Childhood periodic syndromes: a population-based study.

The objective of the present study was to estimate the prevalence and relative risk of symptoms suggestive of childhood periodic syndrome in migraine, migraine subtypes, and tension-type headache, relative to control subjects. The target population was all children (age 5-12 years) enrolled in public elementary schools in one Brazilian city (n = 2173). Consent was obtained for 1994 children; analyzable data were available for 1906 children, for a final sample of 1113 children with migraine, tension-type headache, or no headache. Parents were interviewed using validated questionnaires. Headache diagnosis was assigned according to the International Classification of Headache Disorders, 2nd edition. Relative risk of symptoms was drawn by headache categories relative to controls. For episodic migraine, the relative risk of all symptoms except nocturnal enuresis was significantly increased: motion sickness, recurrent limb pain, recurrent abdominal pain, and parasomnias, such as sleep talking, somnambulism, and bruxism. For tension-type headache, only nocturnal enuresis and motion sickness were not more common than in controls. In multivariate analyses, any interictal symptom was independently associated with any headache (P < 0.001), migraine headaches (P < 0.001), and tension-type headaches (P < 0.01). These findings indicate that interictal symptoms suggestive of childhood periodic syndromes are common in the population, and are associated with migraine and specific migraine subtypes, but also with tension-type headache.