Musculoskeletal System Flashcards
SLE
Positive ANA, anti–double-stranded DNA, anti-Smith Antibodies
Skin & Joints:
Malar rash.
Arthritis
Cardiovascular manifestations of SLE:
accelerated atherosclerosis.
verrucous (Libman-Sacks) endocarditis.
Renal involvement in SLE:
(Nephritis or nephrotic Syndrome)
diffuse proliferative glomerulonephritis (characterized by proliferative and necrotizing lesions with crescent formation during active disease).
Light microscopy also classically shows diffuse thickening of the glomerular capillary walls with “wire-loop” structures due to subendothelial immune complex deposition
Osteoarthritis
Onset >40; increases with age
Knees,Hips,DIP joint1st CMC joint
Morning stiffness None/brief (<30 min)
No systemic Involvement
Hard, bony enlargement of joints
Rheumatoid arthritis
Onset 40-60; often younger
MCP, PIP, Wrists
Prolonged Morning Stiffness
Systemic Symptoms: Fever, Fatigue, Weight loss
Soft/spongy, warm joints
Acute rheumatic fever
Endemic in developing countries
Occurs 2-4 weeks after acute group A streptococcal pharyngitis
Molecular mimicry: Anti-streptococcal antibodies attack cardiac & neuronal antigens
Acute/subacute
Migratory arthritis
Pancarditis (mitral regurgitation)
Sydenham chorea
Chronic
Mitral stenosis
Note:
Rupture of Chordae tendonae causes mitral regurge.
“ J ❤️ N E S “
J = Joints (polyarthritis)
❤️ = Myocarditis / MVP
N = Nodes (subcutaneous nodule over bony
prominence)
E = Erythema Marginatum
S = Sydenham Chorea (antibody mediated destruction of corpus straitum of basal ganglia)
Trigeminal Neuralgia
Sudden severe pain in the distribution of CN-V (particularly V1 &V2)
Pain is like stabbing or electric shock
triggered by chewing, brushing, shaving, washing the effected area etc.
Carbamazepine is DOC
Reactive arthritis
associated with HLA-B27
Urethritis, conjunctivitis, arthritis in a male
Duchenne muscular dystrophy
XLR
Mutation in DMD gene encoding Dystrophin, a cytoplasmic protien that plays imp role in anchoring muscle Actin filament to plasma membrane
(Gowers sign)
Child uses arms to stand up from squatting postion,
Weakness of lower limb girdle
Proximal muscle weakness after a period of relatively normal development.
Complication include dilated cardiomyopathy and respiratory insufficiency
Abnormal protien accumulated in cytoplasm.
Becker muscular dystrophy
(X-linked non-frameshift deletions in dystrophin; less severe than Duchenne)
Slow, progressive muscle weakness in boys
Ehlers-Danlos syndrome
(type V collagen defect, type III collagen defect seen in vascular subtype of ED)
Elastic skin, hypermobility of joints, Inc bleeding tendency.
Osteogenesis imperfecta
(type I collagen defect)
Blue sclera, multiple fractures, dental problems,
conductive hearing loss
Bells Palsy
Isolated facial nerve palsy (CN-VII)
Typically secondary to HSV reactivation
Complete ipsilateral facial weakness involving forehead,
1- Loss of forehead or brow movements.
2- Inability to close eyes & drooping of eyelids.
3- Loss of nasolablial folds & drooping lower lip
Taste and hearing abnormalities, (Loss of taste ant 2/3 of tounge & Hyperacusis)
Decreased tear production
Loss of sensation from portions of pinna to EAC
Myotonic Dystrophy
Expansion of Trinucleotide repeat CTG
Type-1 : DMPK gene
Type-2 : CNBP gene
Characterized by:
Ptosis, Facial muscle atropy, Muscles weakness, Myotonia, Cataracts, Frontal balding, Cardiac arythmias, Hypogonadism.
More frequently affected muscles are facial muscles, sternlcloidomastoid, distal forearm, instrinsic hand and ankle dorsiflexion.
It is assosiated with presence of ring fibers and central nuclei on muscle biopsy.
Dermatomyositis
Presents with Cutaneous and Musculoskeletal manifestation
Heliotrope rash (pink or light purple rash over upper eyelid), pink papules over dorsal fingers (Gottron papule), Piokilodermatous rash in shawal distribution (pink to iliac colouref patches with talengectaseias over upper back and sun exposed chest)
Proximal muscle and extremity weakness (i.e difficulty lifting arms over head for example to comb the hairs)
Cancers like Adenocarcinoma of ovaries is assosiated with Dermatomyositis as paraneoplastic syndrome.
Anti-nuclear antibody, Anti-Jo antibody, Anti-SRP, Anti-Mi-2 antibodies.
Urge Incontinence
urgency leads to complete voiding,
detrusor spasticity leads to small bladder volume;
PVRV: 5-10mL
Overflow Incontinence
cannot completely empty bladder
PVRV: residual volume > 100ml
Stress Incontinence
weak pelvic floor muscles
urinating when coughing, laughing, etc.
estrogen effect;
PVRV = 50ml
Reactive Arthritis
Traid of:
- Uretheritis
- Conjunctivitis
- Mono/oligo articulaticular arthritis
Assosiated with HLA-B27 & Sacroilitis
Scleroderma/ Systemic Sclerosis
It can be localized called as localized scleroderma or diffuse/systemic scleroderma called as systemic sclerosis.
AKA “ C R E S T syndrome ”
C = Calcinosis (Ca+2 deposit in skin)
R = Raynauds Phenomenon
E = Esophageal dysfunction(acid reflux,↓motility)
S = Sclarodactyly (thickening & tightening of
skin on fingers & hands)
T = Telangectasias
– Anti-Centromere Antibodies are classic for CREST syndrome.
– Anti-Topoisomerase (Anti-Scl-70) are seen in diffuse systemic sclerosis.
Pulmonary fibrosis can be caused secondary to CREST syndrome, both limited and diffuse systemic sclerosis can lead to pulmonary fibrosis.
Myasthenia gravis (MG)
- Autoantibody-mediated attack on the acetylcholine receptors of the postsynaptic neuromuscular junction
- Leading to a reduced number of acetylcholine receptors
- It is characterized by fatigable weakness of the skeletal muscles; respiratory failure can occur due to diaphragmatic weakness.
- Difficulty rising from seated position (proximal muscle weakness), Difficulty raising arms over head, Ocular (Diplopia , Ptosis), Bulbar (Dysarthria , Fatigue able chewing), Facial muscle weakness
- Respiratory failure (↓ pH, ↑ pCO2, ↓ O2)
- Weakness increases with use
- Most patients also have Thymic Diseases i.e. Thymic Hyperplasia or Thymoma
Lambert-Eaton syndrome
- Autoantibodies against voltage-gated calcium channels on the (pre) synaptic membrane of the neuromuscular junction
- Weakness decrease with use due to Ach accumulation by repetitive movement
- Associated with Small cell lung cancer (SCLC)
Achondroplasia
- Achondroplasia is an autosomal (dominant) condition.
- It is caused by a mutation in FGFR3 gene, which causes an inhibition of (chondrocyte) proliferation.
- Short limbs but normal head and torso
Lichen planus
(6 P’s)
Pruritic, purple, polygonal, planar papules and plaques
Osgood-Schlatter disease (OSD)
A common cause of knee pain in adolescents due to overuse of the quadriceps muscle group
(i.e. rectus femoris, vastus intermedius, vastus lateralis, vastus medialis)
Repetitive traction at the tibial tubercle due to quadriceps contraction can lead to avulsion and fragmentation of the tibial tubercle in skeletally immature children, causing Osgood-Schlatter disease.
Acute gouty arthritis
- Usually involves first metatarsophalangeal joint or knee
- Swelling, erythema & exquisite tenderness
- Symptoms develop rapidly over 24hr
- Joint aspiration shows needle-shaped, negatively birefringent crystals
Rx:
- Nonsteroidal anti-inflammatory drugs (eg,naproxen, indomethacin) preferred if no contraindications
- Colchicine used as second-line therapy
Septic Arthritis
- Fever
- Acute Mono arthritis
- Pain + erythema + Decrease range of motion
