Medicine:Simpson test
| Simpson test | |
|---|---|
| Medical diagnostics | |
| Purpose | determine ocular myasthenia gravis |
Simpson test is a clinical test used in neurology to determine ocular myasthenia gravis.[1] It was first described by the Scottish neurologist John Alexander Simpson.[2]
Procedure
In myaesthenia gravis, there is a variable weakness of skeletal muscles, which is exacerbated by repeated contraction. To cause sustained contraction of levator palpebrae superioris muscle, the patient is asked to gaze upward for an extended period of time, without lifting the head. After a few minutes, the patient with myasthenia gravis starts to show drooping of upper eyelids, while normal individuals do not show any drooping.[3] Thus, this test can be used to clinically differentiate between ocular myasthenia gravis and normal individuals. Since myasthenia gravis affects all skeletal muscles, eyelid drooping is often bilateral. It is sometimes done in conjunction with tensilon test, where edrophonium is injected to look for reversibility of eyelid drooping. In myaesthenia gravis, eyelid drooping is no longer detectable after tensilon test. This test is less sensitive than anti-AChR antibody titers and electromyography, and hence is used only as a screening test in clinical setup.
References
- ↑ Nair, Akshay Gopinathan; Patil-Chhablani, Preeti; Venkatramani, Devendra V; Gandhi, Rashmin Anilkumar (2014). "Ocular myasthenia gravis: A review". Indian Journal of Ophthalmology 62 (10): 985–991. doi:10.4103/0301-4738.145987. ISSN 0301-4738. PMID 25449931.
- ↑ Riggs, Allison J.; Riggs, Jack E. (2004-02-10). ""Guessing it right," John A. Simpson, and myasthenia gravis: the role of analogy in science". Neurology 62 (3): 465–467. doi:10.1212/01.wnl.0000106936.27018.ec. ISSN 1526-632X. PMID 14872032.
- ↑ "Archived copy". http://www.lipteh.com/Study-Notes/Eyelids/myasthenia-clinical%20eye%20signs.pdf.
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