title: The role of the posterior fossa in developing Chiari I malformation in children with craniosynostosis syndromes.
abstract: OBJECTIVE
  Patients with craniosynostosis syndromes are at risk of increased intracranial pressure (ICP) and Chiari I malformation (CMI), caused by a combination of restricted skull growth, venous hypertension, obstructive sleep apnea (OSA), and an overproduction or insufficient resorption of cerebrospinal fluid. This study evaluates whether craniosynostosis patients with CMI have an imbalance between cerebellar volume (CV) and posterior fossa volume (PFV), that is, an overcrowded posterior fossa.
  
  
  METHODS
  Volumes were measured in 3D-SPGR T1-weighted MR scans of 28 'not-operated' craniosynostosis patients (mean age: 4.0 years; range: 0-14), 85 'operated' craniosynostosis patients (mean age: 8.0 years; range: 1-18), and 34 control subjects (mean age: 5.4 years; range: 0-15). Volumes and CV/PFV ratios were compared between the operated and not-operated craniosynostosis patients, between the individual craniosynostosis syndromes and controls, and between craniosynostosis patients with and without CMI. Data were logarithmically transformed and studied with analysis of covariance (ANCOVA).
  
  
  RESULTS
  The CV, PFV, and CV/PFV ratios of not-operated craniosynostosis patients and operated craniosynostosis patients were similar to those of the control subjects. None of the individual syndromes was associated with a restricted PFV. However, craniosynostosis patients with CMI had a significantly higher CV/PFV ratio than the control group (0.77 vs. 0.75; p = 0.008). The range of CV/PFV ratios for craniosynostosis patients with CMI, however, did not exceed the normal range.
  
  
  CONCLUSIONS
  Volumes and CV/PFV ratio cannot predict which craniosynostosis patients are more prone to developing CMI than others. Treatment should focus on the skull vault and other contributing factors to increased ICP, including OSA and venous hypertension.
authors.affiliation: Department of Plastic and Reconstructive Surgery and Hand Surgery, Dutch Craniofacial Center, Erasmus University Medical Center/Sophia Children's Hospital, Rotterdam, The Netherlands. Electronic address: b.rijken@erasmusmc.nl.
authors.forename: Bianca Francisca Maria
authors.initials: BF
authors.lastname: Rijken
authors.affiliation: Department of Pediatric Radiology, Dutch Craniofacial Center, Erasmus University Medical Center/Sophia Children's Hospital, Rotterdam, The Netherlands.
authors.forename: Maarten Hans
authors.initials: MH
authors.lastname: Lequin
authors.affiliation: Department of Radiology, Erasmus University Medical Center, Rotterdam, The Netherlands; Department of Medical Informatics, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Fedde
authors.initials: F
authors.lastname: van der Lijn
authors.affiliation: Department of Pediatric Neurosurgery, Dutch Craniofacial Center, Erasmus University Medical Center/Sophia Children's Hospital, Rotterdam, The Netherlands.
authors.forename: Marie-Lise Charlotte
authors.initials: ML
authors.lastname: van Veelen-Vincent
authors.affiliation: Department of Biostatistics, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Johan
authors.initials: J
authors.lastname: de Rooi
authors.affiliation: Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Yoo Young
authors.initials: YY
authors.lastname: Hoogendam
authors.affiliation: Department of Radiology, Erasmus University Medical Center, Rotterdam, The Netherlands; Department of Medical Informatics, Erasmus University Medical Center, Rotterdam, The Netherlands; Faculty of Applied Sciences, Delft University of Technology, The Netherlands.
authors.forename: Wiro Joep
authors.initials: WJ
authors.lastname: Niessen
authors.affiliation: Department of Plastic and Reconstructive Surgery and Hand Surgery, Dutch Craniofacial Center, Erasmus University Medical Center/Sophia Children's Hospital, Rotterdam, The Netherlands.
authors.forename: Irene Margreet Jacqueline
authors.initials: IM
authors.lastname: Mathijssen
mesh_terms: D000168:Acrocephalosyndactylia / Q000150:complications; D000293:Adolescent; D001139:Arnold-Chiari Malformation / Q000209:etiology*; D001933:Brain Stem / Q000000981:diagnostic imaging / Q000473:pathology; D002531:Cerebellum / Q000000981:diagnostic imaging / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D003388:Cranial Fossa, Posterior / Q000000981:diagnostic imaging / Q000473:pathology*; D003394:Craniofacial Dysostosis / Q000150:complications; D003398:Craniosynostoses / Q000150:complications* / Q000601:surgery; D005260:Female; D005539:Foramen Magnum / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009929:Organ Size; D019651:Plastic Surgery Procedures / Q000379:methods
keywords: Cerebellum; Chiari I malformation; Craniosynostosis syndromes; Posterior fossa