Asymmetrical muscular disorder with normal creatine kinase (CK) and electromyography (EMG): the challenging diagnosis of muscular polyarteritis nodosa (MPAN), case report and literature review.

Alexandre Dib, Hippolyte Lequain, Tanguy Fenouil, Antoine Pegat, Philippe Petiot, Andras Barta, Charles Mayard, Alessio Balletti, Emilie Virot, Isabela Pascu, Arnaud Hot, Laure Gallay

Journal: Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology 2026;47(7):

PMID: 42370969

View on PubMed

Abstract

We report a case of muscular polyarteritis nodosa in a 23-year-old man with no past medical history presenting with diffuse myalgias, weight loss, fatigue, hypertension, and elevated C-reactive protein. Normal creatine kinase and electromyography contributed to a delayed diagnosis. MRI-guided muscular biopsy confirmed necrotizing vasculitis. Corticosteroid therapy led to rapid improvement.

Address: Department of Internal Medicine and Clinical Immunology, Edouard Herriot University Hospital, Hospices Civils de Lyon, University Claude Bernard, Lyon, France. [email protected].; Service ENMG Et de Pathologies Neuromusculaires, Centre de Référence Des Maladies Neuromusculaires PACA-Réunion-Rhône Alpes, Hôpital Neurologique P. Wertheimer, Hospices Civils de Lyon, Bron, France. [email protected].; Department of Internal Medicine, Centre de Référence Des Maladies Auto-Inflammatoires Et de L'Amylose Inflammatoire (CéRéMAIA), Hôpital de La Croix-Rousse, Hospices Civils de Lyon, Université Claude-Bernard Lyon 1, Lyon, France.; Institute of Pathology - East Site, Groupement Hospitalier Est, Hospices Civils de Lyon, Bron, France.; Service ENMG Et de Pathologies Neuromusculaires, Centre de Référence Des Maladies Neuromusculaires PACA-Réunion-Rhône Alpes, Hôpital Neurologique P. Wertheimer, Hospices Civils de Lyon, Bron, France.; Department of Diagnostic and Interventional Radiology, Hôpital Edouard Herriot, Hospices Civils de Lyon, Lyon, France.; Department of Internal Medicine and Clinical Immunology, Edouard Herriot University Hospital, Hospices Civils de Lyon, University Claude Bernard, Lyon, France.; Department of Internal Medicine and Clinical Immunology, Edouard Herriot University Hospital, Hospices Civils de Lyon, University Claude Bernard, Lyon, France.; Constitutive Reference Center, Major Sickle Cell Syndromes, Thalassemia and Other Rare Pathologies of Red Blood Cell and Erythropoiesis, Edouard Herriot Hospital, Lyon, France.; Department of Internal Medicine and Clinical Immunology, Edouard Herriot University Hospital, Hospices Civils de Lyon, University Claude Bernard, Lyon, France.; Institut NeuroMyoGène, Laboratoire Physiopathologie Et Génétique du Neurone Et du Muscle, CNRS UMR 5261 - Inserm U1315, Université Claude Bernard Lyon 1, Lyon, France.

DOI: 10.1007/s10072-026-09178-y

MeSH Terms: Humans, Polyarteritis Nodosa, Male, Electromyography, Young Adult, Creatine Kinase, Muscular Diseases, Muscle, Skeletal, Magnetic Resonance Imaging