Facioscapulohumeral Muscular Dystrophy

September 14, 2005
Donald J. Kovacs, MD
Donald J. Kovacs, MD

Proximal bilateral upper extremity weakness had slowly progressed in a 34-year-old woman until she could no longer raise her arms above her shoulders. She first noticed the weakness at age 18; previously, she had been active in sports and her development had been normal.

Proximal bilateral upper extremity weakness had slowly progressed in a 34-year-old woman until she could no longer raise her arms above her shoulders. She first noticed the weakness at age 18; previously, she had been active in sports and her development had been normal.

The patient also described difficulty in going up and down stairs and in rising from a squatting position. However, the weakness in her legs was not as severe as that in her arms. Limb-girdle muscular dystrophy had been diagnosed in her half-brother (same father).

The patient complained of considerable pain, especially in her shoulders and hips. Winging of the scapulae and bilateral foot drop were prominent. Moderate weakness of eye closure and a weak smile were apparent.

The creatine kinase level was 408 U/L. An electromyogram (EMG) revealed an abnormal myopathic process; moderate myopathic changes were seen in the muscle biopsy.1

Dr Donald J. Kovacs of Boiling Springs, Pa, diagnosed facioscapulohumeral (FSH) muscular dystrophy, an autosomal dominant disorder. Elevated creatine kinase levels and abnormal EMG and biopsy findings confirm the diagnosis of muscular dystrophy but do not identify the type. Physical findings in patients with FSH dystrophy are fairly specific; the earliest and most severe weakness occurs in the facial and shoulder girdle muscles. Because both lips protrude, the mouth is rounded and appears puckered. Scapular winging is prominent, even in infants. The biceps and triceps muscles become weak, and the hip girdles and thighs also weaken and eventually atrophy; Gowers sign-the need to use the hands to climb up the legs to assume a standing position-appears.2

Four criteria for FSH muscular dystrophy have been suggested: onset in facial and shoulder muscles with sparing of extraocular, pharyngeal, lingual, and cardiac muscles; autosomal dominant inheritance pattern; facial weakness in half or more of affected family members; and myopathic changes on EMG with biopsy findings of variation in fiber diameter, centrally located nuclei, and “moth-eaten” fibers.3

The prognosis for patients with FSH dystrophy is good; life span is not significantly decreased.3 Unlike patients with Duchenne, Becker, or Emery-Dreifuss muscular dystrophies, those with FSH or limb-girdle dystrophy usually have no cardiac involvement.4 However, progressive weakness does occur over time; approximately 20% of patients need to use a wheelchair.1 Sensorineural hearing loss and retinal telangiectasis and chronic, progressive exudative retinopathy (Coats disease) are associated with one form of FSH dystrophy.1 Early photocoagulation of retinal abnormalities is recommended.3

While there is no definitive treatment for FSH dystrophy, physical and occupational therapies can help patients maintain function.

REFERENCES:1. Cecil RL, Goldman L, Bennett JC. Cecil Textbook of Medicine. 21st ed. Philadelphia: WB Saunders Company; 2000:2209.
2. Behrman RE, Kliegman R, Jenson HB, eds. Nelson Textbook of Pediatrics. 16th ed. Philadelphia: WB Saunders Company; 2000:1880.
3. Goetz CG, Pappert EJ, eds. Textbook of Clinical Neurology. Philadelphia: WB Saunders Company; 1999:706.
4. Griffith HW. Griffith's 5-Minute Clinical Consult. Baltimore: Williams & Wilkins; 2001:710.