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Anti-VGKC-complex encephalitis are caused by antibodies against the voltage gated potassium channel-complex (VGKC-complex) and are implicated in several autoimmune conditions including limbic encephalitis, epilepsy and neuromyotonia (i.e. Isaacs' Syndrome). Research into autoimmune encephalitis have advanced a lot recently. Both tumour associated (paraneoplastic) and non-tumour associated conditions are recognized. Different antibodies are more or less selective for different parts of the brain. Antibodies are directed towards intracellular antigens in the classic paraneoplastic syndromes or synaptic proteins in paraneoplastic or non-tumour associated conditions. The VGKC-complex associated autoimmune encephalitis is an example of the latter form. Antibodies directed against VGKC were first reported in neuromyotonia. Further studies led to VGKC antibodies being recognized in Morvan’s syndrome and limbic encephalitis as well. It was for many years erroneously presumed that antibodies detected in a VGKC assay were targeted against the channel itself. But the heterogeneous presentation of patients was difficult to explain. The original assays for the detection of VGKC antibodies used Iodine-125 labelled dendrotoxin and the relatively mild detergent 2% digitonin on mammalian brain homogenate, and VGKC with complexed proteins was extracted.〔 Co-precipitated proteins would thus also be detected in this assay. It’s now acknowledged that most VGKC antibodies are instead directed towards associated/complexed proteins. In a particular study of 96 patients with VGKC antibodies detected with the radioimmunoprecipitation assay, only 3 (3%) had antibodies towards the Kv1 subunit of the VGKC channel, 55 (57%) had antibodies against Leucine-rich, glioma Inactivated 1 (LGI1), 19 had antibodies reacting with Contactin-associated protein 2 (CASPR 2), 5 had antibodies against Contactin-2 and 18 (19%) had antibodies with unknown specificity. Of the patients with Contactin-2 antibodies, 4/5 had antibodies against other antigens as well. ==Signs and symptoms== Signs and symptoms depend on the targeted antigen, but the features in patients with different antibodies often overlap. The most characteristic feature found in a case series was cognitive impairment and seizures in anti-LGI-1 positive patients, and peripheral motor hyperexcitability in anti-CASPR2 positive patients. Some patients have other coexisting autoimmune diseases. ''anti-LGI-1 encephalitis'': Patients with anti-LGI1 encephalitis have limbic encephalitis with amnesia and/or confusion (100%) and seizures (84-92 %) 〔 Other reported features include hyponatremia (in 60%), movement disorders (myoclonus/dyskinesia), sleep disorders (hypersomnia, insomnia, REM sleep behavior disorder, sleep reversal) and ataxia. Tonic seizures, with movements of the leg, arm or face, refractory to treatment with anti-epileptic drugs may precede the disorders, and should lead to testing for anti-LGI1 antibodies. ''Anti-CASPR2 nervous system manifestations'': Patients with anti-CASPIR2 antibodies develop symptoms from the CNS and/or the peripheral nervous system. The classic presentation is with Morvan’s syndrome, a disease with the features of neuromyotonia (i.e. peripheral hyperexcetability) and limbic encephalitis. Other patients present with isolated neuromyotonia or limbic encephalitis. Patients with anti-DPPX encephalitis present with symptoms of hyperexcetability such as agitation, tremor, muscle rigidity and gastrointestinal symptoms.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Anti-VGKC-complex encephalitis」の詳細全文を読む スポンサード リンク
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