Headache evaluation is complicated by patients with overlapping symptoms and more than one type of headache. The major types of headache include migraine (with or without aura), tension-type headaches and drug-rebound (or chronic daily) headaches. Maizels reviewed the steps involved in evaluating and managing the patient with headache.
Migraine headaches are usually accompanied by nausea, photophobia or phonophobia. Auras, most commonly described as visual flashing lights, zig-zag lines or blind spots, may also be present. Migraine headaches are likely to have reliable triggers and patterns, and are usually relieved after sleep. Tension-type headaches may exist in a continuum with migraine headaches and are not directly related to muscle tenderness; rather, muscle tenderness is a secondary phenomenon. It is believed that migraines result from a disturbance of the serotonergic system of the midbrain and that all migraine abortive and prophylactic medications influence the serotonin pathway. Vascular changes are most likely secondary rather than causative. The etiology of the tension-type headache is less clear but is thought to be an integration of vascular, myofascial and supraspinal factors.
Drug-rebound headaches presenting as chronic daily headaches are common. The use of analgesic medications, even as little as 1,000 mg per day of aspirin or acetaminophen, can cause this type of headache. Any symptomatic headache remedy may cause drug rebound headache, but it is most likely with the use of ergotamines, narcotics and products that combine caffeine or butalbital with aspirin or acetaminophen. Many clinicians limit the use of all symptomatic medication to two days a week. Patients need much encouragement when attempting withdrawal from the causative medication and should be told they will feel worse for about two weeks. The addition of amitriptyline (10 to 25 mg) or a nonsteroidal anti-inflammatory drug (NSAID) such as naproxen may provide relief.
Treatment of acute headache should be based on the past experience of the patient, the headache severity, associated symptoms and the medication side-effect profile. Some choices are described in the accompanying table. Headaches accompanied by severe nausea may be treated by adding a dopamine antagonist anti-emetic such as metoclopramide. More severe headaches may require parenteral therapy with dihydroergotamine or a specific serotonin1 (5-HT1) receptor agonist such as sumatriptan or one of the newer triptans.
Headache prophylaxis includes resolution of trigger factors. Medication withdrawal should be considered. Prophylactic medication can be offered if severe attacks occur more than two or three times monthly or if attacks cannot be easily controlled with abortive medications. Prophylaxis may reduce migraine frequency by 50 to 60 percent. First-line agents are tricyclic antidepressants and beta blockers. Calcium-channel blockers and NSAIDS are less effective but may be tried before giving drugs that have greater side effects. Third-line agents include methysergide and monoamine oxidase inhibitors. Selective serotonin reuptake inhibitors should be considered for use in patients in whom depression is a significant factor of the headache symptoms. Divalproex sodium may be useful in reducing the frequency of migraine attacks.
In a discussion of worrisome headaches, the author concludes by discrediting the symptoms of the “classic” brain tumor headache. Neuroimaging is appropriate when the headache (1) is accompanied by unexpected neurologic signs or symptoms, (2) has new onset after age 50 or occurs in a patient with a history of cancer, (3) is triggered by cough, coitus or exertion, (4) is severe and sudden (“thunderclap headache”), (5) is different from a previously stable headache pattern or (6) is not diagnosable as a “primary” benign headache. Imaging is not necessary in the patient with a stable migraine pattern. There are no specific guidelines for the neuroimaging of tension-type headaches.