Migraine triggers

Twin studies suggest 50% heritabUity of migraine, with a multifactorial polygenic basis. Migraine triggers may be modulators of the genetic set point that predisposes to migraine headache. 

Panconesi A (2008). Alcohol and migraine trigger factor, consumption, mechanisms a review. J Headache Pain, 9 19-27. 

Features of central sensitization are pain in response to normally innocuous tactile stimuli, and the spread of pain sensitivity beyond the site of tissue injury. Central sensitization plays a major role in acute post-traumatic pain, and also in migraine, neuropathic pain (see below) and some diffuse chronic pain syndromes, such as fibromyalgia and irritable bowel syndrome. In these conditions, which have no detectable peripheral trigger, an autonomous central sensitization may be the pathology, increasing the gain in neuronal activity in the CNS and thereby producing abnormal responses to normal inputs. 

Certain foods can trigger a migraine attack by effects on neurotransmitter release or metabolism in the brain. For example, a number of foods contain tryptamine which is known to cause release of other amines (dopamine, noradrenaline and 5-hydroxytryptamine) from both nerve terminals and platelets. This release could initiate the sequence of events that results in the migraine attack. Elimination of such foods from the diet can decrease the number of headaches. Compounds that discourage platelet aggregation (e.g. aspirin) may prevent such attacks. 

Bolay H, Reuter U, Dunn AK, Huang Z, Boas DA, Moskowitz MA (2002) Intrinsic brain activity triggers trigeminal meningeal afferents in a migraine model. Nat Med 8 136-142. 

Exclusion or elimination diets are used to detect foods suspected of causing food allergies or intolerance, or triggering attacks of illness, such as migraine. Suspected foods are avoided for about 2 weeks and then reintroduced one at a time. 

Cured meats may contain high levels of tyramine, which triggers migraine in susceptible people and causes serious hypertension in patients taking a monoamine oxidase inhibitor such as tranylcypromine. 

Q4 Outline the causative factors that trigger migraine. 

Q7 The mechanisms which trigger migraine remain controversial. The underlying pathophysiology could be due to vasoconstriction of the cerebral arteries, causing transient ischaemia. This would be followed by compensatory vasodilation of the cerebral blood vessels to protect the ischaemic areas. This vasodilation may lead to an increase in intracranial pressure, which causes a severe headache. These events may be followed by changes in nerve activity and neurotransmitter levels. Inflammatory components are also likely to be involved in the pathology of this condition. 

A wide variety of foods, dmgs, envircnmental cues, and personal events are known to tri er migraines. It is not known how most triggers set off the events of migraine, nor why individual migraine sufferers are affected by particular ti%gers but not others. 

The frequency of migraine may be lessened by avoiding triggers. It is useful to keep a headache journal, recording the particulars and noting possible triggers for each attack. Specific measures that may help include ... 

Triggers/associated factors Certain foods Migraine... 

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