title: Continuous muscle activity, Morvan's syndrome and limbic encephalitis: ionic or non ionic disorders?
abstract: The early pathophysiologic study showed increasing evidence that autoimmunity is implicated in the pathogenesis of neuromyotonia. Antibodies to voltage gated potassium channel were detected in the serum of patients who had peripheral nerves hyperexcitability and also Morvan's disease or limbic encephalitis. These discoveries offered new approaches to treatments. Recently, antibodies previously attributed to VGKC recognise 2 surface antigens LGI1 and CASPR2 into the VGKC complex. Finally, VGKC antibodies are directed to 2 proteins the first one is a key hippocampic protein containing pre and post synaptic proteins. The second one CASPR2 is an hippocampic and paranodal protein. There clinical significance is different: hyperexcitability, limbic encephalitis without thymoma for LGI1, hyperexcitability, Morvan limbic encephalitis and frequent thymoma for CASPR2. In conclusion, the term NMT--LE--VGKC should be changed to NMT--LE with LGII and CASPR2 antibodies and classified as auto immune synaptic disorders. Mutations in genes encoding both these proteins are found in hereditary epilepsy and other syndromes. Various potassium channelopathies are closely linked to Morvan's syndromes. A new classification of antibodies will be necessary.
authors.affiliation: CHU Timone, Université de la Méditerranée, Marseille, France. georges.serratrice@dbmail.com
authors.forename: G
authors.initials: G
authors.lastname: Serratrice
authors.forename: J
authors.initials: J
authors.lastname: Serratrice
mesh_terms: D001323:Autoantibodies / Q000032:analysis*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D020386:Isaacs Syndrome / Q000175:diagnosis / Q000276:immunology*; D020363:Limbic Encephalitis / Q000175:diagnosis / Q000276:immunology*; D008565:Membrane Proteins / Q000276:immunology; D009419:Nerve Tissue Proteins / Q000276:immunology; D024642:Potassium Channels, Voltage-Gated / Q000276:immunology*; D011506:Proteins / Q000276:immunology; D013595:Syringomyelia / Q000175:diagnosis
chemical_list: D001323:Autoantibodies; C403049:CNTNAP2 protein, human; D047908:Intracellular Signaling Peptides and Proteins; C116499:LGI1 protein, human; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D024642:Potassium Channels, Voltage-Gated; D011506:Proteins