title: Volumetric analysis of the posterior cranial fossa in a family with four generations of the Chiari malformation Type I.
abstract: OBJECTIVE
  Many authors have concluded that the Chiari malformation Type I (CM-I) is due to a smaller than normal posterior cranial fossa. In order to establish this smaller geometry as the cause of hindbrain herniation in a family, the authors of this paper performed volumetric analysis in a family found to have this malformation documented in 4 generations.
  
  
  METHODS
  Members from this family found to have a CM-I by imaging underwent volumetric analysis of their posterior cranial fossa using the Cavalieri method.
  
  
  RESULTS
  No member of this family found to have CM-I on preoperative imaging had a posterior fossa that was significantly smaller than that of age-matched controls.
  
  
  CONCLUSIONS
  The results of this study demonstrate that not all patients with a CM-I will have a reduced posterior cranial fossa volume. Although the mechanism for the development of hindbrain herniation in this cohort is unknown, this manifestation can be seen in multiple generations of a familial aggregation with normal posterior fossa capacity.
authors: Department of Cell Biology, University of Alabama at Birmingham, Birmingham, Alabama 35233, USA. rstubbs@uab.edu
authors: R Shane
authors: RS
authors: Tubbs
authors: Mark
authors: M
authors: Hill
authors: Marios
authors: M
authors: Loukas
authors: Mohammadali M
authors: MM
authors: Shoja
authors: W Jerry
authors: WJ
authors: Oakes
mesh_terms: D000293:Adolescent; D000328:Adult; D001139:Arnold-Chiari Malformation / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D003388:Cranial Fossa, Posterior / Q000033:anatomy & histology*; D004677:Encephalocele / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods; D010375:Pedigree; D012249:Rhombencephalon / Q000473:pathology / Q000601:surgery; D014427:Twins / Q000235:genetics