Muscular dystrophies Flashcards
What is muscular dystrophy?
An umbrella term for genetic conditions that cause gradual weakening and wasting of the muscles
What is Gower’s sign?
Seen when asking a child to stand from a lying position
Postive Gower’s - the child will walk their hands up their legs in order to reach standing
Positive Gower’s is indicative of proximal muscle weakness
What is the inheritance pattern of muscular dystrophy?
X-linked recessive
What is the most common form of muscular dystrophy?
Duchenne muscular dystrophy
What is the aetiology of duchenne muscular dystrophy?
The gene for dystrophin on the X (p21) chromosome is faulty
What is the aetiology of becker’s muscular dystrophy?
The dystrophin gene is also faulty, but is partially expressed, unlike in duchenne’s where it is virtually absent
What are the main presenting symptoms of duchenne muscular dystrophy?
Calf pseudohypertrophy
Progressive proximal muscle weakness
May have intellecutual impairment
Positive gower’s sign
When is the typical onset of duchenne muscular dystrophy?
3-5 years
When is the typical onset of Becker’s muscular dystrophy?
8-12 years
What are the symptoms of myotonic muscular dystrophy?
Progressive muscle weakness
Prolonged muscle contraction
Cataracts
Cardiac arrythmias
What is the gold standard investigation for duchenne and becker’s muscular dystrophy?
Genetic testing
What are the first line investigations for duchenne and becker’s muscular dystrophy?
Creatinine kinase
What is the management of muscular dystrophy?
Glucocorticoids (to slow progression of muscle weakness)
Physical therapy
Supportive care for respiratory and cardiac complications
Ventilation
Scoliosis surgery
Palliative care
Counselling
What are the complications of muscular dystrophy?
Dilated cardiomyopathy
Respiratory complications
Unable to walk - wheelchair bound
Survival until 25-30
