title: Pediatric Chiari malformation Type 0: a 12-year institutional experience.
abstract: OBJECTIVE
  In 1998 the authors identified 5 patients with syringomyelia and no evidence of Chiari malformation Type I (CM-I). Magnetic resonance imaging of the entire neuraxis ruled out other causes of a syrinx. Ultimately, abnormal CSF flow at the foramen magnum was the suspected cause. The label "Chiari 0" was used to categorize these unique cases with no tonsillar ectopia. All of the patients underwent posterior fossa decompression and duraplasty identical to the technique used to treat patients with CM-I. Significant syrinx and symptom resolution occurred in these patients. Herein, the authors report on a follow-up study of patients with CM-0 who were derived from over 400 operative cases of pediatric CM-I decompression.
  
  
  METHODS
  The authors present their 12-year experience with this group of patients.
  
  
  RESULTS
  Fifteen patients (3.7%) were identified. At surgery, many were found to have physical barriers to CSF flow near the foramen magnum. In most of them, the syringomyelia was greatly diminished postoperatively.
  
  
  CONCLUSIONS
  The authors stress that this subgroup represents a very small cohort among patients with Chiari malformations. They emphasize that careful patient selection is critical when diagnosing CM-0. Without an obvious CM-I, other etiologies of a spinal syrinx must be conclusively ruled out. Only then can one reasonably expect to ameliorate the clinical course of these patients via posterior fossa decompression.
authors: Pediatric Neurosurgery, Children's Hospital, Birmingham, Alabama 35233, USA.
authors: Joshua J
authors: JJ
authors: Chern
authors: Amber J
authors: AJ
authors: Gordon
authors: Martin M
authors: MM
authors: Mortazavi
authors: R Shane
authors: RS
authors: Tubbs
authors: W Jerry
authors: WJ
authors: Oakes
mesh_terms: D000293:Adolescent; D001139:Arnold-Chiari Malformation / Q000145:classification / Q000175:diagnosis* / Q000601:surgery*; D002574:Cervical Vertebrae / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D003399:Craniotomy; D019299:Decompression, Surgical / Q000379:methods*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D012189:Retrospective Studies; D013595:Syringomyelia / Q000145:classification / Q000175:diagnosis* / Q000601:surgery*