Short Description or Definition
Myasthenia gravis (MG) is an uncommon autoimmune disorder of the neuromuscular junction (NMJ) resulting in skeletal muscle weakness. Disruption of the postsynaptic receptors on the muscle membranes is caused by antibodies to the acetylcholine receptors (AChR), which prevent adequate amounts of acetylcholine from reaching the receptors and thus inhibiting muscle action potential. Abnormalities of thymus are common in MG patients and present as hyperplasia (70%) or thymomas (20%) (Kothari 2004; Romi et al. 2005). MG is characterized by a decrease in ocular, facial, respiratory, pharyngeal, and limb muscle strength that is exacerbated by repeated use of those muscles and generally improves with rest. Symptoms, however, can also fluctuate without apparent reason, and the disease may go into remission spontaneously in 10–20% of all MG patients lasting for years (Thomann and Pandya 1995).
Categorization and Presentation
References and Readings
- Oosterhuis, H. J. G. H. (1997). Myasthenia gravis. Groningen: Groningen Neurological Press.Google Scholar
- Sanders, D. B., & Howard Jr., J. F. (2004). Disorders of neuromuscular transmission. In W. G. Bradley, R. B. Daroff, G. M. Fenichel, et al. (Eds.), Neurology in clinical practice, the neurological disorders (pp. 2441–2461). Philadelphia: Butterworth Heinemann.Google Scholar