Disorders Related to Muscles

Muscular dystrophy is a gradual, wasting disease affecting various groups of muscles; these conditions are genetically inherited in families. Usually the voluntary skeletal muscles are weakened, whereas internal muscles such as the diaphragm are not affected. The Duchenne type usually occurs in boys, affecting the lower limbs. Limb-girdle muscular dystrophy affects the muscles of the shoulders or hips, and usually starts in adults aged 20-35 years. No treatment currently appears to cure the disease.

Myasthenia gravis is a weakness of the skeletal muscles caused by an abnormality at the neuromuscular junction that partially blocks contraction. It is an autoimmune disorder, caused by an excess of certain antibodies in the bloodstream, which bind to the acetylcholine receptors of the neuromuscular junction; this blocks transmission of nerve impulses to the muscle fibres, causing progressive and extensive muscle weakness. It may affect the eye and eyelid movements, facial expression, and swallowing, and the …