Skip to main content

Epidemiology of Chiari I Malformation

  • Chapter
  • First Online:
The Chiari Malformations

Abstract

Almost 1% of normal adults studied with magnetic resonance imaging (MRI) of the brain will have a finding of Chiari I malformation based on 5 mm or more of cerebellar tonsillar ectopia, while as many as 3.6% of normal children will have a Chiari I malformation finding using the same criteria. The proportion of adults with symptoms and MRI evidence of Chiari I malformation is estimated to be in the range of 0.01–0.04%. Symptoms of Chiari I malformation occurred in 0.007% of children in one study. Symptoms occur most commonly when tonsillar ectopia exceeds 13 mm and when lesser degrees of ectopia are accompanied by narrowing of the cerebrospinal fluid (CSF) space posterior to the cerebellar tonsils, molding of the tonsils, and syringomyelia. Tonsillar ectopia and morphologic changes in the cerebellum and medulla found in Chiari I malformation are thought to arise from decreased development of the bones of the inferior part of the posterior fossa. Thus, factors that prevent normal development of these bones impact the development of Chiari I malformation. In monozygotic twins and triplets, the symptomatic index cases have considerably greater tonsillar ectopia than their generally asymptomatic monozygotic siblings, suggesting that a genetic predisposition to reduced development of the posterior fossa is not the only factor involved in creating tonsillar ectopia and in narrowing the CSF pathways. Factors reported to increase the likelihood of developing Chiari I malformation include birth injury, trauma, pseudotumor cerebri, hydrocephalus, ancestry from a Pacific island, female gender in adults in the United States, and male gender in the Tatarstan, Russia. Epigenetic changes due to environmental factors or normal aging and differences in the placenta and amniotic sac are also suspected of playing a role in the development of Chiari I malformation. Going forward, more rigorous measurements of the prevalence and incidence of Chiari I malformation would result from prospective epidemiologic studies of large populations designed for this purpose than from retrospective queries of the databases of private and governmental healthcare organizations.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 129.00
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 169.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info
Hardcover Book
USD 249.99
Price excludes VAT (USA)
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

References

  1. Anonymous. Epidemiology. Oxford dictionaries online. Oxford: Oxford University Press; 2012.

    Google Scholar 

  2. Anonymous. Disease. Oxford dictionaries online. Oxford: Oxford University Press; 2012.

    Google Scholar 

  3. Merrill RM. Introduction to epidemiology. 5th ed. Sudbury: Jones and Bartlett Publishers; 2010.

    Google Scholar 

  4. Posada de la Paz M, Villaverde-Hueso A, Alonso V, Janos S, Zurriaga O, Pollan M, et al. Rare diseases epidemiology research. In: Posada de la Paz M, Groft SC, editors. Rare diseases epidemiology. Advances in experimental medicine and biology, vol. 686. Dordrecht: Springer Science+Business Media B.V.; 2010. p. 17–39.

    Chapter  Google Scholar 

  5. Groft SC, Brooks PJ, Demory M, Eckstein DJ, Eddy M, Ferguson J, et al. Chiari malformation type 1. Bethesda: Office of Rare Diseases Research, National Institutes of Health; 2012. Available from: http://rarediseases.info.nih.gov/GARD/Condition/9230/Chiari_malformation_type_1.aspx.

    Google Scholar 

  6. Groft SC, Brooks PJ, Demory M, Eckstein DJ, Eddy M, Ferguson J, et al. Rare diseases and related terms. Bethesda: Office of Rare Diseases Research, National Institutes of Health; 2012. Available from: http://rarediseases.info.nih.gov/RareDiseaseList.aspx?PageID=1.

    Google Scholar 

  7. Groft SC, Posada de la Paz M. Rare diseases–avoiding misperceptions and establishing realities: the need for reliable epidemiological data. In: Posada de la Paz M, Groft SC, editors. Rare diseases epidemiology. Advances in experimental medicine and biology, vol. 686. Dordrecht: Springer Science+Business Media B.V.; 2010. p. 3–13.

    Chapter  Google Scholar 

  8. Pillay PK, Awad IA, Little JR, Hahn JF. Surgical management of syringomyelia: a five year experience in the era of magnetic resonance imaging. Neurol Res. 1991;13(1):3–9.

    Article  CAS  PubMed  Google Scholar 

  9. Aitken LA, Lindan CE, Sidney S, Gupta N, Barkovich AJ, Sorel M, et al. Chiari type I malformation in a pediatric population. Pediatr Neurol. 2009;40(6):449–54.

    Article  PubMed  PubMed Central  Google Scholar 

  10. Mikulis DJ, Diaz O, Egglin TK, Sanchez R. Variance of the position of the cerebellar tonsils with age: preliminary report. Radiology. 1992;183(3):725–8.

    Article  CAS  PubMed  Google Scholar 

  11. Maher CO, Piatt JH Jr, Section on Neurologic Surgery, American Academy of Pediatrics. Incidental findings on brain and spine imaging in children. Pediatrics. 2015;135(4):e1084–96.

    Article  PubMed  Google Scholar 

  12. Barkovich AJ, Wippold FJ, Sherman JL, Citrin CM. Significance of cerebellar tonsillar position on MR. AJNR Am J Neuroradiol. 1986;7(5):795–9.

    CAS  PubMed  PubMed Central  Google Scholar 

  13. Vernooij MW, Ikram MA, Tanghe HL, Vincent AJ, Hofman A, Krestin GP, et al. Incidental findings on brain MRI in the general population. N Engl J Med. 2007;357(18):1821–8.

    Article  CAS  PubMed  Google Scholar 

  14. Elster AD, Chen MY. Chiari I malformations: clinical and radiologic reappraisal. Radiology. 1992;183(2):347–53.

    Article  CAS  PubMed  Google Scholar 

  15. Tubbs RS, Elton S, Grabb P, Dockery SE, Bartolucci AA, Oakes WJ. Analysis of the posterior fossa in children with the Chiari 0 malformation. Neurosurgery. 2001;48(5):1050–4; discussion 4–5.

    CAS  PubMed  Google Scholar 

  16. Meadows J, Kraut M, Guarnieri M, Haroun RI, Carson BS. Asymptomatic Chiari type I malformations identified on magnetic resonance imaging. J Neurosurg. 2000;92(6):920–6.

    Article  CAS  PubMed  Google Scholar 

  17. Milhorat TH, Chou MW, Trinidad EM, Kula RW, Mandell M, Wolpert C, et al. Chiari I malformation redefined: clinical and radiographic findings for 364 symptomatic patients. Neurosurgery. 1999;44(5):1005–17.

    Article  CAS  PubMed  Google Scholar 

  18. Brewis M, Poskanzer DC, Rolland C, Miller H. Neurological disease in an English city. Acta Neurol Scand. 1966;S24:1–89.

    Google Scholar 

  19. Klekamp J, Batzdorf U, Samii M, Bothe HW. The surgical treatment of Chiari I malformation. Acta Neurochir. 1996;138(7):788–801.

    Article  CAS  PubMed  Google Scholar 

  20. Brickell KL, Anderson NE, Charleston AJ, Hope JK, Bok AP, Barber PA. Ethnic differences in syringomyelia in New Zealand. J Neurol Neurosurg Psychiatry. 2006;77(8):989–91.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  21. Boman K, Iivanainen M. Prognosis of syringomyelia. Acta Neurol Scand. 1967;43(1):61–8.

    Article  CAS  PubMed  Google Scholar 

  22. Arnautovic A, Splavski B, Boop FA, Arnautovic KI. Pediatric and adult Chiari malformation type I surgical series 1965–2013: a review of demographics, operative treatment, and outcomes. J Neurosurg Pediatr. 2015;15(2):161–77.

    Article  PubMed  Google Scholar 

  23. Cavender RK, Schmidt JH 3rd. Tonsillar ectopia and Chiari malformations: monozygotic triplets. Case report. J Neurosurg. 1995;82(3):497–500.

    Article  CAS  PubMed  Google Scholar 

  24. Iwasaki Y, Hida K, Onishi K, Nanba R. Chiari malformation and syringomyelia in monozygotic twins: birth injury as a possible cause of syringomyelia–case report. Neurol Med Chir (Tokyo). 2000;40(3):176–8.

    Article  CAS  Google Scholar 

  25. Stovner LJ, Cappelen J, Nilsen G, Sjaastad O. The Chiari type I malformation in two monozygotic twins and first-degree relatives. Ann Neurol. 1992;31(2):220–2.

    Article  CAS  PubMed  Google Scholar 

  26. Tubbs RS, Wellons JC, Blount JP, Oakes WJ. Syringomyelia in twin brothers discordant for Chiari I malformation: case report. J Child Neurol. 2004;19(6):459–62.

    Article  PubMed  Google Scholar 

  27. Turgut M. Chiari type I malformation in two monozygotic twins. Br J Neurosurg. 2001;15(3):279–80.

    Article  CAS  PubMed  Google Scholar 

  28. Fraga M, Ballestar E, Paz M, Ropero S, Setien F, Ballestar M, et al. Epigenetic differences arise during the lifetime of monozygotic twins. Proc Natl Acad Sci U S A. 2005;102(30):10604–9.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  29. Atkinson JL, Kokmen E, Miller GM. Evidence of posterior fossa hypoplasia in the familial variant of adult Chiari I malformation: case report. Neurosurgery. 1998;42(2):401–3. discussion 4

    Article  CAS  PubMed  Google Scholar 

  30. Hida K, Iwasaki Y, Imamura H, Abe H. Birth injury as a causative factor of syringomyelia with Chiari type I deformity. J Neurol Neurosurg Psychiatry. 1994;57(3):373–4.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  31. Aghakhani N, Parker F, David P, Morar S, Lacroix C, Benoudiba F, et al. Long-term follow-up of Chiari-related syringomyelia in adults: analysis of 157 surgically treated cases. Neurosurgery. 2009;64(2):308–15; discussion 15.

    Article  PubMed  Google Scholar 

  32. Tubbs RS, McGirt MJ, Oakes WJ. Surgical experience in 130 pediatric patients with Chiari I malformations. J Neurosurg. 2003;99(2):291–6.

    Article  PubMed  Google Scholar 

  33. Williams B. Difficult labour as a cause of communicating syringomyelia. Lancet. 1977;2(8028):51–3.

    Article  CAS  PubMed  Google Scholar 

  34. Wan MJ, Nomura H, Tator CH. Conversion to symptomatic Chiari I malformation after minor head or neck trauma. Neurosurgery. 2008;63(4):748–53; discussion 53.

    Article  PubMed  Google Scholar 

  35. Spina A, Boari N, Gagliardi F, Donofrio CA, Mortini P. Sudden onset of Chiari malformation type 1 in a young child after trauma. Childs Nerv Syst. 2015;31(9):1589–94.

    Article  PubMed  Google Scholar 

  36. Bogdanov EI, Faizutdinova AT, Mendelevich EG, Sozinov AS, Heiss JD. Epidemiology of symptomatic Chiari malformation in tatarstan: regional and ethnic differences in prevalence. Neurosurgery. 2019;84(5):1090–7.

    Article  PubMed  Google Scholar 

  37. Bogdanov EI, Mendelevich EG. Syrinx size and duration of symptoms predict the pace of progressive myelopathy: retrospective analysis of 103 unoperated cases with craniocervical junction malformations and syringomyelia. Clin Neurol Neurosurg. 2002;104(2):90–7.

    Article  CAS  PubMed  Google Scholar 

  38. Bogdanov EI, Heiss JD, Mendelevich EG. The post-syrinx syndrome: stable central myelopathy and collapsed or absent syrinx. J Neurol. 2006;253(6):707–13.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  39. Bogdanov EI, Heiss JD, Mendelevich EG, Mikhaylov IM, Haass A. Clinical and neuroimaging features of “idiopathic” syringomyelia. Neurology. 2004;62(5):791–4.

    Article  CAS  PubMed  Google Scholar 

  40. Heiss JD, Oldfield EH, Zhuang Z, Lubensky I, Patronas N, Smith R, et al. Genetic analysis of the Chiari I malformation; 2000. Available from: http://clinicaltrials.gov/ct2/show/NCT00004738?term=chiari+AND+genetics&rank=2.

  41. Krucoff MO, Cook S, Adogwa O, Moreno J, Yang S, Xie J, et al. Racial, socioeconomic, and gender disparities in the presentation, treatment, and outcomes of adult Chiari I malformations. World Neurosurg. 2017;97:431–7.

    Article  PubMed  Google Scholar 

  42. Nyland H, Krogness KG. Size of posterior fossa in Chiari type 1 malformation in adults. Acta Neurochir. 1978;40(3–4):233–42.

    Article  CAS  PubMed  Google Scholar 

  43. Nishikawa M, Sakamoto H, Hakuba A, Nakanishi N, Inoue Y. Pathogenesis of Chiari malformation: a morphometric study of the posterior cranial fossa. J Neurosurg. 1997;86(1):40–7.

    Article  CAS  PubMed  Google Scholar 

  44. Noudel R, Jovenin N, Eap C, Scherpereel B, Pierot L, Rousseaux P. Incidence of basioccipital hypoplasia in Chiari malformation type I: comparative morphometric study of the posterior cranial fossa. Clinical article. J Neurosurg. 2009;111(5):1046–52.

    Article  PubMed  Google Scholar 

  45. Leikola J, Koljonen V, Valanne L, Hukki J. The incidence of Chiari malformation in nonsyndromic, single suture craniosynostosis. Childs Nerv Syst. 2010;26(6):771–4.

    Article  PubMed  Google Scholar 

  46. Harding BN, Copp AJ. Malformations. In: Graham DI, Lantos PL, editors. Greenfield’s neuropathology. 1. 7th ed. London: Arnold; 2002. p. 357–483.

    Google Scholar 

  47. Decq P, Le Guerinel C, Sol JC, Brugieres P, Djindjian M, Nguyen JP. Chiari I malformation: a rare cause of noncommunicating hydrocephalus treated by third ventriculostomy. J Neurosurg. 2001;95(5):783–90.

    Article  CAS  PubMed  Google Scholar 

  48. Banik R, Lin D, Miller NR. Prevalence of Chiari I malformation and cerebellar ectopia in patients with pseudotumor cerebri. J Neurol Sci. 2006;247(1):71–5.

    Article  PubMed  Google Scholar 

  49. Rijken BF, Lequin MH, Van Veelen ML, de Rooi J, Mathijssen IM. The formation of the foramen magnum and its role in developing ventriculomegaly and Chiari I malformation in children with craniosynostosis syndromes. J Craniomaxillofac Surg. 2015;43(7):1042–8.

    Article  PubMed  Google Scholar 

  50. Nakai T, Asato R, Miki Y, Tanaka F, Matsumoto S, Konishi J. A case of achondroplasia with downward displacement of the brain stem. Neuroradiology. 1995;37(4):293–4.

    Article  CAS  PubMed  Google Scholar 

  51. Yundt KD, Park TS, Tantuwaya VS, Kaufman BA. Posterior fossa decompression without duraplasty in infants and young children for treatment of Chiari malformation and achondroplasia. Pediatr Neurosurg. 1996;25(5):221–6.

    Article  CAS  PubMed  Google Scholar 

  52. Kyoshima K, Kuroyanagi T, Oya F, Kamijo Y, El-Noamany H, Kobayashi S. Syringomyelia without hindbrain herniation: tight cisterna magna. Report of four cases and a review of the literature. J Neurosurg. 2002;96(2 Suppl):239–49.

    PubMed  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to John D. Heiss .

Editor information

Editors and Affiliations

Rights and permissions

Reprints and permissions

Copyright information

© 2020 Springer Nature Switzerland AG

About this chapter

Check for updates. Verify currency and authenticity via CrossMark

Cite this chapter

Heiss, J.D., Argersinger, D.P. (2020). Epidemiology of Chiari I Malformation. In: Tubbs, R., Turgut, M., Oakes, W. (eds) The Chiari Malformations. Springer, Cham. https://doi.org/10.1007/978-3-030-44862-2_21

Download citation

  • DOI: https://doi.org/10.1007/978-3-030-44862-2_21

  • Published:

  • Publisher Name: Springer, Cham

  • Print ISBN: 978-3-030-44861-5

  • Online ISBN: 978-3-030-44862-2

  • eBook Packages: MedicineMedicine (R0)

Publish with us

Policies and ethics