Migraine Headaches

THE CLINICAL SYNDROME

Migraine headache is defined as a periodic unilateral headache that may begin in childhood but almost always develop before the age of 30. Attacks may occur with a variable frequency ranging from every few days to once every several months. More frequent migraine headaches are often associated with a phenomenon called analgesic rebound. Between 60% and 70% of patients suffering from migraines are female, and many report a family history of migraine headaches. Migraineurs have been described as a having a unique personality type characterized by a meticulous, neat, compulsive, and often rigid nature. They tend to be obsessive in their daily routines and often find it hard to cope with the stresses of every day life. Migraine headaches may be triggered by changes in sleep patterns or diet or by the ingestion of tyramine-containing foods, monosodium glutamate, nitrates, chocolate, or citrus fruits. Changes in endogenous and exogenous hormones occur such as with the use of birth control pills can also trigger migraine headaches. Approximately 20% of patients suffering from migraine headache also experience a painless neurologic event before the onset of headache pain that is called aura. Aura most often takes the form of visual disturbance but may also present as an alteration in smell or hearing; these are called olfactory and auditory aura, respectively.

Migraine headache is an episodic, unilateral headache which occurs more commonly in females.

Clinical Signs and Symptoms

Migraine headache is by definition a unilateral headache. Although with each episode the headache may change sides, the headache is never bilateral. The pain of migraine headache is usually periorbital or retro-orbital. It is pounding in nature, and its intensity is severe. The onset-to-peak of migraine headache is rapid, ranging from 20 minutes to 1 hour. In contradistincion to tension-type headache, migraine headache is often associated with systemic symptoms, including nausea and vomiting, photophobia, and sonophobia, as well as alterations in appetitie, mood, and libido. Menstruation is also a common trigger of migraine headaches. Migraine that presents without other neurologic symptoms is called migraine without aura.

Rare patients who suffer from migraine will experience prolonged neurologic dysfunction associated with their headache pain. Such neurologic dysfunction may last for more than 24 hours and is termed migraine with prolonged aura. Although extremely rare, such patients are at risk for the development of permanent neurologic deficit, and risk factors such as hypertension, smoking, and oral contraceptives must be addressed. Even less common than migraine with prolonged aura is migraine with complex aura. Patients suffering from migraine with complex aura experience significant neurologic dysfunction associated with their headache pain. This dysfunction may include aphasia or hemiplegia. As with migraine with prolonged aura, patients suffering from migraine with complex aura may develop permanent neurologic deficits.

The patients suffering from all forms of migraine headache will appear systemically ill. Pallor, tremulousness, diaphoresis, and light sensitivity are common physical finding. Tenderness of the temporal artery and associated area may also be present. If aura is present, neurologic examination results will be abnormal; otherwise, the neurologic examination is within normal limits, before, during, and after migraine without aura.

Abortive Therapy

For abortive therapy to be effective in the treatment of migraine headache, it must be initiated at the first sign of headache. This can often be difficult because of the short onset-to-peak of migraine headache coupled with the fact that migraine sufferers often experience nausea and vomiting that may limit the use of oral medications. By altering the route of administration to parenteral or transmucosal, this problem can be avoided.

Abortive medications that can be considered in migraine headache patients include compounds that contain isometheptene mucate (e.g., Midrin), the non-steroidal anti-inflammatory drug naproxen, ergot alkaloids, the triptans including sumatriptan, and the intravenous administration of lidocaine combined with antiemetic compounds. The inhalation of 100% oxygen may also abort migraines headache, as well as the use of sphenopalatine ganglion block with local anesthetic. Caffeine-containing preparations, barbiturates, ergotamines, the triptans, and narcotics have a propensity to cause a phenomenon called analgesic rebound headache, which may ultimately be more difficult to treat than the patient’s original migraine headaches. The ergotamines and triptans should not be used in patients with coexistent peripheral vascular disease, coronary artery disease, or hypertension.

Prophylactic Therapy

For most patients who suffer from migraine headaches, prophylactic therapy represents a better option. The mainstay of the prophylactic therapy of migraine is B-blocking agents. Propranolol and most of the other drugs of this class will help control or decrease the frequency and intensity of migraine headache and help prevent aura. Generally, an 80-mg daily dose of the long-acting formulation is a reasonable starting point for most patients with migraine. Propranolol should not be used in patients with asthma or other reactive airway diseases.

Valproic acid, the calcium channel blockers such as verapamil, clonidine, the tricyclic antidepressants, and the nonsteroidal anti-inflammatory drugs have also been used in the prophylaxis of migraine headache. Each of these drugs has its own profile of advantages and disadvantages, and the clinician should try to pharmacologically tailor a treatment plan that best meets the needs of the individual patient.

Clinical Pearls

The most common reason that a patient thought to be suffering from migraine headaches does not respond to traditional treatments is that the patient does not have migraine headache but is in fact suffering from tension-type headache, analgesic rebound headache, or a combination.