MSK FIRST AID REVIEW_QUESTIONS MISSED Flashcards Preview

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Flashcards in MSK FIRST AID REVIEW_QUESTIONS MISSED Deck (45):
1

Most common form of Osteogenesis Imperfecta - transmission? Genes?

Autosomal Dominant: Mutation in 2 collagen A genes: COLA-1 and COLA-2 genes

2

Defect that causes Osteogenesis Imperfecta?

Caused by a faulty substitution of glycine by a bulky acid in Type I Collagen

3

Clinical Findings that lead to Osteogenesis Imperfecta? Give a possible clinical scenario for each if possible.

1. Pathologic features at birth: "normal healthy baby, but fractures in large bones without a prior history of trauma"
2. Blue sclera: reflection of the underlying choroidal veins through the thin sclera
3. Deafness in some patients: Deformity of middle ear bones
4. Dental imperfections --> lack of dentin

4

Treatment of Osteogenesis Imperfecta?

Bisphosphonates to increase bone mineralization

5

In Osteogenesis Imperfecta, _______ is defective. Describe what changes to the macromolecular structure of _________.

with the bulky acidic a.a. group substituting glycine in Collagen Type I --> can't form a triple helix

6

In 3 descriptors, Describe Osteogenesis Imperfecta?

Multiple fractures w/o prior trauma (may occur during birth process for Fx in infants)
Blue sclera
Hearing Loss

7

Incidence of Osteogenesis Imperfecta

1/10,000

8

A 6 y/o boy is brought into the ED with a femoral fracture. when you send him for an X-ray, you note multiple healed fractures in multiple bones. What two states/conditions can be attributed?

1. Osteogenesis imperfecta
2. Child abuse

9

Ehrlos-Danlos is a disorder characterized by what Signs/Symptoms?

- Increased range of Motion (Joint hyper-mobility)
- Highly stretchable skin (Cutaneous Fragility and hyper extensibility)
- Dark Pigmentation over bony prominences

10

What is the classic sign of Ehrlos-Danlos Syndrome (EDS)?

Hyperextension fo the fingers so they are parallel to the extensor surface of the forearm.

11

What is the major fibrous component of Connective Tissue?

collagen

12

What is the structural unit of collagen? what is its structure?

Tropocollagen, triple helix of alpha-chains (Path, pg. 48)

13

what is the inheritance pattern of Ehrlos-Danlos Syndrome?

Mendelian

14

EDS is characterized by a defect in what macromolecule? Types, if any?

Collagen I and III

15

T/F: EDS is a homogeneous Ds. Explain your choice.

FALSE - EDS is a HETEROGENEOUS disorder, that has a wide range of severity, with EDS Type I < < < EDS Type IV

16

What is the most severe type of EDS?

Type IV EDS is the most severe

characterized by a decreased amount of Type III Collagen --> structural protein in blood vessels.

17

A 4-month pregnant woman arrives in the ER due to a uterine rupture. You also see that she is very flexible, showing you that she can even bend her fingers back towards her wrist. She is worried about the laxity of her hips, as she dislocated it easily before arriving at the ER (scaring the EMTs!). You suspect that she has a collagen Disorder - which one?

Ehrlos Danlos type IV - the most severe type

patients typically have a shortened life span because of spontaneous rupture of large arteries

18

In a person with Ehrlos-Danlos type IV, why is a headache very concerning?

Because of the Collagen III being in such low [ ] in the vessels - the probability of rupture is very high. In the setting of headache and this (+) PMH - a headache is concerning because we would suspect a possible arterial rupture or aneurysm.

19

Which bones are commonly involved in Osteogenesis Imperfecta?

Long bones
Arms
Ribs
Small bones of hands and feet

20

Osteogenesis Imperfecta: Ranking of Severity?

Type I < Type II < Type III

Type III are the most severely affected
Bad Type II may die in utero or during parturition

21

When should Osteogenesis Imperfecta be suspected? (8)

OI should be on the DDx in the presence of any combination of the following:
- bone fragility
- scoliosis
- short stature
- basilar skull fractures (think Battle Sign!)
- Blue Sclerae
- Hearing loss
- Dental Abnormalities
- Easy bruising

22

What is the inheritance pattern of Duchenne Muscular Dystrophy (DMD)?

X-linked recessive (XR)

23

What is the incidence of Duchenne Muscular Dystrophy?

1/35,00 MALE births

24

What type of mutation causes Duchenne MD?

frameshift mutation of the dystrophin gene on the X-chromosome

25

What is the normal action of dystrophin in the muscles?

Dystrophin anchors actin to the membrane glycoprotein

26

Duchenne vs. Becker Muscular dystrophy: What is the difference in terms of the dystrophin protein?

Duchenne is a complete absence of the protein

Becker is either a partial deficiency or a defective version of the protein

27

What causes the S/Sx seen with Duchenne MD?

Absence of dystrophin protein --> progressive degeneration of type I and type II fibers

28

Describe the evolution of "champagne bottle calves" seen in Duchenne MD patients?

this findings if caused by the fibrosis and fatty infiltrate into the gastrocnemius muscle tissue, thus producing the pseudohypertrophy of the calf muscles.

this will produce the classic sign of "champagne bottle calves" of Duchenne children.

29

When do symptoms normally present in children affected by Duchenne MD?

Between the ages of 2-5 years

30

What are the S/Sx typically associated with Duchenne MD?

- Weakness and wasting of pelvic muscles
- Gower Maneuver
- Waddling (duck-like) gait
- Cardiac involvement: Cardiomyopathy --> heart failure and arrythmias
Respiratory muscle weakness eventually leads to respiratory failure

31

When do patients with Duchenne MD typically expire? What is usually the cause?

Typically patients w/ Duchenne will have a progressive weakness of their respiratory muscles, leading to respiratory failure.
the average age of death is 20 y/o

32

Clinical S/Sx of Sjogren's Syndrome?

Dry Eyes: "Sand in my Eyes"
Dry mouth: "Doctor, I can't swallow dry crackers"
Dental Caries
One other connective tissue / AIDx: typically Rheumatoid Arthritis

33

The eye and mouth dryness seen with Sjogren's Syndrome is due to ______?

Autoimmune destruction of the salivary and lacrimal glands

34

Sjogren's Syndrome is a symptom of what two underlying neoplastic diseases?

Non-Hodgkin Lymphoma
Salivary Gland and GI Lymphomas

35

Classic patient profile in Sjogren's Syndrome?

Female dominant AIDx that commonly presents with rheumatoid arthritis

36

Why are dental caries a finding in Sjogren's Syndrome?

Sjogren's Syndrome presents with auto-immune destruction of the salivary glands. Saliva, however, is essential at maintaining the oral pH ~7.0. If this doesn't happen, then bacterial acids will start leaching Ca2+ from enamel, thus leading to caries.

37

In serological studies, what tests indicate Sjogren's Syndrome?

Positive ANA --> tells you there is an AIDx
Positive serum RF [90%] - this is a non-specific test that tells you there is a connective tissue inflammation disorder afoot
Anti-SS-A antibodies (Anti-Ro; 70%-95%)
Anti-SS-B antibodies (Anti-La; 60-90%)

38

How do you confirm the DDx of Sjogren's Syndrome? What histological pattern do you see?

Lip biopsy --> Lymphoid structures of the minor salivary glands

39

Treatment of Sjogren's Syndrome?

Artificial tears
Pilocarpine or cyclosporine eye drops
Cevimeline (MxR agonist) --> Dry mouth

40

(+) VDRL test in SLE - Why?

They have so many auto-antibodies that they come up positive

41

Most specific autoantibodies in SLE?

Anti-Smith
Anti-dsDNA

42

Most common population for SLE?

women of childbearing age, blacks, asians, hispanics > whites

43

Environmental triggers for SLE

EBV, UV light, Estrogen, Meds

44

Skin findings in SLE

Malar "butterfly" rash over cheeks with UV light exacerbation
IF studies = IC deposition along BM in both involved and uninvolved areas

45

Musculoskeletal findings in SLE

Arthralgia -most common complaint
morning stiffness in hands - very common
Arthritis - most common in PIP and MCP joints of hands and wrists
Typically symmetric and non-erosive and non-deforiming (unlike Rheumatoid Arthritis = deforming)