MIGRAINE HEADACHE
Migraine headaches are a type of recurrent, primary headache syndrome, without an identifiable underlying etiology, characterized by a constellation of symptoms, and which generally respond to one or more specific anti-migraine therapies. The incidence of migraines is highest in patients between the ages of 25 to 55 years, although patients from the pediatric population are frequently affected. In fact, frequent primary headaches in a pediatric patient should probably be considered migraines until proven otherwise. Women are affected at a much greater rate than are men (18% of women versus 6% of men in the United States population). It is important to note this extremely common form of headache is underdiagnosed and therefore, often improperly treated. Migraine headache should be strongly considered in any patient with recurrent headaches with a normal neurologic exam despite a lack of "characteristic symptoms".
Every patient who presents for their initial evaluation of cephalgia should have a complete history and physical examination with special attention to the neurologic exam. If the initial evaluation is negative for any suspicious findings then a primary headache disorder (tension, migraine or cluster) should be suspected. Features which suggest migraine as the etiology include unilateral pain that is described as pulsatile, with associated nausea and to a lesser extent vomiting, a family history of migraines, photophobia, phonophobia, visual disturbances, and exacerbation of pain with routine physical activities. Migraine suffers often relate that the pain is localized to the retro-orbital or frontotemporal regions and the pain may radiate to the occiput, neck, face or shoulders. Although unilateral pain is characteristic, it may also be bilateral or even radiate globally around the head. Often, a residual sensation of scalp tenderness may persist for hours after the headache has resolved (postdromal phase). Classic migraines, now called migraines with aura (only 15-20% of migraines are associated with the phenomenon of aura), are less common than migraines without aura; however, when patients relate experiencing aura before head pain (aura usually precedes the headache by 5-30 minutes), migraine should always be suspected. Migraines are often self diagnosed by patients as sinusitis or sinus headaches. This confusion is often due to the fact that nasal congestion, rhinorrhea and lacrimation may occur as part of a patient’s migraine secondary to autonomic activation of the facial nerve.
In patients in whom the diagnosis is fairly secure, neuroimaging is not necessary. However, if there are abnormal findings on the neurologic exam, altered consciousness on presentation, new onset of atypical headaches, onset of pain with exertion, coitus, coughing or sneezing, worsening pain, nuchal rigidity, if the headaches first start in a patient greater than 50 years old, or if the patient claims this is the “worst” headache of their life, then neuroimaging is appropriate. Head CT without contrast is effective when an intracranial bleed is suspected. MRI is preferable in other circumstances. Other tests such as a lumbar puncture or an EEG are not indicated unless specific findings raise concerns for an alternate diagnosis.
Treatment of migraines should include patient education about their condition. Any medication with the potential to cause or exacerbate headache should be discontinued if possible. Patients should be instructed that they should maintain their daily schedule on a strict regimen. Bedtime and waking hours should always be kept the same. Patients should be warned that staying up late or sleeping in late may exacerbate their headache symptoms. Mealtimes should also be regimented, and patients should be discouraged from missing meals or extreme diets. Patients should keep a journal to try to identify any activities or foods/drinks which may exacerbate their symptoms. Biofeedback may be effective for some patients.
Migraine medical therapy is broken into acute pain treatment (abortive) and preventive (prophylactic) therapy. Acute treatment is rendered to stop the pain during a headache and is most effective when administered early in the course of a migraine. Patients who require frequent abortive therapy may suffer from worsening of their headaches due to excessive ingestion of analgesics, a phenomenon called rebound headache. Patients who do require frequent abortive therapy should be considered as candidates for prophylactic therapy in order to prevent migraines from occurring. It is important to relate to patients at the initial visit that there are many available therapies, and that each person responds to each therapy differently. Therefore, initially it may take some time before the patients symptoms are controlled adequately, but by having an open line of communication and a trusting relationship, a motivated patient and an empathetic physician have a great chance of effectively treating migraines.
Abortive migraine therapies include NSAIDs, midrin (isometheptene mucate, dichloralphenazone and acetaminophen), ergotamine derivatives, triptan drugs, and antiemetics/neuroleptics (chlorpromazine, prochlorperazine, and metoclopramide). Narcotics which are a tempting easy choice should be avoided unless absolutely necessary because of the potential for abuse, drug seeking, and rebound. Patients should be instructed to take abortive medications early in the course of their headache and then to rest in a quiet, dark room for 20-30 minutes after taking the medication. If the headache persists, encourage patients to take repeat doses as frequently as needed and allowed for each specific therapy. Each therapy should be given an adequate amount of time (1-2 months) before determining if it is effective in each individual case. If a specific therapy is ineffective, a trial with a drug from a different class should be initiated. It is important to remember when dealing with these medications that triptans should not be given within 24 hours of ergotamine products. Ergot products and triptans may be used separately but with caution in patients with severe coronary artery disease.
Prophylactic therapy should be offered when headaches occur frequently. The reason to prevent headaches aside from the obvious is that patients who require abortive therapy frequently (>3 times/week) are at risk for rebound headache and/or a gradual decline in the effectiveness of the medication with frequent use. Prophylactic therapies include propranolol, non-dihydropiridine calcium channel blockers, NSAIDs, tricyclic antdepressants, divalproex sodium, carbamazepine, topiramate, and lithium carbonate.
Women whose migraines flare before or during menstruation have menstrual migraines. These headaches are often difficult to treat. Abortive therapies as above may be effective, but in refractory cases, narcotics may be required. Addiction and rebound headache should not be a problem as the medications should only be required for a few days each month. Prophylactic therapy may be effective if taken before the time migraines start in the menstrual cycle. Prophylactic therapies include ergotamine preparations, NSAIDs, magnesium supplements, and combination products with ergotamine/phenobarbital/belladonna alkaloids (Bellergal-S).
Emergency treatment for severe, refractory migraines includes subcutaneous sumatriptan, intravenous antiemetic/narcotic combinatio (prochlorperazine/meperidine-10/100mg), intramuscular or intravenous ketorolac, intravenous neuroleptics, intravenous steroids (dexamethasone or methylprednisolone), intravenous magnesium sulfate or intravenous antiemetic and dihydroergotamine combinations.