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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]
© Watson Headache Institute 2014 I All Rights Reserved
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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?
© Watson Headache Institute 2014 I All Rights Reserved
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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
© Watson Headache Institute 2014 I All Rights Reserved
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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(?)
© Watson Headache Institute 2014 I All Rights Reserved
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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
© Watson Headache Institute 2014 I All Rights Reserved
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Sensitisation ‘INTERICTALLY’
Evidence of hyper excitability / dis inhibition of
trigeminal nociception at the TCN / Brainstem level
• Menstrual Migraine[29] (TCR)
© Watson Headache Institute 2014 I All Rights Reserved
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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
© Watson Headache Institute 2014 I All Rights Reserved
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‘Triptans’ effective in relieving ....
• Menstrual Migraine[30]
• Cluster Headache[31,32]
• Tension Headache[33,34]
• CeH[35]
© Watson Headache Institute 2014 I All Rights Reserved
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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]
© Watson Headache Institute 2014 I All Rights Reserved
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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]
© Watson Headache Institute 2014 I All Rights Reserved
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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.
© Watson Headache Institute 2014 I All Rights Reserved
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© Watson Headache Institute 2014 I All Rights Reserved
SENSITISED BRAINSTEM / TCN12