Autoimmune neurological diseases

Journal article

Myasthenia gravis (MG) is one of the best understood autoantibody-mediated disorders. The pathogenic antibodies against the acetylcholine receptor (AChR) have been well characterized and are known to impair neuromuscular transmission by direct blockade, complement-mediated damage and accelerated receptor-mediated endocytosis. The clinical presentation is characterized by fatigable weakness, with a predilection for the extra-ocular, facial, bulbar, respiratory and proximal limb muscles. Diagnosis is confirmed by the presence of antibodies against the AChR or muscle-specific kinase in the serum. Electrophysiology demonstrates a decrement on repetitive nerve stimulation and increased jitter on single-fibre studies. Symptomatic relief is attained with an acetylcholinesterase inhibitor, pyridostigmine, but definitive treatment requires immunosuppressive drugs. Thymectomy is indicated for 10-15% of patients who have thymomas and may be indicated in young patients with AChR antibodies to try to improve their MG. Lambert-Eaton myasthenic syndrome is associated with small cell lung cancer in 50% of patients, particularly smokers. Immunosuppressive treatment regimens are similar to those used in MG, but 3,4-diaminopyridine is used for symptomatic relief. Limbic encephalitis associated with antibodies to voltage-gated potassium channel antibodies (VGKC) is a newly described disorder characterized by the subacute onset of short-term memory loss, seizures and confusion. Investigations reveal low serum sodium, high signal in the hippocampi on magnetic resonance imaging, a high titre of VGKC antibodies, and anterograde and retrograde memory loss on neuropsychological assessment. Patients respond very well to prolonged treatment with high-dose corticosteroids. © 2012 Elsevier Ltd. All rights reserved.

Authors: Buckley, C

• Journal: Medicine (United Kingdom)
• Volume: 40
• Issue: 10
• Pages: 553-557
• Publication date: 2012-10-01
• DOI: 10.1016/j.mpmed.2012.07.002
• EISSN: 1365-4357
• ISSN: 1357-3039
• Language: English
• Keywords: limbic encephalitis; neuromuscular junction; myasthenia gravis; autoantibody; immunosuppression