Myasthenia Gravis

Question 1

What is myasthenia gravis?

Answer 1

Autoimmune disorder of the neuromuscular junction

Question 2

In myasthenia gravis, what are the antibodies directed against?

Answer 2

postsynaptic acetylcholine receptors

Question 3

What are the symptoms?

Answer 3

Fatiguability - symptoms worse throughout day

Weakness - extra ocular, bulbar, facial weakness

Question 4

What are some eye symptoms?

Answer 4

ptosis

diplopia

Question 5

What can worsen the weakness is myasthenia gravis?

Answer 5

pregnancy 
hypokalaemia 
infection 
emotion 
exercise 
change of climate

Question 6

What is the cause of myasthenia gravis?

Answer 6

antibodies to nicotinic acetylcholine receptors –> reduced number of functioning receptors –> muscle weakness and fatiguability

Question 7

How is myasthenia gravis diagnosed?

Answer 7

anti AChR antibodies (90%)

Question 8

What is it associated with?

Answer 8

thymus hyperplasia or thymoma

other autoimmune diseases

Question 9

What is the treatment of myasthenia gravis?

Answer 9

anti cholinesterase e.g. pyridostigmine
immunosuppression e.g. prednisolone, azathioprine, methotrexate
thymectomy

Question 10

What is the main complication of myasthenia gravis?

Answer 10

myasthenic crisis - weakness of resp muscles during a relapse