Myositis

Question 0

myositis is NOT to be confused with

Answer 0

myopathy

Question 1

categories of myositis/myopathies

Answer 1

1) myositis
2) rhabdo
3) drug-induced myopathy
4) metabolic myopathy

Question 2

different types of mypotis

Answer 2

polymyositis
dermatomyositis
inclusion body myositis

Question 3

criteria for myositis

Answer 3

symmetrical weakness of limb-girdle muscles and anterior flexors

Question 4

what do we typically measure for suspected myositis

Answer 4

CPK
aldolase
AST, ALT
LDH

Question 5

what increases CPK

Answer 5

acute muscle injury
trauma
exercise
drugs
benign hyperCPKemia

Question 6

EMG findings in myositis

Answer 6

short, small, polyphasia motor units
fibrillations with SHARP waves
bizarre, repetitive discharges

Question 7

gender and myositises

Answer 7

F>M in DM/P

M>F for IBM

Question 8

progression of myositis

Answer 8

slow, fixed proximal muscle weakness

Question 9

by fixed we mean

Answer 9

weak ALL THE TIME, but also have fatigue, post-exertion aches, and pains

Question 10

why is there an increased risk of malignancy?

Answer 10

secondary to myositis or if myositis is a paraneoplastic syndrome

Question 11

other things you may see with myositis

Answer 11

raynauds
arthritis
pitting edema of extremities
pulmonary involvement

Question 12

CDs in polymyositis

Answer 12

CD8>CD4

Question 13

how to dx polymyositis (4)

Answer 13

prox muslce weakness
increased muscle enzymes
abnormal EMG
abnormal muscle bx

Question 14

muslce atrorphy in polymyo

Answer 14

sparred until the very late in dz

Question 15

what muscles are spared in polymyo

Answer 15

ocular and facial

Question 16

other things yo may see in poly

Answer 16

dysphagia (pharyngeal muslce weakness)
raynauds
SOB (resp muscles) (+ILD –>dyspnea, cough, hypoxemia)

Question 17

30% of patients exhibit

Answer 17

autoantibody to histidyltransfer RNA synthetase (Jo-1 antigen)

Question 18

tx polymyo

Answer 18

prednisone

if needed- MTX and azathioprine

Question 19

dermatomyositis pathophys

Answer 19

humoral ( b cells + CD4>CD8 t cells)–> inflammation in perifasicular and perivascular areas–> muscle fibeer necrosis and degen

*likely to be a paraneoplastic syndrome

Question 20

skin finds in dermatomyo

Answer 20

-violaceous with scaly desquamation–>occur in sun exposed areas (malar, chest shawl sign), extensor surfaces of elbows and knees, knucles (Gottron’s papules and Gottron’s sign), helicotrorpe

Question 21

other finding in dermatomyo

Answer 21

dilated nailfold capillaries

Question 22

juvenile dermatomyositis is adult form +

Answer 22

vasculitis
lipodystrophy
calcinosis

Question 23

amyopathic dermatomyositis

Answer 23

typical dermatomyo, but NO MUSCLE WEAKNESS

Question 24

anti-synthetase syndrome

Answer 24

PM or DM associated with anti-Jo-1 antbody | --strong association with ILD--also associated with Raynaud's, arthritis, mechanic's hands

Question 25

characteristics of inclusion body myositis

Answer 25

inflammatory myopathy with neuropathic features, causing paresthesias (tingling) and early involvement of distal muscles

Question 26

who does IBM usually affect?

Answer 26

middle-aged men--slowly progressive non-painful proximal myopathy w/ no response to treatment and progresses until it kills them

Question 27

what type of drugs induce drug-induced myopathy?

Answer 27

statin induced myopathy | -steroid-induced myopathy

Question 28

statin-induced myopathy

Answer 28

rare, but we use statins a lot so we see it--can be used with any dose and can occur at anytime -->relieved by stopping, but sometimes need steroids

Question 29

steroid induced myopathy

Answer 29

common, occurs with any dose of steroids | proximal muscle weakness, w/o tenderness and atrophy, normal CPK

Question 30

bx of steroid induced myopathy shows

Answer 30

no inflammation

Question 31

polymyalgia rheumatica

Answer 31

does NOT involve musles--inflam of soft tissue

Question 32

polymyalgia rheumatic clinical presentation

Answer 32

acute onset of morning stiffness and pain esp at shoulder and hip girdle + muscle and joint pain, fatigue maybe weight loss, depression, fever **NO MUSCLE WEAKNESS

Question 33

labs in PR

Answer 33

increase ESR | normochromic normocytic anemia

Question 34

EMG in PR

Answer 34

normal@

Question 35

tx of PR

Answer 35

daily lose dose steroids-resolves within 24 hours

Question 36

metabolic myopathy symptoms

Answer 36

exercise intolerance secondary to cramps or weakness | myoglobin breakdown

Question 37

primary metabolic myopathy

Answer 37

abnormal glycogen lipid, purine metabolism mitochondrial abnormality

Question 38

secondary metabolic myopathy

Answer 38

``` endocrine disorder electrolyte disorder uremia liver failure vit d/e def ```