History
The typical headache of migraine is throbbing or pulsatile. It is initially unilateral and localized in the frontotemporal and ocular area, then builds up over a period of 1-2 hours, progressing posteriorly and becoming diffuse. It typically lasts from several hours to a whole day. Pain intensity is moderate to severe, prompting the patient to remain still as it intensifies even with routine physical activity.
* The attack commonly occurs when the patient is already awake, although it may have already started upon awakening and less commonly may awaken the patient at night.
* Nausea and vomiting usually occur later in the attack in about 80% and 50% of patients, respectively, along with anorexia and food intolerance.
* Some patients have been noted to be pale and clammy, especially if nausea develops.
* Photophobia and/or phonophobia also commonly are associated with the headache.
* The headache usually subsides gradually within a day and after a period of sleep; a majority of patients report being tired and weak afterwards.
* About 60% of people who experience migraines report a prodrome, often occurring hours to days before headache onset. Patients describe a change in mood or behavior that may include psychological, neurological, constitutional, or autonomic features.
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o These symptoms may be difficult to diagnose as part of the migraine complex if they occur in isolation from the headache or if they are mild. The prodrome of migraine has yet to receive significant investigational attention.
o Because of the set periodicity of migraine, linkage to the suprachiasmatic nucleus of the hypothalamus that governs circadian rhythm has been proposed. Discovering the central trigger for migraine would help identify better prophylactic agents.
* The migraine aura is a complex of neurologic symptoms that may precede or accompany the headache phase or may occur in isolation.
o It usually develops over 5-20 minutes and lasts less than 60 minutes.
o The aura can be visual, sensory, motor, or any combination of these.
o The most characteristic visual aura of migraine is a scintillating scotoma (occurring in about 64% of cases), beginning as a hazy spot from the center of a visual hemifield followed by shimmering light of different patterns expanding peripherally to involve a greater part of the hemifield with scotoma.
o Paresthesias, occurring in 40% of cases, constitute the next most common aura; they are often cheiro-oral with numbness starting in the hand then migrating to the arm and then jumping to involve the face, lips, and tongue.
o As with visual auras, positive symptoms typically are followed by negative symptoms; paresthesias may be followed by numbness.
* Sensory aura rarely occurs in isolation and usually follows visual aura.
o The rate of spread of sensory aura is helpful in distinguishing it from transient ischemic attack (TIA) or a sensory seizure.
o Just as a visual aura spreads across the visual field slowly, the paresthesias may take 10-20 minutes to spread, which is slower than the spread of sensory symptoms of TIA.
o The migrainous aura generally resolves within a few minutes and then is followed by a latent period before the onset of headache, although merging of the 2 also is reported.
* Motor symptoms may occur in 18% of patients and usually are associated with sensory symptoms.
o Motor symptoms often are described as a sense of heaviness of the limbs before a headache but without any true weakness.
o Speech and language disturbances have been reported in 17-20% of patients, commonly associated with upper extremity heaviness or weakness.
* Whether migraine with and without aura (prevalences, 36% and 55%, respectively) represent 2 distinct processes remains debatable; however, the similarities of the prodrome, headache, and resolution phases of the attacks, similarity in therapeutic response, and the fact that 9% of patients experience both suggest that they are the same entity.
* When an aura is not followed by a headache, it is called a migraine equivalent or acephalic migraine. This is reported most commonly in patients older than 40 years who have a history of recurrent headache. Scintillating scotoma has been considered to be diagnostic of migraine even in the absence of a headache; however, paresthesias, weakness, and other transient neurologic symptoms are not. In the absence of a prior history of recurrent headache and first occurrence after age 45 years, TIA should be considered and must be investigated fully.
* Although headache is a very common reason for seeking medical care, the majority of headache complaints are benign in origin. However, migraine with its protean manifestation may simulate or be simulated by primary and secondary headache disorders. Also, it can coexist with a secondary headache disorder. When headache is episodic, recurrent, and with a well-established pattern, a primary headache disorder is likely. Differentiating between migraine, tension-type, and cluster headaches is important, as optimal treatment may differ.
* Any of the following features suggest a secondary headache disorder and warrant further investigation:
o Atypical history or unusual character that does not fulfill the criteria for migraine
o Occurrence of a new, different, or truly "worst" headache
o Change in frequency of episodes or major characteristics of the headache
o Abnormal neurologic examination
o Inadequate response to optimal therapy