1 the role of oestrogen€¦ · the role of oestrogen •menstrual migraine (mm) - occurs as a...

The role of oestrogen

• Menstrual migraine (MM) - occurs as a result

of a fall in oestrogen[23, 24]

• MM sufferers generally do not have hormonal

irregularities[25]

• Abnormal central nervous system response to

normal fluctuations in hormones is the likely

underlying cause of MM[25]

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The role of oestrogen

• Fluctuations in oestrogen levels affect serotonin

levels[26,27]

• is it up- or down-regulated?[27]

• assumed that decreased serotonin occurs as a

result of decreased oestrogen[27] • MM occurs as a result of sensitisation of the TCN /

Brainstem secondary to decreased serotonin?

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The role of oestrogen

What about mid cycle headache(?)...

… there is increased oestrogen and therefore increased

serotonin with subsequent inhibition / desensitisation

of the TCN / Brainstem

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3

The role of oestrogen

• oestrogen levels affect tone in smooth muscle in

the walls of intracranial blood vessels[28]

• decreased oestrogen > decreased tone >

dilatation of intracranial vessels

• Could mechanical information from trigeminally

innervated vessels be misinterpreted /

exaggerated by a sensitised TCN / Brainstem(?)

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4

The role of oestrogen

• at mid cycle i.e., increased oestrogen >

vasoconstriction occurs and this (normally

occurring ‘mechanical’ event) is magnified and

interpreted as a noxious event leading to

headache

• whether serotonin increases or decreases in

relation to oestrogen levels is irrelevant; a

mechanical action of the intracranial vasculature

occurs as a result of changing oestrogen levels

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Sensitisation ‘INTERICTALLY’

Evidence of hyper excitability / dis inhibition of

trigeminal nociception at the TCN / Brainstem level

• Menstrual Migraine[29] (TCR)

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MM… oestrogen/hormonal levels(?)

or…

… failure to inhibit sub threshold afferent information

from a seemingly normal event – an action which is

magnified by a sensitised TCN / Brainstem and

perceived as noxious resulting in headache –

headache probably throbbing in nature

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‘Triptans’ effective in relieving ....

• Menstrual Migraine[30]

• Cluster Headache[31,32]

• Tension Headache[33,34]

• CeH[35]

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8

The role of diet

... specific dietary substances themselves may not

precipitate a headache attack, but may predispose

the individual to a headache attack when other

factors are present[36]

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9

The ‘migraine brain’

“…headache triggers such as stress,

ingestants, menstruation may ‘prime’ the

system for headache, making an individual

more sensitive to other headache

triggers.”[37]

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10

The ‘migraine brain’

... the system is already ‘primed’ by a sensitised TCN

/ Brainstem which is vulnerable to normal or

subclinical events in the trigeminal field; occurring

in response to a myriad of triggers, triggers which

have been shown to be common to a range of

benign recurring / primary headache.

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© Watson Headache Institute 2014 I All Rights Reserved

SENSITISED BRAINSTEM / TCN12