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Masciocchi S, Businaro P, Scaranzin S, Morandi C, Franciotta D, Gastaldi M. General features, pathogenesis, and laboratory diagnostics of autoimmune encephalitis. Crit Rev Clin Lab Sci 2024; 61:45-69. [PMID: 37777038 DOI: 10.1080/10408363.2023.2247482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 08/09/2023] [Indexed: 10/02/2023]
Abstract
Autoimmune encephalitis (AE) is a group of inflammatory conditions that can associate with the presence of antibodies directed to neuronal intracellular, or cell surface antigens. These disorders are increasingly recognized as an important differential diagnosis of infectious encephalitis and of other common neuropsychiatric conditions. Autoantibody diagnostics plays a pivotal role for accurate diagnosis of AE, which is of utmost importance for the prompt recognition and early treatment. Several AE subgroups can be identified, either according to the prominent clinical phenotype, presence of a concomitant tumor, or type of neuronal autoantibody, and recent diagnostic criteria have provided important insights into AE classification. Antibodies to neuronal intracellular antigens typically associate with paraneoplastic neurological syndromes and poor prognosis, whereas antibodies to synaptic/neuronal cell surface antigens characterize many AE subtypes that associate with tumors less frequently, and that are often immunotherapy-responsive. In addition to the general features of AE, we review current knowledge on the pathogenic mechanisms underlying these disorders, focusing mainly on the potential role of neuronal antibodies in the most frequent conditions, and highlight current theories and controversies. Then, we dissect the crucial aspects of the laboratory diagnostics of neuronal antibodies, which represents an actual challenge for both pathologists and neurologists. Indeed, this diagnostics entails technical difficulties, along with particularly interesting novel features and pitfalls. The novelties especially apply to the wide range of assays used, including specific tissue-based and cell-based assays. These assays can be developed in-house, usually in specialized laboratories, or are commercially available. They are widely used in clinical immunology and in clinical chemistry laboratories, with relevant differences in analytic performance. Indeed, several data indicate that in-house assays could perform better than commercial kits, notwithstanding that the former are based on non-standardized protocols. Moreover, they need expertise and laboratory facilities usually unavailable in clinical chemistry laboratories. Together with the data of the literature, we critically evaluate the analytical performance of the in-house vs commercial kit-based approach. Finally, we propose an algorithm aimed at integrating the present strategies of the laboratory diagnostics in AE for the best clinical management of patients with these disorders.
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Affiliation(s)
- Stefano Masciocchi
- Neuroimmunology Research Section, IRCCS Mondino Foundation, Pavia, Italy
- Department of Brain and Behavioral Sciences, Università degli Studi di Pavia, Pavia, Italy
| | - Pietro Businaro
- Neuroimmunology Research Section, IRCCS Mondino Foundation, Pavia, Italy
- Department of Brain and Behavioral Sciences, Università degli Studi di Pavia, Pavia, Italy
| | - Silvia Scaranzin
- Neuroimmunology Research Section, IRCCS Mondino Foundation, Pavia, Italy
| | - Chiara Morandi
- Neuroimmunology Research Section, IRCCS Mondino Foundation, Pavia, Italy
| | - Diego Franciotta
- Neuroimmunology Research Section, IRCCS Mondino Foundation, Pavia, Italy
| | - Matteo Gastaldi
- Neuroimmunology Research Section, IRCCS Mondino Foundation, Pavia, Italy
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2
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Ryding M, Mikkelsen AW, Nissen MS, Nilsson AC, Blaabjerg M. Pathophysiological Effects of Autoantibodies in Autoimmune Encephalitides. Cells 2023; 13:15. [PMID: 38201219 PMCID: PMC10778077 DOI: 10.3390/cells13010015] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 12/15/2023] [Accepted: 12/18/2023] [Indexed: 01/12/2024] Open
Abstract
The heterogeneity of autoantibody targets in autoimmune encephalitides presents a challenge for understanding cellular and humoral pathophysiology, and the development of new treatment strategies. Thus, current treatment aims at autoantibody removal and immunosuppression, and is primarily based on data generated from other autoimmune neurological diseases and expert consensus. There are many subtypes of autoimmune encephalitides, which now entails both diseases with autoantibodies targeting extracellular antigens and classical paraneoplastic syndromes with autoantibodies targeting intracellular antigens. Here, we review the current knowledge of molecular and cellular effects of autoantibodies associated with autoimmune encephalitis, and evaluate the evidence behind the proposed pathophysiological mechanisms of autoantibodies in autoimmune encephalitis.
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Affiliation(s)
- Matias Ryding
- Department of Clinical Research, University of Southern Denmark, 5000 Odense, Denmark;
- Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, 5000 Odense, Denmark
| | - Anne With Mikkelsen
- Department of Clinical Immunology, Odense University Hospital, 5000 Odense, Denmark;
| | | | - Anna Christine Nilsson
- Department of Clinical Research, University of Southern Denmark, 5000 Odense, Denmark;
- Department of Clinical Immunology, Odense University Hospital, 5000 Odense, Denmark;
| | - Morten Blaabjerg
- Department of Clinical Research, University of Southern Denmark, 5000 Odense, Denmark;
- Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, 5000 Odense, Denmark
- Department of Neurology, Odense University Hospital, 5000 Odense, Denmark;
- Brain Research—Inter Disciplinary Guided Excellence (BRIDGE), 5000 Odense, Denmark
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3
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Papadopoulos VE, Papadimas GK, Androudi S, Anagnostouli M, Evangelopoulos ME. Stiff-Leg Syndrome Associated with Autoimmune Retinopathy and Its Treatment with IVIg-A Case Report and Review of the Literature. Brain Sci 2023; 13:1361. [PMID: 37891730 PMCID: PMC10605544 DOI: 10.3390/brainsci13101361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/17/2023] [Accepted: 09/20/2023] [Indexed: 10/29/2023] Open
Abstract
Antibodies to glutamic acid decarboxylase (GAD) have been predominantly associated with stiff-person syndrome (SPS), which is often accompanied by organ-specific autoimmune diseases, such as late-onset type 1 diabetes. Autoimmune retinal pathology in SPS has recently been suggested to coexist in patients suffering from this disease; however, evidence reporting potential treatment options for the neurological and visual symptoms these patients experience remains scarce. We provide a review of the relevant literature, presenting a rare case of a middle-aged woman with autoimmune retinopathy (AIR) followed by stiff-leg syndrome who responded to intravenous immune globulin treatment (IVIg). Our report adds to previously reported data supporting the efficacy of IVIg in SPS spectrum disorders while also proposing the potential effect of IVIg in treating SPS spectrum patients with coexisting AIR.
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Affiliation(s)
- Vassilis E Papadopoulos
- First Department of Neurology, School of Medicine, Eginition Hospital, National and Kapodistrian University of Athens, 11528 Athens, Greece
| | - George K Papadimas
- First Department of Neurology, School of Medicine, Eginition Hospital, National and Kapodistrian University of Athens, 11528 Athens, Greece
| | - Sofia Androudi
- Department of Ophthalmology, University of Thessaly, 41110 Larissa, Greece
| | - Maria Anagnostouli
- First Department of Neurology, School of Medicine, Eginition Hospital, National and Kapodistrian University of Athens, 11528 Athens, Greece
| | - Maria-Eleftheria Evangelopoulos
- First Department of Neurology, School of Medicine, Eginition Hospital, National and Kapodistrian University of Athens, 11528 Athens, Greece
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4
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Mitoma H, Manto M. Advances in the Pathogenesis of Auto-antibody-Induced Cerebellar Synaptopathies. CEREBELLUM (LONDON, ENGLAND) 2023; 22:129-147. [PMID: 35064896 PMCID: PMC9883363 DOI: 10.1007/s12311-021-01359-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 12/12/2021] [Indexed: 02/07/2023]
Abstract
The presence of auto-antibodies that target synaptic machinery proteins was documented recently in immune-mediated cerebellar ataxias. The autoantigens include glutamic acid decarboxylase 65 (GAD65), voltage-gated Ca2+ channel (VGCC), metabotropic glutamate receptor type 1 (mGluR1), and glutamate receptor delta (GluRdelta). GAD65 is involved in the synthesis, packaging, and release of GABA, whereas the other three play important roles in the induction of long-term depression (LTD). Thus, the auto-antibodies toward these synaptic molecules likely impair fundamental synaptic machineries involved in unique functions of the cerebellum, potentially leading to the development of cerebellar ataxias (CAs). This concept has been substantiated recently by a series of physiological studies. Anti-GAD65 antibody (Ab) acts on the terminals of inhibitory neurons that suppress GABA release, whereas anti-VGCC, anti-mGluR1, and anti-GluR Abs impair LTD induction. Notably, the mechanisms that link synaptic dysfunction with the manifestations of CAs can be explained by disruption of the "internal models." The latter can be divided into three levels. First, since chained inhibitory neurons shape the output signals through the mechanism of disinhibition/inhibition, impairments of GABA release and LTD distort the conversion process from the "internal model" to the output signals. Second, these antibodies impair the induction of synaptic plasticity, rebound potentiation, and LTD, on Purkinje cells, resulting in loss of restoration and compensation of the distorted "internal models." Finally, the cross-talk between glutamate and microglia/astrocytes could involve a positive feedback loop that accelerates excitotoxicity. This mini-review summarizes the pathophysiological mechanisms and aims to establish the basis of "auto-antibody-induced cerebellar synaptopathies."
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Affiliation(s)
- Hiroshi Mitoma
- Department of Medical Education, Tokyo Medical University, Tokyo, Japan
| | - Mario Manto
- Unité des Ataxies Cérébelleuses, Service de Neurologie, Médiathèque Jean Jacquy, CHU-Charleroi, 6000 Charleroi, Belgium ,Service des Neurosciences, University of Mons, 7000 Mons, Belgium
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5
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Muñiz-Castrillo S, Vogrig A, Ciano-Petersen NL, Villagrán-García M, Joubert B, Honnorat J. Novelties in Autoimmune and Paraneoplastic Cerebellar Ataxias: Twenty Years of Progresses. CEREBELLUM (LONDON, ENGLAND) 2022; 21:573-591. [PMID: 35020135 DOI: 10.1007/s12311-021-01363-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/23/2021] [Indexed: 06/14/2023]
Abstract
Major advances in our knowledge concerning autoimmune and paraneoplastic cerebellar ataxias have occurred in the last 20 years. The discovery of several neural antibodies represents an undeniable contribution to this field, especially those serving as good biomarkers of paraneoplastic neurological syndromes and those showing direct pathogenic effects. Yet, many patients still lack detectable or known antibodies, and also many antibodies have only been reported in few patients, which makes it difficult to define in detail their clinical value. Nevertheless, a notable progress has additionally been made in the clinical characterization of patients with the main neural antibodies, which, although typically present with a subacute pancerebellar syndrome, may also show either hyperacute or chronic onsets that complicate the differential diagnoses. However, prodromal and transient features could be useful clues for an early recognition, and extracerebellar involvement may also be highly indicative of the associated antibody. Moreover, important advances in our understanding of the pathogenesis of cerebellar ataxias include the description of antibody effects, especially those targeting cell-surface antigens, and first attempts to isolate antigen-specific T-cells. Furthermore, genetic predisposition seems relevant, although differently involved according to cancer association, with particular HLA observed in non-paraneoplastic cases and genetic abnormalities in the tumor cells in paraneoplastic ones. Finally, immune checkpoint inhibitors used as cancer immunotherapy may rarely induce cerebellar ataxias, but even this undesirable effect may in turn serve to shed some light on their physiopathology. Herein, we review the principal novelties of the last 20 years regarding autoimmune and paraneoplastic cerebellar ataxias.
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Affiliation(s)
- Sergio Muñiz-Castrillo
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, 59 Boulevard Pinel, 69677, Bron Cedex, France
- SynatAc Team, Institut NeuroMyoGène, INSERM U1217, CNRS, UMR 5310, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Alberto Vogrig
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, 59 Boulevard Pinel, 69677, Bron Cedex, France
- SynatAc Team, Institut NeuroMyoGène, INSERM U1217, CNRS, UMR 5310, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Nicolás Lundahl Ciano-Petersen
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, 59 Boulevard Pinel, 69677, Bron Cedex, France
- SynatAc Team, Institut NeuroMyoGène, INSERM U1217, CNRS, UMR 5310, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Macarena Villagrán-García
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, 59 Boulevard Pinel, 69677, Bron Cedex, France
- SynatAc Team, Institut NeuroMyoGène, INSERM U1217, CNRS, UMR 5310, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Bastien Joubert
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, 59 Boulevard Pinel, 69677, Bron Cedex, France
- SynatAc Team, Institut NeuroMyoGène, INSERM U1217, CNRS, UMR 5310, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Jérôme Honnorat
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, 59 Boulevard Pinel, 69677, Bron Cedex, France.
- SynatAc Team, Institut NeuroMyoGène, INSERM U1217, CNRS, UMR 5310, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France.
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6
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Dalakas MC. Stiff-person Syndrome and GAD Antibody-spectrum Disorders: GABAergic Neuronal Excitability, Immunopathogenesis and Update on Antibody Therapies. Neurotherapeutics 2022; 19:832-847. [PMID: 35084720 PMCID: PMC9294130 DOI: 10.1007/s13311-022-01188-w] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/11/2022] [Indexed: 01/10/2023] Open
Abstract
Although antibodies against Glutamic Acid Decarboxylase (GAD) were originally associated with Stiff Person Syndrome (SPS), they now denote the "GAD antibody-spectrum disorders (GAD-SD)" that include Cerebellar Ataxia, Autoimmune Epilepsy, Limbic Encephalitis, PERM and eye movement disorder. In spite of the unique clinical phenotype that each of these disorders has, there is significant overlapping symptomatology characterized by autoimmune neuronal excitability. In addition to GAD, three other autoantibodies, against glycine receptors, amphiphysin and gephyrin, are less frequently or rarely associated with SPS-SD. Very high serum anti-GAD antibody titers are a key diagnostic feature for all GAD-SD, commonly associated with the presence of GAD antibodies in the CSF, a reduced CSF GABA level and increased anti-GAD-specific IgG intrathecal synthesis denoting stimulation of B-cell clones in the CNS. Because anti-GAD antibodies from the various hyperexcitability syndromes recognize the same dominant GAD epitope, the clinical heterogeneity among GAD-SD patients remains unexplained. The paper highlights the biologic basis of autoimmune hyperexcitability connected with the phenomenon of reciprocal inhibition as the fundamental mechanism of the patients' muscle stiffness and spasms; addresses the importance of high-GAD antibody titers in diagnosis, pinpointing the diagnostic challenges in patients with low-GAD titers or their distinction from functional disorders; and discusses whether high GAD-antibodies are disease markers or pathogenic in the context of their association with reduced GABA level in the brain and CSF. Finally, it focuses on therapies providing details on symptomatic GABA-enhancing drugs and the currently available immunotherapies in a step-by-step approach. The prospects of future immunotherapeutic options with antibody therapies are also summarized.
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Affiliation(s)
- Marinos C Dalakas
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA, USA.
- Neuroimmunology Unit National and Kapodistrian University of Athens Medical School, Athens, Greece.
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7
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Acute Cerebellar Inflammation and Related Ataxia: Mechanisms and Pathophysiology. Brain Sci 2022; 12:brainsci12030367. [PMID: 35326323 PMCID: PMC8946185 DOI: 10.3390/brainsci12030367] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/07/2022] [Accepted: 03/08/2022] [Indexed: 12/11/2022] Open
Abstract
The cerebellum governs motor coordination and motor learning. Infection with external microorganisms, such as viruses, bacteria, and fungi, induces the release and production of inflammatory mediators, which drive acute cerebellar inflammation. The clinical observation of acute cerebellitis is associated with the emergence of cerebellar ataxia. In our animal model of the acute inflammation of the cerebellar cortex, animals did not show any ataxia but hyperexcitability in the cerebellar cortex and depression-like behaviors. In contrast, animal models with neurodegeneration of the cerebellar Purkinje cells and hypoexcitability of the neurons show cerebellar ataxia. The suppression of the Ca2+-activated K+ channels in vivo is associated with a type of ataxia. Therefore, there is a gap in our interpretation between the very early phase of cerebellar inflammation and the emergence of cerebellar ataxia. In this review, we discuss the hypothesized scenario concerning the emergence of cerebellar ataxia. First, compared with genetically induced cerebellar ataxias, we introduce infection and inflammation in the cerebellum via aberrant immunity and glial responses. Especially, we focus on infections with cytomegalovirus, influenza virus, dengue virus, and SARS-CoV-2, potential relevance to mitochondrial DNA, and autoimmunity in infection. Second, we review neurophysiological modulation (intrinsic excitability, excitatory, and inhibitory synaptic transmission) by inflammatory mediators and aberrant immunity. Next, we discuss the cerebellar circuit dysfunction (presumably, via maintaining the homeostatic property). Lastly, we propose the mechanism of the cerebellar ataxia and possible treatments for the ataxia in the cerebellar inflammation.
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8
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Kamat V, Radtke JR, Hu Q, Wang W, Sweet IR, Hampe CS. Autoantibodies directed against glutamate decarboxylase interfere with glucose-stimulated insulin secretion in dispersed rat islets. Int J Exp Pathol 2022; 103:140-148. [PMID: 35246889 PMCID: PMC9264341 DOI: 10.1111/iep.12437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 01/17/2022] [Accepted: 02/20/2022] [Indexed: 11/28/2022] Open
Abstract
Islet autoantibodies, including autoantibodies directed against the 65kDa isoform of glutamate decarboxylase (GAD65Ab), are present in the majority of patients with newly diagnosed type 1 diabetes (T1D). Whereas these autoantibodies are historically viewed as an epiphenomenon of the autoimmune response with no significant pathogenic function, we consider in this study the possibility that they impact the major islet function, namely glucose-stimulated insulin secretion. Two human monoclonal GAD65Ab (GAD65 mAb) (b78 and b96.11) were investigated for uptake by live rat beta cells, subcellular localization and their effect on glucose-stimulated insulin secretion. The GAD65 mAbs were internalized by live pancreatic beta cells, where they localized to subcellular structures in an epitope-specific manner. Importantly, GAD65 mAb b78 inhibited, while GAD65 mAb b96.11 enhanced, glucose-stimulated insulin secretion (GSIS). These opposite effects on GSIS rule out non-specific effects of the antibodies and suggest that internalization of the antibody leads to epitope-specific interaction with intracellular machinery regulating insulin granule release. The most likely explanation for the alteration of GSIS by GAD65 Abs is via changes in GABA release due to inhibition or change in GAD65 enzyme activity. This is the first report indicating an active role of GAD65Ab in the pathogenesis of T1D.
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Affiliation(s)
- Varun Kamat
- Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Jared R Radtke
- Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Qingxun Hu
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, Washington, USA
| | - Wang Wang
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, Washington, USA
| | - Ian R Sweet
- Department of Medicine, University of Washington, Seattle, Washington, USA
| | - Christiane S Hampe
- Department of Medicine, University of Washington, Seattle, Washington, USA
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9
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OVERLAPPING GAD65-ASSOCIATED AUTOIMMUNE NEUROLOGICAL SYNDROMES AND TYPE 1 DIABETES. Immunol Lett 2022; 244:40-42. [DOI: 10.1016/j.imlet.2022.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 02/22/2022] [Accepted: 03/05/2022] [Indexed: 11/20/2022]
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10
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Cerebellar tDCS as Therapy for Cerebellar Ataxias. CEREBELLUM (LONDON, ENGLAND) 2022; 21:755-761. [PMID: 35060077 DOI: 10.1007/s12311-021-01357-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/07/2021] [Indexed: 12/28/2022]
Abstract
In recent years, a growing body of literature has investigated the use of non-invasive brain stimulation (NIBS) techniques to influence cerebellar activity and the effects of cerebellar stimulation on other brain regions through its multiple complex projections. From the early 1990s, with the discovery of the so-called cerebellar inhibition (CBI), several studies have focused their attention on the use of cerebellar NIBS as treatment for different motor disorders. Cerebellar ataxias (CAs) represent the prototypical clinical manifestation of cerebellar alterations, but other movement disorders, such as Parkinson's disease, essential tremor, and dystonia have also been associated with alterations of networks which include the cerebellum, or of the cerebellum itself. Cerebellar transcranial direct current stimulation (ctDCS) could indeed represent an economical, non-invasive therapeutic tool with minimal side effects, thus improving the clinical management of patients and their quality of life. Studies show that ctDCS is effective as a therapeutic option for motor symptoms in patients with CAs, and especially in those with less severe forms, suggesting that ctDCS efficacy could result from augmented neuronal compensation, which itself relies on preserved cerebellar volume. Evidence for the efficacy of ctDCS is less conclusive for the other aforementioned motor disorders, although preliminary results are promising. Future studies should adopt more rigorous methods (e.g., larger sample sizes, double blinding, better characterization of the sample, reliable biomarkers), in order to allow the scientific community to derive higher-quality evidence on the efficacy of ctDCS as a therapeutic option for motor disorders.
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11
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Manto MU. Endocrine Disorders. HANDBOOK OF THE CEREBELLUM AND CEREBELLAR DISORDERS 2022:2283-2300. [DOI: 10.1007/978-3-030-23810-0_92] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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12
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Manto M, Argyropoulos GPD, Bocci T, Celnik PA, Corben LA, Guidetti M, Koch G, Priori A, Rothwell JC, Sadnicka A, Spampinato D, Ugawa Y, Wessel MJ, Ferrucci R. Consensus Paper: Novel Directions and Next Steps of Non-invasive Brain Stimulation of the Cerebellum in Health and Disease. CEREBELLUM (LONDON, ENGLAND) 2021; 21:1092-1122. [PMID: 34813040 DOI: 10.1007/s12311-021-01344-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/08/2021] [Indexed: 12/11/2022]
Abstract
The cerebellum is involved in multiple closed-loops circuitry which connect the cerebellar modules with the motor cortex, prefrontal, temporal, and parietal cortical areas, and contribute to motor control, cognitive processes, emotional processing, and behavior. Among them, the cerebello-thalamo-cortical pathway represents the anatomical substratum of cerebellum-motor cortex inhibition (CBI). However, the cerebellum is also connected with basal ganglia by disynaptic pathways, and cerebellar involvement in disorders commonly associated with basal ganglia dysfunction (e.g., Parkinson's disease and dystonia) has been suggested. Lately, cerebellar activity has been targeted by non-invasive brain stimulation (NIBS) techniques including transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) to indirectly affect and tune dysfunctional circuitry in the brain. Although the results are promising, several questions remain still unsolved. Here, a panel of experts from different specialties (neurophysiology, neurology, neurosurgery, neuropsychology) reviews the current results on cerebellar NIBS with the aim to derive the future steps and directions needed. We discuss the effects of TMS in the field of cerebellar neurophysiology, the potentials of cerebellar tDCS, the role of animal models in cerebellar NIBS applications, and the possible application of cerebellar NIBS in motor learning, stroke recovery, speech and language functions, neuropsychiatric and movement disorders.
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Affiliation(s)
- Mario Manto
- Service de Neurologie, CHU-Charleroi, 6000, Charleroi, Belgium.,Service Des Neurosciences, UMons, 7000, Mons, Belgium
| | - Georgios P D Argyropoulos
- Division of Psychology, Faculty of Natural Sciences, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, UK
| | - Tommaso Bocci
- Aldo Ravelli Research Center for Neurotechnology and Experimental Neurotherapeutics, Department of Health Sciences, University of Milan, 20142, Milan, Italy.,ASST Santi Paolo E Carlo, Via di Rudinì, 8, 20142, Milan, Italy
| | - Pablo A Celnik
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Louise A Corben
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Children's Research Institute, Department of Paediatrics, University of Melbourne, Parkville. Victoria, Australia
| | - Matteo Guidetti
- Aldo Ravelli Research Center for Neurotechnology and Experimental Neurotherapeutics, Department of Health Sciences, University of Milan, 20142, Milan, Italy.,Department of Electronics, Information and Bioengineering, Politecnico Di Milano, 20133, Milan, Italy
| | - Giacomo Koch
- Fondazione Santa Lucia IRCCS, via Ardeatina 306, 00179, Rome, Italy
| | - Alberto Priori
- Aldo Ravelli Research Center for Neurotechnology and Experimental Neurotherapeutics, Department of Health Sciences, University of Milan, 20142, Milan, Italy.,ASST Santi Paolo E Carlo, Via di Rudinì, 8, 20142, Milan, Italy
| | - John C Rothwell
- Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London, UK
| | - Anna Sadnicka
- Motor Control and Movement Disorders Group, St George's University of London, London, UK.,Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
| | - Danny Spampinato
- Fondazione Santa Lucia IRCCS, via Ardeatina 306, 00179, Rome, Italy
| | - Yoshikazu Ugawa
- Department of Human Neurophysiology, Fukushima Medical University, Fukushima, Japan
| | - Maximilian J Wessel
- Defitech Chair of Clinical Neuroengineering, Center for Neuroprosthetics (CNP) and Brain Mind Institute (BMI), Swiss Federal Institute of Technology (EPFL), Geneva, Switzerland.,Defitech Chair of Clinical Neuroengineering, Center for Neuroprosthetics (CNP) and Brain Mind Institute (BMI), Swiss Federal Institute of Technology (EPFL Valais), Clinique Romande de Réadaptation, Sion, Switzerland
| | - Roberta Ferrucci
- Aldo Ravelli Research Center for Neurotechnology and Experimental Neurotherapeutics, Department of Health Sciences, University of Milan, 20142, Milan, Italy. .,ASST Santi Paolo E Carlo, Via di Rudinì, 8, 20142, Milan, Italy.
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13
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Wang SM, Chan YW, Tsui YO, Chu FY. Effects of Anodal Cerebellar Transcranial Direct Current Stimulation on Movements in Patients with Cerebellar Ataxias: A Systematic Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:10690. [PMID: 34682435 PMCID: PMC8535754 DOI: 10.3390/ijerph182010690] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/04/2021] [Accepted: 10/07/2021] [Indexed: 01/26/2023]
Abstract
Cerebellar transcranial direct current stimulation (cerebellar tDCS) is a promising therapy for cerebellar ataxias and has attracted increasing attention from researchers and clinicians. A timely systematic review focusing on randomized sham-controlled trials and repeated measures studies is warranted. This study was to systematically review existing evidence regarding effects of anodal cerebellar tDCS on movements in patients with cerebellar ataxias. The searched databases included Web of Science, MEDLINE, PsycINFO, CINAHL, EMBASE, Cochrane Library, and EBSCOhost. Methodological quality of the selected studies was assessed using the Physiotherapy Evidence Database scale. Five studies with 86 patients were identified. Among these, four studies showed positive effects of anodal cerebellar tDCS. Specifically, anodal cerebellar tDCS decreased disease severity and improved finger dexterity and quality of life in patients, but showed incongruent effects on gait control and balance, which may be due to heterogeneity of research participants and choices of measures. The protocols of anodal cerebellar tDCS that improved movements in patients commonly placed the anode over the whole cerebellum and provided ten 2-mA 20-min stimulation sessions. The results may show preliminary evidence that anodal cerebellar tDCS is beneficial to reducing disease severity and improving finger dexterity and quality of life in patients, which lays the groundwork for future studies further examining responses in the cerebello-thalamo-cortical pathway. An increase in sample size, the use of homogeneous patient groups, exploration of the optimal stimulation protocol, and investigation of detailed neural mechanisms are clearly needed in future studies.
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Affiliation(s)
- Shu-Mei Wang
- Department of Rehabilitation Sciences, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Kowloon, Hong Kong; (Y.-W.C.); (Y.-O.T.); (F.-Y.C.)
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14
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Muñiz-Castrillo S, Vogrig A, Joubert B, Pinto AL, Gonçalves D, Chaumont H, Rogemond V, Picard G, Fabien N, Honnorat J. Transient Neurological Symptoms Preceding Cerebellar Ataxia with Glutamic Acid Decarboxylase Antibodies. THE CEREBELLUM 2021; 19:715-721. [PMID: 32592031 DOI: 10.1007/s12311-020-01159-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
A prompt diagnosis and treatment of patients with autoimmune cerebellar ataxia (CA) with antibodies against glutamic acid decarboxylase (GAD-Abs) may lead to a better prognosis. Herein, we report prodromal transient neurological symptoms that should raise clinical suspicion of CA with GAD-Abs. We initially identified a 70-year-old man who presented a first acute episode of vertigo, diplopia, and ataxia lasting 2 weeks. Two months later, he experienced a similar episode along with new-onset gaze-evoked nystagmus. After 4 months, downbeat nystagmus, left limb dysmetria, and gait ataxia progressively appeared, and an autoimmune CA was diagnosed based on the positivity of GAD-Abs in serum and cerebrospinal fluid (CSF). We searched retrospectively for similar presentations in a cohort of 31 patients diagnosed with CA and GAD-Abs. We found 11 (35.4%) patients (all women, median age 62 years; 8/11 [72.7%] with autoimmune comorbidities) with transient neurological symptoms antedating CA onset by a median of 3 months, including vertigo in 9 (81.8%; described as paroxysmal in 8) and fluctuating diplopia in 3 (27.3%) patients. The identification of transient neurological symptoms of unknown etiology, such as paroxysmal vertigo and fluctuating diplopia, should lead to GAD-Abs testing in serum and CSF, especially in patients with autoimmune comorbidities.
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Affiliation(s)
- Sergio Muñiz-Castrillo
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, Bron, France
- Institut NeuroMyoGène, INSERM U1217/CNRS UMR 5310, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
- Neurology Department, Hospital Universitario Infanta Cristina, Madrid, Spain
| | - Alberto Vogrig
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, Bron, France
- Institut NeuroMyoGène, INSERM U1217/CNRS UMR 5310, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Bastien Joubert
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, Bron, France
- Institut NeuroMyoGène, INSERM U1217/CNRS UMR 5310, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Anne-Laurie Pinto
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, Bron, France
- Institut NeuroMyoGène, INSERM U1217/CNRS UMR 5310, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - David Gonçalves
- Immunology Department, Hospices Civils de Lyon, Centre Hospitalier Lyon Sud, Lyon, France
| | - Hugo Chaumont
- Neurology Department, Centre Hospitalier Universitaire de la Guadeloupe, Point-à-Pitre, France
| | - Véronique Rogemond
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, Bron, France
- Institut NeuroMyoGène, INSERM U1217/CNRS UMR 5310, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Géraldine Picard
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, Bron, France
- Institut NeuroMyoGène, INSERM U1217/CNRS UMR 5310, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Nicole Fabien
- Immunology Department, Hospices Civils de Lyon, Centre Hospitalier Lyon Sud, Lyon, France
| | - Jérôme Honnorat
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, Bron, France.
- Institut NeuroMyoGène, INSERM U1217/CNRS UMR 5310, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France.
- Service de Neuro-Oncologie, Hôpital Neurologique Pierre Wertheimer, 59 Boulevard Pinel, 69677, Bron Cedex, France.
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15
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Tsiortou P, Alexopoulos H, Dalakas MC. GAD antibody-spectrum disorders: progress in clinical phenotypes, immunopathogenesis and therapeutic interventions. Ther Adv Neurol Disord 2021; 14:17562864211003486. [PMID: 33854562 PMCID: PMC8013924 DOI: 10.1177/17562864211003486] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 02/27/2021] [Indexed: 12/14/2022] Open
Abstract
Antibodies against glutamic acid decarboxylase (GAD), originally linked to stiff person syndrome (SPS), now denote the "GAD antibody-spectrum disorders" (GAD-SD) that also include autoimmune epilepsy, limbic encephalitis, cerebellar ataxia and nystagmus with overlapping symptomatology highlighting autoimmune neuronal excitability disorders. The reasons for the clinical heterogeneity among GAD-antibody associated syndromes remain still unsettled, implicating variable susceptibility of GABAergic neurons to anti-GAD or other still unidentified autoantibodies. Although anti-GAD antibody titers do not correlate with clinical severity, very high serum titers, often associated with intrathecal synthesis of anti-GAD-specific IgG, point to in-situ effects of GAD or related autoantibodies within the central nervous system. It remains, however, uncertain what drives these antibodies, why they persist and whether they are disease markers or have pathogenic potential. The review, focused on these concerns, describes the widened clinical manifestations and overlapping features of all GAD-SD; addresses the importance of GAD antibody titers and potential significance of GAD epitopes; summarizes the biologic basis of autoimmune hyperexcitability; highlights the electrophysiological basis of reciprocal inhibition in muscle stiffness; and provides practical guidelines on symptomatic therapies with gamma-aminobutyric acid-enhancing drugs or various immunotherapies.
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Affiliation(s)
- Popianna Tsiortou
- Neuroimmunology Unit, Department of Pathophysiology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Harry Alexopoulos
- Neuroimmunology Unit, Department of Pathophysiology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Marinos C Dalakas
- Department of Neurology, Thomas Jefferson University, 900 Walnut Street, Philadelphia, PA 19107, USA; Neuroimmunology Unit, National and Kapodistrian University of Athens, Athens, Greece
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16
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Mitoma H, Manto M, Hadjivassiliou M. Immune-Mediated Cerebellar Ataxias: Clinical Diagnosis and Treatment Based on Immunological and Physiological Mechanisms. J Mov Disord 2021; 14:10-28. [PMID: 33423437 PMCID: PMC7840241 DOI: 10.14802/jmd.20040] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 09/04/2020] [Indexed: 12/24/2022] Open
Abstract
Since the first description of immune-mediated cerebellar ataxias (IMCAs) by Charcot in 1868, several milestones have been reached in our understanding of this group of neurological disorders. IMCAs have diverse etiologies, such as gluten ataxia, postinfectious cerebellitis, paraneoplastic cerebellar degeneration, opsoclonus myoclonus syndrome, anti-GAD ataxia, and primary autoimmune cerebellar ataxia. The cerebellum, a vulnerable autoimmune target of the nervous system, has remarkable capacities (collectively known as the cerebellar reserve, closely linked to plasticity) to compensate and restore function following various pathological insults. Therefore, good prognosis is expected when immune-mediated therapeutic interventions are delivered during early stages when the cerebellar reserve can be preserved. However, some types of IMCAs show poor responses to immunotherapies, even if such therapies are introduced at an early stage. Thus, further research is needed to enhance our understanding of the autoimmune mechanisms underlying IMCAs, as such research could potentially lead to the development of more effective immunotherapies. We underscore the need to pursue the identification of robust biomarkers.
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Affiliation(s)
- Hiroshi Mitoma
- Department of Medical Education, Tokyo Medical University, Tokyo, Japan
| | - Mario Manto
- Service de Neurologie, Médiathèque Jean Jacquy, CHU-Charleroi, Charleroi, Belgium.,Service des Neurosciences, University of Mons, Mons, Belgium
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Fundamental Mechanisms of Autoantibody-Induced Impairments on Ion Channels and Synapses in Immune-Mediated Cerebellar Ataxias. Int J Mol Sci 2020; 21:ijms21144936. [PMID: 32668612 PMCID: PMC7404345 DOI: 10.3390/ijms21144936] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 07/07/2020] [Accepted: 07/09/2020] [Indexed: 12/13/2022] Open
Abstract
In the last years, different kinds of limbic encephalitis associated with autoantibodies against ion channels and synaptic receptors have been described. Many studies have demonstrated that such autoantibodies induce channel or receptor dysfunction. The same mechanism is discussed in immune-mediated cerebellar ataxias (IMCAs), but the pathogenesis has been less investigated. The aim of the present review is to evaluate what kind of cerebellar ion channels, their related proteins, and the synaptic machinery proteins that are preferably impaired by autoantibodies so as to develop cerebellar ataxias (CAs). The cerebellum predictively coordinates motor and cognitive functions through a continuous update of an internal model. These controls are relayed by cerebellum-specific functions such as precise neuronal discharges with potassium channels, synaptic plasticity through calcium signaling pathways coupled with voltage-gated calcium channels (VGCC) and metabotropic glutamate receptors 1 (mGluR1), a synaptic organization with glutamate receptor delta (GluRδ), and output signal formation through chained GABAergic neurons. Consistently, the association of CAs with anti-potassium channel-related proteins, anti-VGCC, anti-mGluR1, and GluRδ, and anti-glutamate decarboxylase 65 antibodies is observed in IMCAs. Despite ample distributions of AMPA and GABA receptors, however, CAs are rare in conditions with autoantibodies against these receptors. Notably, when the autoantibodies impair synaptic transmission, the autoimmune targets are commonly classified into three categories: release machinery proteins, synaptic adhesion molecules, and receptors. This physiopathological categorization impacts on both our understanding of the pathophysiology and clinical prognosis.
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18
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Graus F, Saiz A, Dalmau J. GAD antibodies in neurological disorders — insights and challenges. Nat Rev Neurol 2020; 16:353-365. [DOI: 10.1038/s41582-020-0359-x] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/03/2020] [Indexed: 01/07/2023]
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19
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Immune-mediated epilepsy with GAD65 antibodies. J Neuroimmunol 2020; 341:577189. [PMID: 32087461 DOI: 10.1016/j.jneuroim.2020.577189] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 02/11/2020] [Accepted: 02/11/2020] [Indexed: 12/18/2022]
Abstract
Anti-GAD65 antibodies have been identified in both acute/subacute seizures (limbic encephalitis and extralimbic encephalitis) and chronic isolated epilepsy. The evidence of high serum titers and intrathecal synthesis play a fundamental role in diagnosis but poorly correlate with disease severity or response to therapies. It remains controversial whether anti-GAD65 Abs are the pathogenic entity or only serve as a surrogate marker for autoimmune disorders mediated by cytotoxic T cells. Unlike other immune-mediated epilepsy, although multiple combinations of therapeutics are used, the efficacy and prognosis of patients with GAD65-epilepsy patients are poor. Besides, GAD65-epilepsy is more prone to relapse and potentially evolve into a more widespread CNS inflammatory disorder. This article reviews the recent advances of GAD65-epilepsy, focusing on the diagnosis, epidemiology, pathophysiology, clinical features, and treatment, to better promote the recognition and provide proper therapy for this condition.
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20
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Abstract
PURPOSE OF REVIEW The current review develops the clinical presentations of nonparaneoplastic autoimmune cerebellar ataxia (ACA) and analyzes the association with autoantibodies. RECENT FINDINGS Emerging evidence suggests that autoimmunity is involved in a significant proportion of sporadic ataxia cases. Moreover, numerous autoantibodies have recently been described in association with sporadic cerebellar ataxia, improving diagnosis and patient categorization. SUMMARY Nonparaneoplastic ACA encompasses postinfectious acute cerebellar ataxia, opsoclonus-myoclonus-ataxia syndrome, and pure cerebellar ataxia with or without autoantibodies. There is still confusion about how to diagnose and classify the patients, and retrospective data suggest that these very rare entities are in fact largely underrecognized. Numerous autoantibodies have been found associated with sporadic ataxia, improving diagnosis accuracy, and patient categorization. However, although anti-glutamate decarboxylase isotype 65 (GAD65), anti-contactin-associated protein 2 (CASPR2), and anti metabotropic glutamate receptor (mGluR1) antibodies are well recognized biomarkers, many other autoantibodies have been described in very small numbers of patients and their specificity is unknown. Efficient biomarkers for ACA are still lacking and in many cases the diagnosis has to rely on a body of converging evidence.
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21
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Hampe CS, Radtke JR, Wester A, Carlsson A, Cedervall E, Jönsson B, Ivarsson SA, Elding Larsson H, Larsson K, Lindberg B, Neiderud J, Rolandsson O, Lernmark Å. Reduced display of conformational epitopes in the N-terminal truncated GAD65 isoform: relevance for people with stiff person syndrome or DQ8/8-positive Type 1 diabetes mellitus. Diabet Med 2019; 36:1375-1383. [PMID: 30264481 PMCID: PMC6437014 DOI: 10.1111/dme.13827] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/25/2018] [Indexed: 12/26/2022]
Abstract
AIMS To investigate whether the N-terminal truncated glutamic acid decarboxylase 65 (GAD65) isoform is as well recognized by people with stiff person syndrome as it is by people with Type 1 diabetes, and whether conformational GAD65 antibody epitopes are displayed properly by the isoform. METHODS GAD65 antibody-positive healthy individuals (n=13), people with stiff-person syndrome (n=15) and children with new-onset Type 1 diabetes (n=654) were analysed to determine binding to full-length GAD65 and the N-terminal truncated GAD65 isoform in each of these settings. GAD65 autoantibody epitope specificity was correlated with binding ratios of full-length GAD65/N-terminal truncated GAD65. RESULTS The N-terminal truncated GAD65 isoform was significantly less recognized in GAD65Ab-positive people with stiff-person syndrome (P=0.002) and in healthy individuals (P=0.0001) than in people with Type 1 diabetes. Moreover, at least two specific conformational GAD65Ab epitopes were not, or were only partially, presented by the N-terminal truncated GAD65 isoform compared to full-length GAD65. Finally, an N-terminal conformational GAD65Ab epitope was significantly less recognized in DQ8/8 positive individuals with Type 1 diabetes (P=0.02). CONCLUSIONS In people with stiff person syndrome preferred binding to the full-length GAD65 isoform over the N-terminal truncated molecule was observed. This binding characteristic is probably attributable to reduced presentation of two conformational epitopes by the N-terminal truncated molecule. These findings support the notion of disease-specific GAD65Ab epitope specificities and emphasize the need to evaluate the applicability of novel assays for different medical conditions.
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Affiliation(s)
- C S Hampe
- Department of Medicine, University of Washington, Seattle, WA, USA
| | - J R Radtke
- Department of Medicine, University of Washington, Seattle, WA, USA
| | - A Wester
- Department of Clinical Sciences, Lund University/CRC, Skåne University Hospital SUS, Malmo, Sweden
| | - A Carlsson
- Department of Clinical Sciences, Lund University/CRC, Skåne University Hospital SUS, Malmo, Sweden
| | - E Cedervall
- Department of Paediatrics, Ängelholm Hospital, Ängelholm, Malmo, Sweden
| | - B Jönsson
- Department of Paediatrics, Ystad Hospital, Ystad, Sweden
| | - S A Ivarsson
- Department of Clinical Sciences, Lund University/CRC, Skåne University Hospital SUS, Malmo, Sweden
| | - H Elding Larsson
- Department of Clinical Sciences, Lund University/CRC, Skåne University Hospital SUS, Malmo, Sweden
| | - K Larsson
- Department of Paediatrics, Kristianstad Hospital, Kristianstad, Sweden
| | - B Lindberg
- Department of Clinical Sciences, Lund University/CRC, Skåne University Hospital SUS, Malmo, Sweden
| | - J Neiderud
- Department of Paediatrics, Helsingborg Hospital, Helsingborg, Sweden
| | - O Rolandsson
- Department of Public Health and Clinical Medicine, Section of Family Medicine, Umeå University, Umeå, Sweden
| | - Å Lernmark
- Department of Clinical Sciences, Lund University/CRC, Skåne University Hospital SUS, Malmo, Sweden
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22
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Bruton A, Fuller L. Paroxysmal Kinesigenic Dyskinesia Symptoms Markedly Reduced with Parenteral Vitamins and Minerals: A Case Report. Perm J 2019; 23:19.036. [PMID: 31634116 DOI: 10.7812/tpp/19.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Paroxysmal kinesigenic dyskinesia (PKD) is a rare movement disorder triggered by sudden voluntary movements. The disorder involves attacks of chorea, which resolve within minutes, that may occur frequently throughout the day. CASE PRESENTATION A 61-year-old woman presented to the clinic with a 13-year history of PKD first diagnosed in 2002. This patient had frequent episodic attacks of PKD, which were so severe she had difficulty with ambulation and other activities of daily living. The case was complicated by an additional diagnosis of chronic fatigue syndrome. She refused antiseizure medication because of concerns about it exacerbating her fatigue. In the office, she was given weekly parenteral doses of vitamins and minerals, which almost completely eliminated her symptoms between treatments and allowed her to return to activities of daily living. DISCUSSION Genetic testing, not related to her PKD diagnosis, revealed several mutations that could offer an explanation for the apparent efficacy of parenteral therapy in this patient.
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Affiliation(s)
- Alisha Bruton
- Helfgott Research Institute at Natural University of Natural Medicine, Portland, OR.,Natural University of Natural Medicine, Portland, OR.,Oregon Health and Science University, Portland, OR
| | - Leslie Fuller
- Natural University of Natural Medicine, Portland, OR.,University of Western States, Portland, OR
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23
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Manto M, Mitoma H, Hampe CS. Anti-GAD Antibodies and the Cerebellum: Where Do We Stand? THE CEREBELLUM 2019; 18:153-156. [PMID: 30343467 PMCID: PMC6443918 DOI: 10.1007/s12311-018-0986-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Anti-GAD65 antibodies (anti-GAD65 Abs) are associated with cerebellar ataxia (CA). The significance of anti-GAD65 Abs has been a focus of debates. Since GAD65 is intracellularly located and associated with type 1 diabetes mellitus and different clinical neurological phenotypes such as CA, stiff-person syndrome, and epilepsy, some researchers have argued that anti-GAD65 Abs have no pathogenic roles. On the other hand, recent physiological studies in vitro and in vivo have elucidated that binding of GAD65 by anti-GAD65 Abs elicits loss of GAD65 functions pertaining GABA release with an epitope dependence, leading to the development of CA. Internalization of autoantibodies has been also clarified. These studies provide substantial evidence of the pathogenesis of anti-GAD65 Abs in CA. We also discuss methodological problems in the identification of anti-GAD65 Abs.
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Affiliation(s)
- Mario Manto
- Service de Neurologie, Médiathèque Jean Jacquy, CHU-Charleroi, 6000, Charleroi, Belgium.,Service des Neurosciences, University of Mons, 7000, Mons, Belgium
| | - Hiroshi Mitoma
- Medical Education Promotion Center, Tokyo Medical University, Tokyo, Japan.
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24
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Baizabal-Carvallo JF. The neurological syndromes associated with glutamic acid decarboxylase antibodies. J Autoimmun 2019; 101:35-47. [DOI: 10.1016/j.jaut.2019.04.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 04/07/2019] [Accepted: 04/08/2019] [Indexed: 12/12/2022]
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25
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Yilmaz FM, Little D, Gallagher M, Colcher A. Anti-glutamate Dehydrogenase Antibody Positive Cerebellar Ataxia and Stiff Person Syndrome Responding to Dual Treatment with Steroids and Intravenous Immunoglobulin: A Case Presentation and Literature Review. Cureus 2019; 11:e4851. [PMID: 31410334 PMCID: PMC6684109 DOI: 10.7759/cureus.4851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Anti-glutamic acid decarboxylase (anti-GAD) antibody syndrome (aGAS) has various presentations including cerebellar ataxia (CA) and stiff person syndrome (SPS). This is a treatable cause of CA and SPS. We present a case of a 49-year-old man who developed blurred vision, slurred speech, difficulty walking, unsteady gait, and clumsiness which had progressed over four months. The patient was found to have anti-GAD ab (+) CA and SPS and experienced significant symptomatic improvements after treatment with intravenous (IV) steroids followed by intravenous immunoglobulin (IVIG). The patient’s improvement persisted when he was reevaluated at follow up one month later. Since anti-GAD ab related diseases, including anti-GAD CA and SPS, are rarely diagnosed, there is limited data regarding the treatment of this condition. As there are only a few cases in the literature similar to this one, highlighting the successful treatment of anti-GAD ab cerebellar ataxia and SPS with dual therapy (steroids followed by IVIG) is important.
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Affiliation(s)
- Furkan M Yilmaz
- Neurology, Cooper Neurological Institute, Cooper University Hospital, Camden, USA
| | - Dena Little
- Neurology, Cooper Neurological Institute, Cooper University Hospital, Camden, USA
| | - Micheal Gallagher
- Neurophysiology, University of Maryland Medical Center, Baltimore, USA
| | - Amy Colcher
- Neurology, Cooper Neurological Institute, Cooper University Hospital, Camden, USA
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26
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Mitoma H, Manto M, Hampe CS. Immune-mediated Cerebellar Ataxias: Practical Guidelines and Therapeutic Challenges. Curr Neuropharmacol 2019; 17:33-58. [PMID: 30221603 PMCID: PMC6341499 DOI: 10.2174/1570159x16666180917105033] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Revised: 07/06/2018] [Accepted: 09/03/2018] [Indexed: 12/11/2022] Open
Abstract
Immune-mediated cerebellar ataxias (IMCAs), a clinical entity reported for the first time in the 1980s, include gluten ataxia (GA), paraneoplastic cerebellar degenerations (PCDs), antiglutamate decarboxylase 65 (GAD) antibody-associated cerebellar ataxia, post-infectious cerebellitis, and opsoclonus myoclonus syndrome (OMS). These IMCAs share common features with regard to therapeutic approaches. When certain factors trigger immune processes, elimination of the antigen( s) becomes a priority: e.g., gluten-free diet in GA and surgical excision of the primary tumor in PCDs. Furthermore, various immunotherapeutic modalities (e.g., steroids, immunoglobulins, plasmapheresis, immunosuppressants, rituximab) should be considered alone or in combination to prevent the progression of the IMCAs. There is no evidence of significant differences in terms of response and prognosis among the various types of immunotherapies. Treatment introduced at an early stage, when CAs or cerebellar atrophy is mild, is associated with better prognosis. Preservation of the "cerebellar reserve" is necessary for the improvement of CAs and resilience of the cerebellar networks. In this regard, we emphasize the therapeutic principle of "Time is Cerebellum" in IMCAs.
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Affiliation(s)
- Hiroshi Mitoma
- Address correspondence to this author at the Medical Education Promotion Center, Tokyo Medical University, Tokyo, Japan;, E-mail:
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27
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Honnorat J, Joubert B. Movement disorders in autoimmune encephalitis and paraneoplastic neurological syndromes. Rev Neurol (Paris) 2018; 174:597-607. [DOI: 10.1016/j.neurol.2018.07.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 07/27/2018] [Accepted: 07/27/2018] [Indexed: 12/14/2022]
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28
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Abstract
Transcranial magnetic and electric stimulation of the brain are novel and highly promising techniques currently employed in both research and clinical practice. Improving or rehabilitating brain functions by modulating excitability with these noninvasive tools is an exciting new area in neuroscience. Since the cerebellum is closely connected with the cerebral regions subserving motor, associative, and affective functions, the cerebello-thalamo-cortical pathways are an interesting target for these new techniques. Targeting the cerebellum represents a novel way to modulate the excitability of remote cortical regions and their functions. This review brings together the studies that have applied cerebellar stimulation, magnetic and electric, and presents an overview of the current knowledge and unsolved issues. Some recommendations for future research are implemented as well.
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Abstract
Immune-mediated cerebellar ataxia (CA) comprises a group of rare diseases that are still incompletely described, and are probably underdiagnosed. Both acute and progressive progressions are possible. Different syndromes have been identified, including CA associated with anti-GAD antibodies, the cerebellar type of Hashimoto encephalopathy, primary autoimmune CA, gluten ataxia, opsoclonus-myoclonus syndrome, and paraneoplastic cerebellar degenerations. Most of these syndromes are associated with autoantibodies targeting neuronal antigens. Additionally, autoimmune CA can be triggered by infections, especially in children, and in rare cases occur in the context of an autoimmune multisystem disease, such as systemic lupus erythematosus, sarcoidosis, or Behçet disease. A careful workup is needed to distinguish autoimmune CA from other causes. In adults, a paraneoplastic origin must be ruled out, especially in cases with subacute onset. Neurologic outcome in adults is frequently poor, and optimal therapeutic strategies remain ill defined. The outcome in children is in general good, but children with a poor recovery are on record. The precise pathophysiologic mechanisms even in the presence of detectable autoantibodies are still largely unknown. Further research is needed on both the clinical and mechanistic aspects of immune-mediated CA, and to determine optimal therapeutic strategies.
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Affiliation(s)
- Bastien Joubert
- French Reference Centre for Paraneoplastic Neurological Syndromes, Lyon Neurological Hospital, Lyon, France; Institut NeuroMyoGene, Université Claude Bernard Lyon 1, Lyon, France
| | - Kevin Rostásy
- Department of Pediatric Neurology, Witten/Herdecke University, Children's Hospital Datteln, Datteln, Germany
| | - Jérôme Honnorat
- French Reference Centre for Paraneoplastic Neurological Syndromes, Lyon Neurological Hospital, Lyon, France; Institut NeuroMyoGene, Université Claude Bernard Lyon 1, Lyon, France.
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Balint B, Vincent A, Meinck HM, Irani SR, Bhatia KP. Movement disorders with neuronal antibodies: syndromic approach, genetic parallels and pathophysiology. Brain 2018; 141:13-36. [PMID: 29053777 PMCID: PMC5888977 DOI: 10.1093/brain/awx189] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/10/2017] [Accepted: 06/13/2017] [Indexed: 01/17/2023] Open
Abstract
Movement disorders are a prominent and common feature in many autoantibody-associated neurological diseases, a group of potentially treatable conditions that can mimic infectious, metabolic or neurodegenerative disease. Certain movement disorders are likely to associate with certain autoantibodies; for example, the characteristic dyskinesias, chorea and dystonia associated with NMDAR antibodies, stiff person spectrum disorders with GAD, glycine receptor, amphiphysin or DPPX antibodies, specific paroxysmal dystonias with LGI1 antibodies, and cerebellar ataxia with various anti-neuronal antibodies. There are also less-recognized movement disorder presentations of antibody-related disease, and a considerable overlap between the clinical phenotypes and the associated antibody spectra. In this review, we first describe the antibodies associated with each syndrome, highlight distinctive clinical or radiological 'red flags', and suggest a syndromic approach based on the predominant movement disorder presentation, age, and associated features. We then examine the underlying immunopathophysiology, which may guide treatment decisions in these neuroimmunological disorders, and highlight the exceptional interface between neuronal antibodies and neurodegeneration, such as the tauopathy associated with IgLON5 antibodies. Moreover, we elaborate the emerging pathophysiological parallels between genetic movement disorders and immunological conditions, with proteins being either affected by mutations or targeted by autoantibodies. Hereditary hyperekplexia, for example, is caused by mutations of the alpha subunit of the glycine receptor leading to an infantile-onset disorder with exaggerated startle and stiffness, whereas antibodies targeting glycine receptors can induce acquired hyperekplexia. The spectrum of such immunological and genetic analogies also includes cerebellar ataxias and some encephalopathies. Lastly, we discuss how these pathophysiological considerations could reflect on possible future directions regarding antigen-specific immunotherapies or targeting the pathophysiological cascades downstream of the antibody effects.
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Affiliation(s)
- Bettina Balint
- Sobell Department of Motor Neuroscience and Movement Disorders UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
- Department of Neurology, University Hospital, Heidelberg, Germany
- Neuroimmunology Group, Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
| | - Angela Vincent
- Neuroimmunology Group, Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
| | | | - Sarosh R Irani
- Neuroimmunology Group, Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
| | - Kailash P Bhatia
- Sobell Department of Motor Neuroscience and Movement Disorders UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
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Manto M, Hampe CS. Endocrine disorders and the cerebellum: from neurodevelopmental injury to late-onset ataxia. HANDBOOK OF CLINICAL NEUROLOGY 2018; 155:353-368. [PMID: 29891071 DOI: 10.1016/b978-0-444-64189-2.00023-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Hormonal disorders are a source of cerebellar ataxia in both children and adults. Normal development of the cerebellum is critically dependent on thyroid hormone, which crosses both the blood-brain barrier and the blood-cerebrospinal fluid barrier thanks to specific transporters, including monocarboxylate transporter 8 and the organic anion-transporting polypeptide 1C1. In particular, growth and dendritic arborization of Purkinje neurons, synaptogenesis, and myelination are dependent on thyroid hormone. Disturbances of thyroid hormone may also impact on cerebellar ataxias of other origin, decompensating or aggravating the pre-existing ataxia manifesting with motor ataxia, oculomotor ataxia, and/or Schmahmann syndrome. Parathyroid disorders are associated with a genuine cerebellar syndrome, but symptoms may be subtle. The main conditions combining diabetes and cerebellar ataxia are Friedreich ataxia, ataxia associated with anti-GAD antibodies, autoimmune polyglandular syndromes, aceruloplasminemia, and cerebellar ataxia associated with hypogonadism (especially Holmes ataxia/Boucher-Neuhäuser syndrome). The general workup of cerebellar disorders should include the evaluation of hormonal status, including thyroid-stimulating hormone and free thyroxine levels, and hormonal replacement should be considered depending on the laboratory results. Cerebellar deficits may be reversible in some cases.
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Affiliation(s)
- Mario Manto
- Neurology Service, CHU-Charleroi, Charleroi, Belgium; Neuroscience Service, Université de Mons, Mons, Belgium.
| | - Christiane S Hampe
- Department of Medicine, University of Washington, Seattle, United States
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Mitoma H, Manto M, Hampe CS. Immune-mediated cerebellar ataxias: from bench to bedside. CEREBELLUM & ATAXIAS 2017; 4:16. [PMID: 28944066 PMCID: PMC5609024 DOI: 10.1186/s40673-017-0073-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 09/07/2017] [Indexed: 02/08/2023]
Abstract
The cerebellum is a vulnerable target of autoimmunity in the CNS. The category of immune-mediated cerebellar ataxias (IMCAs) was recently established, and includes in particular paraneoplastic cerebellar degenerations (PCDs), gluten ataxia (GA) and anti-GAD65 antibody (Ab) associated-CA, all characterized by the presence of autoantibodies. The significance of onconeuronal autoantibodies remains uncertain in some cases. The pathogenic role of anti-GAD65Ab has been established both in vitro and in vivo, but a consensus has not been reached yet. Recent studies of anti-GAD65 Ab-associated CA have clarified that (1) autoantibodies are generally polyclonal and elicit pathogenic effects related to epitope specificity, and (2) the clinical course can be divided into two phases: a phase of functional disorder followed by cell death. These features provide the rationale for prompt diagnosis and therapeutic strategies. The concept “Time is brain” has been completely underestimated in the field of immune ataxias. We now put forward the concept “Time is cerebellum” to underline the importance of very early therapeutic strategies in order to prevent or stop the loss of neurons and synapses. The diagnosis of IMCAs should depend not only on Ab testing, but rather on a rapid and comprehensive assessment of the clinical/immune profile. Treatment should be applied during the period of preserved cerebellar reserve, and should encompass early removal of the conditions (such as remote primary tumors) or diseases that trigger the autoimmunity, followed by the combinations of various immunotherapies.
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Affiliation(s)
- Hiroshi Mitoma
- Tokyo Medical University, Medical Education Promotion Center, 6-7-1 Nishi-Shinjyuku, Shinjyuku-ku, Tokyo, 160-0023 Japan
| | - Mario Manto
- Unité d'Etude du Mouvement (UEM), FNRS, ULB-Erasme, 1070 Bruxelles, Belgium.,Service des Neurosciences, University of Mons, 7000 Mons, Belgium
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Baizabal-Carvallo JF, Alonso-Juarez M. Cerebellar disease associated with anti-glutamic acid decarboxylase antibodies: review. J Neural Transm (Vienna) 2017; 124:1171-1182. [PMID: 28689294 DOI: 10.1007/s00702-017-1754-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 07/03/2017] [Indexed: 12/28/2022]
Abstract
Several neurological syndromes have been recognized associated to GAD antibodies. Among those disorders, cerebellar ataxia (CA) is one of the most common, along with stiff-person syndrome. Patients with GAD associated CA present with a progressive pancerebellar syndrome, with a subacute or chronic evolution, along with other neurological manifestations such as stiffness, oculomotor dysfunction, epilepsy, and cognitive dysfunction. These symptoms may be preceded by the so-called "brainstem attacks", where manifestations consistent with transient dysfunction of the brainstem may be observed. These patients frequently have extra-neurologic autoimmune manifestations such as diabetes mellitus type 1, polyendocrine autoimmune syndrome, pernicious anemia, vitiligo, etc. A proportion of patients may present with an underlying neoplasia, but the course is less aggressive than in those patients with classical paraneoplastic CA with onconeural antibodies. The diagnosis is based on the present of high serum and CSF titers of GAD antibodies, with intrathecal production of such antibodies. Treatment is aimed to decrease the immunological response with intravenous immunoglobulin, steroids, rituximab and oral immunosuppressive drugs. A subacute presentation and rapid initiation of immunotherapy seem to be the predictors of a favorable clinical response.
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Affiliation(s)
- José Fidel Baizabal-Carvallo
- Department of Neurology, Parkinson's Disease Center and Movement Disorders Clinic, Baylor College of Medicine, Houston, TX, USA.
- Department of Internal Medicine, University of Guanajuato, 20 de Enero no. 927, C.P. 37320, León, Guanajuato, Mexico.
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Bodranghien FCAA, Langlois Mahe M, Clément S, Manto MU. A Pilot Study on the Effects of Transcranial Direct Current Stimulation on Brain Rhythms and Entropy during Self-Paced Finger Movement using the Epoc Helmet. Front Hum Neurosci 2017; 11:201. [PMID: 28503139 PMCID: PMC5408787 DOI: 10.3389/fnhum.2017.00201] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 04/06/2017] [Indexed: 11/13/2022] Open
Abstract
Transcranial direct current stimulation (tDCS) of the cerebellum is emerging as a novel non-invasive tool to modulate the activity of the cerebellar circuitry. In a single blinded study, we applied anodal tDCS (atDCS) of the cerebellum to assess its effects on brain entropy and brain rhythms during self-paced sequential finger movements in a group of healthy volunteers. Although wearable electroencephalogram (EEG) systems cannot compete with traditional clinical/laboratory set-ups in terms of accuracy and channel density, they have now reached a sufficient maturity to envision daily life applications. Therefore, the EEG was recorded with a comfortable and easy to wear 14 channels wireless helmet (Epoc headset; electrode location was based on the 10-20 system). Cerebellar neurostimulation modified brain rhythmicity with a decrease in the delta band (electrode F3 and T8, p < 0.05). By contrast, our study did not show any significant change in entropy ratios and laterality coefficients (LC) after atDCS of the cerebellum in the 14 channels. The cerebellum is heavily connected with the cerebral cortex including the frontal lobes and parietal lobes via the cerebello-thalamo-cortical pathway. We propose that the effects of anodal stimulation of the cerebellar cortex upon cerebral cortical rhythms are mediated by this key-pathway. Additional studies using high-density EEG recordings and behavioral correlates are now required to confirm our findings, especially given the limited coverage of Epoc headset.
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Affiliation(s)
- Florian C. A. A. Bodranghien
- Unité d’Etude du Mouvement (UEM-GRIM), Fonds de la Recherche Scientifique, Université Libre De BruxellesBruxelles, Belgium
| | | | - Serge Clément
- Haute Ecole Libre de Bruxelles Ilya Prigogine (HELB)Bruxelles, Belgium
| | - Mario U. Manto
- Unité d’Etude du Mouvement (UEM-GRIM), Fonds de la Recherche Scientifique, Université Libre De BruxellesBruxelles, Belgium
- Haute Ecole Libre de Bruxelles Ilya Prigogine (HELB)Bruxelles, Belgium
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35
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McKeon A, Tracy JA. GAD65 neurological autoimmunity. Muscle Nerve 2017; 56:15-27. [PMID: 28063151 DOI: 10.1002/mus.25565] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 01/04/2017] [Indexed: 12/11/2022]
Abstract
The glutamic acid decarboxylase 65-kilodalton isoform (GAD65) antibody is a biomarker of autoimmune central nervous system (CNS) disorders and, more commonly, nonneurological autoimmune diseases. Type 1 diabetes, autoimmune thyroid disease, and pernicious anemia are the most frequent GAD65 autoimmune associations. One or more of these disorders coexists in approximately 70% of patients with GAD65 neurological autoimmunity. Neurological phenotypes have CNS localization and include limbic encephalitis, epilepsy, cerebellar ataxia, and stiff-person syndrome (SPS), among others. Classic SPS is a disorder on the spectrum of CNS hyperexcitability which also includes phenotypes that are either more restricted (stiff-limb syndrome) or more widespread (progressive encephalomyelitis with rigidity and myoclonus). GAD65 antibody is not highly predictive of a paraneoplastic cause for neurological disorders, but diverse cancer types have been occasionally reported. For all phenotypes, responses to immunotherapy are variable (approximately 50% improve). GAD65 autoimmunity is important to recognize for both coexisting nonneurological autoimmune associations and potential immunotherapy-response. Muscle Nerve 56: 15-27, 2017.
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Affiliation(s)
- Andrew McKeon
- Department of Neurology, College of Medicine, Mayo Clinic, 200 1st Street SW, Rochester, Minnesota, 55905, USA.,Department of Laboratory Medicine and Pathology, College of Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Jennifer A Tracy
- Department of Neurology, College of Medicine, Mayo Clinic, 200 1st Street SW, Rochester, Minnesota, 55905, USA
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Pathogenic Roles of Glutamic Acid Decarboxylase 65 Autoantibodies in Cerebellar Ataxias. J Immunol Res 2017; 2017:2913297. [PMID: 28386570 PMCID: PMC5366212 DOI: 10.1155/2017/2913297] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 12/05/2016] [Accepted: 01/10/2017] [Indexed: 12/12/2022] Open
Abstract
Reports suggesting a pathogenic role of autoantibodies directed against glutamic acid decarboxylase 65 (GAD65Abs) in cerebellar ataxias (CAs) are reviewed, and debatable issues such as internalization of antibodies by neurons and roles of epitopes are discussed. GAD65 is one of two enzymes that catalyze the conversion of glutamate to the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). A pathogenic role of GAD65Ab in CAs is suggested by in vivo and in vitro studies. (1) Intracerebellar administration of cerebrospinal fluid (CSF) immunoglobulins (IgGs) obtained from GAD65Ab-positive CA patients impairs cerebellar modulation of motor control in rats. (2) CSF IgGs act on terminals of GABAergic neurons and decrease the release of GABA in cerebellar slices from rats and mice. (3) Absorption of GAD65Ab by recombinant GAD65 diminishes the above effects, and monoclonal human GAD65Ab (b78) mimic the effects of CSF IgGs in vivo and in vitro. Studies using GAD65-KO mice confirm that the target molecule is GAD65. (4) Notably, the effects of GAD65Ab depend on the epitope specificity of the monoclonal GAD65Ab. Taken together, these results indicate that epitope-specific GAD65Ab-induced impairment of GABA release is involved in the pathogenesis of GAD65Ab-positive CA and support the early detection of GAD65Ab-associated CA to initiate immunotherapy before irreversible neuronal death in the cerebellum.
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Aguiar TS, Fragoso A, Albuquerque CRD, Teixeira PDF, Souza MVLD, Zajdenverg L, Alves-Leon SV, Rodacki M, Lima MASDD. Clinical characteristics of patients with cerebellar ataxia associated with anti-GAD antibodies. ARQUIVOS DE NEURO-PSIQUIATRIA 2017; 75:142-146. [DOI: 10.1590/0004-282x20170011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 12/05/2016] [Indexed: 01/25/2023]
Abstract
ABSTRACT The enzyme glutamic acid decarboxylase (GAD), present in GABAergic neurons and in pancreatic beta cells, catalyzes the conversion of gamma-aminobutyric acid (GABA). The cerebellum is highly susceptible to immune-mediated mechanisms, with the potentially treatable autoimmune cerebellar ataxia associated with the GAD antibody (CA-GAD-ab) being a rare, albeit increasingly detected condition. Few cases of CA-GAD-ab have been described. Methods This retrospective and descriptive study evaluated the clinical characteristics and outcomes of patients with CA-GAD-ab. Result Three patients with cerebellar ataxia, high GAD-ab titers and autoimmune endocrine disease were identified. Patients 1 and 2 had classic stiff person syndrome and insidious-onset cerebellar ataxia, while Patient 3 had pure cerebellar ataxia with subacute onset. Patients received intravenous immunoglobulin therapy with no response in Patients 1 and 3 and partial recovery in Patient 2. Conclusion CA-GAD-ab is rare and its clinical presentation may hamper diagnosis. Clinicians should be able to recognize this potentially treatable autoimmune cerebellar ataxia.
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Affiliation(s)
| | | | | | | | | | | | - Soniza Vieira Alves-Leon
- Universidade Federal do Rio de Janeiro, Brasil; Universidade Federal do Estado do Rio de Janeiro, Brasil
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Ganelin-Cohen E, Modan-Moses D, Hemi R, Kanety H, Ben-zeev B, Hampe CS. Epilepsy and behavioral changes, type 1 diabetes mellitus and a high titer of glutamic acid decarboxylase antibodies. Pediatr Diabetes 2016; 17:617-622. [PMID: 26711844 PMCID: PMC4927419 DOI: 10.1111/pedi.12346] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Revised: 11/20/2015] [Accepted: 11/20/2015] [Indexed: 11/30/2022] Open
Abstract
Autoantibodies to the 65 kDa isoform of glutamate acid decarboxylase (GAD65Ab) are associated with a range of clinical disorders, including type 1 diabetes (T1D) and stiff-person syndrome (SPS). In this article we describe a young girl who was diagnosed with T1D at the end of her first year of life and developed drug-resistant epilepsy 18 months later, followed by behavioral disturbances. She was admitted to our center at the age of 5 yr, at which time high GAD65Ab titers were detected in the patient's serum and cerebrospinal fluid (CSF). The titer remained elevated during 19 months of follow-up. Furthermore, GAD65Ab in both serum and CSF showed epitope binding characteristics similar to those observed for GAD65Ab in SPS patients, and GAD65Ab in the serum reduced GAD65 enzyme activity. Our results suggest an association between high GAD65Ab titers and epilepsy in children with T1D. Careful titration and characterization of GAD65Ab regarding inhibition of enzyme activity and epitope specificity may be helpful in identifying T1D patients at risk for neurological complications.
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Affiliation(s)
- Esther Ganelin-Cohen
- Pediatric Neurology Unit, The Edmond and Lily Safra Children's Hospital, Chaim Sheba Medical Center, Ramat-Gan, Israel. .,The Sackler School of Medicine, Tel Aviv University, Ramat Aviv, Israel.
| | - Dalit Modan-Moses
- The Sackler School of Medicine, Tel Aviv University, Ramat Aviv, Israel,Pediatric Endocrinology and Diabetes Unit, The Edmond and Lily Safra Children’s Hospital, Chaim Sheba Medical Center, Ramat-Gan, Israel
| | - Rina Hemi
- Institute of Endocrinology, Chaim Sheba Medical Center, Ramat-Gan, Israel
| | - Hannah Kanety
- Institute of Endocrinology, Chaim Sheba Medical Center, Ramat-Gan, Israel
| | - Bruria Ben-zeev
- Pediatric Neurology Unit, The Edmond and Lily Safra Children’s Hospital, Chaim Sheba Medical Center, Ramat-Gan, Israel,The Sackler School of Medicine, Tel Aviv University, Ramat Aviv, Israel
| | - Christiane S. Hampe
- Department of Medicine, Division of Metabolism, Endocrinology and Nutrition, University of Washington, Seattle, WA, USA
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Sinmaz N, Nguyen T, Tea F, Dale RC, Brilot F. Mapping autoantigen epitopes: molecular insights into autoantibody-associated disorders of the nervous system. J Neuroinflammation 2016; 13:219. [PMID: 27577085 PMCID: PMC5006540 DOI: 10.1186/s12974-016-0678-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 08/17/2016] [Indexed: 01/09/2023] Open
Abstract
Background Our knowledge of autoantibody-associated diseases of the central (CNS) and peripheral (PNS) nervous systems has expanded greatly over the recent years. A number of extracellular and intracellular autoantigens have been identified, and there is no doubt that this field will continue to expand as more autoantigens are discovered as a result of improved clinical awareness and methodological practice. In recent years, interest has shifted to uncover the target epitopes of these autoantibodies. Main body The purpose of this review is to discuss the mapping of the epitope targets of autoantibodies in CNS and PNS antibody-mediated disorders, such as N-methyl-D-aspartate receptor (NMDAR), α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR), leucine-rich glioma-inactivated protein 1 (Lgi1), contactin-associated protein-like 2 (Caspr2), myelin oligodendrocyte glycoprotein (MOG), aquaporin-4 (AQP4), 65 kDa glutamic acid decarboxylase (GAD65), acetylcholine receptor (AChR), muscle-specific kinase (MuSK), voltage-gated calcium channel (VGCC), neurofascin (NF), and contactin. We also address the methods used to analyze these epitopes, the relevance of their determination, and how this knowledge can inform studies on autoantibody pathogenicity. Furthermore, we discuss triggers of autoimmunity, such as molecular mimicry, ectopic antigen expression, epitope spreading, and potential mechanisms for the rising number of double autoantibody-positive patients. Conclusions Molecular insights into specificity and role of autoantibodies will likely improve diagnosis and treatment of CNS and PNS neuroimmune diseases.
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Affiliation(s)
- Nese Sinmaz
- Brain Autoimmunity Group, Institute for Neuroscience and Muscle Research, The Kids Research Institute at the Children's Hospital at Westmead, University of Sydney, Locked Bag 4001, Westmead, NSW, 2145, Australia
| | - Tina Nguyen
- Brain Autoimmunity Group, Institute for Neuroscience and Muscle Research, The Kids Research Institute at the Children's Hospital at Westmead, University of Sydney, Locked Bag 4001, Westmead, NSW, 2145, Australia
| | - Fiona Tea
- Brain Autoimmunity Group, Institute for Neuroscience and Muscle Research, The Kids Research Institute at the Children's Hospital at Westmead, University of Sydney, Locked Bag 4001, Westmead, NSW, 2145, Australia
| | - Russell C Dale
- Brain Autoimmunity Group, Institute for Neuroscience and Muscle Research, The Kids Research Institute at the Children's Hospital at Westmead, University of Sydney, Locked Bag 4001, Westmead, NSW, 2145, Australia.,Discipline of Child and Adolescent Health, Sydney Medical School, University of Sydney, Sydney, Australia
| | - Fabienne Brilot
- Brain Autoimmunity Group, Institute for Neuroscience and Muscle Research, The Kids Research Institute at the Children's Hospital at Westmead, University of Sydney, Locked Bag 4001, Westmead, NSW, 2145, Australia. .,Discipline of Child and Adolescent Health, Sydney Medical School, University of Sydney, Sydney, Australia.
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Bodranghien F, Manto M, Lebon F. Enhancing transcranial direct current stimulation via motor imagery and kinesthetic illusion: crossing internal and external tools. J Neuroeng Rehabil 2016; 13:50. [PMID: 27246465 PMCID: PMC4888405 DOI: 10.1186/s12984-016-0156-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 05/11/2016] [Indexed: 11/18/2022] Open
Abstract
Background Transcranial direct current stimulation is a safe technique which is now part of the therapeutic armamentarium for the neuromodulation of motor functions and cognitive operations. It is currently considered that tDCS is an intervention that might promote functional recovery after a lesion in the central nervous system, thus reducing long-term disability and associated socio-economic burden. Discussion A recent study shows that kinesthetic illusion and motor imagery prolong the effects of tDCS on corticospinal excitability, overcoming one of the limitations of this intervention. Conclusion Because changes in excitability anticipate changes in structural plasticity in the CNS, this interesting multi-modal approach might very soon find applications in neurorehabilitation.
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Affiliation(s)
- Florian Bodranghien
- Unité d'Etude du Mouvement, Laboratoire de Neurologie Expérimentale, ULB, Brussels, Belgium
| | - Mario Manto
- Unité d'Etude du Mouvement, Laboratoire de Neurologie Expérimentale, ULB, Brussels, Belgium. .,Service des Neurosciences, Université de Mons, Mons, Belgium. .,UEM, FNRS-ULB, 808 Route de Lennik, 1070, Bruxelles, Belgium.
| | - Florent Lebon
- Laboratoire INSERM U1093 Cognition, Action et Plasticité Sensorimotrice, Université de Bourgogne Franche-Comté, Dijon, France.,UFR STAPS, Université de Bourgogne Franche-Comté, Dijon, France
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41
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van Dun K, Bodranghien FCAA, Mariën P, Manto MU. tDCS of the Cerebellum: Where Do We Stand in 2016? Technical Issues and Critical Review of the Literature. Front Hum Neurosci 2016; 10:199. [PMID: 27242469 PMCID: PMC4862979 DOI: 10.3389/fnhum.2016.00199] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 04/19/2016] [Indexed: 01/23/2023] Open
Abstract
Transcranial Direct Current Stimulation (tDCS) is an up-and-coming electrical neurostimulation technique increasingly used both in healthy subjects and in selected groups of patients. Due to the high density of neurons in the cerebellum, its peculiar anatomical organization with the cortex lying superficially below the skull and its diffuse connections with motor and associative areas of the cerebrum, the cerebellum is becoming a major target for neuromodulation of the cerebellocerebral networks. We discuss the recent studies based on cerebellar tDCS with a focus on the numerous technical and open issues which remain to be solved. Our current knowledge of the physiological impacts of tDCS on cerebellar circuitry is criticized. We provide a comparison with transcranial Alternating Current Stimulation (tACS), another promising transcranial electrical neurostimulation technique. Although both tDCS and tACS are becoming established techniques to modulate the cerebellocerebral networks, it is surprising that their impacts on cerebellar disorders remains unclear. A major reason is that the literature lacks large trials with a double-blind, sham-controlled, and cross-over experimental design in cerebellar patients.
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Affiliation(s)
- Kim van Dun
- Clinical and Experimental Neurolinguistics, Vrije Universiteit Brussel Brussels, Belgium
| | - Florian C A A Bodranghien
- Unité d'Etude du Mouvement, Laboratoire de Neurologie Expérimentale, Université libre de Bruxelles (ULB) Brussels, Belgium
| | - Peter Mariën
- Clinical and Experimental Neurolinguistics, Vrije Universiteit BrusselBrussels, Belgium; Department of Neurology and Memory Clinic, ZNA Middelheim General HospitalAntwerp, Belgium
| | - Mario U Manto
- Unité d'Etude du Mouvement, Laboratoire de Neurologie Expérimentale, Université libre de Bruxelles (ULB)Brussels, Belgium; Service des Neurosciences, Université de MonsMons, Belgium
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42
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Mitoma H, Adhikari K, Aeschlimann D, Chattopadhyay P, Hadjivassiliou M, Hampe CS, Honnorat J, Joubert B, Kakei S, Lee J, Manto M, Matsunaga A, Mizusawa H, Nanri K, Shanmugarajah P, Yoneda M, Yuki N. Consensus Paper: Neuroimmune Mechanisms of Cerebellar Ataxias. CEREBELLUM (LONDON, ENGLAND) 2016; 15:213-32. [PMID: 25823827 PMCID: PMC4591117 DOI: 10.1007/s12311-015-0664-x] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In the last few years, a lot of publications suggested that disabling cerebellar ataxias may develop through immune-mediated mechanisms. In this consensus paper, we discuss the clinical features of the main described immune-mediated cerebellar ataxias and address their presumed pathogenesis. Immune-mediated cerebellar ataxias include cerebellar ataxia associated with anti-GAD antibodies, the cerebellar type of Hashimoto's encephalopathy, primary autoimmune cerebellar ataxia, gluten ataxia, Miller Fisher syndrome, ataxia associated with systemic lupus erythematosus, and paraneoplastic cerebellar degeneration. Humoral mechanisms, cell-mediated immunity, inflammation, and vascular injuries contribute to the cerebellar deficits in immune-mediated cerebellar ataxias.
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Affiliation(s)
- Hiroshi Mitoma
- Department of Medical Education, Tokyo Medical University, Tokyo, Japan.
| | - Keya Adhikari
- Department of Haematology, Nil Ratan Sircar Medical College, 138 A J C Bose Road, Kolkata, 700014, West Bengal, India
| | - Daniel Aeschlimann
- Matrix Biology &Tissue Repair Research Unit, School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Cardiff, Wales, UK
| | - Partha Chattopadhyay
- Department of General Medicine, College of Medicine & Sagore Dutta Hospital, 578 B T Road, Kamarhati-Kolkata, 700056, West Bengal, India
| | | | - Christiane S Hampe
- School of Medicine, University of Washington, 850 Republication, Seattle, WA, 98109, USA
| | - Jérôme Honnorat
- University Lyon 1, University Lyon, Rue Guillaume Paradin, 69372, Lyon Cedex 08, France
- INSERM, UMR-S1028, CNRS, UMR-5292, Neuro-Oncology and Neuro-Inflammation Team, 7, Lyon Neuroscience Research Center, Rue Guillaume Paradin, 69372, Lyon Cedex 08, France
- National Reference Centre for Paraneoplastic Neurological Diseases, Hospices Civils de Lyon, Hôpital Neurologique, 69677, Bron, France
- Hospices Civils de Lyon, Neuro-oncology, Hôpital Neurologique, 69677, Bron, France
| | - Bastien Joubert
- University Lyon 1, University Lyon, Rue Guillaume Paradin, 69372, Lyon Cedex 08, France
- INSERM, UMR-S1028, CNRS, UMR-5292, Neuro-Oncology and Neuro-Inflammation Team, 7, Lyon Neuroscience Research Center, Rue Guillaume Paradin, 69372, Lyon Cedex 08, France
| | - Shinji Kakei
- Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Jongho Lee
- Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Mario Manto
- Unité d'Etude du Mouvement, FNRS, Neurologie ULB-Erasme, 808 Route de Lennik, 1070, Brussels, Belgium
| | - Akiko Matsunaga
- Department of Neurology, University of Fukui Hospital, Fukui, Japan
| | | | - Kazunori Nanri
- Department of Neurology, Tokyo Medical University Hachioji Medical Center, Tokyo, Japan
| | - Priya Shanmugarajah
- Academic Department of Neurosciences, Royal Hallamshire Hospital, Sheffield, UK
| | - Makoto Yoneda
- Faculty of Nursing and Social Welfare Sciences, Fukui Prefectural University, Fukui, Japan
| | - Nobuhiro Yuki
- Departments of Medicine and Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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Chefdeville A, Honnorat J, Hampe CS, Desestret V. Neuronal central nervous system syndromes probably mediated by autoantibodies. Eur J Neurosci 2016; 43:1535-52. [PMID: 26918657 DOI: 10.1111/ejn.13212] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Revised: 02/09/2016] [Accepted: 02/15/2016] [Indexed: 01/17/2023]
Abstract
In the last few years, a rapidly growing number of autoantibodies targeting neuronal cell-surface antigens have been identified in patients presenting with neurological symptoms. Targeted antigens include ionotropic receptors such as N-methyl-d-aspartate receptor or the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor, metabotropic receptors such as mGluR1 and mGluR5, and other synaptic proteins, some of them belonging to the voltage-gated potassium channel complex. Importantly, the cell-surface location of these antigens makes them vulnerable to direct antibody-mediated modulation. Some of these autoantibodies, generally targeting ionotropic channels or their partner proteins, define clinical syndromes resembling models of pharmacological or genetic disruption of the corresponding antigen, suggesting a direct pathogenic role of the associated autoantibodies. Moreover, the associated neurological symptoms are usually immunotherapy-responsive, further arguing for a pathogenic effect of the antibodies. Some studies have shown that some patients' antibodies may have structural and functional in vitro effects on the targeted antigens. Definite proof of the pathogenicity of these autoantibodies has been obtained for just a few through passive transfer experiments in animal models. In this review we present existing and converging evidence suggesting a pathogenic role of some autoantibodies directed against neuronal cell-surface antigens observed in patients with central nervous system disorders. We describe the main clinical symptoms characterizing the patients and discuss conflicting arguments regarding the pathogenicity of these antibodies.
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Affiliation(s)
- Aude Chefdeville
- Institut NeuroMyoGène, INSERM U1217/UMR CNRS 5310, Lyon, France.,Université de Lyon, Lyon, France
| | - Jérôme Honnorat
- Institut NeuroMyoGène, INSERM U1217/UMR CNRS 5310, Lyon, France.,Université de Lyon, Lyon, France.,French Reference Center on Paraneoplastic Neurological Syndrome, F-69677, Bron, France.,Department of Neurology, Hospices Civils de Lyon, Hôpital Neurologique, F-69677, Bron, France
| | | | - Virginie Desestret
- Institut NeuroMyoGène, INSERM U1217/UMR CNRS 5310, Lyon, France.,Université de Lyon, Lyon, France.,French Reference Center on Paraneoplastic Neurological Syndrome, F-69677, Bron, France.,Department of Neurology, Hospices Civils de Lyon, Hôpital Neurologique, F-69677, Bron, France
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44
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Bradl M, Lassmann H. Neurologic autoimmunity: mechanisms revealed by animal models. HANDBOOK OF CLINICAL NEUROLOGY 2016; 133:121-43. [PMID: 27112675 DOI: 10.1016/b978-0-444-63432-0.00008-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Over the last decade, neurologic autoimmunity has become a major consideration in the diagnosis and management of patients with many neurologic presentations. The nature of the associated antibodies and their targets has led to appreciation of the importance of the accessibility of the target antigen to antibodies, and a partial understanding of the different mechanisms that can follow antibody binding. This chapter will first describe the basic principles of autoimmune inflammation and tissue damage in the central and peripheral nervous system, and will then demonstrate what has been learnt about neurologic autoimmunity from circumstantial clinical evidence and from passive, active, and occasionally spontaneous or genetic animal models. It will cover neurologic autoimmune diseases ranging from disorders of neuromuscular transmission, peripheral and ganglionic neuropathy, to diseases of the central nervous system, where autoantibodies are either pathogenic and cause destruction or changes in function of their targets, where they are harmless bystanders of T-cell-mediated tissue damage, or are not involved at all. Finally, this chapter will summarize the relevance of current animal models for studying the different neurologic autoimmune diseases, and it will identify aspects where future animal models need to be improved to better reflect the disease reality experienced by affected patients, e.g., the chronicity or the relapsing/remitting nature of their disease.
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Affiliation(s)
- Monika Bradl
- Department of Neuroimmunology, Center for Brain Research, Medical University Vienna, Vienna, Austria.
| | - Hans Lassmann
- Department of Neuroimmunology, Center for Brain Research, Medical University Vienna, Vienna, Austria
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Baizabal-Carvallo JF, Jankovic J. Stiff-person syndrome: insights into a complex autoimmune disorder. J Neurol Neurosurg Psychiatry 2015; 86:840-8. [PMID: 25511790 DOI: 10.1136/jnnp-2014-309201] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 11/21/2014] [Indexed: 02/06/2023]
Abstract
Stiff-person syndrome (SPS) is characterised by progressive rigidity and muscle spasms affecting the axial and limb muscles. Since its initial description in 1956, marked progress has been made in the clinical characterisation, understanding of pathogenesis and therapy of this disorder. SPS can be classified according to the clinical presentation into classic SPS and SPS variants: focal or segmental-SPS, jerking-SPS and progressive encephalomyelitis with rigidity and myoclonus. Most patients with SPS have antibodies directed against the glutamic acid decarboxylase, the rate-limiting enzyme for the production of the inhibitory neurotransmitter γ-aminobutyric acid (GABA). Antibodies directed against GABA(A) receptor-associated protein, and the glycine-α1 receptor can also be observed. Paraneoplastic SPS is commonly associated with antiamphiphysin antibodies and breast cancer. Treatment of SPS with drugs that increase the GABAergic tone combined with immunotherapy can improve the neurological manifestations of these patients. The prognosis, however, is unpredictable and spontaneous remissions are unlikely.
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Affiliation(s)
- José Fidel Baizabal-Carvallo
- Department of Neurology, Parkinson's Disease Center and Movement Disorders Clinic, Baylor College of Medicine, Houston, Texas, USA
| | - Joseph Jankovic
- Department of Neurology, Parkinson's Disease Center and Movement Disorders Clinic, Baylor College of Medicine, Houston, Texas, USA
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Manto M, Honnorat J, Hampe CS, Guerra-Narbona R, López-Ramos JC, Delgado-García JM, Saitow F, Suzuki H, Yanagawa Y, Mizusawa H, Mitoma H. Disease-specific monoclonal antibodies targeting glutamate decarboxylase impair GABAergic neurotransmission and affect motor learning and behavioral functions. Front Behav Neurosci 2015; 9:78. [PMID: 25870548 PMCID: PMC4375997 DOI: 10.3389/fnbeh.2015.00078] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 03/12/2015] [Indexed: 12/21/2022] Open
Abstract
Autoantibodies to the smaller isoform of glutamate decarboxylase (GAD) can be found in patients with type 1 diabetes and a number of neurological disorders, including stiff-person syndrome, cerebellar ataxia and limbic encephalitis. The detection of disease-specific autoantibody epitopes led to the hypothesis that distinct GAD autoantibodies may elicit specific neurological phenotypes. We explored the in vitro/in vivo effects of well-characterized monoclonal GAD antibodies. We found that GAD autoantibodies present in patients with stiff person syndrome (n = 7) and cerebellar ataxia (n = 15) recognized an epitope distinct from that recognized by GAD autoantibodies present in patients with type 1 diabetes mellitus (n = 10) or limbic encephalitis (n = 4). We demonstrated that the administration of a monoclonal GAD antibody representing this epitope specificity; (1) disrupted in vitro the association of GAD with γ-Aminobutyric acid containing synaptic vesicles; (2) depressed the inhibitory synaptic transmission in cerebellar slices with a gradual time course and a lasting suppressive effect; (3) significantly decreased conditioned eyelid responses evoked in mice, with no modification of learning curves in the classical eyeblink-conditioning task; (4) markedly impaired the facilitatory effect exerted by the premotor cortex over the motor cortex in a paired-pulse stimulation paradigm; and (5) induced decreased exploratory behavior and impaired locomotor function in rats. These findings support the specific targeting of GAD by its autoantibodies in the pathogenesis of stiff-person syndrome and cerebellar ataxia. Therapies of these disorders based on selective removal of such GAD antibodies could be envisioned.
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Affiliation(s)
- Mario Manto
- Unité d'Etude du Mouvement, FNRS Neurologie, ULB Erasme Brussels, Belgium
| | | | | | | | | | | | - Fumihito Saitow
- Department of Pharmacology, Nippon Medical School Tokyo, Japan
| | - Hidenori Suzuki
- Department of Pharmacology, Nippon Medical School Tokyo, Japan
| | - Yuchio Yanagawa
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine and JST, CREST, Maebashi City Gunma, Japan
| | | | - Hiroshi Mitoma
- Department of Medical Education, Tokyo Medical University Tokyo, Japan
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Gresa-Arribas N, Ariño H, Martínez-Hernández E, Petit-Pedrol M, Sabater L, Saiz A, Dalmau J, Graus F. Antibodies to inhibitory synaptic proteins in neurological syndromes associated with glutamic acid decarboxylase autoimmunity. PLoS One 2015; 10:e0121364. [PMID: 25774787 PMCID: PMC4361655 DOI: 10.1371/journal.pone.0121364] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 01/31/2015] [Indexed: 12/12/2022] Open
Abstract
Antibodies to glutamic acid decarboxylase (GAD-ab) associate to different neurological syndromes. It is unknown if the diversity in syndrome association represents epitopes in different immunodominant domains or co-existence of antibodies to other proteins of the inhibitory synapsis. We examined the serum and CSF of 106 patients with anti-GAD related syndromes (39 cerebellar ataxia, 32 stiff-person syndrome [SPS], 18 epilepsy, and 17 limbic encephalitis [LE]). GAD65-ab titres were quantified by ELISA. Immunoblot was used to determine if the antibody-targeted epitopes of GAD65 and GAD67 were linear. A cell-based assay (CBA) with HEK293 cells expressing the GAD65 N-terminal, central catalytic domain, or C-terminal was used to investigate the immunodominant domains. Antibodies to GAD67, gamma-aminobutyric acid A receptor (GABAaR), glycine receptor (GlyR), GABAaR-associated protein (GABARAP), and gephyrin were determined with CBA. GAD-ab internalization was investigated using cultured rat hippocampal neurons. CSF GAD65-ab titres were higher in patients with cerebellar ataxia and LE compared to those with SPS (p = 0.02). GAD67-ab were identified in 81% of sera and 100% of CSF. GAD65-ab recognized linear epitopes in 98% of the patients and GAD67-ab in 42% (p<0.001). The GAD65 catalytic domain was recognized by 93% of sera, and the three domains by 22% of sera and 74% of CSF (p<0.001). Six patients had GABAaR-ab and another 6 had GlyR-ab without association to distinctive symptoms. None of the patients had gephyrin- or GABARAP-ab. GAD65-ab were not internalized by live neurons. Overall, these findings show that regardless of the neurological syndrome, the CSF immune response against GAD is more widespread than that of the serum and that there is no specific association between clinical phenotype and the presence of antibodies against other proteins of the inhibitory synapsis.
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Affiliation(s)
- Nuria Gresa-Arribas
- Neuroimmunology Program, Institut d’Investigació Biomèdica August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Helena Ariño
- Neuroimmunology Program, Institut d’Investigació Biomèdica August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Service of Neurology, Hospital Clinic, Universitat de Barcelona, Barcelona, Spain
| | - Eugenia Martínez-Hernández
- Neuroimmunology Program, Institut d’Investigació Biomèdica August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Service of Neurology, Hospital Clinic, Universitat de Barcelona, Barcelona, Spain
| | - Mar Petit-Pedrol
- Neuroimmunology Program, Institut d’Investigació Biomèdica August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Lidia Sabater
- Neuroimmunology Program, Institut d’Investigació Biomèdica August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Albert Saiz
- Neuroimmunology Program, Institut d’Investigació Biomèdica August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Service of Neurology, Hospital Clinic, Universitat de Barcelona, Barcelona, Spain
| | - Josep Dalmau
- Neuroimmunology Program, Institut d’Investigació Biomèdica August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Francesc Graus
- Neuroimmunology Program, Institut d’Investigació Biomèdica August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Service of Neurology, Hospital Clinic, Universitat de Barcelona, Barcelona, Spain
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48
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Ariño H, Gresa-Arribas N, Blanco Y, Martínez-Hernández E, Sabater L, Petit-Pedrol M, Rouco I, Bataller L, Dalmau JO, Saiz A, Graus F. Cerebellar ataxia and glutamic acid decarboxylase antibodies: immunologic profile and long-term effect of immunotherapy. JAMA Neurol 2014; 71:1009-16. [PMID: 24934144 DOI: 10.1001/jamaneurol.2014.1011] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
IMPORTANCE Current clinical and immunologic knowledge on cerebellar ataxia (CA) with glutamic acid decarboxylase 65 antibodies (GAD65-Abs) is based on case reports and small series with short-term follow-up data. OBJECTIVE To report the symptoms, additional antibodies, prognostic factors, and long-term outcomes in a cohort of patients with CA and GAD65-Abs. DESIGN, SETTING, AND PARTICIPANTS Retrospective cohort study and laboratory investigations at a center for autoimmune neurologic disorders among 34 patients with CA and GAD65-Abs, including 25 with long-term follow-up data (median, 5.4 years; interquartile range, 3.1-10.3 years). MAIN OUTCOMES AND MEASURES Analysis of clinicoimmunologic features and predictors of response to immunotherapy. Immunochemistry on rat brain, cultured neurons, and human embryonic kidney cells expressing GAD65, GAD67, α1-subunit of the glycine receptor, and a repertoire of known cell surface autoantigens were used to identify additional antibodies. Twenty-eight patients with stiff person syndrome and GAD65-Abs served as controls. RESULTS The median age of patients was 58 years (range, 33-80 years); 28 of 34 patients (82%) were women. Nine patients (26%) reported episodes of brainstem and cerebellar dysfunction or persistent vertigo several months before developing CA. The clinical presentation was subacute during a period of weeks in 13 patients (38%). Nine patients (26%) had coexisting stiff person syndrome symptoms. Systemic organ-specific autoimmunities (type 1 diabetes mellitus and others) were present in 29 patients (85%). Twenty of 25 patients with long-term follow-up data received immunotherapy (intravenous immunoglobulin in 10 and corticosteroids and intravenous immunoglobulin or other immunosuppressors in 10), and 7 of them (35%) improved. Predictors of clinical response included subacute onset of CA (odds ratio [OR], 0.50; 95% CI, 0.25-0.99; P = .047) and prompt immunotherapy (OR, 0.98; 95% CI, 0.96-0.99; P = .01). Similar frequencies of serum GAD67-Abs were found in patients with CA (24 of 34 patients [71%]) and in patients with stiff person syndrome (20 of 28 patients [71%]). However, GAD67-Abs were found in all of the cerebrospinal fluid samples examined (22 samples from patients with CA and 17 samples from patients with stiff person syndrome). Glycine receptor antibodies but not other cell surface antibodies were identified in 4 patients with CA. The presence of glycine receptor antibodies did not correlate with any specific clinical feature. CONCLUSIONS AND RELEVANCE In patients with CA and GAD65-Abs, subacute onset of symptoms and prompt immunotherapy are associated with good outcome. Persistent vertigo or brainstem and cerebellar episodes can herald CA and should lead to GAD65-Ab testing, particularly in patients with systemic organ-specific autoimmunities.
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Affiliation(s)
- Helena Ariño
- Neurology Service, Hospital Clínic, Barcelona, Spain2Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain
| | - Nuria Gresa-Arribas
- Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain
| | - Yolanda Blanco
- Neurology Service, Hospital Clínic, Barcelona, Spain2Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain
| | - Eugenia Martínez-Hernández
- Neurology Service, Hospital Clínic, Barcelona, Spain2Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain
| | - Lidia Sabater
- Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain
| | - Mar Petit-Pedrol
- Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain
| | - Idoia Rouco
- Neurology Service, Department of Neurosciences, Cruces University Hospital, University of the Basque Country, Bizkaia, Spain
| | - Luis Bataller
- Neurology Service, University Hospital Politècnic La Fe, Valencia, Spain
| | - Josep O Dalmau
- Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain5Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain6Department of Neurology, University of Pennsylvania, Philadelp
| | - Albert Saiz
- Neurology Service, Hospital Clínic, Barcelona, Spain2Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain
| | - Francesc Graus
- Neurology Service, Hospital Clínic, Barcelona, Spain2Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain
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Mitoma H, Yoneda M, Saitow F, Suzuki H, Matsunaga A, Ikawa M, Mizusawa H. Presynaptic dysfunction caused by cerebrospinal fluid from a patient with the ataxic form of Hashimoto's encephalopathy. ACTA ACUST UNITED AC 2014. [DOI: 10.1111/ncn3.105] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hiroshi Mitoma
- Department of Medical Education; Tokyo Medical University; Tokyo Japan
| | - Makoto Yoneda
- Faculty of Nursing and Social Welfare Science; Fukui Prefectural University; Fukui Japan
| | - Fumihito Saitow
- Department of Pharmacology; Nippon Medical School; Tokyo Japan
| | - Hidenori Suzuki
- Department of Pharmacology; Nippon Medical School; Tokyo Japan
| | - Akiko Matsunaga
- Department of Neurology; University of Fukui Hospital; Fukui Japan
| | - Masamichi Ikawa
- Department of Neurology; University of Fukui Hospital; Fukui Japan
| | - Hidehiro Mizusawa
- Department of Neurology and Neurological Science; Graduate School of Medical and Dental Sciences; Tokyo Medical and Dental University; Tokyo Japan
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50
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Markakis I, Alexopoulos H, Poulopoulou C, Akrivou S, Papathanasiou A, Katsiva V, Lyrakos G, Gekas G, Dalakas MC. Immunotherapy-responsive limbic encephalitis with antibodies to glutamic acid decarboxylase. J Neurol Sci 2014; 343:192-4. [PMID: 24950904 DOI: 10.1016/j.jns.2014.05.032] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 05/11/2014] [Accepted: 05/15/2014] [Indexed: 12/11/2022]
Abstract
Glutamic acid decarboxylase (GAD) has been recently identified as a target of humoral autoimmunity in a small subgroup of patients with non-paraneoplastic limbic encephalitis (NPLE). We present a patient with NPLE and positive anti-GAD antibodies who showed significant improvement after long-term immunotherapy. A 48-year old female was admitted with a two-year history of anterograde amnesia and seizures. Brain MRI revealed bilateral lesions of medial temporal lobes. Screening for anti-neuronal antibodies showed high anti-GAD titers in both serum and cerebrospinal fluid (CSF) with strong evidence of intrathecal production. The patient received treatment with prednisolone and long-term plasma exchange. During a 12-month follow-up, she exhibited complete seizure remission and an improvement in memory and visuo-spatial skills. Anti-GAD antibodies may serve as a useful marker to identify a subset of NPLE patients that respond to immunoregulatory treatment.
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Affiliation(s)
- Ioannis Markakis
- Department of Neurology, "St. Panteleimon" General State Hospital, 3 Mantouvalou St., 18454 Nikaia, Greece.
| | - Harry Alexopoulos
- Neuroimmunology Unit, Department of Pathophysiology, Medical School, University of Athens, 75 Mikras Asias St., 11527 Athens Greece.
| | - Cornelia Poulopoulou
- Laboratory of Experimental Neurophysiology, Department of Neurology, Medical School, University of Athens, 72-74 Vas. Sophias Ave., 115 28 Athens, Greece.
| | - Sofia Akrivou
- Neuroimmunology Unit, Department of Pathophysiology, Medical School, University of Athens, 75 Mikras Asias St., 11527 Athens Greece.
| | - Athanasios Papathanasiou
- Department of Neurology, Essex Centre for Neurological Sciences, Queen's Hospital, Romford, Essex, UK.
| | - Vassiliki Katsiva
- Department of Radiology, "St. Panteleimon" General State Hospital, 3 Mantouvalou St., 18454 Nikaia, Greece.
| | - Georgios Lyrakos
- Department of Neurology, "St. Panteleimon" General State Hospital, 3 Mantouvalou St., 18454 Nikaia, Greece.
| | - Georgios Gekas
- Department of Neurology, "St. Panteleimon" General State Hospital, 3 Mantouvalou St., 18454 Nikaia, Greece.
| | - Marinos C Dalakas
- Neuroimmunology Unit, Department of Pathophysiology, Medical School, University of Athens, 75 Mikras Asias St., 11527 Athens Greece.
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