DISEASES affecting the muscular system may present difficulties in diagnosis, particularly when they are characterized by atrophy of the muscles. For example, there are striking similarities in the course, signs and symptoms of the late dystrophy of distal type (Gowers) and of progressive muscular atrophy. The former belongs to the group of diseases which may best be described as the primary myopathies, or muscular dystrophies, and the latter to the so-called secondary myopathies.
In the primary muscular diseases, such as progressive muscular dystrophy, the pathologic process is thought to begin within the muscle fibers themselves; the changes result in weakness and paralysis in the presence of an apparently normal motor nerve. In the so-called secondary myopathies, the basic lesion lies within the spinal cord or the peripheral nerve, and the atrophy of the muscle is dependent on changes within the lower motor neuron.
It is possible that histologic examination might
BOWDEN REM, GUTMANN E. OBSERVATIONS IN A CASE OF MUSCULAR DYSTROPHY, WITH REFERENCE TO DIAGNOSTIC SIGNIFICANCE. Arch NeurPsych. 1946;56(1):1-19. doi:10.1001/archneurpsyc.1946.02300180011001