Muscle Disease

Question 1

How do muscle diseases present?

Answer 1

Muscle pain (myalgia) 
Muscle weakness/ tiredness
Stiffness
Abnormal blood tests
Other features

Question 2

Who is likely to get polymositis and dermatomyositis?

Answer 2

Prevalence is 1/100,000
Female to male ratio is 2:1
Peak incidence is 40-50s

Question 3

What will polymyositis look like histologically?

Answer 3

Muscle fibre necrosis, degenration and regeneration

Inflammataory cell infiltrate

Question 4

What are the clinical features of polymyositis/ dermatomyositis?

Answer 4

Muscle weakness- insidious onset, worsening over months, usually symmetrical and affects proximal muscles
Will have specific problems e.g. brushing hair, climbing stairs

Question 5

What cutaneous signs are associated with dermatomyositis?

Answer 5

Gottrons sign
Helitrope rash
Shawl sign

Question 6

How can polymyositis/ dermatomyositis affect the lungs?

Answer 6

ILD

Resp muscle weakness

Question 7

How can polymyositis/ dermatomyositis affect the oesophagus?

Answer 7

Dysphagia

Question 8

How can polymyositis/ dermatomyositis affect the heart?

Answer 8

Myocarditis

Question 9

What other systemic conditions can polymyositis/ dermatomyositis cause?

Answer 9

Fever
Weight loss
Raynauds phenomenon
Non-erosive polyarthrtitis

Question 10

What is the link between polymyositis/ dermatomyositis and malignancy?

Answer 10

15% incidence in dermatomyositis, 9% in polymyositis

Question 11

What malignancies will polymyositis/ dermatomyositis cause?

Answer 11

Ovarian
Breast
Stomach
Lung
Bladder
Colon cancer

Question 12

Who is at the highest risk of polymyositis/ dermatomyositis related malignancy?

Answer 12

Men over 65 years

Question 13

How can a diagnosis of polymyositis/ dermatomyositis be determined from the history?

Answer 13

PS: tired muscles, functional difficulty, muscle pain
PMX: DM, thyroid disease
Drugs: steroids, statins
Social: alcohol, illicit drug use
Systemic Enquiry: WL, cough, SOB, rayanauds

Question 14

What tests can be performed in an examination of polymyositis/ dermatomyositis?

Answer 14

Confrontational testing - direct testing of power

Isotonic testing - 30 second sit to stand test

Question 15

What blood tests should be taken in the diagnosis of polymyositis/ dermatomyositis?

Answer 15

Muscle enzymes - CK
Inflammatory markers
Electrolytes, calcium, PTH, TSH
Autoantibodies: ANA, Anti-Jo-1

Question 16

What will an electromyography show in polymyositis/ dermatomyositis?

Answer 16

Increased fibrilations, abnormal motor potentials, complex repetitive discharges

Question 17

What will muscle biopsy show in polymyositis/ dermatomyositis?

Answer 17

Perivascular inflammation

Muscle necrosis

Question 18

What will an MRI show in polymyositis/ dermatomyositis?

Answer 18

Muscle inflammation
Oedema
Fibrosis
Calcification

Question 19

How is polymyositis/ dermatomyositis treated?

Answer 19

Glucocorticoids
Azathioprine
Methotrexate
Ciclosporin
IV immunoglobulin
Rituximab

Question 20

Who will polymyalgia rheumatica affect?

Answer 20

Those over 50

Higher in northern regions

Question 21

What vasculitis disease is PR associated with?

Answer 21

Temoral arteritis

Question 22

What are the clinical manifestations of PR?

Answer 22

Ache in shoulder and hip girldle
Morning stiffness
Symmetrical 
Fatigue, anorexia, weight loss, fever 
Reduced movement 
NORMAL muslce strength

Question 23

How is PR diagnosed?

Answer 23

Exclude other diagnosis
Raised ESR, PV and CRP
Temporal artery biopsy

Question 24

How is PR treated?

Answer 24

Rapid and dramatic response to low dose steroids

If GCA present, higher steroid dose needed

Question 25

What is fibromyalgia?

Answer 25

Chronic msk pain that is not associated with inflammation

Question 26

Who is likely to be affected by fibromyalgia?

Answer 26

Commonest cause of msk pain in women 22-50 Commoner in women (6:1) Can begin after emotional or physical trauma

Question 27

What are the clinical manifestations of fibromyalgia?

Answer 27

Pain in neck, shoulders, lower back and chest wall Worse with exertion, fatigue and stress Sensation of swelling Fatigue and poor sleep

Question 28

What other extra-articular conditions is fibromyalgia associated with?

Answer 28

``` Pins and needles Headaches Depression IBS Poor concentration and memory ```

Question 29

What are the clinical findings of fibromyalgia on examination?

Answer 29

Excessive tenderness on palpation of soft tissues | 11/18 tender points

Question 30

What is the criterea for diagnosis of fibromyalgia?

Answer 30

Widespread pain with associated symtoms (unrefreshed sleep, cognitive symptoms, fatigue) Symptoms present for more than 3months No other condition explains pain - disease of exclusion

Question 31

How is fibroyalgia treated?

Answer 31

``` Patient education MDT response CBT Acupuncture Atypical analgesics - anti-depressants, gabapentin and pregabalin ```