Faculty Collaboration Database

Quantitative electrophysiologic studies in sporadic inclusion body myositis. Muscle Nerve 1999 Apr;22(4):480-7

Date

04/16/1999

Pubmed ID

10204783

DOI

10.1002/(sici)1097-4598(199904)22:4<480::aid-mus9>3.0.co;2-a

Scopus ID

2-s2.0-0032956899 (requires institutional sign-in at Scopus site)   42 Citations

Abstract

Sporadic inclusion body myositis (S-IBM) is a progressive, acquired disease of unknown etiology. Prior studies have suggested neurogenic involvement based on electrophysiologic data, although the biopsy is compatible with a myopathic process. Quantitative electrophysiologic studies were performed in the biceps brachii of 17 subjects with biopsy-proven S-IBM. Quantitative motor unit action potential (MUAP) analysis was compatible with myopathy in 16 subjects, with the remaining subject being within normal limits. Quantitative interference pattern was myopathic in all 13 subjects studied. Macro-EMG MUAP amplitude was reduced in 3 of 17 studies; the remainder were within normal range, and none was increased as would be expected in neurogenic disease. Fiber density was normal to borderline increased in all subjects. Possible reasons for encountering neurogenic-appearing MUAPs may include choice of muscle studies, because some patients have co-existing polyneuropathy and large-amplitude MUAPs from hypertrophied muscle fibers. The data from this study indicate that S-IBM is a myopathic process.

Author List

Barkhaus PE, Periquet MI, Nandedkar SD

Author

Paul E. Barkhaus MD Professor in the Neurology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Action Potentials
Adult
Aged
Aged, 80 and over
Electromyography
Female
Humans
Male
Middle Aged
Myositis, Inclusion Body
Periodicity