Natural history of migraine in childhood.

Epidemiological studies have shown that 3-7% of the paediatric population suffer from migraine. Despite this high prevalence little has been published about the natural history of migraine or of its prognosis. The objectives of this study were: (i) to outline the natural history of migraine in childhood; and (ii) to identify early predictors of an unfavourable clinical evolution. A prospective, longitudinal, 10-year follow-up study was conducted of the clinical evolution of 181 paediatric patients with migraine. Data analysis was performed by statistical significance and logistic regression tests. In our study 24.3% of children with migraine had their onset before age 6 years and another 57% between 6 and 10 years of age. A positive family history of migraine was recorded in 77.5%. Eighty-eight percent of patients followed a favourable clinical course. The remaining 12% of patients had to be placed on prophylactic treatment owing to the increasing of their headache. Of all parameters investigated, the age of onset was the only statistically significant predictor of an unfavourable clinical evolution. We conclude: (i) most patients with migraine headache starting in childhood do not require prophylactic treatment; (ii) the earlier the disease begins the more likely is an unfavourable clinical course; (iii) genetic factors play an important role in the phenotypic expression of the disease; (iv) our study suggests the existence, at least, of two different populations among childhood migraine patients.