Clinical aspects of neuromuscular transmission disorders.

Abstract

Autoimmune disorders of neuromuscular transmission are caused by antibodies (abs) directed against membrane proteins at the motor end-plate. Myasthenia gravis (MG) is due, in most cases, to abs against the nicotinic acetylcholine receptor (AChR). Anti-AChR-positive MG actually includes different disease entities: weakness can be confined to extrinsic ocular muscles or can be generalized; patients with generalized MG (G-MG) can be subdivided on the basis of age of onset, HLA association and thymic pathology. About 15% of G-MG patients are anti-AChR-negative; in a proportion of these cases serum abs against the muscle- specific kinase (MuSK) are found. Anti-MuSK-positive MG is characterized by predominant involvement of bulbar muscles and very low frequency of thymic pathology. The Lambert-Eaton myasthenic syndrome (LEMS) is caused by abs against voltage-gated calcium channels at nerve terminal. LEMS is characterized by muscle weakness and autonomic disturbances and it is paraneoplastic in over 50% of the cases. In neuromyotonia and cramp-fasciculation syndrome, that are thought to be due to anti-voltage-gated potassium channel abs, signs of peripheral nerve hyperexcitability can be associated with CNS features.

• Authors: Amelia Evoli
• Journal: Acta neurologica Scandinavica. Supplementum (Acta Neurol Scand Suppl) Vol. 183 Pg. 8-11 ( 2006) ISSN: 0065-1427 [Print] Denmark
• PMID: 16637919 (Publication Type: Journal Article, Review)

Topics

• Humans
• Isaacs Syndrome (diagnosis, etiology, therapy)
• Lambert-Eaton Myasthenic Syndrome (diagnosis, etiology, therapy)
• Myasthenia Gravis (diagnosis, etiology, therapy)