June5 M2-Inflammatory Myopathies Flashcards
differences in what can make you unable to go up the stairs or do a task
may be one of these 2 different** things
- muscle fatigue (weakness)
- pain
Oxford grade of power testing
- grade 0: no muscle fct
- grade 1: some visible mvmt
- grade 2: full ROM NOT against gravity (can move but it’s hard)
- grade 3: can do the mvmt against gravity
- grade 4: can do the mvmt against gravity, but if put resistance, will overcome them (can say ‘‘mvmt against SOME resistance, but not against full resistance)
- grade 5: full force and full ROM (can resist full resistance)
list of the different idiopathic inflammatory myopathies
- polymyositis
- dermatomyositis most common (including juvenile dermatomyositis)
- inclusion body myositis
- myositis associated with neoplasia
- myositis associated with CTD
cause of PM and DM
autoimmune disease
PM and DM sx in common
- symmetric proximal muscle weakness
- truncal weakness
- both develop slowly
- myalgia
- swallowing and breathing problems
other muscles that can be affected in PM and DM
respiratory and pharyngeal muscles (swallowing and breathing problems)
muscles that are never affected in PM and DM
eyes, facial
DM: when does the myositis occur
often occurs after onset of cutaneous manifestations, rarely before
diff kinds of skin manifestations in DM (from most common to least common)
- pathognomonic
- highly characteristic
- characteristic
- more common in juvenile DM
- rare in DM
pathognomonic lesion in DM
Gottron’s papules (telegenctasias of SKIN over the joint in hand but spares phalanges. joints not affected)
highly charact lesion of DM
heliotrophe rash (periorbital (eyes) violaceous rash, edema in eyelids)
charact lesions in DM
- Shawl sign and V sign: macular violaceous red rash upper chest post and ant.
- mechanic hands (hyperkeratosis, scaling and horizontal fissuring of palms and fingers bilaterally)
- erythroderma (like shaw sign but more extensive, may go to face, malar region and forehead)
- nailfold telengectasias (periungal erythema), cuticular overgrowth, nailfold capillaries on magnifying glass
manif more common in juvenile DM
cutaneous calcinosis. black and white skin bumps on extensors of hands, elbows, buttocks
some extra-muscular manifestations of idiopathic inflam myopathies in general and important ones
- pulmonary (IMP): hypoventilation, aspiration pneumonia, ILD
- joints: arthralgias and arthritis
- heart: arrhythmia, conduction prob, CHF, myocarditis, pericarditis
- GI: dysphagia** (COMMON)
myositis associated with neoplasma type of IIM is what usually
dermatomyositis assoc with malignancy
risk of malignancy in DM
greatest risk at first year at dx, risk remains at 3-5 years, risk may go back to normal later.
diff types of malignancies in DM assoc with malignancy
- lung
- ovary
- breast
- colon
- rarely hemato
other name for myositis assoc with CTD
overlap myositis
CTDs seen with myositis sometimes
- scleroderma
- SLE
- MCTD
- RA
- Sjogren’s
- are all autoimmune*
most important thing for diagnosis of an IIM (the rest is not specific). the thing that can let you make a dx
biopsy
Abs that are positive in DM and PM (auto-Abs)
- myositis specific autoAbs exist
- also some myositis assoc autoAbs (seen in other diseases)
EMG looks at what
- nerve conduction (velocity diminished in disease)
- response of muscle to needle (stronger in disease)
- tells if prob is muscle vs nerve*
MRI use in IIM
- to find areas of edema, muscle inflammation (where to do the bx)
- also for fibrosis, calcification
IIM (DM) affects what region of the muscles
areas between fasicles (groups of muscle fibers) where arteries and veins travel
- PERIfascicular area* NOT THE MUSCLE FIBERS
- the Abs are against the blood vessels there*
pathology of DM
- Abs attack blood vessels
- MAC, cytokines, immune cells come
- blod vessels make ICAMs and DCAMs which help immune cells adhere
- blood vessel destruction
- perivascular inflammation
- vasculopathy, not vasculitis*
what is done in pathology on the biopsy to dx DM specifically
stain specifically for MAC elements (C5 to C9)
polymyositis and inclusion body myositis pathology
affects the muscle fibers (not perifascicular area)
- CD8 cells, cytokines released, adhesion molecules on vessels, muscle fibers release cytokines too
- CD8 recognize MAC (all caused by autoAbs), MHC1 involved
(imp?) most common IIMs
- dermatomyositis
- myositis associated with CTD
inclusion body myositis charact and symptoms
- in males more
- muscle weakness, DISTAL
- very insidious
- CAN affect facial muscles (still ocular are spared)
- so different from DM and PM classical location*
(imp?) tx in DM and PM
steroids (even though long term steroids give toxic myopathy, you determine what’s best for pt)
