Dystrophic Myopathies

Question 1

4 common dystrophic myopathies

Answer 1

1. Duchenne
2. Becker
3. Myotonic (steinert’s)
4. Fascioscapulohumeral

Question 2

2 most common dystrophic myopathies

Answer 2

1. Duchenne

2. Myotonic dystrophy (steinert’s)

Question 3

Genetics of the 4 dystrophic myopathies

Answer 3

Duchenne = x-linked recessive
Becker = x-linked recessive
Myotonic = autosomal dominant
FSH = autosomal dominant

Question 4

Which of the 4 dystrophic myopathies usually have adult onset

Answer 4

Becker

Question 5

Which dystrophic myopathy is severely progressive and death by 20s

Answer 5

Duchenne

Question 6

All 4 dystrophic myopathies cause proximal > distal muscle weakness, except which one

Answer 6

Myotonic dystrophy causes distal > proximal muscle weakness

Question 7

Which muscle undergoes contracture first in duchenne

Answer 7

IT band

Question 8

People with duchenne are wheelchair bound by how old

Answer 8

12

Question 9

What cardiovascular problem do people with beckers and DMD have?

Answer 9

cardiomyopathy

Question 10

Which dystrophic myopathy has hatchet face

Answer 10

Myotonic dystrophy

Question 11

What is hatchet face

Answer 11

wasting of temporalis and masseter

Question 12

muscle biopsies of beckers vs dmd vs fsh vs myotonic dystrophy

Answer 12

dmd = absent dystrophin
beckers = decreased dystrophin
fsh = muscle necrosis
myotinic dystrophy = type 1 fiber atrophy and type 2 hypertrophy

Question 13

SNAP findings of dystrophic myopathy

Answer 13

normal

Question 14

CMAP findings of dystrophic myopathy

Answer 14

decreased amplitude

Question 15

Which dystrophic myopathy has popeye arm

Answer 15

FSH

Question 16

1 muscle to test in FSH

Answer 16

tibialis anterior