Musculoskeletal System

Question 1

SLE

Answer 1

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

Question 2

Osteoarthritis

Answer 2

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

Question 3

Rheumatoid arthritis

Answer 3

Onset 40-60; often younger
MCP, PIP, Wrists
Prolonged Morning Stiffness
Systemic Symptoms: Fever, Fatigue, Weight loss
Soft/spongy, warm joints

Question 4

Acute rheumatic fever

Answer 4

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)

Question 5

Trigeminal Neuralgia

Answer 5

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

Question 6

Reactive arthritis

Answer 6

associated with HLA-B27
Urethritis, conjunctivitis, arthritis in a male

Question 7

Duchenne muscular dystrophy

Answer 7

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.

Question 8

Becker muscular dystrophy

Answer 8

(X-linked non-frameshift deletions in dystrophin; less severe than Duchenne)
Slow, progressive muscle weakness in boys

Question 9

Ehlers-Danlos syndrome

Answer 9

(type V collagen defect, type III collagen defect seen in vascular subtype of ED)
Elastic skin, hypermobility of joints, Inc bleeding tendency.

Question 10

Osteogenesis imperfecta

Answer 10

(type I collagen defect)
Blue sclera, multiple fractures, dental problems,
conductive hearing loss

Question 11

Bells Palsy

Answer 11

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

Question 12

Myotonic Dystrophy

Answer 12

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.

Question 13

Dermatomyositis

Answer 13

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.

Question 14

Urge Incontinence

Answer 14

urgency leads to complete voiding,
detrusor spasticity leads to small bladder volume;
PVRV: 5-10mL

Question 15

Overflow Incontinence

Answer 15

cannot completely empty bladder
PVRV: residual volume > 100ml

Question 16

Stress Incontinence

Answer 16

weak pelvic floor muscles
urinating when coughing, laughing, etc.
estrogen effect;

PVRV = 50ml

Question 17

Reactive Arthritis

Answer 17

Traid of:

• Uretheritis
• Conjunctivitis
• Mono/oligo articulaticular arthritis

Assosiated with HLA-B27 & Sacroilitis

Question 18

Scleroderma/ Systemic Sclerosis

Answer 18

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.

Question 19

Lambert-Eaton syndrome

Answer 19

autoantibodies against voltage-gated calcium channels on the (pre) synaptic membrane of the neuromuscular junction

Associated with Small cell lung cancer (SCLC)

Question 20

Achondroplasia

Answer 20

• Achondroplasia is an autosomal (dominant) condition.
• It is caused by a mutation in FGFR3 gene, which causes an inhibition
  of (chondrocyte) proliferation.

Question 21

Lichen planus

Answer 21

(6 P’s)
Pruritic, purple, polygonal, planar papules and plaques

Question 23

Osgood-Schlatter disease (OSD)

Answer 23

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.