Arthritis and some myopathies Flashcards
Define Neuromyotonia
A autoimmune disease involving antibodies which act against K+ ion channels. It results in hyperexcitability and therefore prolonged skeletal muscle contraction.
Identify two anticonvulsant treatments of Myotonia
Carbamazapine, Phenytoin
Lambert Eaton Myasthenic Syndrome (LEMS) is associated with what condition?
Small cell bronchial carcinoma
LEMS is associated with the defective release of what neurotransmitter?
ACh
LEMS can have autoimmune causes- Identify which channels are effected in this case
Ca2+ channels
Identify two types of drug used in the treatment of LEMS.
anticholinesterases
potassium channel blockers
Identify the cardinal sign of LEMS.
proximal muscle weakness with some absent tendon reflexes
identify the cardinal signs of Myasthenia gravis
weakness and fatigability in proximal limbs, ocular and bulbar muscles
What is targeted by autoantibodies in the autoimmune disorder Myasthenia Gravis
ACh receptor protein
Identify two types of drugs used to treat MG and an example of each
anticholinesterases- Pyridostigmine, edrophonium
Immunosuppressants- azathioprine
What bacteria produces Botulinum toxin? How does it effect ACh release?
Clostridium Botulinum
irreversibly inhibits ACh release
How do curare like compounds effect the amplitude of epp?
They reduce it below the threshold for an AP by being competitive antagonists to AChRs
10% of myasthenia gravis is caused by ____ ______ while 90% is idiopathic
thymic tumours
Describe the pathophysiology of myasthenia gravis
CD4+ T cells activated by AChRs expressed on thymic cells leading to autoreactive B cell stimulation thus the generation of auto-IgG antibodies for AChRs. AChRs are thus destroyed by the antibodies. The muscle end plate also becomes damaged
Identify the two main tests for Myasthenia Gravis
Auto-IgG antibodies in the serum
repetitive nerve stimulation- the responses gradually decrease
90% of osteomyelitis is caused by what pathogen?
Staphlococcus but also salmonella and H. Influenzae
Osteomyelitis occurs due to ____________ spread to the vascular ___________.
haematogenous
metaphysis
identify two of the conditions in which setting osteomyelitis is found
type 2 diabetes
Chronic skin ulceration ( from venous insufficiency)
_____________ osteomyelitis occurs due to haematogenous spread from the lungs/the GI tract. The __________ are often involved and may collapse and form abscesses
haematogenous
vertebrae
identify four symptoms of osteomyelitis
localized bone pain, fever, tenderness, erythema
which organism is the main cause of septic arthritis?
Staph. Aureus
in young/previously healthy patients identify how septic arthritis would present
red, hot, erythematous, swollen, agonizing pain, held immobile by muscle spasm.
in elderly/immunosuppressed/RA patients may be more insidious with few systemic symptoms
to investigate septic arthritis you would 1. aspirate the joint/get a _______ culture 2. _________ the joint 3. provide __________ 4. administer IV _________.
blood
immobilise
physiotherapy
antibiotics
What is the difference between primary and secondary osteoarthritis?
Primary-idiopathic and with old age
Secondary- due to predisposing conditions
Pathogenesis of OA:
Initial ________ _________ damage leading to surface __________ and ulceration. This causes further ________ loss putting more stress on the bones leading to ____________ and cysts. In the worst case __________ would form which are abnormal sclerotic projections of subchondral bone and they are visible on X-rays..
articular cartilage fibrillation cartilage microfractures osteophytes
explain the effect of inflammatory cytokines on OA pathogenesis.
The stimulation of macrophages and T cells by trauma of joints etc leads to the release of pro-inflammatory cytokines resulting in a disturbance to the cartilage turnover rate leading to articular cartilage degeneration.
identify 5 predisposing risk factors for OA
obesity gender- more common in women trauma sport/occupation genetic predisposition secondary causes: RA, gout, spondyloarthritis, septic arthritis
Identify 3 symptoms of OA
joint pain upon movement and/or weight bearing
functional limitation
short lived morning joint stiffness
identify 5 signs of OA
crepitus reduced movement joint effusion muscle wasting/ bony instability bone enlargement
Identify the most commonly affected sites of OA
cervical spine lumbar spine interphalangeal joints hip joint knee joint ankle great toe metatarsal
identify 5 possible investigations of OA
X-ray- shows progressive disease and is initial test
blood tests
arthroscopy- early injury
aspiration of synovial fluid
MRI-early injury- shows soft tissue involvement
Identify some non-pharmacological treatments of OA
lose weight physiotherapy walking aid hydrotherapy suitable footwear
Identify the various treatments of OA
paracetamol topical then oral NSAIDs capsaicin opioids last resort glucocorticoid injections replacement arthroplasty resurfacing surgery
What are the nodes exhibited in OA of the PIPs and DIPs called
PIP- Bouchard’s nodes
DIP- Heberden’s node’s
Knee OA is associated with what other deformities?
Bakers cyst
Varus/valgus deformities
Which joints are commonly affected in the early stages of RA?
MCP PIP MTP wrist elbows shoulders knees ankles
RA is a chronic ____________ rheumatic disease. patients generally develop chronic ____________ polyarthritis and _________ inflammation.
inflammatory
symmetrical
systemic
what is the most common age of onset of RA?
30 to 50but also may present in early childhood (rare) or late old age
what are the three main type of inflammatory arthritis?
what characterises inflammatory arthritis
RA, spondyloarthritis, crystal arthritis
synovial inflammation
What is the main identifying symptom of inflammatory arthritides? What is typically found raised in a blood sample?
Pain and stiffness worst in the morning and lasting several hours + improves with activity.
Raised ESR and CRP
The presence of certain Haplotypes of __________ _____________ __________ increases susceptibility to RA.
Human Leukocyte Antigens
Immunology of RA:
Genetic and environmental factors lead to the _____________ of self antigens (ACPA). This is detected by B and T cells. this leads to the triggering of of osteoclasts, _________ and __________ _________ combining to cause joint damage.
citrullination
macrophages
synovial fibroblasts
What is citrullination?
the reaction for converting the amino acid arginine to citrulline.
In RA the synovium greatly ___________ causing swelling around joints and tendons and proliferation of the synovium into folds and fronds. _________ of __________ cells occurs. The hyperplastic synovium spreads from joint margins to the _______ surface leading to ________ formation which damages the underlying cartilage by blocking its normal route for _________. angiogenesis also occurs. the proliferation of fibroblasts of the synovium along the course of blood vessels to the epiphysal bone where it causes erosions.
thickens proliferation inflammatory cartilage pannus nutrition
identify four early symptoms of RA
pain and stiffness of joints in morning
monoarthritis- knee/shoulder
carpal tunnel syndrome
sleep disturbance and fatigue
Identify the typical signs of early RA
tenosynovitis signs- warm, tender, swollen joints limited movement muscle wasting deformities-swan neck, Boutonniere, ulnar deviation
Identify two complications of RA
septic arthritis
amyloidosis
What results in the Boutonniere and swan neck deformity in RA?
B- fixed flexion of PIP
SN- fixed hyperextension of PIP
identify some non-articular manifestations of RA
tenosynovitis- leads to trigger finger subcutaneous nodules around joints osteoporosis vasculitis lungs- pleural disease, bronchiectasis, bronchiolitis, interstitial lung disease, nodules Cardio risk factor neuropathies e.g. carpal tunnel syndrome dry mouth and eyes amyloidosis anaemia felty's syndrome- splenomegaly and neutropenia
What are the main investigations for RA
Blood count- anaemia, ESR and CRP raised
serology- ACPA positive
X-rays, ultrasound, MRI
Aspiration if effusion
Identify the three main clinical features of AS.
back pain
buttock pain- either one or both. pain and stiffness worst in the morning, relieved by exercise
retention of lumbar lordosis during spinal flexion
Which test is used to identify retention of lumbar lordosis during spinal flexion?
Schober’s test
What are the two main non-spinal complications of AS?
costochondritis- anterior chest pain
anterior uveitis
identify 3 tests and expected findings for AS.
bloods- raised ESR and CRP
Genes- HLA-B27 positive- adds weight but not diagnostic as is common gene
X-ray- bamboo spine- due to fusion of spinal facet joints, sacroiliac joints lose definition due to erosions and sclerosis.
Name 5 types of spondyloarthritis
ankylosing spondylitis psoriatic arthritis reactive arthritis enteropathic arthritis post-dysenteric reactive arthritis
Name the 5 possible patterns of psoriatic arthritis
mono/oligoarthritis spondylitis symmetrical polyarthritis (like RA) DIP arthritis- most common, dactylitis is characteristic of condition Arthritis mutilans
What is dactylitis?
Where an entire finger or toe is swollen
What percentage of psoriasis patients have psoriatic arthritis?
10%
state three organisms that cause reactive arthritis
shigella
ureaplasma
chlamydia
what is the typical presentation of reactive arthritis?
asymmetrical lower limb arthritis occuring days/weeks after infection
identify three causes of the increasing incidence of gout
changing diets- high saturated fat and fructose containing drinks
alcohol misuse
co-morbidities that promote hyperuricaemia
Gout is more common in ____ than in ____ because serum _____ _____ levels are higher in ____ than in _______.
men women uric acid men women
____ ____ is the product of endogenous and dietary ______ metabolism in humans. The SUA depends on the balance between ______ synthesis and the elimination of _______ by the _______ (66%) and the _________ (33%).
uric acid purine purine urate kidneys intestine
90% of gout is due to what problem? the remaining 10 % is due to what problem?
90- impaired renal excretion
10- increased uric acid production
identify the 5 possible presentations of gout
asymptomatic acute gout- OFTEN REPEATS chronic interval gout chronic polyarticular tophaceous gout- RARE urate renal stone
What is the typical presentation of gout?
Sudden onset of agonizing pain, swelling, redness, of the first MTP joint (great toe). 25% of cases a different joint
Why is the big toe the target of gout?
coolest part of body and thus uric acid crystals most likely to form here.
the clinical picture/ rapid response to NSAIDS/colchicine is normally diagnostic of gout. what other tests may you do?
SUA measured- raised above 600 micromoles/litre
joint fluid microscopy
signs of renal impairment.
What 4 drugs can be used in the initial treatment of acute gout?
naproxen
diclofenac
colchicine
corticosteroids
What dietary advice is given for gout?
avoid alcohol, carbonated drinks
reduce total calorie/cholesterol intake
in Gout patients what is the main drug used to reduce and maintain SUA levels below 360 micro-moles/litre?
Allopurinol
What is allopurinol?
A xanthine oxidase inhibitor used to reduce SUA levels of gout patients
What drug is used in patients who cannot tolerate allopurinol?
febuxostat
What characterises chronic tophaceous gout?
Sodium urate deposits in skin and around joints (tophi) on ear, fingers and achilles tendon. Also chronic joint pain
Tophaceous gout is associated with _____ ___________ and/or the long-term use of _________.
renal impairment
diuretics
when is pegloticase used in gout patients?
if patients are undergoing chemotherapy
if patients suffer from refractory tophaceous gout
What does CPPD stand for? what has it also been named?
Calcium Pyrophosphate dihydrate deposition arthropathy
pseudogout
The presence of Calcium pyrophosphate dehydrate crystals in hyaline and fibrocartilage is the most common cause of ________ ______________.
cartilage calcification
List the three most common forms of inflammatory arthritis
Rheumatoid arthritis
ankylosing spondylitis
CPPD
In which two ways is a diagnosis of CPPD deduced?
CPP crystals in joint fluid
cartilage calcification on xray
Treatments for symptom control in CPPD is similar to that in OA and gout. What two different treatments may be shown?
aspiration of joint- pain relief
injection of corticosteroid
Apart from sodium urate and calcium pyrophosphate dehydrate what other crystals result in arthropathy?
Basic Calcium Phosphate
