Muscle Diseases

Question 1

What is polymyalgia rheumatica

Answer 1

chronic inflammatory condition characteriested by proximal hip and shoulder girdle myalgia with accompanying morning stiffness that lasts >1 hr.

Question 2

Who gets polymyalgia rheumatica

Answer 2

Elderly (v rare under 50 years)

Question 3

What condition is associated with polymyalgia rhuematica

Answer 3

Giant Cell/Temporal arteritis

Question 4

Is weakness a feature of polymyalgia rheumatica?

Answer 4

No! only stiffness

Question 5

Speed of onset of polymyalgia rheumatica

Answer 5

Subacute (<2 weeks)

Question 6

Ix for polymyalgia rheumatica

Answer 6

no specific diagnostic test

ass. with raised CRP and ESR

N.B CK and EMG are NORMAL

Question 7

Tx of polymyalgia rheumatica

Answer 7

15mg prednisolone daily - symptoms dramatically improve

SOMETIMES USED AS DIAGNOSTIC TOOL

Question 8

Usual course length of Tx for polymyalgia rheumatica

Answer 8

around 18 months - symptoms will have resolved in majority of cases

Question 9

what is polymyositis

Answer 9

idiopathic inflammatory myopathy that causes symmetrical proximal muscle weakness

Question 10

what is dermatomyositis

Answer 10

similar to polymyositis but has the addition of cutaneous signs

Question 11

is polymyositis more common in men or women

Answer 11

women > men (2:1)

Question 12

peak incidence of polymyositis

Answer 12

40-60 years

Question 13

autoantibodies associated with myositis

Answer 13

ANA
Anti-Jo-1 antibodies
Anti-SRP antibodies

Question 14

causes of polymyositis

Answer 14

• autoimmune pathogenesis

- paraneoplastic syndrome
from lung, pancreatic, ovarian, bowel malignancy

Question 15

is polymositis or dermatomyositis more common as a paraneoplastic syndrome

Answer 15

dermatomyositis (15%)

- polymyositis 9%

Question 16

presentation of polymyositis

Answer 16

insidious onset of symmetrical proximal muscle weakness (shoulders and hips)

dysphagia and dysphonia secondary to oesophageal and oropharyngeal involvement

respiratory weakness

Question 17

extra-muscular signs that can present in polymyositis

Answer 17

interstitial lung fibrosis 
fever 
arthralgia 
Raynauds 
myocardial involvement (arrhythmias, myocarditis)

Question 18

Cutaneous signs of dermatomyositis

Answer 18

Gottron’s papules - red and purple areas over MCP and PIP joints

Heliotrope rash - rash around eyes

Shawl sign - rash over back and V down front of chest

Question 19

diagnostic test for polymyositis

Answer 19

muscle biopsy

Question 20

Ix for polymyositis

Answer 20

inflammatory markers - raised

serum CK - raised

autoantibodies

MRI (shoes extent of muscle involvement)

EMG (abnormal in 90% )

Question 21

Mx of ongoing polymyositis

Answer 21

Oral Corticosteroids - pred 40mg daily
+
Immunosuppression - azothioprine or methotrexate

Question 22

Mx of polymyositis with acute muscle weakness or respiratory depression

Answer 22

IV Corticosteroids + IVIG

Question 23

Mx of cutaneous signs in dermatomyositis

Answer 23

Hydroxychloroquine (DMARD)

Question 24

what is fibromyalgia

Answer 24

unexplained condition causing widespread muscle pain and fatigue

Question 25

conditions associated with fibromyalgia

Answer 25

``` RA SLE depression IBS migraine ```

Question 26

presentation of fibromyalgia

Answer 26

>3 months widespread pain on both sides of the body, above and below the waist fatigue - disturbed and unrefreshing sleep cognitive difficulties anxiety and/or depression, functional impairment of daily living activities

Question 27

Ix for fibromyalgia

Answer 27

clinical Dx - no specific Ix rule out other conditions (RA, SLE, polymyalgia rheumatica)

Question 28

Mx of fibromyalgia

Answer 28

self-management, advice neuropathic analgesia (amitriptylline, gabapentin, pregabalin) counselling, CBT

Question 29

What is inclusion body myositis

Answer 29

idiopathic condition characterised as progressive muscle weakness, which is distal and often asymmetrical

Question 30

what is inclusion body myositis often misdiagnosed as

Answer 30

polymyositis

Question 31

inclusion body myositis - more common in M or F?

Answer 31

M > F (3:1)

Question 32

causes of inclusion body myositis

Answer 32

autoimmune pathogenesis AND degenerative pathogenesis

Question 33

Ix for inclusion body myositis

Answer 33

CK levels LOWER THAN POLYMYOSITIS Muscle biopsy - shows inclusion bodies

Question 34

Tx for inclusion body myositis

Answer 34

same as for polymyositis - but nothing is consistently effective Oral corticosteroids + Immunosuppression (azothioprine)