Migraine equivalents as part of migraine syndrome in childhood

Background: Migraine equivalents are common clinical conditions without a headache component, occurring as repeated episodes with complete remission between episodes. They include abdominal migraine, cyclical vomiting, benign paroxysmal vertigo, and benign paroxysmal torticollis. Other clinical entities, such as motion sickness and limb pain have been associated with migraine. We aimed to investigate the prevalence of migraine equivalents in a large population of children referred to a pediatric headache center and to analyze the possible relationship between migraine equivalents and headache features.

Methods: A total of 1134 of children/adolescents (73.2% with migraine and 26.8% with tension-type headache) were included. Patients were divided into two groups according to the episode frequency (high and low). Pain intensity was rated on a three-level graduate scale (mild, moderate, and severe pain).

Results: Migraine equivalents were reported in 70.3% of patients. Abdominal migraine (48.9%), limb pain (43.9%), and motion sickness (40.5%) were the most common migraine equivalents. Although headache type (migraine or tension-type headache) did not correlate with migraine equivalents presence (χ(2) = 33.2; P = 0.27), high frequency of headache episodes correlated with the occurrence of migraine equivalents. Moreover, migraine equivalents indicated a protective role for some accompanying feature of the headache episode.

Conclusions: Our results suggest that migraine equivalents should not be considered merely as headache precursors, but they as part of the migrainous syndrome. Thus, their inclusion among the diagnostic criteria for pediatric migraine/tension-type headache is useful.