Migraine in childhood and adolescence. A critical study of the diagnostic criteria and of the influence of age on clinical findings.

We studied 253 children aged <15 years. Phase 1 included 193 children with migraine (1.1 and 1.2) divided into two groups (<10 and > or = 10 years). We studied the relationship between age and migraine type, headache characteristics, and associated symptoms of the International Headache Society (IHS) definition. A higher frequency of migraine with aura, pulsatile quality, and unilateral location was observed in older children. In phase 2 we studied 176 children with headache (excluding migraine with aura), comparing diagnostic criteria, definition items, sensitivity, and specificity. The results showed that item B of the definition was the most frequent cause of exclusion in the 1.7 diagnostic group. Compared with Vahlquist and the IHS, the Prensky criteria were the most sensitive. Sensitivity was >70% for pain of moderate/severe intensity, duration between 2 and 48 h, isolated photophobia, isolated phonophobia, and aggravation with physical activity. Specificity was >70% for nausea, vomiting, phonophobia and photophobia, isolated photophobia, aggravation with physical activity, and isolated phonophobia. Based on three alternative definitions, each modifying one item of the IHS definition, the sensitivity and specificity of these alternative definitions were compared with the "extended" criteria (children with migraine without aura and migrainous disturbance, according to the IHS criteria, grouped together). Exclusion of headache duration increased sensitivity by 10%, compared to restrictive IHS criteria, without decreasing specificity.