Approach to NMJ Disorders

Question 1

Which side of the synapse does Myasthenia Gravis affect?

Answer 1

Post-synaptic

Question 2

Which side of the synapse does Lambert-Eaton Myasthenic Syndrome affect?

Answer 2

Pre-synaptic

Question 3

Myasthenia Gravis involves autoantibodies to?

Answer 3

Ach Receptor

Question 4

In what age/gender is Myasthenia Gravis more common?

Answer 4

Younger women

Older men

Question 5

What type of weakness is seen with Myasthenia Gravis?

Answer 5

Fluctuating weakness = “excessive fatigability”

Question 6

Where is the fluctuating weakness usually located with Myasthenia Gravis?

Answer 6

Ocular muscles – ptosis and diplopia

Question 7

If AchR antibodies are not present with Myasthenia Gravis, what other antibodies may there be?

Answer 7

MUSK

LRP-4

Question 8

With repetitive stimulation, what is the response on the EMG with Myasthenia Gravis?

Answer 8

Decremental response

Question 9

What is a dangerous and no longer used drug injection that can be used to diagnose Myasthenia Gravis?

Answer 9

Tensilon (edrophonium)

Question 10

What side effects can occur with the Tensilon (edrophonium) test?

Answer 10

Bradycardia, ventricular arrhythmias

Question 11

What is the antidote for the Tensilon (edrophonium) test?

Answer 11

Atropine

Question 12

What is a possible treatment for Myasthenia Gravis?

Answer 12

Acetylcholinesterase (-) = Mestinon

Question 13

A Myasthenic crisis can present similarly to?

Answer 13

Cholinergic Crisis

Question 14

MUSK Myasthenia Gravis response to Acetylcholinesterase (-)?

Answer 14

NO response

Question 15

Lambert-Eaton Myasthenic Syndrome is due to?

Answer 15

Antibodies against voltage-gated calcium channels

– blocks Ach release

Question 16

What are some symptoms of Lambert-Eaton Myasthenic Syndrome?

Answer 16

Weakness, dry mouth, loss of DTRs

Question 17

After exercise/stimulation, what change will be seen in Lambert-Eaton Myasthenic Syndrome?

Answer 17

Strength INCREASES

Question 18

(+) anti-VGCC?

Answer 18

LEMS

- Lambert-Eaton Myasthenic Syndrome

Question 19

EMG response for LEMS with repetitive stimulation?

Answer 19

Incremental

Question 20

LEMS is often associated with?

Answer 20

Cancer – look for malignancy

Question 21

Where in the synapse does Botulism affect?

Answer 21

Pre-synaptic

Question 22

Botulism blocks?

Answer 22

Pre-synaptic release of Ach

Question 23

Treatment for Botulism?

Answer 23

ICU monitoring

Question 24

Symptoms of Botulism?

Answer 24

Dry mouth, blurred vision, diplopia, N/V

Question 25

How do Nerve gases like Sarin and VX work?

Answer 25

(-) Acetylcholinesterase to cause a cholinergic crisis

Question 26

Nerve gases cause too much Ach to be around. What does that often cause to occur?

Answer 26

Seizures and increased secretions