Degenerative Muscle Diseases

The progressive damage of muscle cells that leads to weakness and loss of control is caused by degenerative muscle diseases. Also called muscle dystrophy (MD), it leads to progressive weakness of the skeletal muscles, muscle protein abnormalities, muscle cells and tissue death. These are a group of hereditary diseases that are often diagnosed early in life.

Most of these conditions are inherited and genetic in nature. Each disease has a different cause that may include improper coding of a particular protein, autoimmune diseases, viral infection, etc.

There are many types of degenerative muscle diseases that lead to loss of muscle mass and function. The symptoms of these diseases are often related to the progressive weakness of the affected group of muscles. These symptoms include walking disabilities. Diseases like Duchenne muscular dystrophy causes inability to walk.

This is a common degenerative muscle disease in children. These children have walking problems from an early age and may frequently stumble or fall. As the disease progresses, the patient loses his/her total ability to walk. This disease causes the children to become wheelchair bound, by the time they reach 12 years of age.

Another symptom is loss of muscle strength. The intensity of muscle weakness may vary in different diseases. People with amyotrophic lateral sclerosis (ALS), show weakness of the muscles of the hands and legs. They may find holding a pen or even spoon very difficult. Patients with myasthenia gravis may suffer from weakness in the facial muscles. This causes them to suffer from drooping eyelids, or developing an odd facial expression due to twitching of the mouth.

People with myasthenia gravis and similar conditions may suffer from progressive muscle weakness. This muscle fatigue causes the person to suffer from decrease in muscular activity. A little physical activity will cause the person to feel tired and fatigued. Some patients with muscular dystrophy suffer from weakness of the muscles in the mouth and throat.

Thus, they develop slurred speech, chewing difficulties and swallowing problems. These symptoms are mostly seen in conditions like facioscapulohumeral muscular dystrophy, ALS, etc. If the disease strikes the respiratory muscles, it leads to breathing difficulties. In severe cases, the patient requires ventilator support.

There are about 9 diseases that make up the group of muscular dystrophy. These diseases include:

♦ Duchenne muscular dystrophy
This is an X-linked condition that leads to muscle degeneration, walking difficulties, breathing problems and death.

♦ Becker's muscular dystrophy
This is also an X-linked recessive condition that causes progressive leg and pelvis muscle degeneration, loss of walking ability, toe walking, fatigue, muscular and skeletal deformities, heart diseases, etc.

♦ Limb-girdle muscular dystrophy
This is an autosomal condition that is used to describe many of the muscular disorders. The condition causes muscle weakness, myotonia, cardiomyopathy, rippling muscles, etc. It is one of the degenerative muscle diseases in children, adolescents as well as young adults.

♦ Congenital muscular dystrophy
This condition is present at birth and causes muscle weakness, joint deformities etc. in the newborn. However, most of the congenital muscular dystrophy do not affect the life span in any way.

♦ Facioscapulohumeral muscular dystrophy
This is an autosomal dominant condition that affects the facial muscles, scapula and upper arm muscles. It causes eyelid drooping, decreased facial expressions, angry or depressed look, shoulder weakness, hearing loss, loss of strength of abdominal muscles, leg muscles and foot drop.

♦ Myotonic dystrophy
It is a chronic condition that causes muscle wasting, cataracts, endocrine changes and myotonia. This condition can affect a patient at any age.

♦ Oculopharyngeal muscular dystrophy
This is an autosomal dominant neuromuscular disease. It leads to drooping of the eyelids, paralysis of eye muscles, dysphagia and proximal limb weakness.

♦ Distal muscular dystrophy
This condition is associated with the Limb-girdle muscular dystrophy. It affects the muscles of the hands and feet.

♦ Emery-Dreifuss muscular dystrophy
This condition causes the skeletal muscles that help in movement and the cardiac muscles to degenerate over time. Thus, movement of certain joints is affected and the patient shows progressive muscle weakness and wasting. The patients gradually become wheelchair bound.

As mentioned above there is no cure for degenerative muscle disease or muscular dystrophy. However, treatment involves physical therapy, occupational therapy, orthotic intervention and use of orthopedic instruments. The doctor may suggest treatment plans based on the type of degenerative muscle disease affecting the patient.

The prognosis for degenerative muscular diseases depends on the type of disorder. Some disorders take time to develop and some quickly cause functional disabilities. In most cases, degenerative muscle diseases in children lead to death. If one observes unusual muscle weakness or loss of muscular control, they should seek medical opinion at the earliest.