Muscular dystrophy describes a group of genetic diseases that cause muscle weakness.
Each of the diseases that make up muscular dystrophy is progressive. This means these diseases get worse over time. In one of the most common forms of muscular dystrophy, there is a genetic defect in a certain muscle protein. The genetic defects that cause the other forms of muscular dystrophy are not as well understood.
All forms of muscular dystrophy generally have muscle weakness as the main symptom. The location of the weakness and other symptoms depend on the type of muscular dystrophy. Examples of other symptoms include: abnormal curvature of the spineabnormal heart functioninability to walkmental impairment such as low intelligencevision impairmenthearing impairment
The cause is genetic, meaning that these diseases are inherited from either one or both parents. The main risk of these conditions is that the muscles become too weak. The person may thus become unable to walk or even unable to breathe. Death occurs at a young age in many cases of muscular dystrophy.
Because this condition is genetic, nothing can be done to prevent it in an individual. Once parents have an affected child, they may want to seek genetic counseling to determine the risk of having another affected child.
The diagnosis is made through physical examination, blood tests, muscle-stimulation tests, and muscle biopsy. Muscle-stimulation tests, known as electromyography (EMG), use electrical shocks to cause muscle movement. This movement is abnormal in muscular dystrophy.
A muscle biopsy is a procedure in which a healthcare professional removes a tiny piece of a muscle with a special needle. This piece of muscle can be tested and looked at under the microscope to give a diagnosis.
Death at a young age occurs in many cases of muscular dystrophy. The person and his or her family must cope with a life-long disease that slowly gets worse.
This disease is not contagious, so there are no risks to others.
At this time, treatment cannot cure any of these diseases. Corticosteroid medications may slow the progression in some cases. Special braces for the arms or legs may allow a person to continue to be active for longer. Wheelchairs are often required later in the disease course. Surgery may help in some cases if the limbs become deformed. Special treatments may be required to support the person's respiration and circulation.
Corticosteroid medications have many side effects, including bone loss, weight gain, and depression. Surgery may be unsuccessful, or may be complicated by bleeding, infection, or an allergic reaction to the anesthetic.
These diseases virtually all get worse over time and current treatment does little to change this fact.
Symptoms are monitored periodically, as is the person's ability to carry out daily activities, such as walking.
Harrison's Principles of Internal Medicine, 1998, Fauci et al.
