The most notable symptom of childhood migraine is headache. A key clinical feature, however, is normality between attacks. Although a unilateral, throbbing headache is typical with adult migraine, it is more common for children to complain of bilateral or midfrontal headaches. Even though the headache is often bilateral, its onset may be unilateral. If usual questioning does not disclose the location and quality of the headache, the child can be asked to point to the location of onset, and the examiner can supply several adjectives to determine the quality of the pain (eg, pounding, pressing, and burning). One measure of the morbidity is how much school is missed due to migraine attacks. In a survey, 10% of children with migraine missed 1 day of school over a 2-week period, and nearly 1% missed 4 days (Stang and Osterhaus 1993). Use of a migraine disability assessment tool may help to specify the associated disabilities, and can be useful for comparison at follow-up (Hershey et al 2001). A visual aura of scintillating scotomata or flashing lights or, less commonly, a sensory or motor disturbance may precede the headache by 20 to 60 minutes in a third of migrainous children (Mortimer et al 1992), but the pathognomonic fortification spectrum with its gradually expanding "C" shape with a scintillating border is rarely reported. Visual symptoms are usually homonymous, and motor or sensory symptoms are usually unilateral. In children, gastrointestinal symptoms are especially prominent, but the headaches, sometimes lasting less than an hour, are usually of shorter duration than those of adults. Facial pallor commonly occurs before or with the headache, and photophobia and phonophobia may also occur. Although most children with migraine do not experience syncope, migraine is second only to vasovagal syncope as a cause of syncope in children (McHarg et al 1997), and many children report a lightheaded dizziness with the headaches. Nonheadache symptoms often precede the headache, and include irritability, malaise, and hyperactivity. Factors often mentioned as precipitating or exacerbating the headache include stress, light, irregular schedule (eg, meals, sleep times), menses, minor head trauma, heavy exercise, environmental heat, and weather. Medications that may increase the likelihood of headaches include adrenergic agonists (eg, for asthma or ADHD), oral contraceptives, and others. Unfavorable lifestyles (including obesity, low physical activity, and cigarette smoking) are associated with an increased prevalence of headaches. Among 112 adolescents with migraine who underwent a weight-loss program, the 40 who became migraine-free lost more weight than the 72 who continued to experience migraine (Verrotti et al 2014). Dietary substances are generally less important as triggering factors (eg, chocolate, cheese, caffeine, alcohol, nitrites “hot dog headache,” and monosodium glutamate) (Jansen et al 2003).
The criteria for different headache types proposed by the Headache Classification Subcommittee of the International Headache Society may be used for children (Headache Classification Subcommittee of the International Headache Society 2004). However, if a child has not yet had 5 attacks or if the headaches last less than 1 hour, the IHS criteria may be too restrictive.
Diagnostic criteria. Migraine has 2 basic types: (1) migraine without aura and (2) migraine with aura (Headache Classification Subcommittee of the International Headache Society2004).
Migraine without aura.
Migraine with aura. This diagnosis requires 1 or more fully reversible aura symptoms to indicate focal cerebral cortical or brainstem dysfunction. No aura lasts more than 60 minutes. A typical aura may include visual, sensory, or speech symptoms and is usually followed by a typical migraine headache. Aura without headache is exceedingly rare in children and should raise suspicion for a structural lesion.
Subforms of migraine with aura.
Hemiplegic migraine occurs both sporadically and as an inherited autosomal dominant trait. Some of the familial patients have cerebellar signs and may have serious complications, including coma from mild head injury (Curtain et al 2006). Basilar-type migraine has symptoms referable to brainstem (syncope, vertigo, ataxia, dysarthria, nystagmus, diplopia, and somnolence) or to bilateral hemispheric dysfunction (bilateral visual symptoms or blindness).
Childhood periodic syndromes that are commonly precursors of migraine.
The periodic syndromes are considered precursors to migraine or are considered migraine equivalents. However, a clear link with migraine remains questionable. The most common of these are recurrent abdominal pain (abdominal migraine) and cyclical vomiting. Other possible migraine equivalents include benign paroxysmal vertigo, benign paroxysmal torticollis, and some also consider acute confusional migraine as part of this group. They are more likely to be accepted as migraine equivalents if the child also has typical episodes of migraine headache that include similar symptoms. For example, coexisting migraine headaches are most typical with abdominal migraine and cyclical vomiting and occur in 70% of the patients, whereas they are least frequent with benign paroxysmal vertigo (10%) (Al Twaijri and Shevell 2002). Although some children with these syndromes later develop migraine, others do not. At this time, there is not a diagnostic marker for migraine that can verify a relationship between migraine and recurrent abdominal pain or cyclical vomiting, and the existence of these disorders as forms of migraine remains uncertain.
Migraine variants. (Kandt and Goldstein 1985)