NMJ diseases

Question 1

the binding of two ACh molecules to the ACh gated ion channel allows

Answer 1

sodium and potassium to enter and exit respectively

Question 2

Is MG an genetic disorder?

Answer 2

Nope it is a genetic predisposition to autoimmune disorder

Question 3

MG is most common in

Answer 3

young woman and older men

Question 4

why is MG a true paraneoplastic disorder

Answer 4

the autoimmune part of the disorder triggers the formation of a thymoma

Question 5

MG is a disorder of ________ that causes muscle weakness

Answer 5

striated muscle

Question 6

what is usually present in MG

Answer 6

fatigable weakness

Question 7

Distribution of Muscle involvement in MG [4]

Answer 7

1. ocular
2. oropharyngeal
3. Limb
4. Respiratory (diaphragm)

Question 8

Ocular symptoms in MG

Answer 8

• double vision: diplopia
• dropping eyelids: ptosis
• difficulty moving eyes: opthalmoplegia

Question 9

tensilon test

Answer 9

this is to determine whether someone is in a cholinergic or MG crisis

they administer this drug, tensilon (edrophonium) that prevents the breakdown of ACh

Question 10

what additional diagnostic work-up should be done besides NCS, tensilon test and Ab?

Answer 10

Chest CT/MRI for thymoma

Question 11

medications for MG

Answer 11

• pyridostigimine to inhibit Achase and allow Ach to stay longer in the synaptic cleft
• corticosteroids to reduce Ab load

Question 12

lamber eaton MS is due to

Answer 12

presynaptic VGCC damage which reduces calcium influx into the presynaptic terminal during a nerve A, which then decreases the amount of ACh release and thus muscle weakness results

Question 13

Is LEMS is a true paraneoplastic disorder?

Answer 13

YASSS, about half with cancer usually SCLC

Question 14

what is a common autonomic symptom for LEMS

Answer 14

dry mouth common

Question 15

is VGCC ab test good?

Answer 15

it has variable sensitivity and good specificity

Question 16

treatment for LEMS

Answer 16

3.4 DAP: Firdapase