Chiari Type 1 Deformity in Children: Pathogenetic, Clinical, Neuroimaging, and Management Aspects

Neuropediatrics. 2016 Oct;47(5):293-307. doi: 10.1055/s-0036-1584563. Epub 2016 Jun 23.


Our understanding of cerebellar tonsillar herniation evolved over time and nowadays various pathomechanisms have been proposed. Causes of tonsillar herniation share a discrepancy between content (fore- and hindbrain) and container (supratentorial cranial vault, posterior fossa), may be associated with abnormalities of the craniocervical junction, and may have a developmental or acquired nature. In tonsillar herniation, the hindbrain is not malformed but deformed. Accordingly, "Chiari type 1 deformity," not "Chiari type 1 malformation" is the correct term to characterize primary tonsillar herniation. Chiari type 1 deformity is commonly seen in pediatric neurology, neuroradiology, and neurosurgery and may have various clinical presentations depending on patient age. In addition, Chiari type 1 deformity is increasingly found by neuroimaging studies as an incidental finding in asymptomatic children. An accurate and reliable selection of patients based on clinical and neuroimaging findings is paramount for the success of neurosurgical treatment. Future studies are needed to provide selection criteria with a higher sensitivity and specificity.

Publication types

  • Review

MeSH terms

  • Arnold-Chiari Malformation / complications
  • Arnold-Chiari Malformation / diagnostic imaging*
  • Arnold-Chiari Malformation / physiopathology
  • Arnold-Chiari Malformation / therapy
  • Ataxia / etiology
  • Cervical Vertebrae / abnormalities
  • Cervical Vertebrae / diagnostic imaging*
  • Conservative Treatment
  • Cranial Fossa, Posterior / abnormalities
  • Cranial Fossa, Posterior / diagnostic imaging*
  • Disease Management
  • Encephalocele / diagnostic imaging*
  • Encephalocele / physiopathology
  • Encephalocele / surgery
  • Headache / etiology
  • Humans
  • Magnetic Resonance Imaging
  • Neck Pain / etiology
  • Neuroimaging
  • Neurosurgical Procedures
  • Nystagmus, Pathologic / etiology
  • Skull Base / abnormalities
  • Skull Base / diagnostic imaging
  • Syringomyelia / diagnostic imaging*
  • Syringomyelia / physiopathology
  • Syringomyelia / therapy