Single-fiber electromyography in myasthenia gravis.


Journal Article

One-hundred-sixty single-fiber EMG studies of the extensor digitorum communis muscle were performed on 127 patients with myasthenia gravis; 131 demonstrated defective neuromuscular transmission. Jitter determinations in the biceps, deltoid or frontalis muscles increased the diagnostic yield significantly. Evoked-potential EMG studies were abnormal in less than 50 percent of patients in whom they were performed. The most sensitive criterion of abnormality was the percentage of fibers with increased jitter; the sensitivity of the test was enhanced, however, if the mean jitter of the tested muscle was also used as a criterion of abnormality. Since increased jitter may also be seen in primary muscle and nerve disease, these disorders must be excluded by other means before diagnosing myasthenia gravis on the basis of the single-fiber studies.

Full Text

Duke Authors

Cited Authors

  • Sanders, DB; Howard, JF; Johns, TR

Published Date

  • January 1, 1979

Published In

Volume / Issue

  • 29 / 1

Start / End Page

  • 68 - 76

PubMed ID

  • 218146

Pubmed Central ID

  • 218146

International Standard Serial Number (ISSN)

  • 0028-3878

Digital Object Identifier (DOI)

  • 10.1212/wnl.29.1.68


  • eng

Conference Location

  • United States