Musculoskeletal diseases

Question 1

Select the statement that BEST describes myasthenia gravis.
a. pregnancy reduces the severity of the symptoms
b. neonates of affected mothers are at risk for muscle weakness
c. Edrophonium impairs muscle strength during symptom exacerbation
d. Acetylcholine production is decreased

Answer 1

B. neonates of affected mothers are at risk for muscle weakness

Question 2

Myasthenia gravis is an

Answer 2

autoimmune disease in which IgG antibodies destroy post-junctional nicotinic receptors at the neuromuscular junction leading to skeletal muscle weakness

Question 3

Signs and symptoms of myasthenia gravis includes

Answer 3

ptosis, dysphagia, dysarthria, and proximal muscle weakness

Question 4

The first line medical treatment for myasthenia gravis is

Answer 4

oral pyridostigmine

Question 5

Overdose of anticholinesterases leads to

Answer 5

cholinergic crisis and muscle weaknesis

Question 6

______________ will help you determine if weakness is due to cholinergic crisis or myasthenic crisis.

Answer 6

Tensilon test

Question 7

The ______ plays a key role for patients with myasthenia gravis, and ___________ brings symptom relief to many paitents.

Answer 7

thymus gland; thymectomy

Question 8

A key feature of myasthenia gravis is

Answer 8

skeletal muscle weakness that becomes worse later in the day or that develops with exercise; periods of rest allow for the recovery of skeletal muscle function

Question 9

Situations that exacerbate myasthenia gravis include

Answer 9

pregnancy
infection
electrolytes abnormalities
surgical and psychological stress
aminoglycoside antibiotics

Question 10

How does myasthenia gravis affect neonates of mother’s with the condition?

Answer 10

anti-AchR IgG antibodies cross the placenta and cause weakness in 15-20% of neonates
this can persist up to 2-4 weeks

Question 11

Treatment for myasthenia gravis includes

Answer 11

anticholinesterases
immunosuppression
plasmapheresis
surgery (thymectomy)

Question 12

The patient with myasthenia gravis will be (select 2):
a. sensitive to vecuronium
b. resistant to rocuronium
c. sensitive to succinylcholine
d. resistant to succinylcholine

Answer 12

a. sensitive to vecuronium
d. resistant to succinylcholine

Question 13

Patients with myasthenia gravis have ________ receptors at the neuromuscular junction.

Answer 13

fewer nicotinic receptors

Question 14

Patients with myasthenia gravis have _________ to nondepolarizing NMBs.

Answer 14

increased sensitivity

Question 15

Patients with myasthenia gravis have _______ to depolarizing NMBs.

Answer 15

increased resistance or decreased sensitivity

Question 16

If a neuromuscular blocker is used for patients with myasthenia gravis, there is an increased risk of

Answer 16

residual neuromuscular blockade

Question 17

Bulbar muscle weakness (mouth and throat) manifests as

Answer 17

difficulty handling oral secretions; this increases the risk of pulmonary aspiration

Question 18

How does pyridostigmine (the mainstay of medical management for myasthenia gravis) affect succinylcholine?

Answer 18

prolongs the duration of succinylcholine because it impairs the efficacy of pseudocholinesterase

Question 19

Patients with myasthenia gravis should be counseled on

Answer 19

the need for postoperative ventilation

Question 20

There is an increased risk for postoperative ventilation for patients with myasthenia gravis with

Answer 20

disease duration >6 years
daily pyridostigmine >750 mg/day
vital capacity <2.9 L
COPD
surgical approach: median sternotomy> transcervical thymectomy

Question 21

Identify the characteristics common to Eaton-Lambert syndrome. (select 3)
a. destruction of voltage-gated calcium channels
b. bulbar muscle weakness
c. diagnosed with Tensilon test
d. destruction of the nicotinic receptor
e. increased sensitivity to succinylcholine
f. small cell lung carcinoma

Answer 21

a. destruction of voltage-gated calcium channels
e. increased sensitivity to succinylcholine
f. small cell lung carcinoma

Question 22

Eaton Lambert syndrome is a

Answer 22

disorder of the neuromuscular junction that results in skeletal muscle weakness
caused by IG-mediated destruction of the presynaptic voltage-gated calcium channel at the presynaptic nerve terminal

Question 23

____________ increases ACh release from the presynaptic nerve terminal and improves the strength of contraction.

Answer 23

3,4 diaminopyridine (DAP)

Question 24

Are anticholinesterases helpful for Eaton-Lambert syndrome?

Answer 24

No

Question 25

Can the Tensilon test be used to diagnose Eaton-Lambert syndrome?

Answer 25

No

Question 26

How do patients respond to paralytics when they have Eaton-Lambert syndrome?

Answer 26

patients are sensitive to succinylcholine & non-depolarizers (reduce doses)

Question 27

Reversal with anticholinesterases for those with Eaton-Lambert syndrome may be

Answer 27

inadequate despite proper dosing

Question 28

Describe the postsynaptic nicotinic receptors with Eaton-Lambert syndrome.

Answer 28

Present in normal quantity and function normally; we just don’t see the adequate release of acetylcholine to simulate them

Question 29

Patients with Lambert-Eaton syndrome are at high risk for postoperative

Answer 29

ventilatory failure

Question 30

Upwards of 60% of patients with Eaton-Lambert syndrome have

Answer 30

small-cell carcinoma of the lung (oat-cell carcinoma)
consider the possibility of this disorder in all patients with suspected lung cancer undergoing mediastinoscopy, bronchoscopy, or thoracoscopy

Question 31

What is the clinical presentation of Lambert-Eaton syndrome?

Answer 31

proximal muscles are affected with weakness generally worse in the morning and better throughout the day
respiratory musculature and diaphragm become weak
autonomic nervous system dysfunction causes orthostatic hypotension, slowed gastric motility, and urinary retention

Question 32

Which disease begins with an influenza-like illness that is followed by ascending paralysis?
a. familial periodic paralysis
b. myotonic dystrophy
c. Charcot-Marie-Tooth
d. Guillain-Barre syndrome

Answer 32

d. Guillain-Barre syndrome

Question 33

________ is the most common cause of acute, generalized paralysis.

Answer 33

Guillain-Barre syndrome

Question 34

Guillain-Barre syndrome is characterized by

Answer 34

an immunologic assault on myelin in the peripheral nerves

Question 35

Medical treatment for Guillain-Barre syndrome includes

Answer 35

plasmapheresis and IV IgG
steroids are not useful

Question 36

Can regional anesthesia be used with Guillain-Barre syndrome?

Answer 36

controversial d/t inconclusive data

Question 37

Describe the use of neuromuscular blocking drugs with Guillain-Barre syndrome.

Answer 37

avoid succinylcholine
decrease the dose of nondepolarizing NMBs

Question 38

Describe the onset of GBS.

Answer 38

flu-like illness usually precedes paralysis by 1-3 weeks
usually persists for 2 weeks and ends with full recovery in 4 weeks

Question 39

Describe the symptoms of GBS.

Answer 39

flaccid paralysis usually begins in the distal extremities and ascends bilaterally towards the proximal extremities, trunk, and face
muscle weakness impairs ventilation and causes difficulty swallowing (risk of aspiration)

Question 40

GBS is characterized by

Answer 40

an immunologic assault on myelin in the peripheral nerves
the action potential can’t be conducted so it never reaches the motor endplate

Question 41

Etiologies of GBS include

Answer 41

Campylobacter jejuni bacteria, Epstein-barr virus, cytomegalovirus, vaccinations, surgery, and lymphomatous disease

Question 42

Patients with GBS may have _________ necessitating the use of _______ intraoperatively

Answer 42

autonomic dysfunction requiring intra-arterial pressure monitoring

Question 43

Patients with GBS have an exaggerated response to __________ due to the upregulation of postjunctional adrenergic receptors

Answer 43

indirect-acting sympathomimetics

Question 44

What is another name for GBS?

Answer 44

acute idiopathic polyneuritis