What is Muscular Dystrophy?

Muscular dystrophy is a group of disorders that causes muscles to weaken and eventually, causes muscle loss. Muscular dystrophy is often referred to by the broad term “dystrophy". Dystrophy is a condition of different inherited muscle diseases that have common features and progressive muscular weakness.  The dystrophy part of the name concerns the abnormal physical structure and physical changes that occur in the muscles, leading to progressive replacement of muscle by fibrous tissues. Muscles may shrink (become atrophic) or enlarge (become hypertrophic), though since this enlargement is not related to increase in working muscle, it is often called pseudohypertrophy, or false hypertrophy.

Muscular dystrophy is caused by a malfunction in the genes that cause problems with the production of proteins that are needed to form healthy muscle. Specific types of muscular dystrophy will affect different collections of muscles, which might include the speaking and swallowing muscles, facial muscles, neck, arms, legs or even the breathing muscle.

Baptist Health is known for advanced, superior care of patients with muscle disease and the diagnosis, management and treatment of muscular dystrophy. The Muscular Dystrophy Association clinic meets at Baptist Health on selected Tuesdays of each month, making neuromuscular disease specialists, therapists and social workers available for patients.

You will appreciate timely appointments and a professional, friendly atmosphere where we take time to listen to your concerns. At Baptist Health, you have access to the region’s most comprehensive, multidisciplinary team of specialists and innovative therapies, including many available only through specialized clinical trials. In every way, we work to demonstrate the utmost in excellent care to those who trust us with their health.

Types of Muscular Dystrophy

Some types of muscular dystrophy can be hereditary. Muscular dystrophy types include:

• Duchenne muscular dystrophy: Most common form of muscular dystrophy, affecting boys and rarely girls. Symptoms typically appear between ages 2 and 3. This leads to a typical progression with loss of the ability to walk, mostly commonly in the teenage years. The heart muscle may also be affected, and the most serious and life-threatening aspect is the development of weakness of breathing muscles.
• Becker muscular dystrophy: A less severe form of Duchenne muscular dystrophy, with symptoms beginning in the late teens or early adulthood. Becker muscular dystrophy is caused by a partial abnormality of the same gene that causes Duchenne dystrophy, and thus is a milder muscle disease, usually diagnosed at a later age, with slower progression and a much longer period of continued ability to walk.
• Myotonic muscular dystrophy: Can develop in anyone and at any age, typically first affecting facial and neck muscles. This is a very common genetic muscle disease, with symptoms of both muscle cramping (myotonia) and looseness of muscles (hypotonia), with variable yet progressive weakness. When severe, it may be diagnosed at birth, but most patients are diagnosed in childhood or adult life. Often, it may be diagnosed in an adult only after it has been diagnosed in some other family member. There are a wide range of muscles which can be affected in myotonic dystrophy, including the face, mouth, arms and legs, but also the heart muscle and even stomach and intestinal muscles. Life-threatening cardiac rhythm problems can also occur.
• Facioscapulohumeral muscular dystrophy (FSH, FSHD): Facioscapulohumeral muscular dystrophy is slow-progressing and typically not life-threatening. Typically occurs from late teen years to age 40 and first affects the face and shoulders. FSH dystrophy may affect the arms and legs in general, yet typically shows its first evidence or is most severe in the face (facio), shoulders (scapulo), and upper arms (humeral) muscles. Some patients can be severely affected and lose the ability to walk, but most do not.
• Limb-girdle muscular dystrophy (LGMD): Develops in late childhood/ early adulthood and first affects the muscles in the hip and shoulder. Limb-girdle dystrophy has long been known as a large collection of different specific muscular dystrophies. Therefore, one person with LGMD may be quite different from another, even though within a family it looks much the same. It can begin and be diagnosed at any age because of its variability from one type to another. Whenever possible, we try to identify the specific genetic type of LGMD since if and when treatment becomes available, it will likely be targeted at the specific type of disease.
• Oculopharyngeal muscular dystrophy: Develops slowly in men and women after the age of 40, causing weakness in the eye (oculo), throat (pharyngeal) and face muscles. Notable weakness in the eye or throat is evident even when mild or early in its course.
• Emery-Dreifuss muscular dystrophy: Develops in males in late childhood/ early adulthood, causing weakness in the upper arms, shoulder and lower legs.
• Distal muscular dystrophy: Develops slowly in men and women, causing weakness in the lower legs, feet, forearms, and hands.

Signs and Symptoms of Muscular Dystrophy

The main sign of muscular dystrophy is progressive muscle weakness. Depending on the type of condition, muscular dystrophy symptoms can include:

• Trouble walking, standing or getting out of a chair
• Muscle spasms or cramps
• Balance problems
• Loss of reflexes
• Curvature of the spine
• Problems breathing or swallowing
• Heart and breathing muscle weakness
• Drooping facial muscles

Muscular Dystrophy Diagnosis

To determine if a person has muscular dystrophy, a physician will evaluate a person for symptoms, perform a physical examination, and take a medical and family history. We then use advanced diagnostic procedures and technology to effectively diagnose, inform treatment and carefully monitor the condition. Diagnostic procedures can include:

• Blood tests: These look for certain enzymes that indicate muscle damage, and help to rule out other conditions.
• Electrocardiogram (EKG) – This test measures the electrical activity of the heart and can help determines if parts of the heart are enlarged, overworked or damaged. The heart’s electrical currents are detected by 12 to 15 electrodes that are attached to the arms, legs and chest via sticky tape.
• Electromyography (EMG):  This test measures the electrical activity of a muscle in response to stimulation or as the muscle is used, as well as the nature and speed of the conduction of electrical impulses along a nerve. It can confirm the presence of nerve damage and assess its severity.
• Genetic testing: In this test, a small sample of blood or muscle tissue is analyzed to determine if the genetic marker for muscular dystrophy is present.
• Lung function tests: In these tests, a person blows into or exhales into a mouthpiece connected to a special instrument called a spirometer. The spirometer measures how well the lungs work.
• Muscle biopsy: In this test, a minor procedure is done to collect a small piece of muscle tissue that is examined for indications of muscular dystrophy.

Muscular Dystrophy Causes

Muscular dystrophy is a genetic condition that is hereditary.

Risk Factors

Family history is the only risk factor associated with muscular dystrophy. Individuals with a family history are at higher risk of developing muscular dystrophy or passing it on to their children.

Prevention

Muscular dystrophy is hereditary, therefore it cannot be prevented. If someone knows they have a family history of muscular dystrophy, genetic testing can help in some cases to provide information to understand if they are at risk of having a child with the condition.

Muscular Dystrophy Prognosis

Prognosis for people with muscular dystrophy depends upon the type of condition and the person’s overall health. Some forms of muscular dystrophy affect the heart and lungs, which limits lifespan. Other forms do not limit life expectancy. Some forms lead to serious physical disabilities requiring canes, walkers or wheelchairs. Milder forms can be less disabling.

Treatment and Recovery

Treatment for the symptoms of muscular dystrophy depends upon the type of condition, the person’s age and health. Treatments for symptoms may include:

• Mobility Assistance: Therapies, special exercise routines and physical aids such as splints, walkers or canes can help with mobility. Rehabilitation Medicine specialists, also known as Physiatrists, are often involved to maximize a patient’s treatment and function.
• Medications: On occasion, certain medications can improve muscle strength, slow deterioration and treat pain.
• Surgical Procedures: Occasionally, surgery may be needed to reduce muscle tightness or correct bone abnormalities.
• Complications: Muscular dystrophy can cause complications including:
• Contracture: This shortening of muscle tissue due to severe tightening of the muscle can inhibit bone growth, cause bones to bend and lead to joint deformities and dislocations.
• Inability to walk: Muscular dystrophy often weakens muscles to the point that a person can no longer walk.
• Breathing problems: The diaphragm and other breathing muscles around the lungs may be affected.
• Spine problems: The weakened muscles around the spine may not be able to hold the spine in the correct position, resulting in a curve.
• Heart problems: The condition can cause heart weakness and certain heartbeat irregularities.
• Swallowing problems: Muscles involved with swallowing may be affected.