Myopathy is characterised by weakness and muscle wasting (of facial, bulbar, and proximal limb muscles) with preservation of tendon reflexes and sensation.
This is an immune disorder of muscle causing a painful or painless myopathy. When it occurs in the elderly, there is often a primary neoplasm elsewhere (non-metastatic syndrome). In children, the skin is also inflammed, causing a rash. This is referred to as dermatomyositis.
Duchenne muscular dystrophy
This is an inherited degenerative disorder of male children (X-linked inheritance). After 2-3 years of age, the child develops progressive weakness of the arms and legs with muscular contractures. The child will be wheelchair bound by the age of 10 and he will probably die as a teenager.