title: The relationship between obesity and symptomatic Chiari I malformation in the pediatric population.
abstract: BACKGROUND
  Concomitant with the rise in childhood obesity in the United States is an increase in the diagnosis of Chiari I malformation (CM1).
  
  
  OBJECTIVE
  To discern a correlation between obesity and CM1, defined as >5 mm of cerebellar tonsillar descent on sagittal magnetic resonance imaging.
  
  
  METHODS
  Charts of CM1 patients aged 2-20 years were retrospectively reviewed. Chiari size, age, body mass index (BMI), and CM1 signs/symptoms were recorded. Patients were stratified by age: 2-9, 10-14, and 15-20 years. Mixed-effect linear models and linear regression analysis were applied to investigate the relationship between BMI-for-age percentiles and CM1 signs/symptoms.
  
  
  RESULTS
  One hundred sixty-seven patients were included (mean age 14.5 ± 2.97 years, BMI 22.98 ± 6.5, and Chiari size 12.27 mm ± 5.91). When adjusted for age, 42% were overweight or obese-higher than normative BMI for children in the studied area (29.6%). When stratified by age, patients between 2 and 9 years were most commonly obese and presented the highest mean BMI (25.66), largest Chiari size (13.58), and highest incidence of headache (75%) and syringomyelia (66.67%). Patients between 15 and 20 years were most commonly overweight and presented the smallest Chiari size (11.76 mm), but the highest incidence of cerebellar (50%) and brainstem (8.55%) compression symptoms. A significant positive correlation existed between BMI and headache in the first two age groups: (R (2): 0.36, P = 0.03; R (2): 0.39, P = 0.01, respectively). Obese patients had higher incidence of headache in the 10-14 group (R (2): 0.37, P = 0.02) and the largest Chiari size in the 15-20 group (R (2): 0.40, P = 0.03).
  
  
  CONCLUSIONS
  The pediatric CM1 population is more likely to be overweight or obese. Younger obese patients presented the highest incidence of Chiari-related headache symptoms, and older obese patients, the highest incidence of findings other than headache. Thus, body weight and age should be considered when evaluating children with CM1.
authors.affiliation: Section of Neurosurgery, The University of Chicago, Chicago, Illinois, USA.
authors.forename: Sandi
authors.initials: S
authors.lastname: Lam
authors.affiliation: Section of Neurosurgery, The University of Chicago, Chicago, Illinois, USA.
authors.forename: Brenda
authors.initials: B
authors.lastname: Auffinger
authors.affiliation: Department of Neurosurgery, Children's Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Tormenti
authors.affiliation: Department of Neurosurgery, Children's Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Bonfield
authors.affiliation: Department of Neurosurgery, Children's Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Greene
keywords: Body mass index; Chiari 1 malformation; idiopathic intracranial hypertension; obesity; pediatric; pseudotumor cerebri; tonsillar descent