Headache in children

Red flags of migraine without aura

The risks of radiation exposure from computerized tomography (CT) imaging and the risk of anesthesia and sedation needed for magnetic resonance imaging (MRI) can often discourage neuroimaging a child with headache. However, the red flag signs and symptoms of a first or isolated headache listed in Box 58.3 should prompt consideration of urgent imaging of a child with headache. In a child with recurrent headaches, the findings of an abnormal neurologic exam should prompt imaging the brain. Emergent and urgent imaging in children or adolescents with headache is often with a CT scan of the head, but a brain MRI in a child is ideal if promptly available because of the superior neuroanatomic detail and lack of radiation.

A study of 1562 children with recurrent headaches presenting to nine pediatric neurology clinics in tertiary hospitals found that 77% of these children had brain imaging, but only 9.3% had abnormal findings on the scans. In those with an abnormal neurologic exam, however, 50% of the scans identified a cause. A new-onset headache during pregnancy in an adolescent female is a red flag symptom, given the increased risk for an underlying etiology such as cerebral venous thrombosis in this setting. Occipital headaches in children in the past were considered a red flag, however, more recent data suggests that in the absence of an atypical history or an abnormal exam, occipital headaches are usually benign. Occipital location of head pain was found in 20% of children with migraine presenting to the emergency room.

Migraine with aura

In 30% of patients with migraine, the migraine attacks are preceded or accompanied by an “aura” characterized by transient focal neurologic symptoms. Migraine with aura ( Box 58.4 ) is defined by recurrent (≥2) attacks, lasting 5–60 minutes, with fully reversible visual, sensory, or other central nervous system symptoms. The aura usually develops gradually over minutes and is followed by associated migraine symptoms and headache. It typically starts before the pain phase begins. However, the aura may begin after the pain starts or continue into the pain phase. If a child meets criteria for typical aura, but has no subsequent headache, the child is diagnosed with typical aura without headache, previously referred to as “acephalgic migraine” or “ocular migraine.”

Visual aura is the most common type of aura in adults and children, and found in 93% of children and adolescents diagnosed with migraine with aura. Positive visual symptoms are most often described as an arc of colored or white zig-zag, jagged, or serrated lines moving to the periphery; however, flashes of light or shapes are also described. The visual symptoms usually disappear after 15–20 minutes. Atypical visual complaints in migraine, but not aura per se , such as complex hallucinations, visual snow, and Alice in Wonderland syndrome, are well described in children.

Other non-visual auras

Sensory disturbance is the next most common aura, found in 5.5% of children with migraine with aura, and is usually described as pins and needles or numbness that slowly spreads (seconds to minutes) away from a point of origin. Migraine with brainstem aura, previously known as basilar migraine, must include at least two brainstem features (dysarthria, vertigo, tinnitus, hyperacusis, diplopia, ataxia, or decreased consciousness). Hemiplegic migraine has an aura that includes motor weakness. If there is a first- or second-degree relative with migraine aura involving motor weakness, then familial hemiplegic migraine from causative gene mutations CACNA1A , SCN1A , or ATP1A2 should be considered.

Migraine visual aura complications

The visual aura typically lasts less than 1 hour (although motor aura can last weeks) and is fully reversible; however, on rare occasions an aura can persist for more than 1 week and last for months. If there is no ischemia found on neuroimaging, persistent aura without infarction is diagnosed. Persistent positive visual phenomena (PPVP) differs from persistent aura without infarction in that the visual phenomena are usually continuous, full-field without vision loss, and not visually disabling. Another rare complication of aura is migrainous infarction, defined as a migraine aura lasting more than 1 hour and associated with infarction in the appropriate territory on neuroimaging. In a recent study, however, no increase in hemorrhagic or ischemic stroke risk in children with migraine was found.