relapse rate=0.60). The most common treatments were rituximab (n=77, 111 patient-years), azathioprine (n=52, 68 patient-years), interferon-β (n=32, 61 patient-years), mitoxantrone (n=34, 32.1 patient-years) and glatiramer acetate (n=17, 10 patient-years). Azathioprine (HR=0.4, 95% CI 0.3 to 0.7, p=0.001) and rituximab (HR=0.6, 95% CI 0.4 to 1.0, p=0.034) reduced the attack risk compared with interferon-β, whereas mitoxantrone and glatiramer acetate did not. Patients who were aquaporin-4-antibody-positive had a higher risk of attacks (HR=2.5, 95% CI 1.3 to 5.1, p=0.009). Every decade of age was associated with a lower risk for attacks (HR=0.8, 95% CI 0.7 to 1.0, p=0.039). A previous attack under the same treatment tended to be predictive for further attacks (HR=1.5, 95% CI 1.0 to 2.4, p=0.065)., Conclusions: Age, antibody status and possibly previous attacks predict further attacks in patients treated for NMOSD. Azathioprine and rituximab are superior to interferon-β., Competing Interests: Competing interests: AB has received honoraria for consultancy or lectures and travel reimbursement from Bayer HealthCare, Biogen, Merck Serono, Mylan, Roche, Novartis and Teva, and grant support from Bayer HealthCare and Chugai. AG has received travel reimbursement from Sanofi Genzyme. BH reports grants from Chugai, grants, personal fees and non-financial support from Roche, personal fees and non-financial support from Biogen, personal fees and non-financial support from Novartis, personal fees and non-financial support from Merck, and personal fees and non-financial support from Bayer. BW has received grants from the German Ministry of Education and Research, Dietmar Hopp Foundation, Biogen, Biotest, Merck, Novartis Pharmaceuticals and Teva Pharma, personal fees from Biogen, Merck, Novartis Pharmaceuticals, Teva Pharma, Bayer HealthCare and Genzyme. CG received honoraria for lectures, travel reimbursement and grant support from Merck Serono, Teva, Novartis and CSL Behring. CT has received honoraria for consultation and expert testimony from Bayer Vital GmbH, Biogen Idec/Biogen GmbH, Genzyme GmbH and Novartis Pharmaceuticals/Pharma GmbH. FL reports travel expenses from Teva Pharma. FlP reports grants from BIH‐Charité Clinical Scientist Program funded by the Charité–Universitätsmedizin Berlin and the Berlin Institute of Health and non-financial support from ECTRIMS-Travel grant 2014. FrP reports grants and personal compensations from Alexion, Bayer, Biogen, Shire, Novartis, Medimmune, Merck and Genzyme. FTB reports grants and others from Bayer, personal fees and others from Biogen Idec, grants and personal fees from CSL Behring, grants from Fresenius, personal fees and others from Genzyme Sanofi, others from Merck Serono, grants, personal fees and others from Novartis, grants, personal fees and others from Teva, grants and others from Actelion, and grants from the German Ministry of Education and Research. HPH received, with approval of the Rector of Heinrich-Heine-University and the CEO of University of Düsseldorf Hospital, honoraria for consulting, serving on steering committees and speaking from Biogen, Geneuro, Genzyme, Medimmune, Merck, Novartis, Opexa, Receptos/Celgene, Roche, Sanofi and Teva. IK has received honoraria for consultancy or lectures and travel reimbursement from Bayer HealthCare, Biogen Idec, Chugai, Novartis, Shire and Roche, and grant support from Biogen Idec, Novartis, Chugai and Diamed. JHF received grant support and honoraria from Novartis, Bayer Vital, Merck, Biogen, Sanofi-Genzyme and Roche. JH reports personal fees and non-financial support from Sanofi Genzyme, Bayer HealthCare, Merck and Novartis Pharma. JPS received honoraria for consultancy or lectures, travel reimbursement and grant support from Biogen, Merck Serono, Novartis, Genzyme and Medimmune. KH reports grants and personal fees from Bayer HealthCare, grants and personal fees from Biogen, grants and personal fees from Teva, grants and personal fees from Merck Serono, grants and personal fees from Novartis, grants and personal fees from Almirall. KLY has nothing to disclose. KR has received research support from the German Ministry of Education and Research (BMBF/KKNMS, Competence Network Multiple Sclerosis) and Novartis, as well as speaking fees and travel grants from Guthy Jackson Charitable Foundation, Bayer HealthCare, Biogen Idec, Merck Serono, Sanofi-Aventis/Genzyme, Teva Pharmaceuticals, Roche and Novartis. LZ has nothing to disclose. MK received grant support, travelling expenses and scientific advisory board honoraria from Novartis, Novartis Foundation, Genzyme, Bayer, Roche and Biogen. MM has received grants from Biogen, Novartis; personal fees from Bayer Vital, Biogen, Genzyme, Merck Serono, Novartis, Sanofi-Aventis and Teva; and non-financial support from Biogen. MR received speaker honoraria from Novartis and Bayer Vital GmbH, and travel reimbursement from Bayer Schering and Biogen Idec. MSch has nothing to disclose. MSt reports grants and personal fees from Bayer HealthCare, personal fees from Baxter/Baxalta, grants and personal fees from Biogen, personal fees from CSL Behring, grants and personal fees from Genzyme, personal fees from Grifols, personal fees from Merck, personal fees from Roche, grants and personal fees from Novartis, personal fees from Sanofi, and grants and personal fees from Teva. NB has received grants from Alexion Pharmaceuticals, Inc. ON has nothing to disclose. RAL reports grants and personal fees from Biogen, personal fees from Bayer, grants and personal fees from Novartis, grants and personal fees from Merck, personal fees from TEVA, personal fees from Roche, personal fees from Genzyme. SJ has received a research grant from the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS). MR received speaker honoraria from Novartis and Bayer Vital GmbH, and travel reimbursement from Bayer Schering and Biogen Idec. TF received honoraria for consultancies (including data monitoring committees and advisoryboards) from Novartis, Biogen, Bayer, AstraZeneca, Janssen, SGS and Pharmalog. TK reports personal fees from Biogen, grants from Novartis, personal fees from Genzyme and from Merck-Serono. UHO reports grants from Genzyme, grants from Zambon, and others from Merck Serono, Bayer, Biogen, Teva and Novartis. UZe has patents, whether planned, pending or issued, broadly relevant to the work. UZi reports personal fees from Biogen Idec GmbH, grants from Biogen Idec GmbH, personal fees from Bayer Vital GmbH, personal fees from Bristol Myers Squibb GmbH, personal fees from CorTec GmbH, personal fees from Medtronic GmbH, grants from Servier, grants from Janssen Pharmaceuticals NV and personal fees from Takeda., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Background: Gender and age at onset are important epidemiological factors influencing prevalence, clinical presentation, and treatment response in autoimmune diseases., Objective: To evaluate the impact of female sex and fertile age on aquaporin-4-antibody (AQP4-ab) status, attack localization, and response to attack treatment in patients with neuromyelitis optica (NMO) and its spectrum disorders (neuromyelitis optica spectrum disorder (NMOSD))., Methods: Female-to-male ratios, diagnosis at last visit (NMO vs NMOSD), attack localization, attack treatment, and outcome were compared according to sex and age at disease or attack onset., Results: A total of 186 NMO/SD patients (82% female) were included. In AQP4-ab-positive patients, female predominance was most pronounced during fertile age (female-to-male ratio 23:1). Female patients were more likely to be positive for AQP4-abs (92% vs 55%; p < 0.001). Interval between onset and diagnosis of NMO/SD was longer in women than in men (mean 54 vs 27 months; p = 0.023). In women, attacks occurring ⩽40 years of age were more likely to show complete remission ( p = 0.003) and better response to high-dose intravenous steroids ( p = 0.005) compared to woman at >40 years., Conclusion: Our data suggest an influence of sex and age on susceptibility to AQP4-ab-positive NMO/SD. Genetic and hormonal factors might contribute to pathophysiology of NMO/SD.

Objective: To evaluate (1) the frequency of aquaporin-4 antibody (AQP4-ab)-seropositive cases among patients treated with natalizumab (NAT) and previously diagnosed with MS (MS NAT ) in a nationwide cohort, (2) the clinical course of NAT-treated AQP4-ab-seropositive neuromyelitis optica spectrum disorder (NMOSD) patients (NMO NAT ), (3) AQP4-ab titers in NMO NAT and AQP4-ab-seropositive NMOSD treated with other immunotherapies (NMO IT ), and (4) immune mechanisms influencing disease activity in NMO NAT ., Methods: MS NAT serum samples were retrospectively screened with a cell-based assay for AQP4-IgG and titers determined by ELISA. The annualized relapse rate (ARR) and disability progression were assessed. Serum levels of proinflammatory cytokines (interleukin [IL]-1β, IL-4, IL-6, IL-8, IL-10, IL-17, IL-21, and interferon [IFN]-γ) and the chemokine CXCL-10 of NMO NAT patients identified in this (n = 4) and a previous study (n = 5) were measured by cytometric bead array and ELISA., Results: Of the 1,183 MS NAT patients (851 female, median 9 NAT infusions), only 4 (0.33%; 3 female, 1 male) had AQP4-IgG. Of these, 2 fulfilled the 2006 NMO criteria and all met the 2015 NMOSD criteria. The ARR was higher in NMO NAT vs MS NAT ( p = 0.0182). All 4 NMO NAT patients had relapses and 2 had an increase of disability. AQP4-ab titers were higher in NMO NAT (n = 9) vs NMO IT (n = 13; p = 0.0059). IL-8, IL-1β, and IFN-γ serum levels were significantly higher, and CXCL-10 was significantly lower in NMO NAT vs NMO IT ., Conclusions: Misdiagnosis of NMOSD with MS is rare. NAT was not able to control disease activity in NMO NAT patients, who had higher serum levels of AQP4-IgG and proinflammatory cytokines than patients with NMOSD treated with other immunotherapies.

Purpose of Review: Serum IgG autoantibodies against the myelin oligodendrocyte glycoprotein (MOG) are present in atypical demyelinating disorders such as neuromyelitis optica spectrum disorders (NMOSD) or acute disseminated encephalomyelitis. Whereas the role of aquaporin-4 antibodies as diagnostic markers for NMOSD is meanwhile well established, the role of MOG antibodies is less clear., Recent Findings: Initial studies suggested that MOG antibodies are associated with a more benign disease course than aquaporin-4antibodies. However, recent findings challenged this view. Data from the two largest cohorts of adult MOG antibody-positive patients with the longest clinical follow-up published so far indicate that the majority of patients develop a recurrent disease course with optic neuritis as the most frequent symptom, particularly in women. Frequent attacks are often associated with accumulating damage and functional impairment. The clinical spectrum of acquired demyelinating syndromes associated with MOG antibodies seems to be broader as anticipated in prior studies, with only a third of patients fulfilling the current diagnostic criteria for NMOSD., Summary: MOG antibodies are associated with an increasing spectrum of age and sex-dependent clinical phenotypes, only partly overlapping with NMOSD and multiple sclerosis and with a high risk of a recurrent disease course.

Pigment-epithelium derived factor (PEDF) is a neurotrophic factor with neuroprotective, anti-tumorigenic, and anti-angiogenic effects. Elevated levels of PEDF have previously been proposed as a cerebrospinal fluid (CSF) biomarker for Alzheimer's disease. However, the origin of PEDF in CSF, i.e. whether it is derived from the brain or from the systemic circulation, and the specificity of this finding hitherto remained unclear. Here, we analyzed levels of PEDF in paired CSF and serum samples by ELISA in patients with Alzheimer's disease (AD, n=12), frontotemporal dementia (FTD, n=6), vascular dementia (n=4), bacterial meningitis (n=8), multiple sclerosis (n=32), pseudotumor cerebri (n=36), and diverse non-inflammatory neurological diseases (n=19). We established CSF/serum quotient diagrams to determine the fraction of intrathecally synthesized PEDF in CSF. We found that PEDF is significantly increased in CSF of patients with AD, FTD, and bacterial meningitis. Remarkably, PEDF concentrations were also significantly elevated in serum of patients with AD. CSF/serum quotient diagrams demonstrated that elevated PEDF concentrations in CSF of patients with AD are mostly due to elevated PEDF concentrations in serum. These findings underscore the importance of relating concentrations of proteins in CSF to their respective concentrations in serum to avoid erroneous interpretations of increased protein concentrations in lumbar CSF., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: It has long been known that the majority of patients with multiple sclerosis (MS) display an intrathecal, polyspecific humoral immune response to a broad panel of neurotropic viruses. This response has measles virus, rubella virus and varicella zoster virus as its most frequent constituents and is thus referred to as the MRZ reaction (MRZR)., Objective: Re-evaluation of the specificity of MRZR as a marker of MS., Methods: Structured review of the existing English-, German- and Spanish-language literature on MRZR testing, with evaluation of MRZR in a cohort of 43 unselected patients with MS and other neurological diseases as a proof of principle., Results: A positive MRZ reaction, defined as a positive intrathecal response to at least two of the three viral agents, was found in 78% of MS patients but only in 3% of the controls (p < 0.00001), corresponding to specificity of 97%. Median antibody index values were significantly lower in non-MS patients (measles, p < 0.0001; rubella, p < 0.006; varicella zoster, p < 0.02). The 30 identified original studies on MRZR reported results from 1478 individual MRZR tests. A positive MRZR was reported for 458/724 (63.3%) tests in patients with MS but only for 19/754 (2.5%) tests in control patients (p < 0.000001), corresponding to cumulative specificity of 97.5% (CI 95% 96-98.4), cumulative sensitivity of 63.3% (CI 95% 59.6-66.8) (or 67.4% [CI 95% 63.5-71.1] in the adult MS subgroup), a positive likelihood ratio of 25.1 (CI 95% 16-39.3) and a negative likelihood ratio of 0.38 (CI 95% 0.34-0.41). Of particular note, MRZR was absent in 52/53 (98.1%) patients with neuromyelitis optica or MOG-IgG-positive encephalomyelitis, two important differential diagnoses of MS., Conclusion: MRZR is the most specific laboratory marker of MS reported to date. If present, MRZR substantially increases the likelihood of the diagnosis of MS. Prospective and systematic studies on the diagnostic and prognostic impact of MRZR testing are highly warranted.

Neuromyelitis optica (NMO) is an autoimmune disorder of the central nervous system (CNS), that predominantly affects the spinal cord and optic nerves. The neuropathologic hallmarks comprise deposits of antibodies and complement as well as loss of astrocytes, secondary degeneration of oligodendrocytes and neurons, and necrotic lesions with infiltration of neutrophilic and eosinophilic granulocytes. Pathognomonic serum autoantibodies against aquaporin-4 (AQP4-IgG, also termed NMO-IgG) are detectable in around 80 % of NMO patients and help to distinguish this rare entity from multiple sclerosis. The target antigen of NMO-IgG, the water channel protein AQP4, is ubiquitously expressed within the CNS and, as a component of the blood-brain barrier, highly concentrated in the endfeet of astrocytes. New international consensus criteria for NMO spectrum disorders, published in 2015, allow earlier diagnosis. Besides the two index manifestations, optic neuritis and transverse myelitis, involvement of the brainstem and diencephalon is relatively common in NMO. Inflammatory lesions of the area postrema typically cause intractable nausea and vomiting and/or hiccups. NMO mostly follows a relapsing course, especially in AQP4-IgG-positive cases. The treatment of acute exacerbations comprises intravenous methylprednisolone pulses and/or plasma exchange, and prevention of attacks requires long-term therapy with immunosuppressants and/or B-cell-depleting monoclonal antibodies., (© Georg Thieme Verlag KG Stuttgart · New York.)

The concept of classical conditioning (CC), strongly connected with the name and work of the Russian physiologist Ivan Petrovich Pavlov (1849-1936), has become the foundation of the modern science of learning and, in particular, of the influential theories of Watson and Skinner and the entire school of behaviourism. In this paper, we give a number of forgotten accounts of CC in the English, French, and German classic literature that pre-date Pavlov's reports by decades or even centuries. These instances are taken from works of the 16th, 18th, and 19th centuries - authored by some of the finest writers of England (Sterne, Locke), France (Rabelais), and Germany (Jean Paul) - and indicate that the psychological mechanisms now described as CC were known long before Pavlov and his successors elaborated on them in a systematic way., (© 2017 S. Karger AG, Basel.)

Background: Multiple sclerosis (MS) patients are at risk of renewed disease activity after discontinuing natalizumab (NAT) treatment., Objective: Assessing the implication of T helper 17 (Th17) cells in MS reactivation after NAT cessation., Methods: We monitored frequencies of Th17 cells and interleukin (IL)-17 cytokine levels in blood samples of 57 MS patients, without, during, and after NAT exposure., Results: Frequencies of both Th17 cells and, in part, also IL-17 levels, in peripheral blood increased under prolonged NAT therapy, returned to baseline after NAT withdrawal and became almost undetectable in blood samples of individuals who experienced relapses during the wash-out phase., Conclusion: Assessing the Th17-cell/IL-17 axis might help to predict rebound MS activity after NAT withdrawal.

Objective: To comparatively assess the B-cell composition in blood and CSF of patients with pediatric-onset multiple sclerosis (pedMS) and adult-onset multiple sclerosis (adMS)., Methods: In this cross-sectional study, we obtained blood and CSF samples from 25 patients with pedMS (8-18 years) and 40 patients with adMS (23-65 years) and blood specimens from 66 controls (1-55 years). By using multicolor flow cytometry, we identified naive, transitional, isotype class-switched memory, nonswitched memory, and double-negative memory B-cell subsets as well as plasmablasts (PB) and terminally differentiated plasma cells (PC). Flow cytometric data were compared to concentrations of B-cell-specific cytokines in serum and CSF as determined by ELISA., Results: Frequencies of circulating naive B-cells decreased with higher age in controls but not in patients with multiple sclerosis (MS). B-cell patterns in CSF differed between pedMS and adMS with an acute relapse: in pedMS-derived CSF samples, high frequencies of nonswitched memory B cells and PB were present, whereas class-switched memory B cells and PC dominated in the CSF of patients with adMS. In pedMS, PB were also elevated in the periphery. Accumulation of PB in the CSF correlated with high intrathecal CXCL-13 levels and augmented intrathecal synthesis of immunoglobulin G and immunoglobulin M., Conclusions: We demonstrate distinct changes in intrathecal B-cell homeostasis in patients with pedMS during active disease, which differ from those in adults by an expansion of plasmablasts in blood and CSF and similarly occur in prototypic autoantibody-driven autoimmune disorders. This emphasizes the particular importance of activated B-lymphocyte subsets for disease progression in the earliest clinical stages of MS.

Background: Regulatory T cells (Tregs) are functionally defective in patients with multiple sclerosis (MS) and this dysfunction is related to an imbalanced composition of naïve and memory Treg subtypes. Several lines of evidence indicate that these abnormalities might result from a premature decline in thymic-dependent Treg neogenesis. Myeloid dendritic cells (mDCs) critically determine Treg differentiation in the thymus, and thymic stromal lymphopoietin receptor (TSLPR) expressed on mDCs is a key component of the signaling pathways involved in this process. TSLPR-expression on mDCs was previously shown to be decreased in MS. We hypothesized that functional alterations in mDCs contribute to aberrant Treg neogenesis and, in turn, to altered Treg homeostasis and function in MS., Methods: We recruited blood samples from 20 MS patients and 20 healthy controls to assess TSLPR expression on mDCs ex vivo by flow cytometry and by activating mDCs induced by recombinant TSLP (rhTSLP) in vitro. As previous studies documented normalization of both function and homeostasis of Tregs under immunomodulatory (IM) therapy with interferon-beta (IFN-beta) and glatiramer acetate (GA), we also tested phenotypes and function of mDCs obtained from IM-treated patients (IFN-beta: n=20, GA: n=20)., Results: We found that TSLP-induced mDC activation and effector function in vitro was reduced in MS and correlated with TSLPR-expression levels on mDCs. IM treatment prompted upregulation of TSLPR on mDCs and an increase in TSLP-induced activation of mDCs together with a normalization of Treg homeostasis., Conclusion: The decreased TSLP-induced activation of MS-derived mDCs in vitro, together with the reduced density of TSLPR on the cell surface of mDCs corroborates the hypothesis of mDCs being critically involved in impairing Treg development in MS., (Copyright © 2016 Elsevier B.V. All rights reserved.)

There is no other field of neurology where clinically relevant serological biomarkers have witnessed a surge in importance over the past decade resembling that in autoimmune encephalitis and cerebellitis. A multitude of newly discovered neuronal autoantibodies facilitate early diagnosis, estimation of prognosis, and therapeutic decision-making. However, this has led to growing uncertainty with regard to meaningful patient selection, the appropriate extent of testing, and management of seronegative cases. This review summarizes the essential aspects of the clinical presentation, diagnostic work-up, pathophysiology, and treatment of autoimmune encephalitis and cerebellitis.

Background: Susac syndrome is characterised by the triad of encephalopathy with or without focal neurological signs, branch retinal artery occlusions and hearing loss. Establishment of the diagnosis is often delayed because the triad is complete only in a minority of patients at disease onset. This leads to a critical delay in the initiation of appropriate treatment. Our objective was to establish criteria for diagnosis of either definite or probable Susac syndrome., Method: The establishment of diagnostic criteria was based on the following three steps: (1) Definition of a reference group of 32 patients with an unambiguous diagnosis of Susac syndrome as assessed by all interdisciplinary experts of the European Susac Consortium (EuSaC) team (EuSaC cohort); (2) selection of diagnostic criteria, based on common clinical and paraclinical findings in the EuSaC cohort and on a review of the literature; and (3) validation of the proposed criteria in the previously published cohort of all Susac cases reported until 2012., Results: Integrating the clinical presentation and paraclinical findings, we propose formal criteria and recommend a diagnostic workup to facilitate the diagnosis of Susac syndrome. More than 90% of the cases in the literature fulfilled the proposed criteria for probable or definite Susac syndrome. We surmise that more patients could have been diagnosed with the recommended diagnostic workup., Conclusions: We propose diagnostic criteria for Susac syndrome that may help both experts and physicians not familiar with Susac syndrome to make a correct diagnosis and to prevent delayed treatment initiation., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Background: Antibodies against myelin oligodendrocyte glycoprotein (MOG-IgG) have been reported in patients with aquaporin-4 antibody (AQP4-IgG)-negative neuromyelitis optica spectrum disorders (NMOSD). The objective of this study was to describe optic neuritis (ON)-induced neuro-axonal damage in the retina of MOG-IgG-positive patients in comparison with AQP4-IgG-positive NMOSD patients., Methods: Afferent visual system damage following ON was bilaterally assessed in 16 MOG-IgG-positive patients with a history of ON and compared with that in 16 AQP4-IgG-positive NMOSD patients. In addition, 16 healthy controls matched for age, sex, and disease duration were analyzed. Study data included ON history, retinal optical coherence tomography, visual acuity, and visual evoked potentials., Results: Eight MOG-IgG-positive patients had a previous diagnosis of AQP4-IgG-negative NMOSD with ON and myelitis, and eight of (mainly recurrent) ON. Twenty-nine of the 32 eyes of the MOG-IgG-positive patients had been affected by at least one episode of ON. Peripapillary retinal nerve fiber layer thickness (pRNFL) and ganglion cell and inner plexiform layer volume (GCIP) were significantly reduced in ON eyes of MOG-IgG-positive patients (pRNFL = 59 ± 23 μm; GCIP = 1.50 ± 0.34 mm 3 ) compared with healthy controls (pRNFL = 99 ± 6 μm, p < 0.001; GCIP = 1.97 ± 0.11 mm 3 , p < 0.001). Visual acuity was impaired in eyes after ON in MOG-IgG-positive patients (0.35 ± 0.88 logMAR). There were no significant differences in any structural or functional visual parameters between MOG-IgG-positive and AQP4-IgG-positive patients (pRNFL: 59 ± 21 μm; GCIP: 1.41 ± 0.27 mm 3 ; Visual acuity = 0.72 ± 1.09 logMAR). Importantly, MOG-IgG-positive patients had a significantly higher annual ON relapse rate than AQP4-IgG-positive patients (median 0.69 vs. 0.29 attacks/year, p = 0.004), meaning that on average a single ON episode caused less damage in MOG-IgG-positive than in AQP4-IgG-positive patients. pRNFL and GCIP loss correlated with the number of ON episodes in MOG-IgG-positive patients (p < 0.001), but not in AQP4-IgG-positive patients., Conclusions: Retinal neuro-axonal damage and visual impairment after ON in MOG-IgG-positive patients are as severe as in AQP4-IgG-positive NMOSD patients. In MOG-IgG-positive patients, damage accrual may be driven by higher relapse rates, whereas AQP4-IgG-positive patients showed fewer but more severe episodes of ON. Given the marked damage in some of our MOG-IgG-positive patients, early diagnosis and timely initiation and close monitoring of immunosuppressive therapy are important.