Citation, DOI, disclosures and article data
At the time the article was created Jeremy Jones had no recorded disclosures.View Jeremy Jones's current disclosures
Initial descriptions were based on autopsy observations. Three types were described, with others added later. Types II and III are thought to be related to each other while type I represents a distinct entity 1.
peg-like cerebellar tonsils displaced into the upper cervical canal through the foramen magnum
described in the literature as both a condition in its own right as well as a variant of Chiari I malformation
caudal descent of cerebellar tonsils and brainstem
displacement of the medulla, fourth ventricle, and cerebellar vermis through the foramen magnum
usually associated with a lumbosacral spinal myelomeningocele
features similar to Chiari II, but with an occipital and/or high cervical encephalocele
herniation of the occipital lobe through the foramen magnum
syrinx without cerebellar tonsillar, or brain stem descent
infrequently used and confusing term to be avoided
based on reports of syrinx improvement after posterior fossa decompression
Treatment and prognosis
The main objective of surgery in Chiari malformation is to improve CSF flow across the foramen magnum and surrounding the brainstem, reduce the extent of the syrinx, and reduce pressure on the brainstem 7.
History and etymology
It was first described by Hans Chiari (1851-1914), an Austrian pathologist, in 1891 3. In this and subsequent papers, Chiari also credited Julius Arnold (1835-1915), Professor of Anatomy at Heidelberg, on the grounds of a previous publication of a case believed by Arnold to be of a Chiari II malformation. It appears that this is not actually the case, and as such the term Arnold-Chiari to denote Chiari II malformations is no longer advocated 4.
- 1. Ketonen L, Hiwatashi A, Sidhu R. Pediatric brain and spine, an atlas of MRI and spectroscopy. Springer Verlag. (2005) ISBN:3540213406. Read it at Google Books - Find it at Amazon
- 2. Elster AD, Chen MY. Chiari I malformations: clinical and radiologic reappraisal. Radiology. 1992;183 (2): 347-53. Radiology (abstract) - Pubmed citation
- 3. Chiari H. Uber veranderungen des kleinhirns infolge von hydrocephalie des grosshimns. Dtsch Med Wochenschr 1891; 17: 1172-i 175
- 4. Pearce JM. Arnold chiari, or "Cruveilhier cleland Chiari" malformation. J. Neurol. Neurosurg. Psychiatr. 2000;68 (1): 13. doi:10.1136/jnnp.68.1.13 - Free text at pubmed - Pubmed citation
- 5. Tubbs RS, Muhleman M, Loukas M et-al. A new form of herniation: the Chiari V malformation. Childs Nerv Syst. 2012;28 (2): 305-7. doi:10.1007/s00381-011-1616-5 - Pubmed citation
- 6. Tubbs RS, Elton S, Grabb P et-al. Analysis of the posterior fossa in children with the Chiari 0 malformation. Neurosurgery. 2001;48 (5): 1050-4. Pubmed citation
- 7. Holly L, Holly BU, Holly. Chiari malformation and syringomyelia. (2019) Journal of neurosurgery. Spine. doi:10.3171/2019.7.SPINE181139 - Pubmed