Duchenne's muscular dystrophy

Alternative names:

muscular dystrophy - Duchenne's; pseudohypertrophic muscular dystrophy

Symptoms:

• muscle weakness
  • rapidly progressive
  • frequent falls
  • difficulty with muscle skills (running, hopping, jumping)

• progressive difficulty walking
  • ability to walk may be lost by age 12

• fatigue
• intellectual retardation (possible)
• skeletal deformities
  • chest and back (scoliosis)

• muscle deformities
  • contractures of heels, legs
  • pseudohypertrophy of calf muscles

Signs and tests:

Muscle wasting (atrophy) begins in the legs and pelvis, then progresses to the muscles of the shoulders and neck, followed by loss of arm muscles and respiratory muscles. Calf muscle enlargement (pseudohypertrophy) is quite obvious. Cardiomyopathy is commonly present but signs of congestive heart failure or arrhythmias (irregular heartbeats) are rare. Respiratory disorders are common during the later stages, including pneumonia and aspiration of food or fluid into the lungs.

• A serum CPK is highly elevated.
• An EMG (electromyography) shows that weakness is caused by destruction of muscle tissue rather than nerve damage.
• A muscle biopsy confirms the diagnosis.