Migraine and the periodic syndrome in 5-15 year-old Aberdeen schoolchildren
The objectives of this project were to study the prevalence and the clinical features of the periodic syndrome including headache, migraine, recurrent abdominal pain, abdominal migraine, recurrent limb pain, cyclical vomiting syndrome and paroxysmal vertigo in the well defined general population of Aberdeen schoolchildren between 5-15 years of age. Children were studied in two stages. At the first stage a random 10% sample of all children attending schools at Aberdeen (2165 children) were asked to complete a screening questionnaire. At the second stage, symptomatic children were invited to attend for clinical interviews and physical examination at the schools' medical rooms to establish the cause of the symptoms and the diagnosis where possible. The response rate for the screening questionnaire was 81% and the overall attendance rate for the interviews was 85%. Parents of about 90% of the children either attended the interviews or gave phone interviews instead. 159 children (estimated prevalence rate 10.6%) fulfilled the criteria for the diagnosis of migraine, 58 children (prevalence rate 4.1%) fulfilled the diagnosis of abdominal migraine, 45 children (2.6%) had recurrent limb pain of unknown aetiology, 34 children (1.9%) had cyclical vomiting syndrome and 45 children (2.6%) had paroxysmal vertigo of childhood. Approximately one third of all children had at least two recurrent disorders at the time of the interview. The five conditions had common patterns of trigger factors, associated symptoms, associated disorders such as atopic illness and travel sickness, relieving factors, family history of migraine and multiple symptomatology suggesting a common pathogenesis of all the conditions possibly related to the migraine syndrome. These findings enforce the notion that the periodic syndrome is likely to be a migraine equivalent or variant.