NMJ Diseases

Question 1

Myasthenia Gravis preferentially affects which 2 age/genders?

Answer 1

Younger females

Older males

Question 2

A majority of patients with Myasthenia Gravis have what?

Answer 2

Autoantibodies to Ach Receptors!

Question 3

Autoantibodies to Ach Receptors is likely?

Answer 3

Myasthenia Gravis

Question 4

A small number of Myasthenia Gravis patients who do not have autoantibodies to AchR, have?

Answer 4

Autoantibodies to sarcolemmal muscle specific receptor tyrosine kinase

Question 5

If patients with Myasthenia Gravis have autoantibodies to sarcolemmal muscle specific receptor tyrosine kinase, what symptoms will be present?

Answer 5

Focal muscle involvement

Question 6

A majority of Myasthenia Gravis patients have what abnormalities?

Answer 6

Thymic Abnormalities

– Thymoma OR Thymic hyperplasia

Question 7

If Myasthenia Gravis patients have Thymic hyperplasia, what will be seen in the thymus?

Answer 7

B cell follicles

Question 8

What disease is often associated with Thymic Abnormalities?

Answer 8

Myasthenia Gravis

Question 9

Describe the symptoms of Myasthenia Gravis?

Answer 9

Fluctuating generalized weakness that WORSENS WITH EXERTION and over the course of the day

Question 10

With repeated stimulation, how do myasthenia gravis patients respond?

Answer 10

DIMINISHED responses with repeated stimulation

Question 11

What specific weaknesses can be noticed with Myasthenia Gravis patients?

Answer 11

Drooping eyelids (ptosis) and double vision 
-- weakness begins with the EOM

Question 12

Weakness that worsens with exertion and over the course of the day, often involving EOM?

Answer 12

Myasthenia Gravis

Question 13

What are some possible treatments for Myasthenia Gravis?

Answer 13

Acetlycholinesterase (-)
Plasmapheresis/immune suppression
Thymectomy

Question 14

Lambert-Eaton Myasthenic Syndrome often has antibodies that?

Answer 14

Block Ach RELEASE by (-) pre-synaptic calcium channels

Question 15

Lambert-Eaton Myasthenic Syndrome often has antibodies that?

Answer 15

Block Ach release by (-) pre-synaptic calcium channel

Question 16

If Lambert-Eaton Myasthenic Syndrome is a paraneoplastic process, what may be causing it?

Answer 16

Small cell (neuroendocrine) carcinoma of the lung

Question 17

Where is the weakness with Lambert-Eaton Myasthenic Syndrome?

Answer 17

Proximal muscle weakness

Question 18

What response will Lambert Eaton Myasthenic Syndrome patients have to repetitive stimulation?

Answer 18

INCREASED muscle response

Question 19

What is a possible treatment for Lambert-Eaton Myasthenic Syndrome?

Answer 19

Increase Ach Release

Question 20

Myasthenia Gravis vs. Lambert-Eaton – responses to repetitive stimulation

Answer 20

Myasthenia Gravis = DIMINISHED response

Lambert-Eaton = INCREASED response

Question 21

Myasthenia Gravis vs. Lambert Eaton – autoantibodies?

Answer 21

Myasthenia Gravis = Ach Receptors

Lambert-Eaton = Block Ach release by (-) pre-synaptic calcium channel

Question 22

What are the symptoms of Congenital Myasthenic Syndromes that present in the perinatal period?

Answer 22

Decreased muscle tone
External eye muscle weakness
Breathing difficulties

Question 23

What are 2 toxins that can cause NMJ diseases?

Answer 23

C. Botulinum (botox)

Curare

Question 24

What does C. Botulinum do?

Answer 24

Blocks release of Ach

Question 25

What does Curare do and what does that cause?

Answer 25

Blocks Ach Receptors => flaccid paralysis