What Are the Complications of Duchenne Muscular Dystrophy?

Patient Presentation
A 17-year-old male with Duchenne muscular dystrophy (DMD) came to the intensive care unit intubated after nephrolithotripsy and surgical evacuation of ureteral stones bilaterally.
The patient had increasing renal colic and with conservative management did not improve.
The past medical history showed that he was diagnosed as a preschooler when he was noted to have muscle weakness.
He became non-ambulatory at age 11. He currently uses a mechanized wheelchair. He had a history of a single urinary stone that was treated conservatively 1 year previously.
The family history was negative for neuromuscular or genetic disease.
The pertinent physical exam showed an intubated male who was awakening after anesthesia.
His face was symmetric with brisk pupillary reflexes.
Heart examination revealed a regular rate and rhythm without murmurs.
He had significant weakness of all extremities (2/5).
He had contractures of elbows, wrists, knees and ankles and moderate right thoracolumbar scoliosis.
A foley catheter was in place with light pink urine.
The diagnosis of ureteral stone extraction and DMD were made.
The patient’s clinical course improved over next day allowing him to be extubated and later transferred to the regular inpatient floor.
He remained on his home respiratory regiment of BiPAP (bilateral positive airway pressure) at night.
He went home on day 3 post-operatively and was to followup with urology in one week.
The laboratory evaluation of the renal caliculi showed them to be calcium oxalate.

Duchenne muscular dystrophy is a progressive, muscle-wasting, lethal disease that affects about 1 in 3500 boys.
It is an X-linked recessive disorder with ~1/3 of patients having a spontaneous mutation.
The genetic abnormality causes an absence or marked deficiency in the quantity of dystrophin protein in muscles.
Muscle cells without dystrophin are more easily damaged during contraction with muscle inflammation, necrosis and fibrosis occurring.
Patients classically have proximal muscle weakness (neck flexor, anterior abdominal, hip and shoulder girdle muscles) that presents usually by late preschool/early school-age. This is associated with a greatly elevated muscle creatinine phosphokinase level.
Over ime, patients become weaker and lose the ability to ambulate between 7-12 years of age typically. Early death in the teens and early 20s is usually due to complications of respiratory insufficiency secondary to muscle weakness.

Prednisone and Deflazacort (a corticosteroid similar to prednisone) have been shown to improve muscle strength and function and are recommended for treatment. Their mechanism of action is as an immunosuppressant.
Prednison or Deflazacort are recommended to start before symptoms and usually are begun in the preschool period. They are stopped based upon patient respone and side effect profile.
Other treatments being evaluated include methods to increase protein synthesis, decrease proteolysis, decrease the inflammatory response, and methods to increase muscle proliferation and regeneration.
Ultimately, gene therapy may be the answer to long-term cure.

Learning Point
Common complications in patients with DMD include:

  • Cardiac
    • Arrhythmias
    • Cardiomyopathy
  • Orthopaedic problems
    • Joint contractures
    • Osteopenia – because of immobility but also secondary to steroid treatment
    • Scoliosis
  • Infectious
    • Pulmonary infections
  • Pulmonary
    • Respiratory insufficiency with decreased total lung capacity, decreased residual lung volume
  • Steroid treatment problems
    • Behavioral changes
    • Bone demineralization
    • Cushingoid appearance
    • Growth suppression
    • Hirsutism
    • Weight gain
  • Miscellaneous
    • Aspartate aminotransferase (AST) elevation
    • Mental retardation
    • Renal stones secondary to bone demineralization

Questions for Further Discussion
1. What other congenital myopathies are in the differential diagnosis of DMD?
2. What resources are available for families with chronic diseases in my local community?
3. When is mechanical ventilation appropriate for patients with DMD?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for this topic: Muscular Dystrophy

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

Roland EH.
Muscular dystrophy.
Pediatr Rev. 2000 Jul;21(7):233-7.

Tidball JG, Wehling-Henricks M.
Evolving therapeutic strategies for Duchenne muscular dystrophy: targeting downstream events.
Pediatr Res. 2004 Dec;56(6):831-41.

Moxley RT 3rd, Ashwal S, Pandya S, Connolly A, Florence J, Mathews K, Baumbach L, McDonald C, Sussman M, Wade C. Quality Standards Subcommittee of the American Academy of Neurology; Practice Committee of the Child Neurology Society.
Practice parameter: corticosteroid treatment of Duchenne dystrophy: report of the Quality Standards Subcommittee of the American Academy of Neurology and the Practice Committee of the Child Neurology Society.
Neurology. 2005 Jan 11;64(1):13-20.

ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    4. Patient management plans are developed and carried out.
    7. All medical and invasive procedures considered essential for the area of practice are competently performed.
    8. Health care services aimed at preventing health problems or maintaining health are provided.
    9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Systems Based Practice
    24. Cost-effective health care and resource allocation that does not compromise quality of care is practiced.
    25. Quality patient care and assisting patients in dealing with system complexities is advocated.

    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital

    October 27, 2008