Page 14 - The clinical aspects and management of chronic migraine Judith Anne Pijpers

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Chapter 1
C. Headache on ≥8 days per month for >3 months, fulfilling any of the following:
1. Criteria for migraine:
a) 4-72 hours
b) At least two out of the four following characteristics: i) unilateral
location; ii) pulsating quality; iii) moderate or severe pain intensity; iv) aggravation by or avoidance of routine physical activity (e.g. walking or climbing stairs)
c) During the headache at least one of the following: i) nausea and/or vomiting ii) photophobia and phonophobia.
2. Believed by the patient to be migraine at onset and relieved by a triptan or ergot derivative.
D. Not better accounted for by another ICHD-3 diagnosis.
Although migraine might be considered as a well-known, prevalent disorder, it remains underdiagnosed and undertreated.12 Many migraine patients use non- specific‘over the counter’pain medication such as paracetamol (acetaminophen) of NSAIDs, instead of acute anti-migraine drugs.12 Even the available acute anti-migraine drugs, triptans and to a lesser extent ergots, generally have a moderate effect, providing initial pain relief in 60% of patients, and sustained pain free rates of approximately 30%.13 Also preventatives, daily medication in order to prevent headache attacks, have a moderate effect, both in episodic migraine as chronic migraine,10 and knowledge in the prevention of chronic migraine is limited.2,10
To enhance treatment of chronic migraine, and ultimately prevent migraine chronification, better understanding of its pathophysiology and trials studying potential treatments are of uttermost importance. Hitherto some hypothesis on the pathophysiology and risk factor have been established.
Pathophysiology of chronic migraine
Migraine headache is caused by activation of the trigeminovascular system, consisting of trigeminal afferents surrounding meningeal blood vessels. The trigeminal afferents connect the meningeal blood vessels to the sensory cortex via the brain stem nucleus (Trigeminal Nucleus Caudatus,TNC) and the thalamus