Myopathies Flashcards
Polymyositis and dermatomyositis are more common in men/women?
Women (2:1)
Myopathies are not associated with a risk of malignancy. True/false?
False (increased risk of paraneoplastic malignancy)
Describe the common presenting features of myositis (5)
1) Muscle weakness
2) Insidious onset (worsens over months)
3) Usually symmetrical, proximal muscles
4) Often associated with specific problems e.g. brushing hair
5) Myalgia is in 25-50% but usually mild
Gottron’s sign is indicative of what…. Where does it present?
Dermatomyositis
Presents over MCP and PIPs especially
Describe the 3 clinical signs of dermatomyositis?
- Shawl sign (on back)
- Gottron’s sign (around MCP and PIP)
- Heliotrope rash (around eyes)
Myositis can affect other organs, including: (3)
1) Lung (ILD)
2) Oesophagus (dysphagia/ loss of swallow)
3) Heart (myocarditis)
Malignancy is increased in dermatomyositis over polymyositis, true or false?
True
Risk highest in men over 45 years old.
Diagnosis of myositis is made primarily following investigations. True/false?
False - mainly by presenting symptoms
Describe the 2 types of muscle testing that can be done to investigate myositis?
- Isotonic testing (30 seconds sit to stand test)
- Confrontational testing (direct test the power)
Autoantibodies in polymyositis include (2)
- ANA
- Anti-Jo-1
Definitive test for polymyositis is
Muscle biopsy
Treatment for polymositis is initially….
Glucocorticoids (short onset, move to immunosuppresants later).
Inclusion body myositis is a type of polymyositis. True/false?
False it’s often misdiagnosed as polymyositis - it’s also commoner in men.
What clinical features distinguish inclusion body myositis from polymyositis?
Inclusion body:
- Weakness asymmetrical
- CK is lower than in polymyositis
- Commoner in men (3:1)
- Responds poorly to corticosteroids
Polymyalgia rheumatica occurs almost exclusively in which age group?
> 50 years old
PMR is higher in which region?
Northern
PMR is associated with which serious condition?
Giant cell arteritis / temporal arteritis (15%)
PMR stiffness should last how long?
<30 minutes
PMR stiffness presents when?
Morning
Jaw claudication and headache are buzzwords for…
Temporal arteritis (claudication is VERY specific for this)
The classical visual change in giant cell arteritis is…
Amaurosis fugax (like a black curtain descending around one eye)
Is there a specific blood test for GCA?
No - generally inflammatory markers will be raised
What’s the “best” test for GCA and its principle drawback?
Temporal artery biopsy. Disease may present with skip lesions.
Treatment of PMR (with NO suspicion of GCA) is with what drug & dose?
Prednisolone - 15mg
If GCA is suspected in PMR, what dose of steroids is started?
40-60mg
Fibromyalgia is an inflammatory disease. True/false?
False
Fibromyalgia is commoner in men/women?
Women - around 6x
What’s a clinical finding for fibromyalgia?
Excessive tenderness on palpation of soft tissue
Is there a specific test for fibromyalgia?
No. Patients have excessive tenderness to palpation: there are 18 tender points and patients need to have 11
What has been shown to be the most effective mechanism of managing fibromyalgia?
Graded exercise
Which drugs can cause myalgia/ muscle wasting?
Statins & steroids
Blood tests for myositis (4)
1) CK
2) Inflammatory markers
3) Electrolytes, calcium, PTH, TSH (to rule out other causes)
4) Autoantibodies (ANA and Anti-Jo-1)
Non-blood test for myositis?
Electromyography (EMG) showing increased fibrillations.
What imaging modality is good in showing response to treatment of myositis?
MRI
Non first-line therapies for myositis include
IVIG, IV Rituximab
What is the key to making a diagnosis of inclusion body myositis?
Presence of inclusion bodies on muscle biopsy
Clinical manifestations of PMR
Ache in shoulder and hip girdle.
Morning stiffness.
Symmetrical stiffness.
Reduced range of movement of shoulders, neck and hips.
Clinical sign of GCA
Temporal artery will be enlarged, tender and non-pulsatile.
Serious complication of GCA
Irreversible blindness
In PMR/GCA, when should steroids begin to be tapered off?
Over 18-24 months
What’s a “test” for PMR involving a medication?
Give trial 15mg prednisolone. If they have PMR they will have a massive response.
What is the commonest cause of MSK pain in young women (22-50 years)?
Fibromyalgia
Fibromyalgia may begin after what precipitating factor?
Emotional or Physical Trauma
Clinical symptoms of fibromyalgia (7)
1) Pain in neck, shoulders, lower back and chest wall
2) Diffuse and chronic
3) Variable intensity
4) Symptoms worse on exertion
5) Poor sleep and mind fog
6) Pain, parasthesia, IBS.
7) Sensation of swelling
What drugs can be used to treat fibromyalgia? (3)
1) Anti-depressants
2) Analgesia
3) Pain modulators (e.g. gabapentin, pregabalin)
Non-pharmacological options for fibromyalgia treatment (5)
1) Patient education
2) MDT response
3) Graded exercise programme
4) CBT
5) Complimentary medicine (e.g. acupuncture)
A 63 year old man presents with onset of pain and stiffness around his shoulders and hips. Ongoing for around 3 weeks. He now needs help to get out of bed in the morning.
Likely diagnosis?
Questions and tests needed?
` (morning stiffness, areas of stiffness).
Questions: Anything to suggest GCA?
Tests: Inflammatory markers, screen autoantibodies (should be negative), temporal biopsy if suggestive of GCA
Is muscle power reduced in PMR?
No it is normal
A 64 year old man has been noticing a heavy feeling in his arms for about 6 months. He is finding it increasingly tiring climbing the stairs.
Likely diagnosis?
Questions?
Tests needed?
Likely diagnosis: Polymyositis (unless cutaneous signs present then dermatomyositis) due to proximal weakness, weakness in activity (climbing stairs), insidious, gradual onset.
Questions: any cutaneous signs?
Tests: Antibody screen (Anti-Jo-1 should be positive), inflammatory markers (should be raised), CK (should be raised), EMG on proximal muscles, muscle biopsy.
A 26 year old woman is referred with a 2 year history of worsening pain “all over”. She has difficulty performing simple tasks like house work due to fatigue. She finds sleep unrefreshing.
Likely diagnosis?
Questions?
Tests needed?
Management?
Fibromyalgia (“all over pain”, female sex, difficulty performing simple tasks due to fatigue, unrefreshing sleep).
Questions: Any history of emotional or physical trauma
Tests: Inflammatory markers (should be normal), autoantibodies (should be none), CK (should be normal).
Management: Graded exercise most benefit
