Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004134 (ataxia)
 15,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Over the last few years, various autoantibodies against cell surface or intracellular antigens were identified in association with several forms of encephalitis, i.e. autoimmune encephalitis. Immunoprecipitaion and sequence analysis of the target protein (proteomics) provided the identification of the antigens corresponding to autoantibodies in autoimmune encephalitis. Appropriate preparation of antigens (synthesized peptides, or recombinant proteins prepared in E.coli or cultured mammalian cells) and assay systems (immunoblot, ELISA, immunoprecipitation or cell-based assay) should be selected for detection of each autoantibodies.Limbic encephalitis characterized by psychosis, dementia, seizures and abnormal movements is a common form of autoimmune encephalitis. Autoantibodies against the NMDA receptor, the AMPA receptor or the VGKC complex (LGI1 and Caspr2) were identified in limbic encephalitis with or without tumor association. Especially, limbic encephalitis associated with anti-NMDA receptor and ovarian teratoma became a distinct neurologic disorder to date.The intracellular antigens are also involved in several forms of encephalitis. Cerebellar ataxia is a common form of autoimmune encephalitis (cerebellits). The autoimmune cerebellar ataxia consists of paraneoplastic ataxia (anti-Yo etc.), anti-GAD-autoantibodies associated ataxia, gluten ataxia (anti-gliadin) and ataxic form of Hashimoto's encephalitis (anti-NAE).The early and accurate diagnosis of autoimmune encephalitis is important because most patients show responses to immunotherapy.
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PMID:[Autoimmune encephalitis and its related-disorders]. 2429 79

Movement disorders (MDs) are common in patients with autoimmune disorders affecting the central and peripheral nervous system. They may be observed in autoimmune disorders triggered by an infectious agent, such as streptococcus in Sydenham's chorea, or in basal ganglia encephalitis with antibodies against the dopamine-D2 receptors. In these patients chorea or dystonia are usually the most prominent hyperkinetic MDs. MDs are also observed in patients with diffuse or limbic encephalitis with antibodies directed against neuronal cell-surface antigens. Anti-NMDA receptor encephalitis is one of the most common and may present with a variety of MDs, including: chorea, stereotypies, dystonia and myorhythmia. The recognition of other abnormal motor phenomena such as "faciobrachial dystonic seizures" and neuromyotonia, observed in patients with LGI1 and Caspr-2 antibodies, is important because they may herald the onset of overt limbic encephalitis. Autoimmunity directed against the intracellular enzyme glutamic acid decarboxylase usually presents with MDs, most commonly stiff-person syndrome or cerebellar ataxia. Chorea may be observed in rheumatologic disorders such as systemic lupus erythematosus or antiphospholipid syndrome. Disorders with uncertain autoimmune mechanisms such as Hashimoto's encephalitis and idiopathic opsoclonus-myoclonus syndrome commonly present with tremor, myoclonus and ataxia. A rapid diagnosis of an autoimmune disorder, which typically presents with subacute onset, is critical as early therapeutic intervention improves long-term prognosis and may be life-saving. Treatment usually involves some form of immunotherapy and symptomatic therapy of the abnormal movements with dopamine depleters, dopamine receptor antagonists, or GABAergic drugs. Detection and removal of an underlying tumor is essential for optimal outcome.
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PMID:Autoimmune and paraneoplastic movement disorders: An update. 2940 2

Autoimmune encephalitides, with an estimated incidence of 1.5 per million population per year, although described only 15 years ago, have already had a remarkable impact in neurology and paved the field to autoimmune neuropsychiatry. Many patients traditionally presented with aberrant behavior, especially of acute or subacute onset, and treated with anti-psychotic therapies, turn out to have a CNS autoimmune disease with pathogenic autoantibodies against synaptic antigens responding to immunotherapies. The review describes the clinical spectrum of these disorders, and the pathogenetic role of key autoantibodies directed against: a) cell surface synaptic antigens and receptors, including NMDAR, GABAa, GABAb, AMPA and glycine receptors; b) channels such as AQP4 water-permeable channel or voltage-gated potassium channels; c) proteins that stabilize voltage-gated potassium channel complex into the membrane, like the LGI1 and CASPR2; and d) enzymes that catalyze the formation of neurotransmitters such as Glutamic Acid Decarboxylase (GAD). These antibodies, effectively target excitatory or inhibitory synapses in the limbic system, basal ganglia or brainstem altering synaptic function and resulting in uncontrolled neurological excitability disorder clinically manifested with psychosis, agitation, behavioral alterations, depression, sleep disturbances, seizure-like phenomena, movement disorders such as ataxia, chorea and dystonia, memory changes or coma. Some of the identified triggering factors include: viruses, especially herpes simplex, accounting for the majority of relapses occurring after viral encephalitis, which respond to immunotherapy rather than antiviral agents; tumors especially teratoma, SCLC and thymomas; and biological cancer therapies (immune-check-point inhibitors). As anti-synaptic antibodies persist after viral infections or tumor removal, augmentation of autoreactive B cells which release autoantigens to draining lymph nodes, molecular mimicry and infection-induced bystander immune activation products play a role in autoimmunization process or perpetuating autoimmune neuroinflammation. The review stresses the importance of early detection, clinical recognition, proper antibody testing and early therapy initiation as these disorders, regardless of a known or not trigger, are potentially treatable responding to systemic immunotherapy with intravenous steroids, IVIg, rituximab or even bortezomid.
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PMID:The immunobiology of autoimmune encephalitides. 3161 Nov 42

In recent years, there have been many developments in the field of autoimmune encephalitis. Autoimmune encephalitis is often treatable, and fast recognition and treatment are essential to prevent irreversible damage. Identification of patients with autoimmune encephalitis is challenging because patients display various symptoms and consequently present to different medical specialists. We describe 3 cases of autoimmune encephalitis due to different antibodies. A 23-year-old woman presented with acute psychosis, followed by seizures and autonomic dysfunction. She was diagnosed with anti-NMDAR encephalitis caused by antibodies that were triggered by ovarian teratoma. A 59-year-old man developed severe behavioural changes, memory deficits, and subtle faciobrachial dystonic seizures. He had anti-LGI1 encephalitis and recovered completely. The third patient was a 57-year-old man who presented with diarrhea and weight loss, and gradually developed progressive rigidity, myoclonus and ataxia over the course of several months. He was ultimately diagnosed with anti-DPPX encephalitis. All patients responded well to immunotherapy with (near-)complete recovery within months to years.
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PMID:[Clinical symptoms of patients with autoimmune encephalitis: a guide to timely recognition and treatment]. 3207 82