A comparison of stapedial reflex fatigue with repetitive stimulation and single-fiber EMG in myasthenia gravis.

Journal Article

The pattern of stapedial reflex fatigue in response to pulsed acoustic stimulation was measured and compared to results of repetitive nerve stimulation and single-fiber electromyography (EMG) in 89 patients with myasthenia gravis. Studies were also made on 22 patients with other neuromuscular disorders and 40 control subjects with no evidence of neuromuscular impairment. Stapedial reflex fatigue exceeded normal control values in 84% of the patients with myasthenia gravis. Repetitive stimulation and single-fiber EMG measurements were abnormal in 56% and 91% of this same population, respectively. Stapedial reflex abnormalities were most prevalent in patients with mild forms of myasthenia (predominantly ocular or oropharyngeal weakness). Of 22 nonmyasthenic patients with neuromuscular disease tested, 6 had abnormal stapedial reflex fatigue according to our normal values, indicating that this form of testing also detects other diseases of the motor unit. The measurement of stapedial reflex fatigue is painless, is easy to perform, and requires minimal patient cooperation. Due to the relatively high occurrence of abnormal stapedial reflex fatigue in patients with myasthenia gravis, this procedure appears to have considerable potential value in screening and monitoring patients for the presence of defects in neuromuscular transmission.

Full Text

Duke Authors

Cited Authors

  • Kramer, LD; Ruth, RA; Johns, ME; Sanders, DB

Published Date

  • June 1981

Published In

Volume / Issue

  • 9 / 6

Start / End Page

  • 531 - 536

PubMed ID

  • 6266332

International Standard Serial Number (ISSN)

  • 0364-5134

Digital Object Identifier (DOI)

  • 10.1002/ana.410090604

Language

  • eng

Conference Location

  • United States