Intercostal muscle biopsy studies in myasthenia gravis: clinical correlations and the direct effects of drugs and myasthenic serum.

Journal Article

We have found a wide range of mean MEPP amplitude in intercostal muscle biopsies from 43 patients with MG, including several values in the normal range. There was no correlation between MEPP amplitude and the severity of clinical disease as assessed by manual muscle testing or by single-fiber EMG measurements of jitter in arm muscles. Through most of these patients were in a state of clinical remission or marked improvement after treatment with prednisone, we could not attribute the difference between our results and those of others to this factor alone. The application of morphine, meperidine and aminoglycoside antibiotics to intercostal muscle in vitro confirms effects previously demonstrated in rat muscle: (1) At equal therapeutic concentrations, meperidine has greater neuromuscular blocking effects than does morphine, but neither has significant effects at concentrations achieved in the serum clinically. (2) Tobramycin, netilmicin and neomycin have varying severity and sites of action, but their effects are the same in human myasthenic muscle as in normal rat muscle. Bath application of serum from myasthenic patients produces an acute, reversible worsening of neuromuscular blockade in myasthenic muscle. Electrophysiologic measurements in intercostal biopsies from patients with MG can provide information about the basic abnormality of neuromuscular transmission in this disease and can confirm the relevance of studies made in animal muscle.

Full Text

Duke Authors

Cited Authors

  • Sanders, DB; Kim, YI; Howard, JF; Johns, TR; Muller, WH

Published Date

  • 1981

Published In

Volume / Issue

  • 377 /

Start / End Page

  • 544 - 566

PubMed ID

  • 6280565

International Standard Serial Number (ISSN)

  • 0077-8923

Language

  • eng

Conference Location

  • United States