Migraine and Emesis

Question 1

What are the stages of a migraine?

Answer 1

Prodrome - yawning, mood or appetite change

1) Aura - initial visual disturbance, shimmers
2) Unilateral throbbing headache - photophobia N&V

Question 2

What are the 3 genes that might be implicated?

Answer 2

Familial hemiplegic migraine, rare autosomal dominant disorder
CACNA2A gene - encodes pore forming a1A subunit (chromosome 19)
ATP1A2 gene encoding Na+/K+ pump a2 subunit
TRESK K2P potassium channel in spinal neurones

Question 3

What causes the aura?

Answer 3

a wave of electrical activity starting in the occipital cortex

Question 4

How does the trigeminal nerve play a role

Answer 4

3 divisions, ophthalmic division innervates and parietal correct, activated in migraine

Question 5

What are the 3 steps of treatment

Answer 5

1) analgesics/NSAIDS
2) Triptans (5-HT1b-d receptor agonists) cause constriction of blood vessels and inhibition of neuropeptide CGRP
3) b blockers, calcium channel blockers, anticonvulsants

Question 6

Where is emesis controlled?

Answer 6

vomiting centre, neurones in medullary reticular formation.

Chemoreceptor trigger zone - neurokinin (substance P) major output transmitter

Question 7

What is the best therapy

Answer 7

NK1 receptor antagonism, aprepitant

H1 and H3 antagonists for motion sickness