Exam 5: Musculoskeletal Pathologies

Question 1

osteoarthritis

Answer 1

• older ppl or athletes
• breakdown of articular cartilage
• exacerbated by use

Question 2

RA

Answer 2

• autoimmune
• small joints
• joints warm / painful / stiff w/ inactivity
• symmetric

ulnar deviation of metacarpophalangeal joints

HANDS

Question 3

RA - histologically

Answer 3

synovium thickened, hyperplastic, lots of lymphoid aggregates

Question 4

gout

Answer 4

excessive uric acid

BIG TOE with TOPHI

Question 5

gout risk factors

Answer 5

age
duration of hyperuricemia
heavy ALCOHOL
obesity
drugs (thiazides)
lead toxicity

Question 6

tophi

Answer 6

• urate crystals with inflammation

- NEEDLE LIKE

Question 7

pseudogout

Answer 7

• calcium phosphate
• hereditary
• RHOMBOID / GEOMETRIC crystals

Question 8

bacteria that can cause infectious arthritis

Answer 8

• TB
• lyme: borrelia burgdorferi
• gonococcus
• staph aureus
• influenza
• salmonella

Question 9

viruses that can cause infectious arthritis

Answer 9

parvovirus
rubella
HCV

Question 10

what kind of patients are associated with salmonella?

Answer 10

sickle cell patients

Question 11

type 1 muscle fiber

Answer 11

• slow twitch
• weight bearing
• mitochondrial / ox phos pathway
• lipid metabolism

Question 12

type 2 muscle fiber

Answer 12

• fast twitch
• purposeful movement
• glycogen metabolism

Question 13

denervation atrophy - histologically

Answer 13

• angular, atrophic
• mm shrinks, nuclei remain on outside and look like giant cells
• target fibers

Question 14

type grouping

Answer 14

• after denervation, the nerve closest to the muscles re-enervates them
• it’s when you see ONE type of mm fibers - lack of checkerboard pattern

Question 15

amylotrophic lateral sclerosis

Answer 15

• 60 years old, M>F
• muscular atrophy
• hand weakness (early)
• progressive + respiratory mm weakness (late)

Question 16

ALS death due to

Answer 16

respiratory failure

bronchopneumonia

Question 17

ALS macroscopic findings

Answer 17

• shrunken / atrophic anterior nerve roots

- distal > proximal

Question 18

ALS microscopic findings

Answer 18

• bunina inclusion bodies

- degeneration of myelinated fibers in the corticospinal tracts

Question 19

a denervation injury always looks like this histologically

Answer 19

angulated, atrophic fibers

Question 20

a myopathy always looks like this histologically

Answer 20

• rounded atrophic fibers
• vacuoles
• degeneration, regeneration, fibrosis

Question 21

2 mutations of dystrophin gene

Answer 21

Duchenne MD,

Becker MD

Question 22

duchenne MD

Answer 22

• dystrophinopathy
• dystrophin ABSENT
• no brown

Question 23

becker MD

Answer 23

dystrophine reduced

- some brown

Question 24

dystrophinopathies - clinically

Answer 24

• proximal weakness
• calf pseudo-hypertrophy
• CK elevated early
• death from respiratory, cardiac failure

Question 25

polymyositis

Answer 25

• an inflammatory myopathy
• infiltrate can be aggressive
• becomes necrotic post infiltration

Question 26

dermatomyositis

Answer 26

• facial rash

- perifascicular atrophy

Question 27

McArdle’s Disease

Answer 27

• glycogen defect
• myophosphorylase deficiency
• PAS stain +

Question 28

Carnitine Palmityl Transferase Deficiency

Answer 28

• lipid defect

- Oil red O stains red

Question 29

mitochondrial myopathies

Answer 29

• proximal weakness

- opthalmoplegia

Question 30

drug induced myopathies can be caused by

Answer 30

• steroids
• statin drugs
• colchicine
• ethanol

Question 31

malignant hyperthermia

Answer 31

• an ion channel myopathy
• hypermetabolic state
• trigger: ANESTHESIA
• gene mutation in Ca channel (RYR1)

Question 32

Myasthenia gravis

Answer 32

• loss of Ach receptors
• post synaptic
• thymus problems
• worsened by exercise
• ptosis

Question 33

Lambert Eaton Syndrome

Answer 33

• ppl with small cell lung cancer
• presynaptic
• Ab to presynaptic voltage gated Ca channels