title: Morphometric Analysis of Predictors of Cervical Syrinx Formation in the Setting of Chiari I Malformation.
abstract: OBJECTIVE
  We performed a morphometric analysis of Chiari I malformations to look for predictors of cervical syrinx formation.
  
  
  METHODS
  Eighteen patients with Chiari I malformation and associated cervical syrinx and 16 patients with Chiari I malformation without associated cervical syrinx were included in the study. Chiari I size was obtained from the radiology report; foramen magnum diameter, cerebellar volume, posterior fossa volume and intracranial volume were calculated using OsiriX software, and average measurements were compared between the two groups.
  
  
  CONCLUSIONS
  Patients with Chiari I with syrinx had an average tonsillar descent of 13.03 ± 5.31 mm compared to 9.25 ± 3.31 mm in the Chiari I without syrinx group (p < 0.05). Patients with Chiari I and syrinx also showed increased cerebellar crowding with a higher cerebellar volume to posterior fossa volume ratio; however, this difference was not significant (0.83 vs. 0.81; p = 0.1872). No difference between groups was found in posterior fossa volume, intracranial volume and foramen magnum diameter. Therefore, only Chiari I size based on the extent of tonsillar herniation was found to be a determinant of cervical syrinx formation.
authors.affiliation: Duke University Medical Center, Durham, N.C., USA.
authors.forename: Kyle G
authors.initials: KG
authors.lastname: Halvorson
authors.forename: Ryan T
authors.initials: RT
authors.lastname: Kellogg
authors.forename: Krista N
authors.initials: KN
authors.lastname: Keachie
authors.forename: Gerald A
authors.initials: GA
authors.lastname: Grant
authors.forename: Carrie R
authors.initials: CR
authors.lastname: Muh
authors.forename: Ben
authors.initials: B
authors.lastname: Waldau
mesh_terms: D000293:Adolescent; D000328:Adult; D001139:Arnold-Chiari Malformation / Q000000981:diagnostic imaging* / Q000453:epidemiology; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013595:Syringomyelia / Q000000981:diagnostic imaging* / Q000453:epidemiology; D055815:Young Adult