What's in a name? The classification of common headaches.

Headache is an almost ubiquitous human experience. In addition, it is a major contemporary health problem about which most clinicians are poorly informed. Over two-thirds of the population report a history of headache, with 28% fulfilling criteria for a diagnosis of migraine and 38% for tension-type headache.' Patients come to medical attention either because of diagnostic doubt (is it a brain tumour?) or because of the negative impact on their quality of life. Addressing the former without the latter leaves only half the job done. Migraine may occur with or without an aura such as scotomata, fortification spectra or paraesthesiae. Migraine headaches usually last 4-72 hours, they are often unilateral , pulsating, moderate or severe intensity and aggravated by routine physical activity. There is frequently concomitant nausea, vomiting, photophobia or phonopho-bia.' Acute treatment with minor analgesics and anti-emetics, ergot alkaloids or sumatriptan is often successful. Prophylaxis is appropriate for patients suffering more than two attacks per month. First line prophylactic agents are beta-blockers, pizotifen and low dose amytriptyline. Tension-type headache lasts minutes to days. The pain is bilateral in location, pressing or tightening in quality and of mild or moderate intensity. Nausea is absent, but photo-phobia or phonophobia may be present.2 It is a misnomer; though it can be associated with stress, so may other headache types and it frequently is not. It is not due to muscle tension as paralysis of pericranial musculature with botulinum toxin fails to give relief.3 Some authors consider it part of a spectrum of headaches that range from classical migraine through to tension-type headache, as many of the same pathophysiological processes underlie these headache types. Perhaps the term non-specific headache would be more honest and less prejudicial. Tension-type headache can respond to 10-25 mg amitriptyline at night. In recent years the entity of chronic daily headache (CDH) has been recognised. This consists of headache for at least 15 days a month during the previous six months. Commonly it is a transformed headache, 78% from migraine, 13% from chronic tension-type headache and only 9% are new daily persistent headache.4 The transformation into CDH is usually due to excessive analgesic, ergotamine or, controversially, sumatriptan usage. Patients are often taking far in excess of the 50 g of paracetamol or other analgesics per month which can cause CDH. Mixed analgesic compounds are probably the strongers inducers of CDH.5 Aspirin alone probably is the least likely to induce …