Q Last months column discussed how to determine the etiology of a patients headache. Once migraines are diagnosed, what is the best course of treatment for these patients?

A The answer depends, in part, on how often patients experience migraines. For example, patients who experience classic or common migraines infrequently may opt for no treatment. Some patients can learn what triggers their migraines and simply avoid those precipitating factors. These should be included in your history, says optometrist Michelle Caputo of Bascom Palmer Eye Institute in Miami.

Precipitating factors include:

• Medications, such as nitroglycerin; Persantine (dipyridamole, Boehringer Ingelheim), which is used following cardiac valve replacement; and birth-control pills.
• Stress.
• Hormonal fluctuations that occur during or after menstruation, ovulation or pregnancy.
• Foods with elevated tyramine content, monosodium glutamate (MSG) and nitrates. Elevated tyramine is found in cheeses, nuts, alcohol, vinegar, yogurt and chocolate. Nitrates are found in hot dogs or processed deli meats.

Some patients, however, experience multiple, severe migraine attacks that can lead to social deprivation, lost time from work, and in some cases, depression. These patients may require treatment to maintain an active lifestyle.

Within the past 10 years, neuro-imaging techniques have allowed researchers to further determine the pathology of migraines. Past theories examined only the vascular component, says optometrist Leonard Messner, vice president for patient care services at Illinois College of Optometry. We now know it is the release of chemical mediators that is responsible for the pain most individuals experience.

Treatment of this disorder has changed significantly in the past few years with the advent of new pharmacologic treatments and routes of administration. Newer medications, such as seratonin agonists, target that process directly. Four of these are currently available in the U.S.: Imitrex (sumatriptan, GlaxoSmithKline), Zomig (zolmi-triptan, AstraZeneca), Amerge (naratriptan, GlaxoSmithKline) and Maxalt (rizatriptan, Merck). The unique aspect of these drugs vs. their progenitors is that they seem to get to the root cause of the problem, Dr. Messner says.

Serotonin agonist drugs are vasoconstrictive, so they are contraindicated in patients with hypertension or in those who have had an arterial or occlusive event of the retina.

Q When should I refer the patient to a neurologist for evaluation?

A Keep in mind that disorders such as connective tissue anomalies, arteriovenous malformations, cardiac vascular disease, tumors and vascular conditions can all cause visual and neurological symptoms with head-aches that imitate migraine, Dr. Caputo says. New onset headaches, a history of migraine that has been self-diagnosed, and other symptoms such as slurred speech, double vision or field defects may point to a neurological cause. If you are suspicious and the patient has not seen a neurologist, refer him or her quickly. If necessary, speak directly to the specialist and explain the patients case.

If all else fails, send the patient to the emergency room for appropriate testing. Neuroimaging, cardiac evaluation and/or hematological testing may be indicated in patients whose symptoms do not follow a typical migraine, says Dr. Caputo.

In working patients up for certain diseases, its often as important to know what symptoms a patient doesnt have as well as what they do, Dr. Messner says. You may not be able to determine the exact cause of the headache, but you can rule out serious conditions.