Migraine without aura and migrainous disorder in children; International Headache Society (IHS) and revised IHS criteria.

The widely used criteria of the IHS to define migraine without aura in children are highly specific but show poor sensitivity, with a large percentage of headaches being classified as migrainous disorder (MD). The objective of this study was to assess how many headache patients in a series of children met the diagnostic criteria of the IHS for migraine without aura or MD and to determine the changes required to convert the greatest number of MD into migraine without aura, without affecting classification of the remaining headache types. A prospective study was undertaken of 131 patients under 15 years old referred to our centre for headache. Patients were classified according to the IHS criteria and according to a modification of these criteria consisting of: (1) reduction of minimum time required for classification into migraine without aura from 2 h to 1 h; (2) acceptance of bifrontal location in addition to hemicranial; (3) acceptance of either phonophobia or photophobia as valid criteria instead of requiring presence of both. Using the IHS criteria, 51 (39%) children were diagnosed as having migraine without aura and 26 (20%) as having MD. According to our revised IHS criteria, 68 (52%) were diagnosed as migraine without aura and nine (7%) as MD. When the three modified criteria were applied, three tension headaches and one unclassifiable headache changed category. When only reduced duration and bifrontal location were applied, none of the headaches other than MD changed category. Application of two modifications to the IHS criteria--reduction in duration of headache to 1 h and acceptance of bifrontal location--increased sensitivity without reducing specificity in classifying migraine without aura in children.