Test 4 Ch. 30 Myasthenia Gravis

Question 1

The most common chronic disorder of neuromuscular junction and interferes (blocks) w/ the chemical of acetylcholine (ACh)

Answer 1

Myasthenia gravis

Question 2

What is the hallmark clinical features of MG is

Answer 2

fluctuating skeletal muscle weakness, often with true muscle fatigue

Question 3

What are the 2 clinical types of myasthenia gravis:

Answer 3

1. ocular
2. generalized

Question 4

The muscle weakness is limited to the eyelids and extra ocular muscles

Answer 4

ocular

Question 5

In generalized myasthenia gravis the muscle weakness involves a variable combination of

Answer 5

1. Muscle of the mouth and throat responsible for speech and swallowing (bulbar muscles)
2. limbs
3. respiratory muscles

Question 6

When the diaphragm is involved vent failure can develop producing

Answer 6

myasthenia crisis

Question 7

Pathologic or structural changes in MG

Answer 7

• Mucus accumulation
• Airway obstruction
• Alveolar consolidation
• Atelectasis

Question 8

MG appears to be related to

Answer 8

ACh receptors antibodies (IgG) that block the nerve impulse transmissions at the neuromuscular junction

Question 9

Pts who have detectable antibodies to the AChR

Answer 9

seropositive MG

Question 10

Lacking both AChR or MuSK antibodies

Answer 10

seronegative MG

Question 11

Typically is the ocular MG (50%)

Answer 11

seropositive

Question 12

90% of cases of generalized MG are

Answer 12

seronegative

Question 13

Screening methods and test used to diagnose MG includes

Answer 13

1. clinical presentation and history
2. bedside test
3. immunologic studies
4. electrodiagnostic studies
5. evaluation of conditions associated w. MG

Question 14

The hallmark of MG is

Answer 14

chronic muscle fatigue

Question 15

Signs and symptoms include

Answer 15

• facial muscle weakness
• ptosis
• diplopia
• ophthalmoplegia
• difficultly in breathing
• speaking
• chewing
• swallowing

Question 16

drooping of one or both eyelids

Answer 16

ptosis

Question 17

double vision

Answer 17

diplopia

Question 18

paralysis or weakness of one of more of the muscles that control eye movement

Answer 18

ophthalmoplegia

Question 19

Ice pack tea is a very _______, _____, and __________ procedure for diagnosing MG in pts who have _______

Answer 19

simple, safe; reliable
ptosis

Question 20

The test consist of the application of an ice pack for __ to __ minutes

Answer 20

3 to 5

Question 21

The test Is considered positive if

Answer 21

there is improvement of the ptosis ( an increase of at least 2 mm in the palpebral fissure from before the test

Question 22

What test is used for pts w/ obvious ptosis or ophthalmoparesis

Answer 22

edrophonium (Tensilon) test

Question 23

Edrophonium is a short acting drug that blocks

Answer 23

cholinesterase from breaking down ACh after it has been released from the terminal axon

Question 24

If it gets better after getting Edophnium (Tensilon) then the pt is

Answer 24

postive

Question 25

Removal of the thymus gland

Answer 25

thymectomy

Question 26

A benign tumor of the thymus gland that may associated w/ MG

Answer 26

thymoma

Question 27

Clinical manifestations of MG

Answer 27

- atelectasis - alveolar consolidation - excessive bronchial secretions

Question 28

Respiratory Rate

Answer 28

- Varies w/ the degree of respiratory muscle paralysis - Apnea (in severe cases)

Question 29

Chest Assessment Findings

Answer 29

- Diminished breath sounds - crackles

Question 30

Radiologic Findings

Answer 30

- Normal - Increased opacity (when atelectasis or consolidation is present)

Question 31

Clinical indicators or impending acute vent failure include:

Answer 31

- FVC <20 mL/kg - MIP below -30 cm H20 - MEP <40 mmHg - pH <7.35

Question 32

The 4 basic therapeutic modalities used to treat MG are:

Answer 32

1. symptomatic treatment (acetylcholinesterase inhibitors) 2. chronic immunotherapies 3. rapid immunotherapies 4. thymectomy

Question 33

These are recommended as the first line of tx for symptomatic MG

Answer 33

acetylcholinesterase inhibitors

Question 34

This is the first choice

Answer 34

Pyridostigmine (Mestinon)

Question 35

Chronic immunotherapies (long term) agents include

Answer 35

- glucocorticoids - Azathioprine - mycophenolate mofetil - cyclosporine

Question 36

Rapid immunotherapies

Answer 36

- Plasmapheresis (plasma exchange ) - Intravenous immune globulin (IVIG)

Question 37

**Questions from the back** The onset of the signs and symptoms of MG is: 1. Slow and insidious 2. Sudden and rapid 3. Intermittent 4. Often elusive

Answer 37

1. Slow and insidious 2. Sudden and rapid 3. Intermittent 4. Often elusive

Question 38

Myasthenia gravis: 1. Is more common in young men 2. Has a peak age of 15 to 35 years 3. Is often provoked by emotional upset physical stress 4. Is associated w/ receptor- binding antibodies

Answer 38

2. Has a peak age of 15 to 35 years 3. Is often provoked by emotional upset physical stress 4. Is associated w/ receptor- binding antibodies

Question 39

Which of the following is associated w/ MG 1.Bronchospasm 2. Mucus accumulation 3. Alveolar hyperinflation 4. Atelectasis

Answer 39

2. Mucus accumulation 4. Atelectasis

Question 40

When monitoring pts w/ MG all of the following are indicators if acute vent failure except: a. pH:7.31 b. PaCO2: 55 mm Hg c. FVC: 25 mL/kg d. MIP:-15 cm H20

Answer 40

c. FVC: 25 mL/kg

Question 41

Which of the following antibodies is believed to block the nerve impulses transmission at the neuromuscular junction in MG a. IgG b. IgE c. IgA d. IgM

Answer 41

a. IgG