Muscle Disease Flashcards
Polymyositis and dermatomyositis are examples of which type of myopathy?
Inflammatory myopathy
Inflammatory myopathies more commonly affect whch gender?
Females
What is the most common clinical feature of the inflammatory myopathies?
Muscle weakness
What is the onset like with polymyositis and dermatomyositis?
Gradual
(over months)
Which muscles are commonly affected with polymoyositis and in which pattern (symmetrical/asymmetrical)?
Proximal muscles
(symmetrical pattern)
Which cutaneous signs are classic for dermatomyositis?
- Gottron’s sign
- Heliotrope rash
- Shawl sign
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Describe Gottron’s sign
- A purple/violet colouring of the skin over the MCP and PIP joints
- This can be painful and may bleed
- Often worsens in sunlight
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How is the respiratory system affected by polymyositis or dermatomyositis?
Interstitial lung disease
Respiratory muscle weakness
How can the cardiovascular system be affected by polymyositis or dermatomyositis?
Myocarditis
Which symptom associated with polymyositis and dermatomyositis involves oesophageal issues?
Dysphagia
Which other non-specific symptoms besides the specific systems symptoms can be seen in polymyositis and dermatomyositis?
- Fever
- Weight loss
- Raynaud’s
- Non-erosive polyarthritis
- SOB
- Cough
Which patient with polymyositis (or dermatomyositis) is most at risk of malignancy?
a) John 75
b) Bertha 70
John
Men >45 have greatest risk of malignancy
Which types of malignancy can be associated with polymyositis or dermatomyositis?
- Ovarian
- Breast
- Stomach
- Lung
- Bladder
- Colon
Which inflammatory myositis (dermatomyositis or polymyositis) is most prone to malignancy?
Dermatomyositis
Which drug class can bring on symptoms similar to those seen in polymyositis or dermatomyositis?
Statins
(or steroids)
Which worrying signs in a social history would strengthen your suspision for dermatomyositis or polymyositis?
- High alcohol consumption
- Illicit drug use
What are the two main methods for testing a patient’s muscle strength?
- Confrontational (direct test of power)
- Isotonic (test how much of a certain exercise they can do in a time limit)
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Which muscle enzyme will be raised in dermatomyositis or polymyositis?
Creatinine kinase
Which antibodies will be found in polymyositis or dermatomyositis?
- Anti-nuclear antibody (ANA)
- Anti-Jo-1
How are inflammatory markers impacted in polymyositis or dermatomyositis?
They are raised
What is electromyography?
The passing of a low volatge electric current through the affected muscle to check normal activity
What is the only definitive test for polymyositis or dermatomyositis and what does it show?
Muscle biopsy
Perivascular inflammation and necrosis of muscle
What can MRI of muscle show in patients with polymyositis or dermatomyositis?
- Muscle inflammation
- Oedema
- Fibrosis
- Calcification
What are the treatment options for polymyositis or dermatomyositis?
- Glucocorticoids
- Immunosuppressants
- IV immunoglobulin
- Rituximab
Why, when treating inflammatory myositis, are glucocorticoids given in initially high doses and then reduced to lower doses?
Glucorticoids have many negative side effects including muscle weakness, which is one of the man complaints of inflammatory myositis
Inclusion body myositis is often misdiagnosed for what?
Polymyositis
Describe the key differences between inclusion body myositis and polymyositis?
- It is not an autoimmune condition
- It is commoner in men
- It generally affects the distal muscles rather than the proximal muscles
- It is usually asymmetrical
- It has slower onset
- Creatinine kinase levels are lower
How does inclusion body myositis respond to therapy?
Poorly
Weakness in muscles is often symmetrical/asymmetrical in inclusion body myositis?
Asymmetrical
What is polymyalgia rheumatica?
A potentially autoimmune condition (cause is unknown) which causes neck, shoulder and hip girdle pain
Polymyalgia affects people of what age bracket?
Almost exclusively those >50
Polymyalgia rheumatica can cause dramatic muscle _________ but not muscle _________
Stiffness
Weakness
Polymyalgia rheumatica is associated with what?
Temporal arteritis
Giant cell arteritis
What is seen on a muscle biopsy with someone who has polymyalgia rheumatica?
Nothing abnormal
Why may vision loss occur in those with temporal arteritis?
The temporal artery supplies the optic nerve
How does temporal arteritis affect the termporal artery?
- Tender and enlarged
- Non-pulsatile
- Prominent
How is the jaw impacted in temporal arteritis?
Jaw claudication when in use
What is the vision loss associated with temoral arteritis called?
Amaurosis fugax
(painless and temporary loss of vision in one or both eyes)
How can temporal arteritis be diagnosed?
- Raised ESR, CRP and PV
- Temporal artery biopsy
Temporal arteritis/giant cell arteritis and polymyalgia rheumatica are ____ - _________ conditions
Self-limiting
What is the treatment for polymyalgia rheumatica?
Low dose steroids
(this causes a drastic and rapid improvement, which can even be used to test if it is polymyalgia rheumatica as this response is unique)
What are the following doses for polymyalgia rheumatica?
a) Starting dose
b) With temporal arteritis
c) With eye problems due to temporal arteritis
a) 15mg
b) 40mg
c) 60mg
Fibromyalgia is an inflammatory condition.
True or false
False
Name some symptoms and syndromes associated with fibromyalgia?
- Irritable bowel syndrome
- Depression
- Poor sleep and fatigue
- Migraines
- Poor concentration and memory
When can fibromyalgia come on?
After physical or emotional trauma
Where are the most commonly painful areas in fibromyalgia?
- Neck
- Shoulders
- Lower back
- Chest wall
Is fibromyalgia diffuse or localised?
Diffuse
What can make fibromyalgia worse?
Exercise
What are the clinical findings for fibromyalgia?
- Excessive tenderness on palpation
- No other abnormalities (all blood tests normal)
What are the treatment options for fibromyalgia?
- Tricyclic antidepressants e.g. amitriptyline
- Gabapentin, pregabalin
- Analgesia
- Acupuncture
- Graded exercise
What are some of the negative side effects of steroids?
- Weight gain
- Osteoporosis (Ca2+, vitamin D + biphosphonates can be given to counteract)
- Infection