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Updated: Aug 20, 2026

Functional and Morphological Assessment of Diaphragm Innervation by Phrenic Motor Neurons
Published on: May 25, 2015
Diaphragmatic dysfunction in patients with idiopathic inflammatory myopathies
Antonio Teixeira1, Patrick Cherin, Alexandre Demoule
1UPRES EA 2397, Université Pierre et Marie Curie Paris VI, Paris, France.
Abstract:
Polymyositis, dermatopolymyositis, and inclusion body myositis imply chronic inflammation of skeletal muscles. Pulmonary complications include aspiration pneumonia, interstitial pneumonitis, or respiratory muscle myositis. This study aims at better describing their impact on respiratory muscle. Twenty-three consecutive patients (12 PM, 5 DM, 6 IBM) were studied (static inspiratory and expiratory pressures; diaphragm function in terms of the mouth and transdiaphragmatic pressure responses to bilateral phrenic stimulation). Pulmonary parenchymatous abnormalities were mild (6 cases) or absent. The mouth pressure produced by phrenic stimulation was 6.83+/-3.01 cm H2O, with 18 patients (78%) diagnosed with diaphragm weakness (<10 cm H2O) and lower values in DM (4.35+/-1.48 cm H2O) than in IBM and in PM (P<0.05). Diaphragm weakness is frequent and probably overlooked in inflammatory myopathies. Further studies are needed to delineate the clinical relevance of these results.
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