Use of the ICHD-II criteria in the diagnosis of pediatric migraine.

OBJECTIVE: To evaluate the sensitivity of the new International Classification of Headache Disorders-2nd edition (ICHD-II) criteria in the diagnosis of childhood migraine and to propose specific criteria for the diagnosis of childhood migraine.

BACKGROUND: In 2004, ICHD-II was adopted by the International Headache Society. The prior version had been criticized for its lack of sensitivity in diagnosing childhood headaches. ICHD-II is felt to be an improvement as it provides for some differences between pediatric and adult migraine diagnosis in its footnotes, however, has yet to be validated. Clinically, it is the impression of many pediatric headache specialists that children's migraines are of shorter duration, tend to be bilateral rather than unilateral, and that children more often report either photophobia or phonophobia, rather than both.

METHODS: The characteristics of headache in 260 patients, ages 18 and under, clinically diagnosed with migraine at two large pediatric headache centers were compiled using standard intake questionnaires. Inter-rater reliability in clinical diagnosis was determined by consensus of the clinical diagnosis. These data were analyzed applying the International Classification of Headache Disorders-1st edition (ICHD-I) and ICHD-II criteria for migraine to determine sensitivity of migraine diagnosis in comparison with clinical impression. Each headache characteristic in ICHD-II was analyzed individually to determine its effect on sensitivity of diagnosis.

RESULTS: 183/260 patients (70.4%) met ICHD-I criteria. 161/260 patients (61.9%) met the ICHD-II criteria with a 4- to 72-hour range. When the footnoted allowance of ICHD-II for short duration (2 hours) was utilized, 187/260 patients (71.9%) met criteria, while this improved to 192/260 patients (73.9%) with 1-hour duration. If duration was excluded, 210/260 patients (80.8%) met criteria. The most common reasons for patients not meeting the standard criteria were the requirement of unilateral location, headache duration and number of associated symptoms. Based on these observations, modified criteria were empirically derived and the sensitivity increased to 84.4%. Data were reanalyzed using the criteria of focal head pain, either bilateral or unilateral, shortened duration, and modified associated symptoms, which resulted in an improved sensitivity in migraine diagnosis of 84.4%.

CONCLUSIONS: Modification of ICHD-II criteria to include bilateral headache, headache duration of 1 to 72 hours, and nausea and/or vomiting plus two of five other associated symptoms (photophobia, phonophobia, difficulty thinking, lightheadedness, or fatigue), in addition to the usual description of moderate to severe pain of a throbbing or pulsating nature worsening or limiting physical activity, improved sensitivity of migraine diagnosis to 84.4%.