Migraine Flashcards
Types of migraine
CLASSIC aura dots/shapes 10-30mins before onset Nausea and vomiting COMMON no preceding neurological disturbances RARE Opthalmoplegic, hemiplegic and basilar migraine with severe motor distubances
What is a migraine?
Extremely painful headache Visual disturbances Nausea and vomiting Photphobia Phonophobia
What causes migraine?
Activation of trigeminovasculature system and pain sensitive meniges account for pain.
Aura due to cortical spreading depression
Two theories vascular or neurogenic.
What is cortical spreading depression?
- wave of neuronal depolarisation followed by neuronal inactivity that spreads across the cortex
- may be clinically silent in common migraine
- caused by stimulation of visual cortex, hormonal changes (progesterone in menstrual cycle), genetic disposition
Neurogenic migraine hypothesis
- Csd activates trigeminovascular system causes vasodilation (by released calcitonin gene-regulated peptide)
- BBB becomes leaky leading to neurogenic inflammation and pain
-evidence=block csd with gluatamte antagonist, blocks vascular changes
What is the vascular hypothesis?
Vascular changes cause changes in blood flow, producing ischaemia and csd
Evidence= not always an aura with migraine.
Role of beta-adrenergic antagoinists
Block vasodilation
PROPANOLOL
TIMOLOL
Prevention of migraine.
Role of antiepileptic drugs
Blocks neuroexcitation
Prevents migraine
TOPIRAMATE
CARBAMAZEPINE
Role of tri-cyclic antidepressants
Prevent migraine
AMITRIPTYLINE
Role of l-type calcium channel blocker
Decrease headache frequency
Prevent migraine, maybe by preventing CSD
VERAPAMIL
Role of botulinum toxin?!
Prevents release of CGRP
Treatment during migraine?
Asprin, acetominophen, NSAIDs,
5HT1 receptor agonists “triptans”
What are triptans?
5HT1 receptor agonists
- effective if given in first 30 mins
- reduces nausea and vomiting
- SUMATRIPTAN, ZOLMINTRIPTAM, NARATRIPTAN, RIZATRIPTAN, ELETRIPTAN
- taken alone or with NSAIDs
What is the MOA of triptans?
5HT1R is an inhibitory autoreceptor on presynaptic serotonergic neurones and blood vessels.
Neurones:
- may counteract neurogenic inflamation blocking CGRP release from trigeminal nerve terminals, dont know mechanism
Blood vessels:
- vasoconstriction, prevents stretching of meninges
Importance of GCRP.
Novel treatment target
Antagonist=OLCEGPANT shows promising results in early trials