Chiari Malformations

  • Mario Manto
  • Herweh Christian
Reference work entry


Chiari malformations designate a group of developmental disorders characterized by anatomical deformities of the posterior fossa. They are either evident at birth or even prenatally or become symptomatic during adolescence or adulthood. Diagnosis relies mainly on MRI. Chiari type I is the most common form and is characterized by herniation of the cerebellar tonsils through the foramen magnum and consecutive forward compression of the lower brainstem. Chiari type II mainly combines a caudal herniation of the cerebellar vermis and brainstem, lumbar myelomeningocele, and supratentorial abnormalities typically of the corpus callosum. Chiari type III associates some intracranial defects of Chiari type II with a high cervical meningomyelocele. Chiari type IV is characterized by cerebellar hypoplasia with aplasia of the tentorium cerebelli. Syringomyelia is the most common spinal cord defect found in association with Chiari malformations. About 40–80% of patients with Chiari type I malformations have a syrinx. The central cavitation is usually located at the cervical level, but may extend cranially to the brainstem or caudally to the lower segments of the spinal cord. Asymptomatic patients diagnosed with Chiari type I in the absence of concomitant syringomyelia are not considered as candidates for surgical therapy in most cases. Surgery of symptomatic malformations consists usually in decompression of the foramen magnum. Nonsurgical therapies include management of neuropathic pain, physical therapy, and rehabilitation.


Obstructive Sleep Apnea Obstructive Sleep Apnea Syndrome Posterior Fossa Central Sleep Apnea Chiari Malformation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



M.M. is supported by FNRS-Belgium.


  1. Abee R, Cooley WB (1892) Syringomyelia. Operation: exploration of cord, withdrawal of fluid, exhibition of patient. J Nerv Ment Dis 19:512–520Google Scholar
  2. Abla AA, Link T, Fusco D, Wilson DA, Sonntag VK (2010) Comparison of dural grafts in Chiari decompression surgery: review of the literature. J Craniovertebr Junction Spine 1(1):29–37PubMedCrossRefGoogle Scholar
  3. Ajis A, Dharmarajah R (2004) Prolonged recovery of balance after a minor head injury as the only presenting feature of Chiari 1 malformation. Br J Neurosurg 18(4):398–400PubMedCrossRefGoogle Scholar
  4. Albert GW, Menezes AH, Hansen DR, Greenlee JD, Weinstein SL (2010) Chiari malformation type I in children younger than age 6 years: presentation and surgical outcome. J Neurosurg Pediatr 5(6):554–561PubMedCrossRefGoogle Scholar
  5. Arnold J (1894) Myelocyste, transposition von gewebskeimen und sympodie. Beitr Pathol Anat 16:1–28Google Scholar
  6. Bahuleyan B, Menon G, Hariharan E, Sharma M, Nair S (2010) Symptomatic posterior fossa and supratentorial subdural hygromas as a rare complication following foramen magnum decompression for Chiari malformation type I. J Neurosurg 114(2):510–513PubMedGoogle Scholar
  7. Barkovich A (1995) Pediatric neuroimaging. Raven Press, New YorkGoogle Scholar
  8. Chiari H (1891) Uber veranderungen des kleinhirns infolge von hydrocephalie des grosshirns. Dtsch Med Wochenschr 17:1172–1175CrossRefGoogle Scholar
  9. Ely EW, McCall WV, Haponik EF (1994) Multifactorial obstructive sleep apnea in a patient with Chiari malformation. J Neurol Sci 126(2):232–236PubMedCrossRefGoogle Scholar
  10. Fernández AA, Guerrero AI, Martínez MI, Vázquez ME, Fernández JB, Chesa i Octavio E, Labrado Jde L, Silva ME, de Araoz MF, García-Ramos R, Ribes MG, Gómez C, Valdivia JI, Valbuena RN, Ramón JR (2009) Malformations of the craniocervical junction (Chiari type I and syringomyelia: classification, diagnosis and treatment). BMC Musculoskelet Disord 10(Suppl 1):S1PubMedCrossRefGoogle Scholar
  11. Gardner WJ (1965) Hydrodynamic mechanism of syringomyelia. J Neurol Neurosurg Psychiatry 28:247–259PubMedCrossRefGoogle Scholar
  12. Gluncic V, Turner M, Burrowes D, Frim D (2010) Concurrent Chiari decompression and spinal cord untethering in children: feasibility in a small case series. Acta Neurochir (Wien) 153:109–114CrossRefGoogle Scholar
  13. Gosalakkal JA (2008) Sleep-disordered breathing in Chiari malformation type 1. Pediatr Neurol 39(3):207–208PubMedCrossRefGoogle Scholar
  14. Herweh C, Akbar M, Wengenroth M, Heiland S, Bendszus M, Stippich C (2010) Reduced anisotropy in the middle cerebellar peduncle in Chiari-II malformation. Cerebellum 9(3):303–309PubMedCrossRefGoogle Scholar
  15. Juranek J, Dennis M, Cirino PT, El-Messidi L, Fletcher JM (2010) The cerebellum in children with spina bifida and Chiari II malformation: quantitative volumetrics by region. Cerebellum 9(2):240–248PubMedCrossRefGoogle Scholar
  16. Krueger KD, Haughton VM, Hetzel S (2010) Peak CSF velocities in patients with symptomatic and asymptomatic Chiari I malformation. AJNR Am J Neuroradiol 31:1837–1841PubMedCrossRefGoogle Scholar
  17. Lew SM, Kothbauer KF (2007) Tethered cord syndrome: an updated review. Pediatr Neurosurg 43(3):236–248PubMedCrossRefGoogle Scholar
  18. Lichtor T, Foroohar M, Kulkarni K, Loth F, Alperin NJ (2001) Application of noninvasive MRI phase-contrast flow studies in patients with Chiari I malformations. Neurosurgery 49:523Google Scholar
  19. Madsen JR, Poussaint TY, Barnes PD (2002) Congenital malformations of the cerebellum and posterior fossa. In: Manto MU, Pandolfo M (eds) The cerebellum and its disorders. Cambridge University Press, Cambridge, UK, pp 161–177Google Scholar
  20. Manto M (2010) Cerebellar disorders: a practical approach to diagnosis and management. Cambridge University Press, Cambridge, UKCrossRefGoogle Scholar
  21. Menezes AH (1999) Primary craniovertebral anomalies and the hindbrain herniation syndrome (Chiari I): data base analysis. Pediatr Neurosurg 23:260–269CrossRefGoogle Scholar
  22. Milhorat TH, Chou MW, Trinidad EM, Kula RW, Mandell M, Wolpert C, Speer MC (1999) Chiari I malformation redefined: clinical and radiographic findings for 364 symptomatic patients. Neurosurgery 44(5):1005–1017PubMedCrossRefGoogle Scholar
  23. Murano T, Rella J (2006) Incidental finding of Chiari I malformation with progression of symptoms after head trauma: case report. J Emerg Med 30(3):295–298PubMedCrossRefGoogle Scholar
  24. Nagib MG (1994) An approach to symptomatic children (ages 4–14 years) with Chiari type I malformation. Pediatr Neurosurg 21(1):31–35PubMedCrossRefGoogle Scholar
  25. O’Shaughnessy BA, Bendok BR, Parkinson RJ, Shaibani A, Walker MT, Shakir E, Batjer HH (2006) Acquired Chiari malformation type I associated with a supratentorial arteriovenous malformation. Case report and review of the literature. J Neurosurg 104:28–32PubMedGoogle Scholar
  26. Payner TD, Prenger E, Berger TS, Crone KR (1994) Acquired Chiari malformations: incidence, diagnosis, and management. Neurosurgery 34(3):429–434PubMedCrossRefGoogle Scholar
  27. Peach B (1965) Arnold-Chiari malformation: anatomic features of 20 cases. Arch Neurol 12:613–621PubMedCrossRefGoogle Scholar
  28. Pollack IF, Pang D, Albright AL, Krieger D (1992) Outcome following hindbrain decompression of symptomatic Chiari malformations in children previously treated with myelomeningocele closure and shunts. J Neurosurg 77(6):881–888PubMedCrossRefGoogle Scholar
  29. Royo-Salvador MB, Solé-Llenas J, Doménech JM, González-Adrio R (2005) Results of the section of the filum terminale in 20 patients with syringomyelia, scoliosis and Chiari malformation. Acta Neurochir (Wien) 147(5):515–523CrossRefGoogle Scholar
  30. Schijman E (2004) History, anatomic forms, and pathogenesis of Chiari I malformations. Childs Nerv Syst 20:323–328PubMedCrossRefGoogle Scholar
  31. Schijman E, Steinbok P (2004) International survey on the management of Chiari I malformation and syringomyelia. Childs Nerv Syst 20(5):341–348PubMedCrossRefGoogle Scholar
  32. Schwalbe E, Gredig M (1907) Uber entwicklungsstorungen des kleinhirns, hirnstamms und halsmarks bei spina bifida (Arnold’sche und Chiari’sche missbildung). Beitr Pathol Anat 40:132–194Google Scholar
  33. Sener RN (1995) Cerebellar agenesis versus vanishing cerebellum in Chiari II malformation. Comput Med Imaging Graph 19(6):491–494PubMedCrossRefGoogle Scholar
  34. Tubbs RS, Elton S, Grabb P, Dockery SE, Bartolucci AA, Oakes WJ (2001) Analysis of the posterior fossa in children with the Chiari 0 malformation. Neurosurgery 48:1050–1055PubMedCrossRefGoogle Scholar
  35. Tubbs RS, McGirt MJ, Oakes WJ (2003) Surgical experience in 130 pediatric patients with Chiari I malformations. J Neurosurg 99(2):291–296PubMedCrossRefGoogle Scholar
  36. Wan MJ, Nomura H, Tator CH (2008) Conversion to symptomatic Chiari I malformation after minor head or neck trauma. Neurosurgery 63(4):748–753PubMedCrossRefGoogle Scholar
  37. Williams B (1980) On the pathogenesis of syringomyelia. A review. J R Soc Med 73:798–806PubMedGoogle Scholar
  38. Wu YW, Chin CT, Chan KM, Barkovich AJ, Ferriero DM (1999) Pediatric Chiari I malformations: do clinical and radiologic features correlate? Neurology 53(6):1271–1276PubMedCrossRefGoogle Scholar
  39. Yanni DS, Mammis A, Ebersole K, Roonprapunt C, Sen C, Perin NI (2010) Revision of Chiari decompression for patients with recurrent syrinx. J Clin Neurosci 17(8):1076–1079, Epub May 26, 2010PubMedCrossRefGoogle Scholar
  40. Zolty P, Sanders MH, Pollack IF (2000) Chiari malformation and sleep-disordered breathing: a review of diagnostic and management issues. Sleep 23(5):637–643PubMedGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  1. 1.Unité d’Etude du Mouvement (UEM)FNRS, Neurologie ULB ErasmeBruxellesBelgium
  2. 2.Department of NeuroradiologyUniversity of Heidelberg, Medical CenterHeidelbergGermany

Personalised recommendations