Protocolo diagnóstico de la debilidad muscular

Abstract

Muscle weakness is a common finding in multiple diseases. It may be present in diseases which affect the central and peripheral nervous system as well as in diseases of the neuromuscular junction and of the muscle itself. A suitable initial clinical approach is fundamental, with an exhaustive, systematic case history that identifies the inheritance pattern, triggering factors, age, form of onset, and specific symptoms. The neurological and general examination will provide fundamental data to begin restricting the diagnostic possibilities. The neurophysiological studies are an extension of the clinical examination. They may suggest a myopathic origin, which are diagnostic in disorders of neuromuscular transmission. Analyses with a muscle enzyme determination (especially creatine kinase) will also help guide the study. Various antibodies are diagnostic in diseases such as inflammatory myopathies or myasthenia gravis. A muscle biopsy shows characteristic traits of different myopathies and can be diagnostic or reduce the differential diagnosis to a few diseases. In hereditary myopathies or congenital myasthenic syndromes, a certain diagnosis is established in many cases by the genetic study which identifies the underlying molecular defect.