Abstract
Migraine headache is a periodic unilateral headache that may begin in childhood, but almost always develops before 30 years of age. Between 60% and 70% of migraine sufferers are female, with many reporting a family history of migraine headaches. Approximately 20% of migraine sufferers experience painless neurologic symptoms known as aura prior to the onset of headache pain. Treatment of migrain is aimed at the treatment of the acute headache pain and associated symptoms and preventing the headache from occuring. Acute treatments include analgesics, sphenopalatine ganglion block, ergotamins, and triptans. Prophylactic treatments include beta blockers, calcium channel blockers, tricylic antidepressants, botulinum toxin A, and valproic acid.
Keywords
migraine headache, aura, scotomata, fortification spectrum, olfactory aura, propranolol, calcium channel blockers, ergotamine, tricyclic antidepressants, sphenopalatine ganglion block
ICD-10 CODE G43.109
The Clinical Syndrome
Migraine headache is a periodic unilateral headache that may begin in childhood, but almost always develops before age 30 years. Attacks occur with 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 who suffer from migraine are female, and many report a family history of migraine headache. The personality type of migraineurs has been described as meticulous, neat, compulsive, and often rigid. They tend to be obsessive in their daily routines and often find it hard to cope with the stresses of everyday life. Migraine headache may be triggered by changes in sleep patterns or diet or by the ingestion of tyramine-containing foods, monosodium glutamate, nitrates, chocolate, wine, or citrus fruits. Changes in endogenous and exogenous hormones, such as with the use of birth control pills, can also trigger migraine headache as can the ingestion of nitroglycerine for angina. The typical migraine headache is characterized by four phases: (1) the prodrome; (2) the aura; (3) the headache; and (4) the postdrome ( Fig. 2.1 ). Some migraineurs will experience a premonition or warning that a migraine may be on the horizon. This premonition or warning is known as a prodrome and may manifest as mood changes, food cravings, frequent yawning, changes in libido, and constipation. Approximately 20% of patients suffering from migraine headache also experience a neurologic event before the onset of pain called an aura. The aura most often takes the form of a visual disturbance, but it may also manifest as an alteration in smell or hearing; these are called olfactory and auditory auras, respectively. Following a migraine headache, some patients will experience a period of confusion, dizziness, weakness, or elation known as a postdrome.
Signs and Symptoms
Migraine headache is, by definition, a unilateral headache. Although the headache may change sides with each episode, the headache is never bilateral at its onset. The pain of migraine headache is usually periorbital or retro-orbital. It is pounding, and its intensity is severe. The time from onset to peak of migraine pain is short, ranging from 20 minutes to 1 hour. In contradistinction to tension-type headache, migraine headache is often associated with systemic symptoms, including nausea and vomiting, photophobia, and sonophobia, as well as alterations in appetite, mood, and libido. Menstruation is a common trigger of migraine headache.
As mentioned, in approximately 20% of patients, migraine headache is preceded by an aura (called migraine with aura). The aura is thought to be the result of ischemia of specific regions of the cerebral cortex. A visual aura often occurs 30 to 60 minutes before the onset of headache pain; this may take the form of blind spots, called scotoma, or a zigzag disruption of the visual field, called fortification spectrum ( Fig. 2.2 ). Occasionally, patients with migraine lose an entire visual field during the aura. Auditory auras usually take the form of hypersensitivity to sound, but other alterations of hearing, such as sounds perceived as farther away than they actually are, have also been reported. Olfactory auras may take the form of strong odors of substances that are not actually present or extreme hypersensitivity to otherwise normal odors, such as coffee or copy machine toner. Migraine that manifests without other neurologic symptoms is called migraine without aura.
Rarely, patients who suffer from migraine experience prolonged neurologic dysfunction associated with the headache pain. Such neurologic dysfunction may last for more than 24 hours and is termed migraine with prolonged aura. These 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 that may include aphasia or hemiplegia. As with migraine with prolonged aura, patients suffering from migraine with complex aura may develop permanent neurologic deficits.
Patients suffering from all forms of migraine headache appear systemically ill ( Fig. 2.3 ). Pallor, tremulousness, diaphoresis, and light sensitivity are common physical findings. The temporal artery and the surrounding area may be tender. If an aura is present, results of the neurologic examination will be abnormal; the neurologic examination is usually within normal limits before, during, and after migraine without aura.
