TY - JOUR
T1 - Inclusion body myositis
T2 - Observations IN 40 patients
AU - Lotz, B. P.
AU - Engel, A. G.
AU - Nishino, H.
AU - Stevens, J. C.
AU - Litchy, W. J.
N1 - Funding Information:
The expert technical assistance of LouAnn Gross and Jean Fischer is gratefully acknowledged. Dr Alison Emslie-Smith provided critical comments. This investigation was supported in part by Research Grant NS-6277 from the National Institutes of Health, by a Research Center Grant from the Muscular Dystrophy Association, and by the Mogg Fund.
PY - 1989/6
Y1 - 1989/6
N2 - SUMMARY. Inclusion body myositis (IBM) was suspected on light microscopic grounds in 48 of 170 consecutive patients with inflammatory myopathies. One or more vacuoles containing membranous material, groups of atrophic fibres, and an autoaggressive endomysial inflammatory exudate occurred in 100, 96 and 92% of the muscle specimens All three of these features were present in 88% of the specimens Electron microscopy confirmed the presence of filamentous inclusions in 40 of 43 patients The inclusions are typically near vacuoles and a minimum of three vacuolated fibres must be scrutinized to detect them with confidence. There is no electromyographic pattern that can reliably distinguish IBM from other inflammatory myopathies The typical clinical features in the patients diagnosed by histological criteria as IBM were: insidious onset after age 50 yrs with painless, proximal lower extremity weakness, slow but relentless progression with selectively severe involvement of quadriceps, iliopsoas, tibialis anterior, biceps and triceps muscles; relatively early depression of the knee reflexes; and a normal or mildly elevated serum creatine kinase level The male : female ratio was 3 : 1. Distal weakness occurred in about 50%, but only in 35% was it as great or greater than proximal weakness. Significant associated illnesses include other autoimmune disorders (15%), diabetes melhtus (20%), and diffuse peripheral neuropathy (18%). Prednisone treatment at dose levels frequently effective in polymyositis failed to prevent disease progression in those patients observed for 2 or more years. Our findings support the notion that IBM is a distinct entity in which a set of pathological features is associated with a constellation of clinical findings.
AB - SUMMARY. Inclusion body myositis (IBM) was suspected on light microscopic grounds in 48 of 170 consecutive patients with inflammatory myopathies. One or more vacuoles containing membranous material, groups of atrophic fibres, and an autoaggressive endomysial inflammatory exudate occurred in 100, 96 and 92% of the muscle specimens All three of these features were present in 88% of the specimens Electron microscopy confirmed the presence of filamentous inclusions in 40 of 43 patients The inclusions are typically near vacuoles and a minimum of three vacuolated fibres must be scrutinized to detect them with confidence. There is no electromyographic pattern that can reliably distinguish IBM from other inflammatory myopathies The typical clinical features in the patients diagnosed by histological criteria as IBM were: insidious onset after age 50 yrs with painless, proximal lower extremity weakness, slow but relentless progression with selectively severe involvement of quadriceps, iliopsoas, tibialis anterior, biceps and triceps muscles; relatively early depression of the knee reflexes; and a normal or mildly elevated serum creatine kinase level The male : female ratio was 3 : 1. Distal weakness occurred in about 50%, but only in 35% was it as great or greater than proximal weakness. Significant associated illnesses include other autoimmune disorders (15%), diabetes melhtus (20%), and diffuse peripheral neuropathy (18%). Prednisone treatment at dose levels frequently effective in polymyositis failed to prevent disease progression in those patients observed for 2 or more years. Our findings support the notion that IBM is a distinct entity in which a set of pathological features is associated with a constellation of clinical findings.
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U2 - 10.1093/brain/112.3.727
DO - 10.1093/brain/112.3.727
M3 - Article
C2 - 2543478
AN - SCOPUS:0024340503
SN - 0006-8950
VL - 112
SP - 727
EP - 747
JO - Brain
JF - Brain
IS - 3
ER -