Muscle Disease Flashcards
Who gets polymyositis and dermatomyositis
F:M 2:1; 40-50yo
What are the deatures seen on histology of polymyositis and dermatomyositis?
muscle fibre necrosis; degenration and regenration adn an inflam cell infiltrate
What is the most common presenting feature in polymyositis and dermatomyositis?
muscle weakness
How does muscle weakness present?
insidiously; usually symmetrial and affects the proximal muscles; specific problems eg brushing hair or climbing hte stairs ; mayb have myalgia (usually mild)
What is also seen with dermatomyositis?
Gottrons sign- pink macules over PIP and DIP
Heliotrope rash- redness round the eyes
Shawl sign- pink pur;le rash around back and making a V shape over the chest
What other organs are affected polymyositis and dermatomyositis?
lung- ILD; resp muscles weakness
GI-dysphagia
cardiac- myocarditis
What are the constitutional symptoms seen with polymyostiis or dermatomyositis?
fever; weight loss ; Raynauds; non-erosie polyarthritis
What are pts with polymyositis or dermatomyositis also at increased risk of??
cancer- ovarian, breast, stomahc, lung, bladder and colon
What pts are at greatest risk of cancer with polymyositis and dermatomyositis?
men over 45 yo
What medical conditions should be asked about with pts with suspected polymyositis and dermatomyositis?
DM and thyroid disease- as can also cause muscle weakness and pain
What tests can be done on exam with pts wtih muscle pain or weakness?
confrontational testing-direct testing of power and isotonic testing-30s sit to stand test
What autoantibodies are seen with polymyositis and dermatomyositis?
ANA, anti-Jo-1
What blood tests are done in pts with suspected polymyositis or dermatomyositis?
muscle enzymes- CK
inflam markers
to exclude other causes- electrlytes, PTH,TSH
What is seen on electromyography in polymyositis?
increased fibrillations; abnormal motor potentials; complex repetitive discharges
What is the definitive test for polymyositis and dermatomyositis?
muscle biopsy
What is seen on muscle biopsy in polymyositis?
perivascular inflammation and muscle necrosis
What is seen on MRI in pts with polymyositis
muscle inflammation, oedema; fibrosis and calcification
What is the dose of steroids given for polymyositis and dermatomyositis?
40mg prednisolone PO
How does rituximab work?
B cell depleting drug
How do steroid factor into treatment for polymyositis?
start along with an immunosuppressant as they work quickly, but are gradullay decreased and the immunosuppressive drug is kept goin
Who gets inclusion body myosiits?
pts >50 years
M:F 3:1
What are the differences between inclusion body myositis and polymyosits?
patients are older; affects men more than women(whereas polymyositis affects females more) IBM has a more insidious onset and the muscles affected tend to be more distal (polymyositis tends to be proximal muscles) and the muscles weakness is ften asymmetrical with IBM; CK levels are lower than in PM
What is the problem with treating inclusion body myostiis?
responds poorly to treatmetns
What age is polymyalgia rheumatica seen in?
almost exclusively in the over 50s
What condition is PMR associated with?
temporal arteritis/giant cell arteritis
What are the clinical manifestations in PMR?
ache in shoulder and hip girdle; morning stiffness; symmetrical; fatigue; anorexia; wt loss and fever; reduced movement
How is muscle strength afffected in PMR?
it isnt- muscle strength is normal
What causes the reduced movement of joints?
paint and stiffness- NOT WEAKNESS
What are the symptoms seen with giant cell arteritis?
granulomatous arteritis of lareg vessles; headaches; scalp tenderness; jaw claudication; visual loss; tender, enlarged, non-pulsatile temporal arteries
What is seen on blood with giant cell arteritis?
raised ESR; PV;CRP
How is giant cell arteritis diagnosed?
temporal artery biopsy
What is the treatment ofr PMR?
steroids which are gradually reduced over 18-24 months
What is the commonest cause of MSK pain in women 22-50 years?
fibromyalgia
What is the gender distribution of fibromyalgia?
F:M 6:1
What may precipitate fibromyalgia?
emotional or physical trauma
What are the clinical manifestions of fibromyalgia?
pain in the neck;shoulders; lower back; chest wall- often diffuse (hurts everywhere- cant place as joitn or bone or muscle pain); worse with ertion, fatiuge and stress; sensation of swelling; fatigue and poor, unrefreshing sleep; headhches; IBS; depression
What is seen on exam of fibromyalgia?
excessive tenderness on palpation of soft tissue - needs to be tenderness in at least 11/18 tender points
What are the treaments for fibromyalgia?
patient education; graded exercise programme; CBT; anti-depressants- tricyclics; analgesia; gabapentin
