3.5, 3.6 Muscle Pathology

Question 1

disease of the anterior horn cell or its axon

Answer 1

individual atrophic angular fibers

Question 2

• humorally mediated microangiopathy with ischemic necrosis of muscle fibers
• rash + proximal weakness
• complement deposition: capillaries

Answer 2

dermatomyositis

Question 3

dermatomyositis has perivascular inflammation of the __________, is associated with cancer, and treatment is ___________

Answer 3

perimysium, immunosuppression

Question 4

• lack of skin involvement
• proximal weakness
• CK elevation, cell mediated injury

Answer 4

polymyositis

Question 5

polymyositis is an ___________ process and treament is ____________

Answer 5

endomysial, immunosuppression

Question 6

• progressive age related muscle disorder
• quads, wrist, finger flexors involved early
• distal, asymmetric weakness

Answer 6

inclusion body myositis

Question 7

inclusion body myositis is resistant to ______________

Answer 7

steroid therapy

Question 8

• inflammtion, fibrosis, intracytplasmic vacuoles surrounded by basophilic granules
• ragged red fibers: mitochondrial proliferation

Answer 8

inclusion body myositis

Question 9

IBM inclusions stain positive for ___________ and have ______ aggregates, implicating defective degradation of misfolded proteins

Answer 9

Congo red (amyloid), protein

Question 10

X linked mutation resulting in dystrophin loss

Answer 10

muscular dystrophies

Question 11

• pelvic girdle weakness
• pseudohypertrophy of calf muscles
• initial CK increase, later decrease

Answer 11

muscular dystrophies

Question 12

dystrophin is a rod-shaped _______ protein that connects ________ of a muscle fiber to surrounding ___________

Answer 12

cytoplasmic, cytoskeleton, extracellular matrix

Question 13

• rod shaped structures in muscle fibers
• proximal weakness
• floppy infant with facial and respiratory weakness
• treatment is supportive care

Answer 13

nemaline myopathy

Question 14

• congenital myopathy with areas in muscle fibers lacking oxidative enzyme activity
• infancy or childhood
• skeletal abnormalities

Answer 14

central core disease

Question 15

central core disease is highly associated with ___________

Answer 15

malignant hyperthermia

Question 16

• young adult with recurrent myoglobinuria precipitated by exercise
• CK elevated only during attacks, muscle normal between attacks
• avoid renal failure, IV glucose for exercise tolerance

Answer 16

carnitine palmitoyltransferase II deficiency

Question 17

• glycogenesis type V
• pain, stiffness, cramps after exercise
• “second wind” phenomenon

Answer 17

McArdle’s Disease

Question 18

• aquired AI disease of post synaptic neuromuscular junction involving young women and older men
• ptosis (droopy eyelid)
• acetylcholine receptor antibodies
• thymic hyperplasia and thymoma common

Answer 18

myasthenia gravis

Question 19

treatment for myasthenia gravis?

Answer 19

cholinesterase inhibitors, thymoma, immunosuppression