MSK path III

Question 1

polymyositis

Answer 1

adult onset inflammatory myopathy that shares myalgia and weakness with dermatomyositis but lacks cutaneous features

Question 2

mononuclear inflammatory cells in endomysial location

Answer 2

polymyositis

Question 3

CD68

Answer 3

macrophages

Question 4

inclusion body myositis

Answer 4

late adulthood >50 years old

Question 5

most common inflammatory myopathy in adults >65 y.o

Answer 5

inclusion body myositis

Question 6

presentation inclusion body myositis

Answer 6

slowly progressive muscle weakness that tends to be most severe in quads and distal Upper extremity muscles

Question 7

trichrome stain

nuclei in center of muscle cells and myofibers have rimmed vacuoles

Answer 7

polymyositis

Question 8

Main Tx for inflammatory myopathies

Answer 8

corticosteroids

Question 9

steroid R disease of inflammatory myopathies

Tx?

Answer 9

azathioprine, MTX, IV Ig, cyclophosphamide, cyclosprine, rituximab

Question 10

will Tx work for inclusion body myositis

Answer 10

responds poorly

Question 11

most common complication statins

Answer 11

myopathy

Question 12

thyrotoxic myopathy

Answer 12

acute or chronic proximal muscle weakness, precedes other Sx hyperthyroidism

Question 13

Bindge drinking can cause what myopathies

Answer 13

rhabdomyolysis, myoglobinuria and renal failure

Question 14

what type of atrophy does alcohol cause in muscle

Answer 14

type II atrophy

Question 15

chromosome 19q13.1 assoc with what gene

inheritance

Answer 15

RYR1- autosomal dominant

Question 16

clinical findings of mutation in RYR 1

Answer 16

floppy infant
scoliosis, hip dislocation, foot deformities,
malignant hyperthermia!!!

Question 17

muscle cells show cytoplasmic cores with central zones of abnormal sarcomeres and decreased mitochondria thorughout

Answer 17

RYR1 mutation

“central core disease”

Question 18

What is NEM

Answer 18

nemaline myopathy

Question 19

presentaiton NEM

Answer 19

weakness, hypotonia

floppy infant

Question 20

histo NEM

Answer 20

spindle shaped particles in type I fibers

gomori stain is best

Question 21

clinical findings centronuclear myopathy

Answer 21

floppy infant
poor prognosis in X linked form
weakness and hypotonia

Question 22

histo centronuclear myopathy

Answer 22

nuclei in center of myofiber especially type I

Question 23

mutation in centronuclear myopathy

Answer 23

XL- myotubularin gene MTM1

CNM2 gene

Question 24

progressive muscle damage that manifests between childhood and adulthood

Answer 24

muscular dystrophies

Question 25

most common muscular dystrophies have what inheritance and what is dysfucntional

Answer 25

X linked

mutation in dystrophin

Question 26

syndromes from loss of function in dystrophin gene on X chromosome

Answer 26

duchenne and becker

Question 27

when are duchenne and becker usually Dx

Answer 27

around a year because slow at walking

Question 28

what does dystrophin do

Answer 28

linkts actin to syntrophins

raltionship between cell membranes and proteins

Question 29

Bx in young boy mm show segmental myofiber degeneration and regeneration with atrophic myofibers
no inflammation
some fat infiltration

Answer 29

beckers or duchenne

Question 30

absent normal sarcolemmal staining on immunohistochem

Answer 30

duchenne

Question 31

reduced sarcolemmal staining on immunohistochem

Answer 31

becker

Question 32

what is pseudohypertorphy

Answer 32

when because losing some muscle fibers the others try to compensate and grow big. look like have big muscles, but lots is fat

Question 33

which muscular dystrophy still has some dystrophin

Answer 33

becker

Question 34

sequelae of muscular dystrophy

Answer 34

joint contractures, scoliosis, worsening respiratory reserve, sleep hypoventilation

Question 35

serum CK MM in dystrophy

Answer 35

elevated in first decade

then falls as disease progresses

Question 36

what confirms muscular dystrophy

Answer 36

genetic studies

Question 37

inheritance of myotonic dystrophy

Answer 37

auto dominant

Question 38

myotonic dystrophy is associated with what other system disorders

Answer 38

skel mm weakness, cataracts, endocrinopathy and cardiomyopathy

Question 39

what is myotonia

Answer 39

sustained involuntary contraction of muscles

Question 40

what causes myotonic dystrophy

Answer 40

expansions CTG triplet repeats at 3’ noncoding region of myotonic dystrophy protein kinase

Question 41

what muscular dystrophy has mutations that encode nuclear lamina proteins

Answer 41

emery dreifuss muscular dystrophy

Question 42

presentation of decrease in lipid or glycogen metabolism

Answer 42

msucle cramping and pain when exercise or fasting
or
slow progressive muscle damage without episodic manifestations

Question 43

What is McArdles disease

Answer 43

cannot breakdown sugars

Question 44

ragged red fibers

Answer 44

mitochondrial deficiency

Question 45

phonogrpah record appearance of mitochonria

Answer 45

mitochondrial abnormality

Question 46

myopathies from mitochondrial problems

Answer 46

elevated CK
rhabdomyolysis
weakness

Question 47

what is spinal muscular atrophy

Answer 47

loss of motor neurons which leads to muscle weakness and atrophy

Question 48

presentation spinal muscular atrophy

Answer 48

floppy infant

Question 49

Sx of ion channel myopathy

Answer 49

elevated, depressed or normal serum K levels

“hyperkalmic, hypokalemic and normokalemic periodic paralysis”

Question 50

malignant hyperthermia

Answer 50

hypermetabolic state: tachycardia, tachypnea, muscle spasms and hyperpyrexia

Question 51

most common trigger for malignant hyperthermia

Answer 51

halogenated inhalaltional agents and succinylcholine

Question 52

CD cells involved in polymyositis

Answer 52

CD8