Age-Stratified Phenotypes of Pediatric Pseudotumor Cerebri: Lower Opening Pressure and Atypical Presentation in Younger Children

<title>Abstract</title> <p>Purpose. Pediatric pseudotumor cerebri (PTC), or idiopathic intracranial hypertension, has been described as two phenotypes separated approximately by puberty, but contemporary data comparing them within a single, ethnically diverse population are limited. We compared younger and older children with PTC. Methods. In this retrospective cohort study, all children aged 0–18 years presenting to a tertiary pediatric emergency department with a first diagnosis of PTC between 2018 and 2023 were identified. Children aged ≤ 10 years were compared with those aged &gt; 10 years across three pre-specified primary comparisons: sex, opening pressure, and headache. Results. Among 117 children (mean age 11.8 years, 50.4% female), 31 were aged ≤ 10 years. Female sex was markedly less common in the younger group (22.6% vs 60.5%, p &lt; 0.001). Opening pressure was lower in younger children (31.8 ± 9.2 vs 39.3 ± 12.5 cm H₂O, p &lt; 0.001) and remained lower after excluding the 28 sub-threshold cases (36.5 ± 7.5 vs 43.1 ± 10.8 cm H₂O, p = 0.003). Adjustment for obesity attenuated this age difference (p = 0.06). Headache was less frequent as the presenting complaint in younger children (58.1% vs 80.2%, p = 0.029), the weakest of the three comparisons. Conclusion. Younger children with PTC showed a more balanced sex distribution and lower opening pressure than older children, with a less certain reduction in headache. The classic profile of obesity, female sex, and headache, and adult opening-pressure thresholds, should not be used to exclude PTC in this age group, and pediatric opening-pressure reference values may need to account for body size as well as age.</p>