Muscle Diseases Flashcards
What is polymyalgia rheumatica
chronic inflammatory condition characteriested by proximal hip and shoulder girdle myalgia with accompanying morning stiffness that lasts >1 hr.
Who gets polymyalgia rheumatica
Elderly (v rare under 50 years)
What condition is associated with polymyalgia rhuematica
Giant Cell/Temporal arteritis
Is weakness a feature of polymyalgia rheumatica?
No! only stiffness
Speed of onset of polymyalgia rheumatica
Subacute (<2 weeks)
Ix for polymyalgia rheumatica
no specific diagnostic test
ass. with raised CRP and ESR
N.B CK and EMG are NORMAL
Tx of polymyalgia rheumatica
15mg prednisolone daily - symptoms dramatically improve
SOMETIMES USED AS DIAGNOSTIC TOOL
Usual course length of Tx for polymyalgia rheumatica
around 18 months - symptoms will have resolved in majority of cases
what is polymyositis
idiopathic inflammatory myopathy that causes symmetrical proximal muscle weakness
what is dermatomyositis
similar to polymyositis but has the addition of cutaneous signs
is polymyositis more common in men or women
women > men (2:1)
peak incidence of polymyositis
40-60 years
autoantibodies associated with myositis
ANA
Anti-Jo-1 antibodies
Anti-SRP antibodies
causes of polymyositis
- autoimmune pathogenesis
- paraneoplastic syndrome
from lung, pancreatic, ovarian, bowel malignancy
is polymositis or dermatomyositis more common as a paraneoplastic syndrome
dermatomyositis (15%)
- polymyositis 9%
presentation of polymyositis
insidious onset of symmetrical proximal muscle weakness (shoulders and hips)
dysphagia and dysphonia secondary to oesophageal and oropharyngeal involvement
respiratory weakness
extra-muscular signs that can present in polymyositis
interstitial lung fibrosis fever arthralgia Raynauds myocardial involvement (arrhythmias, myocarditis)
Cutaneous signs of dermatomyositis
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
diagnostic test for polymyositis
muscle biopsy
Ix for polymyositis
inflammatory markers - raised
serum CK - raised
autoantibodies
MRI (shoes extent of muscle involvement)
EMG (abnormal in 90% )
Mx of ongoing polymyositis
Oral Corticosteroids - pred 40mg daily
+
Immunosuppression - azothioprine or methotrexate
Mx of polymyositis with acute muscle weakness or respiratory depression
IV Corticosteroids + IVIG
Mx of cutaneous signs in dermatomyositis
Hydroxychloroquine (DMARD)
what is fibromyalgia
unexplained condition causing widespread muscle pain and fatigue
conditions associated with fibromyalgia
RA SLE depression IBS migraine
presentation of fibromyalgia
> 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
Ix for fibromyalgia
clinical Dx - no specific Ix
rule out other conditions (RA, SLE, polymyalgia rheumatica)
Mx of fibromyalgia
self-management, advice
neuropathic analgesia (amitriptylline, gabapentin, pregabalin)
counselling, CBT
What is inclusion body myositis
idiopathic condition characterised as progressive muscle weakness, which is distal and often asymmetrical
what is inclusion body myositis often misdiagnosed as
polymyositis
inclusion body myositis - more common in M or F?
M > F (3:1)
causes of inclusion body myositis
autoimmune pathogenesis
AND
degenerative pathogenesis
Ix for inclusion body myositis
CK levels
LOWER THAN POLYMYOSITIS
Muscle biopsy - shows inclusion bodies
Tx for inclusion body myositis
same as for polymyositis - but nothing is consistently effective
Oral corticosteroids + Immunosuppression (azothioprine)
