Muscular Dystrophy Flashcards Preview

Foundations II Exam 4 (Jess) > Muscular Dystrophy > Flashcards

Flashcards in Muscular Dystrophy Deck (12):
1

What are muscular dystrophy disorders?

genetic defects that impair normal muscle fxn

2

How is DMD inherited?

2/3 are inherited from mother carrying genetic mutation on X chromosome
(1/3 spontaneous)

3

What is the mutation involved in DMD?
BMD?

DMD= Xp21 position -> loss of functional expression

BMD= Xp21 -> reduced functional expression

4

What is the patho in muscular dystrophy?

Mutation ->
ongoing degeneration & regeneration of muscle fibers->
progressive breakdown of affected muscle

(starts as muscle hypertrophy, after years has atrophy)

5

What are clinical manifestation of DMD?

-growth delay in 1st year of life
-cognitive impairment
-clinical onset of weakness begins 2-3 years old
-lower extremities before upper

6

What is Gower's sign, DMD?

using hand to support when arising from the ground (because legs are affected before upper extremities)

7

How is respiratory fxn affected in DMD? What is needed?

scoliosis
gradual weakening of respiratory muscles

ventilator support by 25 years old

8

How is the cardiac sx involved in DMD?

-primary dilated cardiomyopathy
-conduction abnormalities

9

How does BMD compare to DMD?

BMD:
-growth delay is uncommon
-cognitive impairment is uncommon
-muscle involvement later in life (common to retain strength, contracture are less common)
-Cardiac involvement MORE predominant
-Less respiratory involvement

10

What unexplained labs might you see in a pt w/ muscular dystrophy?

AST and ALT

11

Dx studies for muscular dystrophy

-Serum creatine kinase
(DMD 50-100x nl, BMD 5x nl)
-genetic testing for Xp21 mutation

Others:
-EMG
-Muscle biopsy

12

Tx of DMD and BMD

Prednisone 0.75 mg/kg once daily or on alternate days (can delay wheel chair dependence)