Muscle diseases with prominent joint contractures: Main entities and diagnostic strategy

Muscle diseases may have various clinical manifestations including muscle weakness, atrophy or hypertrophy and joint contractures. A spectrum of non-muscular manifestations (cardiac, respiratory, cutaneous, central and peripheral nervous system…) may be associated. Few of these features are specific. Limb joint contractures or spine rigidity, when prevailing over muscle weakness in ambulant patients, are of high diagnostic value for diagnosis orientation. Within this context, among several disorders, four groups of diseases should systematically come to mind including the collagen VI-related myopathies, the Emery–Dreifuss muscular dystrophies, the SEPN1 and FHL1 related myopathies. More rarely other genetic or acquired myopathies may present with marked contractures. Diagnostic work-up should include a comprehensive assessment including family history, neurological, cardiologic and respiratory evaluations. Paraclinical investigations should minimally include muscle imaging and electromyography. Muscle and skin biopsies as well as protein and molecular analyses usually help to reach a precise diagnosis. We will first describe the main muscle and neuromuscular junction diseases where contractures are typically a prominent symptom of high diagnostic value for diagnosis orientation. In the following chapters, we will present clues for the diagnostic strategy and the main measures to be taken when, at the end of the diagnostic work-up, no definite muscular disease has been identified. Les signes cliniques des affections musculaires sont variés : faiblesse et/ou fatigabilité, atrophie et/ou hypertrophie musculaires mais aussi rétractions tendineuses, de topographie variable. Peuvent s’y associer des symptômes extramusculaires (cardiaques, respiratoires, neurologiques centraux ou périphériques, ophtalmologiques, métaboliques, cutanés). Parmi les symptômes clés qui orientent la démarche clinique, les rétractions tendineuses peuvent être d’un apport décisif pour poser un diagnostic précis quand elles sont au premier plan. Leur existence et leur topographie (axiale et/ou au niveau des membres), notamment chez un patient encore ambulatoire, apportent un élément d’orientation important à l’équation clinique. Dans ce cadre, quatre groupes d’affections musculaires sont à évoquer systématiquement : les myopathies liées aux collagène VI, les myopathies de type Emery-Dreifuss, les myopathies liées aux gènes FHL1 et SEPN1. D’autres affections musculaires héréditaires ou acq