Muscular Dystrophy Flashcards
What is muscular dystrophy?
Muscular dystrophy is a group of genetic disorders characterised by progressive muscle weakness and degeneration.
What causes muscular dystrophy?
Mutations in genes responsible for producing proteins essential for healthy muscle function.
What are the most common types of muscular dystrophy?
Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD), and myotonic dystrophy.
What is Duchenne muscular dystrophy (DMD)?
DMD is an X-linked recessive disorder caused by mutations in the dystrophin gene, leading to severe muscle weakness.
What is Becker muscular dystrophy (BMD)?
BMD is a milder form of dystrophin-related muscular dystrophy with a later onset and slower progression compared to DMD.
What is the function of dystrophin?
Dystrophin provides structural support to muscle fibres, linking the cytoskeleton to the extracellular matrix.
What are the initial symptoms of Duchenne muscular dystrophy?
Delayed motor milestones, difficulty walking, frequent falls, and calf pseudohypertrophy.
At what age do symptoms of Duchenne muscular dystrophy typically present?
Symptoms usually appear between 2 and 5 years of age.
What is calf pseudohypertrophy in muscular dystrophy?
Enlargement of the calf muscles due to fat and connective tissue replacing muscle fibres.
What is Gower’s sign?
A clinical sign where a child uses their hands to “climb up” their legs to stand, indicative of proximal muscle weakness.
What are the complications of Duchenne muscular dystrophy?
Respiratory failure, cardiomyopathy, scoliosis, and joint contractures.
How is muscular dystrophy inherited?
Most forms, including DMD and BMD, are inherited in an X-linked recessive pattern.
What investigations are used to diagnose muscular dystrophy?
Serum creatine kinase (CK), genetic testing, muscle biopsy, and electromyography (EMG).
What is the role of creatine kinase (CK) testing in muscular dystrophy?
Elevated CK levels indicate muscle damage and are a hallmark of muscular dystrophy.
How is genetic testing used in muscular dystrophy?
It identifies mutations in specific genes, such as the dystrophin gene in DMD and BMD.
What imaging techniques can support muscular dystrophy diagnosis?
MRI and ultrasound can assess muscle structure and detect fatty replacement of muscle tissue.
What is the mainstay of treatment for muscular dystrophy?
Supportive care, including physiotherapy, corticosteroids, respiratory support, and management of complications.
What is the role of corticosteroids in muscular dystrophy?
Corticosteroids (e.g., prednisolone) help slow disease progression and preserve muscle strength.
What surgical interventions may be needed in muscular dystrophy?
Surgery to correct scoliosis, release joint contractures, or manage cardiac complications.
What is the prognosis for Duchenne muscular dystrophy?
Life expectancy is reduced, with most patients living into their late teens or early twenties without advanced care.
How does Becker muscular dystrophy differ in prognosis from Duchenne muscular dystrophy?
BMD has a slower progression and milder symptoms, with many patients living into middle or late adulthood.
What are the respiratory complications of muscular dystrophy?
Weakness of respiratory muscles can lead to hypoventilation, chest infections, and respiratory failure.
What cardiac issues are associated with muscular dystrophy?
Cardiomyopathy and arrhythmias are common, particularly in DMD and BMD.
What are the goals of physiotherapy in muscular dystrophy management?
To maintain mobility, prevent contractures, and improve quality of life.
What psychological support is essential for patients with muscular dystrophy?
Counseling and support groups can help manage the emotional impact of a chronic, progressive condition.
