Muscle Diseases Flashcards
how do muscle diseases present
myalgia (muscle pain)
muscle weakness/tiredness
stiffness
abnormal blood tests
what type of myopathy are polymyositis and dermatomyositis
idiopathic inflammatory myopathies
who is more likely to get polymyositis and dermatomyositis
females 2 : males 1
40-50 years
what there an increased incidence of in patients with polymositis and dermatomyositis
malignancy
what is seen histologically in polymyositis and dermatomyositis
muscle biopsy: muscle fibre necrosis, degeneration, regeneration and an inflammatory cell infiltrate.
perivascular necrosis
what are the clinical features of idiopathic inflammatory myopathy (polymyositis and dermatomyositis)
MUSCLE WEAKNESS
insidious onset, worsening over months
usually symmetrical, proximal muscles
myalgia in 25-50%
what extra features distinguish the clinical presentation of dermatomyositis from polymyositis
cutaneous signs
- gottrons sign
- heliotrope rash
- shawl sign
what other organs can be involved in inflammatory myositis
lung (ILD, resp muscle weakness)
oesophagus (dysphagia
cardiac (myocarditis)
also:
fever, weight loss, raynauds, non-erosive polyarthritis)
what cancers are associated with inflammatory myositis
ovarian, breast, stomach, lung, bladder and colon cancer
in a history of a patient with an inflammatory myositis, what are other common medical problems
Dermatomyositis, thyroid disease, raynauds
what is isotonic testing
30 second sit to stand test
what tests can be included to test muscle function
confrontational testing- tests direct power
isotonic testing
what blood tests can be done into inflammatory myositis
muscle enzymes- creatine kinase (CK)
inflammatory markers
electrolytes, calcium, PTH, TSH (to exclude other causes)
autoantibodies (ANA, Anti-Jo-1)
what is seen in electromyography in inflammatory myositis
increased fibrillations
abnormal motor potentials
complex repetitive discharges
what is the definitive test for inflammatory myositis
muscle biopsy
what is seen in biopsy of inflammatory myositis
muscle inflammation,
oedema,
fibrosis,
calcification
what is the treatment for idiopathic inflammatory myosisitis (polymyositis and dermatomyositis)
glucocorticoids azathioprine methotrexate ciclosporin IV immunoglobulin rituximab
what medication might cause a similar presentation to myositis
atorvastatin
what is polymyalgia rheumatica
idiopathic inflammatory condition associated with temporal arteritis/ giant cell arteritis
who gets polymyalgia rheumatica
over 50s
what is the clinical presentation of polymyalgia rheumatica
ache in shoulder and hip girdle
morning stiffness
usually symmetrical
fatigue, anorexia, weight loss, fever
reduced movement of shoulders, neck and hips
what is muscle strength like in polymyalgia rheumatica
normal
what is temporal arteritis/ giant cell artheritis
granulomatous arteritis of large vessels
what are the symptoms of temporal arteritis/ giant cell arteritis
headache, scalp tenderness, jaw claudication, visual loss, tender, enlarged, non pulsatile temporal arteries
how do you diagnose temporal arteritis/ (GCA)
raised ESR, plama viscosity, CRP
temporal artery biopsy
how do you treat temporal arteritis/ GCA
steroids (prednisolone 40mg, 60mg if visual impairment)- gradually reduced over around 18 months to 2 years
steroids as a diagnostic tool- Symptoms respond very dramatically to low dose steroids (prednisolone 15mg daily)
what is fibromyalgia
idiopathic chronic (MSK) pain disorder
is fibromyalgia associated with inflammation
no
who gets fibromyalgia
females 6 : males 1
22-50 y/o
when does fibromyalgia pain sometimes begin
after emotional or physical trauma
what is the pathology of fibromyalgia
dorsal horn neurones become hyperresponsive to nociceptive and nonnociceptive somatic senation due to extracellular Ca+ and nitric acid diffusing into neurones resulting in exaggerated release of sustance P and glutamate
hyperalgesia
what are the clinical manifestations of fibromyalgia
pain; neck, shoulders, lower back, chest wall
diffuse and chronic, varies in intensity
symptoms worse with exertion, fatigue and stress
sensation of swelling, fatigue, poor, unrefreshing sleep
pins and needles/ tingling, headaches, depression, abdominal pain (IBS), poor concentration and memory
what are the clinical findings in fibromyalgia
excessive tenderness on palpation of soft tissues
11/18 tender points
no abnormalities of MSK system
what is the treatment for fibromyalgia
education
exercise programme
congitive behavioural therapy
complemetary medicine (acupuncture)
anti depressants (tricylics- amitriptyline)
analgesia
gabapentin and pregabalin
does morphine help in fibromyalgia
no
what is pain of the shoulder and hips without weakness in in 70s
polymyalgia rheumatica
what condition commonly co exists with PMR
giant cell vacsulitis
what responds rapidly to steroids
PMR
what is CK raised in
polymyositis only (and dermomyositis
what anti body for polymyositis
anti jo 1
what palpation can show firbomyalgia
excessive tenderness of palpation of soft tissue in 11 out of 18 sites
what is difficulty climbing the stairs a sign of
polymyositis
