Question

Discuss muscular dystrophy, causes, the pathophysiology, clinical manifestations, and prognosis.

Answer 1

Answer: Muscular dystrophy is a group of diseases that cause progressives weakness and loss of muscle mass.In muscular dystrophy,abnormal genes (mutations) interfere with the production of proteins needed to form healthy muscle.

Causes: Certain genes are involved in making proteins that protect muscle fibers.Muscular dystrophy occurs when one of these genes is defective.Each form of muscular dystrophy is caused by a genetic mutation particular to that type of the disease.Most of these mutations are inherited.

Pathophysiology: Over time, the dead muscle shell is replaced by a fibrofatty infiltrate,which clinically appears as pseudohypertrophy of the muscle.The lack of functioning muscle units causes weakness and,eventually,contractures.Other types of Muscular dystrophy are caused by alterations in the coding of one of the DAG complex proteins.

Clinical manifestations/ Signs and Symptoms:

The main sign of muscular dystrophy is progressive muscle weakness.Specific signs and symptoms begin at different ages and in different muscle groups,depending on the type of muscular dystrophy.

Duchenne type muscular dystrophy: This is the most common form.Although girls can be carriers and mildly affected,it’s much more common in boys.

Signs and symptoms,which typically appear in early childhood,might include:

• Frequent falls
• Difficulty rising from a lying or sitting position
• Trouble running and jumping
• Waddling gait
• Walking On the toes
• Large calf muscles
• Muscle pain and stiffness
• Learning disabilities
• Delayed growth

Becker muscular dystrophy: Signs and symptoms are similar to those of Duchenne muscular dystrophy,but tend to be milder and progress more slowly.Symptoms generally being in the teens but might occur until the mid-20s or later.

Other types of muscular dystrophy:

• Myotonic: This is characterized by an inability to relax muscles following contractions.Facial and neck muscles are usually the first to be affected.People with this form typically have long,thin faces,drooping eyelids and swanlike necks.
• Facioscapulohumeral(FSHD):Muscle weakness typically begins in the face,hip and shoulders.The shoulder blades might stick out like wings when arms are raised.Onset usually occurs in the teenage years but can begin in childhood or as late as age 50
• Congenital: This type affects boys and girls and is apparent at birth or before age 2.Some forms progress slowly and cause only mild disability,while others progress rapidly and cause severe impairment.
• Limb- girdle: Hip and shoulder muscles are usually affected first.People with this type of muscular dystrophy might have difficulty lifting the front part of the foot and so might trip frequently.Onset usually begins in childhood or the teenage years.

Prognosis: There is no cure for muscular dystrophy.But medications and therapy can help manage symptoms and slow the course of the disease.