Neuromuscular Conditions

Question 1

what is myasthenia gravis

Answer 1

autoimmune condition where there is antibodies to post-synaptic acetylcholine receptors

Question 2

antibodies in myasthenia gravis

Answer 2

anti-AchR antibodies

Question 3

characteristic presentation of the muscle weakness in myasthenia gravis

Answer 3

weakness that gets worse with muscle use and improves with rest
- symptoms minimal in the morning, worse at end of day

Question 4

which muscles are first affected in myasthenia gravis

Answer 4

eye muscles

• ptosis
• diplopia

Question 5

symptoms of myasthenia gravis

Answer 5

proximal limb weakness
facial weakness
weak swallow
slurred speech
ptosis, diplopia
jaw fatigue

Question 6

what is myasthenia gravis linked to

Answer 6

thymomas / thymus hyperplasia

Question 7

treatment of myasthenia gravis

Answer 7

oral pyridostigmine (acetylcholinesterase inhibitor)
immunosuppression with prednisolone
thymectomy

Question 8

what is Lambert Eaton syndrome

Answer 8

antibodies to pre-synaptic calcium channels causing proximal muscle weakness + weakness of eye/facial muscles

Question 9

what is Lambert Eaton strongly associated with

Answer 9

small cell lung cancer

Question 10

what is myotonia?

where is the defect?

Answer 10

myotonia = failure of muscle relaxation after use

defect in chloride channel

Question 11

what is myotonic dystrophy

Answer 11

autosomal dominant chloride channelopathy

Question 12

symptoms of myotonic dystrophy

Answer 12

distal weakness
sternocleidomastoid / facial muscle weakness
cataracts 
cardiomyopathy 
male frontal baldness

Question 13

presentation of polymyositis

Answer 13

symmetrical proximal muscle weakness

muscle + point pain

Question 14

what is raised in polymyositis

Answer 14

CK

Question 15

antibody in polymyositis

Answer 15

Anti-Jo antibody

Question 16

diagnostic investigation for polymyositis

Answer 16

muscle biopsy

Question 17

treatment of polymyositis

Answer 17

prednisolone

Question 18

what is inclusion body myositis

Answer 18

slowly progressive inflammatory myopathy

Question 19

presentation of inclusion body myositis

Answer 19

slowly progressive asymmetrical weakness

affects finger flexors
- thumb sparing

affects pharyngeal muscles
- dysphagia

Question 20

what is rhabdomyolysis

Answer 20

damage to skeletal muscle causes leakage of large quantities of toxic intracellular contents into plasma

Question 21

symptoms of rhabodomyolysis

Answer 21

myalgia
muscle weakness
myoglobinuria

Question 22

what drug causes neuromuscular junction dysfunction

Answer 22

curare

- blocks action potential – no muscle contraction – no respiration

Question 23

what causes botulism

Answer 23

clostridium botulinum bacteria

- found in soil

Question 24

symptoms of botulism

Answer 24

rapid onset weakness without sensory loss

Question 25

who typically gets botulism

Answer 25

IV drug users

Question 26

what is a myasthenic crisis

Answer 26

complication of myasthenia gravis

• acute worsening of symptoms
• triggered by illness / drugs

Question 27

what drugs can trigger a myasthenic crisis

Answer 27

beta blockers
lithium
phenytoin
gentamicin, quinolone

Question 28

treatment of restless leg syndrome

Answer 28

ropinerole (dopamine agonist)

Question 29

symptoms of restless leg syndrome

Answer 29

uncontrollable urge to move legs

parasthesias e.g crawling / throbbing sensations

Question 30

treatment of myasthenia crisis

Answer 30

IV immunoglobulins + plasmaelectropheresis