Development of Benign Enlargement of Subarachnoid Spaces Growth Charts.

BACKGROUND

This study aimed to develop head circumference (HC) growth charts specific to infants and young children diagnosed with benign enlargement of the subarachnoid spaces. By modeling HC trajectories, we sought to establish normative curves that distinguish benign macrocephaly from pathologic causes of head enlargement. Our objective was to support accurate monitoring, reduce unnecessary imaging, and guide appropriate referral decisions in pediatric patients with macrocephaly.

STUDY DESIGN

A retrospective analysis of HC measurements was conducted using data from 137 patients aged 0-6 years diagnosed with benign macrocephaly at the Children's Hospital of Eastern Ontario. Generalized Additive Models for Location, Scale, and Shape were employed to create growth charts.

RESULTS

The study included 137 children with neuroimaging confirming benign macrocephaly diagnoses. Exclusion criteria were applied to ensure the cohort was representative of isolated benign macrocephaly cases. Benign macrocephalic percentile charts for HC were generated, showing accelerated early growth followed by stabilization around ages 2-3. For both boys and girls, the 50th centile tracks consistently above the 97th in World Health Organization data for non-benign macrocephalic patients. The majority of benign macrocephalic patients fell above the 97.5th percentile of the World Health Organization reference curves. We identified pathological growth by examining HCs greater than 60 cm and assessing for rapidly progressive HC growth patterns that required surgical intervention.

CONCLUSIONS

We provide novel benign macrocephaly growth charts that enable accurate monitoring of HC in clinical settings. Furthermore, the use of these curves may help differentiate patients with benign macrocephaly from other entities that may warrant surgical intervention such as hydrocephalus. Future research should validate these findings in multicenter prospective studies for practitioners to remain abreast in clinical management strategies for infants with benign macrocephaly.