Pathoma - Skeletal Muscle/Neuromuscular Junction

Question 1

Dermatomyositis - what is it?

Answer 1

inflammatory condition of skin and skeletal muscle

Question 2

Dermatomyositis - etiology

Answer 2

unknown- some association with carcinoma

Question 3

Dermatomyositis - clinical presentation

Answer 3

bilateral proximal muscle weakness (can’t comb hair or climb stairs)
rash on eyelids
malar rash may be seen

Question 4

Dermatomyositis - Lab values

Answer 4

increased creatine kinase (CK)
+ ANA
+ anti-Jo1

Question 5

Dermatomyositis - treatment

Answer 5

corticosteroids

Question 6

Dermatomyositis - muscle biopsy

Answer 6

perimysial inflammation w. perifasicular atrophy

Question 7

Polymyositis - what is it?

Answer 7

inflammation of skeletal muscle (no skin involvement)

Question 8

Polymyositis - muscle biopsy

Answer 8

endomysial inflammation

Question 9

X-linked muscular dystrophy (Duchenne’s) - what is it?

Answer 9

degenerative disorder w/ muscle wasting

Question 10

X-linked (Duchenne’s) muscular dystrophy - cause

Answer 10

dystrophin deletion

Question 11

X-linked muscular dystrophy - clinical presentation

Answer 11

proximal muscle weakness at 1 year age
progresses distally
calf pseudohypertrophy

Question 12

X-linked muscular dystrophy - lab values

Answer 12

increased creatine kinase (CK)

Question 13

Becker muscular dystrophy - cause

Answer 13

dystrophin mutation

Question 14

Becker muscular dystrophy - clinical presentation

Answer 14

milder disease

presents later

Question 15

Myasthenia gravis - cause

Answer 15

autoAb’s against post-synaptic Ach receptors

Question 16

Myasthenia gravis - clinical presentation

Answer 16

women
worsens w/ use
ptosis
improves with anticholinesterase agents

Question 17

Myasthenia gravis - association

Answer 17

thymic hyperplasia or thymoma

Question 18

Lambert-Eaton syndrome - cause

Answer 18

autoAb’s against pre-synaptic Ca2+ channels (also impairs Ach release)

Question 19

Lambert Eaton - association

Answer 19

Paraneoplastic syndrome (small cell carcinoma most common)

Question 20

Lambert Eaton - clinical presentation

Answer 20

improves w/ use
eyes not affected
anticholisterase agents don’t help
improves w/ tumor removal