Myopathies with early contractures

Abstract

Publisher Summary A contracture is defined as fixed tightening of muscle, tendons, ligaments, or skin. It prevents normal movement of the associated body part and can cause permanent deformity. This chapter discusses skeletal muscle contractures although there is no certainty about the nature of the contractures in the collagen VI myopathies, Bethlem myopathy, and Ullrich congenital muscular dystrophy. In chronic progressive myopathies, contractures will ultimately develop due to longstanding muscle weakness. The chapter focuses on the early occurrence of contractures in myopathies. Early-onset contractures, hypotonia, and muscle weakness in infants suggest a neuromuscular disease rather than central nervous system (CNS) dysfunction for which impaired visual alertness, convulsions, and abnormal movements are generally suggestive. Bethlem myopathy is an autosomal-dominantly inherited myopathy, and is characterized by early-onset slowly progressive muscle weakness and wasting associated with early contractures of multiple joints. In most limb girdle muscular dystrophies (LGMD) contractures develop late in the course of the disease as in Duchenne and Becker muscular dystrophies. Because there is a clear relationship between weakness and the occurrence of contractures, patients with early-onset LGMD are tip-toe walkers associated with ankle contractures. Congenital muscular dystrophies (CMD) constitute a group of disorders characterized by early-onset muscular weakness and joint contractures, as well as dystrophic features identified by the morphological analysis of skeletal muscle.