Q. Many patients present complaining of migraine headaches, but often have not been diagnosed. How can I determine the etiology of the headache?

A. According to the International Headache Society (IHS), close to 90% of the population has experienced some form of headache. Since an abundant number of headache symptoms may have visual disturbances, or are located within surrounding ocular tissue, optometrists will frequently be confronted by patients complaining of this, says optometrist Michelle Caputo of Bascom Palmer Eye Institute in Miami.

Migraine headaches are characterized by a specific group of signs and symptoms. Patients may not realize this, though, so they describe their headaches as migraines.

It is imperative that O.D.s be able to distinguish which headaches have a simple vs. ominous course, says Bernard H. Blaustein of Pennsylvania College of Optometry. Ask patients about the location, frequency, duration and type of pain associated with the headache. Also determine the age of onset, nutritional regimen and family history. Dr. Blaustein also notes women are three times as likely as men to experience true migraines.

Migraines fall into five types, as outlined by the IHS:
Migraine with aura, also called the classic migraine. These patients typically experience a unilateral, throbbing headache with moderate to severe pain and gradual onset. Associated symptoms include photophobia, sonophobia, nausea and with severe pain, vomiting.

Migraine auras usually occur between five and 60 minutes before onset. Shimmering or wave-like photopsias, fortification scotomas or other distortions typically start paracentrally and expand across the periphery in a hemifacial pattern.

Neurologic symptoms include aphasia (defect or loss of power of expresion), vertigo, alexia (inability to understand written language) and neuropsychological symptoms.

Migraine without aura, also called the common migraine. These patients experience the headache associated with a classic migraine but without the visual disturbances.

Migraine aura without headache. Patients with this type of migraine present with neurologic or visual complaints but no headache.

Ocular or retinal migraine. This is a vasospastic event limited to the eye. These patients will most likely present with transient visual disturbances and possibly branch or central retinal vein occlusion.  

Ophthalmoplegic migraine. These generally occur in children and usually involve a third-nerve palsy. Patients will often present with a painful pupil.

Use caution if you suspect one of the latter three types. You need to work in reverse with these patients and rule out other possible causes before diagnosing the patient with a migraine, says Leonard Messner, O.D., vice president for patient care services at Illinois College of Optometry in Chicago.

Some signs may indicate a pathology other than a migraine:
Intracranial pressure. Signs include abrupt and severe onset, progressive worsening, consistently one-sided, associated optic nerve edema, fever, and pain that intensifies with positional changes, exertion, straining or coughing.

Ophthalmoplegic migraine. Approach any adult with symptoms resembling an ophthalmoloplegic migraine cautiously. Most cases appear in young patients in the first decade of life. If patients present with no history of migraines, or a headache associated with severe pain, rule out intracranial aneurysm or inflammatory conditions before diagnosing.

Age. Examine other factors in patients past age 40 with no history of prior migraines. Be especially cautious in patients past age 65, and always rule out temporal arteritis, giant cell arteritis and cardiac embolism, regardless of whether other symptoms are present.

Next month: How to treat a migraine headache.

Vol. No: 141:08Issue: 8/15/04