The relationship between obesity and symptomatic Chiari I malformation in the pediatric population

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.