Migrane and emesis

Question 1

when do migranes peak? which sex is more common?

Answer 1

middle age, women

Question 2

whats a predromal sign?

Answer 2

60% of migranes have them. hyperactivity, yawning, food craving

Question 3

what is thought to be the cause of migranes? how is this shown in an MRI?

Answer 3

neurovascular, trigemal nerve activated causing vasodilation near neuronal blood flow. (via release of CGRP) trigeminal nn projects to Trigeminal nucleus then to cortex = pain

MRI shows decreased blood flow by 27% during aura then prolonged increase

Question 4

are migranes hereditory?

Answer 4

3 x more common if 1st degree relative has.

Question 5

what is an aura in a migrane and how does it occur

Answer 5

wave of electrical impulse starting from the occipital cortex and spreading slowly (if across visual field hallucinations)

Question 6

what is spreading depression in a migrane and when is it seen

Answer 6

severe migranes. sustained depolarisation, metabolic over stim then inhibiton

Question 7

therapy for migranes?

Answer 7

ACUTE - analgesics antiemetics

TRIPTAINS ( seratonin agonist) causes vasoconstriction (some cv risk)

Question 8

prophylactic migrane therapy?

Answer 8

b blockers, ca channel blockers, anticonvulsants, TCA

Question 9

what do you give resistant cases of migranes

Answer 9

botulum toxin type A or acupuncture or gabapentin

Question 10

describe the process of vomiting(emesis)

Answer 10

higher centres stim 
resp stop
increased intra abdo pressure, intrgastric pressure (diaphragm and abdo muscles contract)
antiperistalsis 
LES relaxes
glottis closes over trachea

Question 11

what happens in retching

Answer 11

incomplete - LES does not open

Question 12

what is emesis controlled by

Answer 12

medullary reticular formation (vomiting centre)

Question 13

causes of emesis

Answer 13

iatrogenic (dr) chemo etc
motion sickness
pregnancy
poisoning
gastroenteritis
meningitis (increased ICP)
bulimia

Question 14

Which other centres can also trigger vomiting

Answer 14

1. CTZ is at the base of the 4th vent and has multiple receptors. - substance p = OUTPUT to stim vomiting
2. area postrema detects changes in blood chemicals
3. vestibular system - motion sickness
4. vagall nn - gag reflex
5. vagal and GI afferents (irritation of GI mucosa)
6. descending inputs from higher centres (sight smell stress etc)

Question 15

what does ipecacuanha do?

Answer 15

induce emesis

Question 16

where do these anti emesis drugs act:

1. NK antags
2. 5ht antags
3. H, M , DA antags

Answer 16

1. VC –> motor
2. stomach –>VC
3. CTZ –> VC

Question 17

which is the most effective drug for emesis

Answer 17

NK antagonist (sub P output from VC)
combination therapy best

Question 18

if chemo induced emesis what drugs should you use

Answer 18

corticosteroids and dopamine ANTAG (+5hT antag)

Question 19

how do you control nausea

Answer 19

antiemetics and mild sedation