Muscle Disease

Question 1

what are the 4 main inflammatory causes of primary muscle disease?

Answer 1

polymyositis
dermatomyositis
inclusion body myositis
polymyalgia rheumatica

Question 2

How do muscle diseases present?

Answer 2

muscle pain
muscle weakness
muscle stiffness
muscle wasting

Question 3

which inflammatory cause of primary muscle disease has a noticeable increased incidence of malignancy?

Answer 3

dermatositis

Question 4

what muscles are usually affected by dermatomyositis or polymyositis?

Answer 4

proximal muscles

eg muscles around pectoral girdle and pevlic girdle

Question 5

what are the features of cutaneous disease of dermatomyositis?

Answer 5

Gottrons sign
Heliotrope rash
Shawl sign

Question 6

what is Gottrons sign?

Answer 6

papules over metacarple phalangeal (MCP) joints and proximal interphalangeal joints

Question 7

what is a heliotrope rash?

Answer 7

a purpley-reddish rash around the eyes

Question 8

what is a shawl sign?

Answer 8

a purpley-reddish rash around the neck

Question 9

what drugs used in the treatment of patients with a certain cardiovascular risk factor can cause muscle pain and inflammation?

Answer 9

statins

Question 10

what illict drug is known for causing muscle pain and inflammation?

Answer 10

cocaine

Question 11

what 2 types of muscle testing are important features of examining a patient with suspected inflammatory muscle disease?

Answer 11

1. confrontational testing- direct test of power

2. isotonic testing- muscle power with repeated exercise

Question 12

how might you do a confrontational muscle test?

Answer 12

by applying force in the opposite direction to the patient

Question 13

how might you do a isotonic muscle test?

Answer 13

30s sit to stand test

Question 14

what enzyme is usually raised in polymyositis?

Answer 14

creatine kinase

Question 15

what autoantibodies can be present in polymyositis and dermatomyositis?

Answer 15

ANA

anti-Jo-1

Question 16

what is the gold standard definitive test for polymyositis and dermatomyositis?

Answer 16

muscle biopsy

Question 17

why are MRI’s useful in the diagnosis of polymyositis and dermatomyositis?

Answer 17

help pinpoint an affected muscle to biopsy

Question 18

what is the treatment for polymyositis and dermatomyositis?

Answer 18

steroids (only used acutely)
immunosuppressant drugs
IV immunoglobulin
biologic (rituximab)

Question 19

compare the onset of weakness between polymyositis, dermatomyositis and inclusional body myositis?

Answer 19

polymyositis- months
dermatomyositis- months
inclusional body myositis- years

Question 20

compare the location of weakness between polymyositis, dermatomyositis and inclusional body myositis?

Answer 20

polymyositis- proximal muscles
dermatoymyositis- proximal muscles
inclusion body myositis- distal muscles

Question 21

compare the distribution of muscle weakness between polymyositis, dermatomyositis and inclusional body myositis?

Answer 21

polymyositis- symmetrical
dermatomyositis- symmetrical
inclusional body myositis- asymmetrical

Question 22

compare the creatine kinase levels between polymyositis, dermatomyositis and inclusional body myositis?

Answer 22

polymyositis- elevated
dermatomyositis- normal or elevated
inclusional body myositis- normal or slighly elevated

Question 23

what is the classic muscle biopsy findings of polymyositis?

Answer 23

endomysial inflammation with CD8+ T cells

Question 24

what is the classic muscle biopsy findings of dermatomyositis?

Answer 24

perimysial inflammation with CD4+ T cells
+
perifascular atrophy

Question 25

what is the classic muscle biopsy findings of inclusional body myositis?

Answer 25

rimmed vacules

Question 26

compare the response of treatment between polymyositis, dermatomyositis and inclusional body myositis?

Answer 26

polymyositis- good response dermatomyositis- good response inclusional body myositis- poor response

Question 27

why is polymyalgia rheumatica an unusual inflammatory muscle disease?

Answer 27

biopsy looks normal | only pain and stiffness- no muscle weakness

Question 28

what muscles are affected in polymyalgia rheumatica? (distribution and location)

Answer 28

symmetrical proximal muscles around shoulder and hip girdle

Question 29

what is temporal arteritis? | giant cell arteritis

Answer 29

inflammation of the lining of the temporal artery

Question 30

what is the major serious consequence of temporal arteritis? | giant cell arteritis

Answer 30

permanent blindness | temporal artery suplies the optic nerve

Question 31

what happens to the jaw in temporal arteritis? | giant cell arteritis

Answer 31

jaw claudication- aching in muscles when chewing

Question 32

what kind of headache presents in temporal arteritis? | giant cell arteritis

Answer 32

unilateral, able to localie

Question 33

what happens to the temporal arteries in temporal arteritis? | (giant cell arteritis?

Answer 33

granulomatous inflammation of the temporal artery | artery becomes tender, enlarged (but with lumen narrowing), and non-pulsatile

Question 34

why is the temporal artery non-pulsative in temporal arteritis?

Answer 34

vessel wall is so thick due to inflammation: | pulse isn't conducted through it

Question 35

why is biopsy not totally effective in suspected temporal arteritis?

Answer 35

skip lesions | there are patches where there is no granulomatous inflammation

Question 36

what is the treatment of polymyalgia rheumatica? (with no temporal arteritis)

Answer 36

low dose steroids | rapid and dramatic response

Question 37

what is the treatment of polymyalgia rheumatica with temporal arteritis?

Answer 37

high dose steroids, gradually decreasing dose for 18 -24 months

Question 38

what is the most common cause of chronic musculoskeletal pain?

Answer 38

fibromyalgia

Question 39

what may trigger fibromyalgia?

Answer 39

emotional or physical trauma

Question 40

how do you diagnose fibromyalgia?

Answer 40

absence of abnormal features | inflammatory markers also normal

Question 41

what is the treatment for fibromyalgia?

Answer 41

``` education graded exercise complementary medicine (eg acupuncture) anti-depressants anti-convulsants analgesia ```

Question 42

who tends to get polymyalgia rheumatica?

Answer 42

elderly individuals | very rare under 50

Question 43

how do the symptoms of polymyalgia change over the day?

Answer 43

morning stiffness which lasts for more than an hour | symptoms improve as the day goes on (and with movement)

Question 44

why can dysphagia occur in polymyositis?

Answer 44

secondary to oroparyngeal and esophageal muscle involvement -poor prognostic sign

Question 45

what is crucial to diagnose polymyositis and dermatomyositis?

Answer 45

muscle biopsy

Question 46

what is seen on muscle biopsy of polymyositis?

Answer 46

inflammation, necrosis and regeneration chronic inflammatory infiltrate with cytotoxic T cell

Question 47

what should additionally be screened for in dermatomyositis that isn't screened for on polymyositis?

Answer 47

malignancy

Question 48

what is fibromyalgia thought to be a disorder of?

Answer 48

the central pain processing | syndrome of central sensitivity