What is the management approach for Duchenne Muscular Dystrophy (DMD)?

Management Approach for Duchenne Muscular Dystrophy (DMD)

The management of Duchenne Muscular Dystrophy requires a comprehensive multidisciplinary approach with glucocorticoid therapy as the pharmacological cornerstone, alongside coordinated specialty care addressing respiratory, cardiac, orthopedic, rehabilitative, nutritional, and psychosocial needs. 1

Diagnosis and Initial Assessment

• Suspect DMD in male children with abnormal muscle function, increased serum creatine kinase, or unexplained elevated transaminases 1
• Confirm diagnosis through genetic testing for dystrophin mutations (deletions, duplications, point mutations) 1
• If genetic testing is inconclusive, muscle biopsy showing absence of dystrophin protein may be necessary 1
• Full characterization of the mutation is essential for genetic counseling and consideration of mutation-specific therapies 1

Pharmacological Management

Glucocorticoid Therapy

• Initiate glucocorticoid therapy as the primary pharmacological intervention to slow disease progression 2, 1
• Deflazacort is FDA-approved for DMD treatment in patients 5 years and older at a recommended dose of 0.9 mg/kg/day 3
• Prednisone/prednisolone is an alternative at 0.75 mg/kg/day (maximum 40 mg/day) 2, 4
• Glucocorticoids slow decline in muscle strength and function, reduce risk of scoliosis, and stabilize pulmonary and possibly cardiac function 2
• Monitor for side effects including weight gain, Cushingoid appearance, increased appetite, behavioral changes, and decreased bone density 3

Specialty Care Components

Neuromuscular Management

• Perform regular assessments (at least every 6 months) of function, strength, and range of movement 2, 1
• Use standardized testing methods including manual muscle testing, goniometry, and timed function tests to track progression 1
• Ensure immunization schedule is complete 2

Rehabilitation Management

• Implement preventive measures to maintain muscle extensibility and minimize contractures 2, 1
• Encourage appropriate exercise and activity based on disease stage 2, 1
• Provide adaptive devices as needed to support function and participation 2, 1
• Schedule specialist physical and occupational therapy assessments every 4 months 2

Respiratory Management

• Monitor respiratory function regularly with pulmonary function tests 1
• Implement airway clearance techniques and respiratory support as needed 1
• Screen for sleep-disordered breathing, particularly as disease progresses 1
• Consider preoperative evaluation by pulmonologist before any surgical procedures 1

Cardiac Management

• Perform echocardiogram at diagnosis or by age 6 years 2, 1
• Schedule cardiac evaluations every 24 months until age 10, then annually thereafter 2, 1
• Initiate standard heart failure interventions (ACE inhibitors, beta-blockers) with deterioration of function, even if asymptomatic 2, 1

Orthopedic Management

• Monitor for development of scoliosis, particularly after loss of ambulation 1
• Consider surgical intervention for scoliosis when Cobb angle reaches 30-50 degrees 1
• Evaluate for joint contractures, particularly in lower extremities (hip, knee, ankle) 1
• Consider surgical options for tendo-Achilles contractures in specific situations 2, 1

Nutritional and GI Management

• Monitor for normal weight gain appropriate for age 2, 1
• Perform nutritional assessments for both overweight and underweight concerns 2, 1
• Evaluate for possible dysphagia, particularly in advanced stages 2, 1

Psychosocial Management

• Provide family support and early assessment/intervention for development, learning, and behavior 2, 1
• Conduct comprehensive neurocognitive assessment at diagnosis and before entering formal schooling 2, 1
• Screen for autism spectrum disorders, speech/language delays, and other neurodevelopmental issues 1
• Promote independence and social development appropriate to disease stage 2, 1
• Plan for transition to adult services as the patient ages 2, 1

Disease Stage-Specific Considerations

Ambulatory Stage

• Focus on preserving muscle function and delaying progression with glucocorticoids 2
• Implement physical therapy with emphasis on stretching to prevent contractures 2, 4
• Monitor for side effects of glucocorticoid therapy 3
• Use functional assessments like timed 10m walk, Gowers' maneuver, and time to climb stairs 2

Transition to Non-Ambulatory Stage

• Shift management focus to cardiac, respiratory, orthopedic, nutritional needs, and upper limb function 5
• Intensify monitoring for scoliosis development 1
• Evaluate need for adaptive equipment and environmental modifications 2
• Continue glucocorticoid therapy as it provides benefits even after loss of ambulation 2

Advanced Stage

• Implement respiratory support including assistive cough devices and non-invasive ventilation 4
• Manage cardiac dysfunction with appropriate medications 2, 1
• Provide palliative care for pain management and emotional/spiritual support 2
• Consider hospice care for end-stage patients 2

Special Considerations

• Avoid chiropractic manipulation due to risks associated with joint instability and progressive scoliosis 1
• Optimize cardiac, nutritional, and respiratory status before any surgical procedures 1
• Provide genetic counseling for at-risk female family members 1
• Do not administer live or live-attenuated vaccines to patients on immunosuppressive doses of glucocorticoids 3
• Monitor for behavioral and mood disturbances including euphoria, insomnia, mood swings, and depression 3

Emerging Therapies

• Gene transfer therapy using adeno-associated virus vectors is being investigated 6
• Exon skipping agents are available for specific mutations and produce a smaller but partially functional dystrophin protein 6
• Vascular-targeted therapies focusing on nitric oxide and vascular endothelial growth factor pathways are under investigation 7