Has rising pediatric obesity increased the incidence of idiopathic intracranial hypertension in children?

Objective: Idiopathic intracranial hypertension (IIH) in children is an uncommon but significant cause of morbidity, including permanent visual loss. It is important to understand if, like obesity, IIH in children is on the rise and is related to that increase. The aim of this study is to compare the recent incidence rate of pediatric IIH in a tertiary care hospital with earlier data published from that same hospital. Design: Retrospective chart review. Participants: All children aged 2 to 16 years diagnosed with IIH at the IWK Health Centre in Halifax between 1997 and 2007. Methods: Charts of eligible patients were reviewed to ensure all diagnostic criteria for IIH were met. Incidence and obesity rates were calculated based on data from Statistics Canada. Results: Twelve cases (5 males, 7 females) fulfilling the diagnostic criteria for IIH were identified, for an annual incidence of 0.6 cases per 100,000 children with no sex predilection (p = 0.51). Obesity was noted in 75% of patients examined (9/12). Children older than 12 years were more likely to be obese (6/6, 100%) compared with those younger than 12 years (3/6, 50%). Conclusions: The calculated incidence is lower than that found in an earlier study for the same geographic region (0.9 cases per 100,000 children) despite increasing obesity rates. This decrease may be a reflection of improved diagnostic techniques or may indicate that factors other than obesity govern IIH predilection in younger children.