Migraine - Nelson Review

Migraine

The prevalence of migraine among school-aged children between 7 and 15 yr of age was 4% in a comprehensive Swedish study and ranges from 8 to 23% in adolescents.

Cortical spreading depression (CSD), a phenomenon thought to be responsible for the aura of migraine, is associated with elevation of CNS hydrogen and potassium ions, with the release of glutamate and nitrous oxide. These changes result in regional cortical oligemia and activation of the caudal portion of the trigeminal ganglion. Excitation of the trigeminal-vascular system initiates the release of vasoactive intestinal polypeptides causing vasodilation followed by extravasation of plasma proteins from the dural vessels resulting in localized inflammation of the dural vessels. Neurogenic vascular inflammation causes excitation of pain sensitive receptors and the onset of pain. CSD is considered to be an inherited physiologic response to a variety of stimuli that are responsible for triggering the migraine process.

Migraine without aura

This migraine is not associated with an aura and is the most prevalent type of migraine in children. The headache is throbbing or pounding and tends to be unilateral at onset or throughout its duration but may also be located in the bifrontal or temporal regions. It may not be hemicranial in children and is less intense compared with the migraine in adults. The headache usually persists for 1–3 hr, although the pain may last for as long as 72 hr. The pain may inhibit daily activity, because physical activity aggravates the pain. A characteristic feature of childhood migraine is intense nausea and vomiting, which may be more bothersome than the headache. The vomiting may be associated with abdominal pain and fever; conditions such as appendicitis and a systemic infection may be erroneously confused with the primary diagnosis. Additional symptoms include extreme paleness, photophobia, light-headedness, phonophobia, osmophobia (aversion to odors), and paresthesias of the hands and feet. A positive family history, particularly on the maternal side, is present in ≈90% of children with migraine without aura. Considerable caution should be exercised when making the diagnosis of migraine in the absence of a positive family history. Additional features of all migraines may include near synchrony with perimenstrual or periovulation timing, gradual appearance after sustained exercise, relief with sleep, stereotypical prodromes (hypersomnia, food craving, irritability, moodiness), precipitation by food or odors, and onset after a letdown or high period of stress

Migraine with an Aura.

In this disorder, an aura precedes the onset of the headache. Visual auras are uncommonly described by young children with migraine, but when they occur they may take the form of blurred vision, scotoma (an area of depressed vision within the visual field), photopsia (flashes of light), fortification spectra (brilliant white zigzag lines), or irregular distortion of objects. Some patients also have vertigo and light-headedness during this stage of the headache. Sensory symptoms include perioral paresthesias and numbness of the hands and feet. Distortions of body image (Alice in Wonderland syndrome) may predominate as a prelude to a classic migraine headache. After the onset of the aura, the patient develops typical symptoms of a migraine as described earlier.

Hemiplegic migraine is considered a migraine aura and is characterized by the onset of unilateral sensory or motor signs during an episode of migraine. Hemisyndromes are more common in children than in adults and may be characterized by numbness of the face, arm, and leg; unilateral weakness; and aphasia. Hemiplegic migraine in an older child or adolescent has a relatively good prognosis, and a positive family history of similar hemiplegic events is often elicited. Familial hemiplegic migraine (FHM) is an autosomal dominant disorder. FHM is characterized by hemiplegia during the headache and, in some kindreds, progressive cerebellar atrophy.

Basilar-type migraine is considered to represent a precursor of childhood migraine. Brainstem signs predominate in these patients because of vasoconstriction of the basilar and posterior cerebral arteries. The major symptoms include vertigo, tinnitus, diplopia, blurred vision, scotoma, ataxia, and an occipital headache. The pupils may be dilated, and ptosis may be evident. Alterations in consciousness followed by a generalized seizure may result. After the attack, there is a complete resolution of the neurologic symptoms and signs. Most affected children have a strongly positive family history of migraine

TABLE 595-3 -- Diagnostic Criteria for Migraine

WITHOUT AURA

A At least five attacks B Headache attack lasts 4–72 hr (untreated or unsuccessfully treated). C Headache has at least two of the following characteristics: Unilateral location Pulsating quality Moderate or severe intensity Aggravation by or avoidance of routine physical activity (i.e., walking or climbing stairs) D During headache at least one of the following: Nausea, vomiting, or both Photophobia and phonophobia E Not attributed to another disorder

WITH AURA (CLASSIC MIGRAINE)

A At least two attacks B Migraine aura fulfills criteria for typical aura, hemiplegic aura, or basilar-type aura. C Not attributed to another disorder

TYPICAL AURA

1 Fully reversible visual, sensory, or speech symptoms (or any combination) but no motor weakness 2 Homonymous or bilateral visual symptoms including positive features (e.g., flickering lights, spots, lines) or negative features (e.g., loss of vision), or unilateral sensory symptoms including positive features (e.g., visual loss, pins and needles) or negative features (i.e., numbness), or any combination 3 At least one of: a) At least one symptom develops gradually over a minimum of 5 min, or different symptoms occur in succession, or both b) Each symptom lasts for at least 5 min and for no longer than 60 min 4 Headache that meets criteria for migraine without aura begins during the aura or follows aura within 60 min

From Silberstein SD: Migraine. Lancet 2004;363:381–391.

The most common precipitators of migraine headaches are stress, fatigue, and anxiety. The parents may be asked to create a diary or calendar relating the onset of headache to a particular food to determine if dietary factors are responsible for the child's migraine. Elimination of the incriminating foodstuff is indicated if the history suggests a relationship between the ingestion of a particular food and the onset of headache

TABLE 595-2 -- Indications for Neuroimaging in a Child with Headaches

Abnormal neurologic signs Recent school failure, behavioral change, fall-off in linear growth rate Headache awakens child during sleep; early morning headache, with increase in frequency and severity Periodic headaches and seizures coincide, especially if seizure has a focal onset Migraine and seizure occur in the same episode, and vascular symptoms precede the seizure (20–50% risk of tumor or arteriovenous malformation) Cluster headaches in child; any child <5–6> Focal neurologic symptoms or signs developing during a headache (i.e., complicated migraine) Focal neurologic symptoms or signs (except classic visual symptoms of migraine) develop during the aura, with fixed laterality; focal signs of the aura persisting or recurring in the headache phase Visual graying-out occurring at the peak of a headache instead of the aura Brief cough headache in a child or adolescent

Modified from Barlow CF: Headaches and Migraine in Childhood. Philadelphia, JB Lippincott, 1984, p 205.

Intravenous prochlorperazine, 0.15 mg/kg (max 10 mg), is highly effective in aborting intractable migraine in children who have not responded to acute management of the headache

Management of an acute attack of migraine should include the use of analgesics and antiemetics ( Table 595-4 ). Most migraine headaches in children can be treated by the judicious use of acetaminophen (15 mg/kg) or ibuprofen (7.5–10 mg/kg) dispensed in the gel capsule formulation, particularly if the headaches are mild, infrequent, and of short duration. The child usually prefers to rest in a quiet, darkened room and typically awakens, refreshed and headache free, several hours later after a deep sleep. Triptans (e.g., Sumatriptan) are specific and selective 5-hydroxytryptamine receptor agonists that are effective abortive drugs in treating the acute phase of migraine with and without aura if the use of conventional analgesics is ineffective. Sumatriptan may be administered subcutaneously, nasally, or orally. The nasal spray formulation is the preferred route of administration for children. The suggested dose is 5 mg in children <25 style="background: yellow none repeat scroll 0% 0%; -moz-background-clip: border; -moz-background-origin: padding; -moz-background-inline-policy: continuous;">10 mg (two sprays) in those weighing 25–50 kg, and 20 mg sumatriptan in children ≥50 kg