Facioscapulohumeral muscular dystrophy involves progressive muscle weakness and loss of muscle tissue. It primarily affects the face, shoulder, and upper arm muscles.
Causes, incidence, and risk factors
Facioscapulohumeral muscular dystrophy is a type of muscular dystrophy that affects the upper body, unlike some other types that affect primarily the lower body (including Duchenne muscular dystrophy and Becker muscular dystrophy). It is a genetic disorder with a autosomal dominant inheritance pattern. This means the disorder appears in both men and women and may develop in a child if either parent carries the gene for the disorder.
This disorder is extremely variable in the extent and severity of the symptoms, and in the age when symptoms appear. Symptoms often do not appear until ages 10 to 26, but it is not uncommon for symptoms to appear much later. In some cases, symptoms never develop.
Symptoms are usually mild and very slowly progressive. Facial muscle weakness is common. Shoulder muscle weakness causes deformities such as scapular winging and sloping shoulders. There is difficulty raising the arms because of shoulder and arm muscle weakness. Weakness of the lower legs is possible as the disorder progresses and can be severe enough to interfere with walking. Other body systems are usually not affected, and intellectual function is normal.
Facioscapulohumeral muscular dystrophy affects approximately 5 out of 100,000 people. It affects men and women equally.
- Facial muscle weakness o Eyelid drooping o Inability to whistle o Decreased facial expression o Depressed or angry facial expression o Difficulty pronouncing words
- Shoulder weakness o Difficulty working with the arms raised o Sloping shoulders o Pronounced shoulder blades (scapular winging)
- Hearing loss (rare)
- Abnormal heart rhythm (rare)
Signs and tests
A physical examination reveals weakness of the facial and shoulder muscles. Other body symptoms are rare. High blood pressure may occur but is usually mild.
- A serum creatine kinase test may be slightly elevated.
- An EMG (electromyography) may be nonspecific or may have mixed features of muscle and nerve involvement.
- A muscle biopsy may be nonspecific, or may confirm the diagnosis.
- A hearing test may indicate hearing loss
- An electrocardiogram (EKG) may indicate abnormal heart rhythm
- An eye exam may show changes in the blood vessels in the back of the eye.
There is no known cure for facioscapulohumeral muscular dystrophy. Treatment is aimed at control of the symptoms to maximize the quality of life. Activity is encouraged. Inactivity such as bedrest can worsen the muscle disease. Physical therapy may be helpful to maintain muscle strength.
Progressive disability occurs very slowly with facioscapulohumeral muscular dystrophy. The patient’s disability is often minor and life span is usually not affected.
- Permanent, progressive disability o Decreased mobility o Decreased ability to care for self
- Deformities of the face and shoulders
- Hearing loss
- Vision loss (rare)
Calling your health care provider
Call for an appointment with your health care provider if symptoms indicate facioscapulohumeral muscular dystrophy may be present.
Call for an appointment with your health care provider if you are planning a family and you, your spouse, or family members have been diagnosed with facioscapulohumeral muscular dystrophy.
Genetic counseling may be advised if there is a family history of facioscapulohumeral muscular dystrophy. Genetic counseling is advised for people with this disorder who plan to have children.
by David A. Scott, M.D.
All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.