Quantification of Cerebellar Crowding in Type I Chiari Malformation


This study was focused on a semi-automated morphometric analysis of the cerebellum in the mid-sagittal plane as an alternative to tonsillar descent alone in the evaluation of Chiari malformation type 1 (CMI) patients. Morphometric analyses of posterior fossa structures were performed on mid-sagittal MRI images of 375 individuals (females, > 18 years, 235 CMI and 140 healthy controls). Twenty-six parameters including linear, angular and area measurements together with non-dimensional ratios were calculated. Eighteen parameters were found to be significantly different between CMI and control subjects. Smaller posterior cranial fossa (PCF) area in CMI subjects was attributed to a smaller PCF area anterior to the brainstem. The cerebellar area was found to be larger in CMI subjects as compared to controls (15.1%), even without inclusion of the tonsillar area below the foramen magnum (FM) (8.4%). The larger cerebellar area in CMI subjects was due to cranial–caudal elongation of the cerebellum, predominately below the fastigium. The cerebrospinal fluid spaces below the FM were smaller in CMI subjects as compared to controls. Overall, greater cerebellar crowding was identified in CMI subjects relative to healthy controls. These observations may improve our understanding of the pathophysiology of CMI in adult female patients.

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  1. 1.

    Allen, P.A., D. Delahanty, K.P. Kaut, X. Li, M. Garcia, J.R. Houston, D.M. Tokar, F. Loth, J. Maleki, S. Vorster, and M.G. Luciano. Chiari 1000 registry project: assessment of surgical outcome on self-focused attention, pain, and delayed recall. Psychol Med. 1–11, 2017.

  2. 2.

    Allen, P. A., J. R. Houston, J. W. Pollock, C. Buzzelli, X. Li, A. K. Harrington, B. A. Martin, F. Loth, M. C. Lien, J. Maleki, and M. G. Luciano. Task-specific and general cognitive effects in Chiari malformation type I. PLoS ONE. 9(4):e94844, 2014.

    Article  Google Scholar 

  3. 3.

    Alperin, N., J.R. Loftus, C.J. Oliu, A.M. Bagci, S.H. Lee, B. Ertl-Wagner, B. Green, and R. Sekula. Magnetic resonance imaging measures of posterior cranial fossa morphology and cerebrospinal fluid physiology in Chiari malformation type I. Neurosurgery. 75(5):515–522; discussion 522, 2014.

  4. 4.

    Aydin, S., H. Hanimoglu, T. Tanriverdi, E. Yentur, and M.Y. Kaynar. Chiari type I malformations in adults: a morphometric analysis of the posterior cranial fossa. Surg Neurol. 64(3):237–241; discussion 241, 2005.

  5. 5.

    Badie, B., D. Mendoza, and U. Batzdorf. Posterior-fossa volume and response to suboccipital decompression in patients with Chiari-I malformation. Neurosurgery. 37(2):214–218, 1995.

    CAS  Article  Google Scholar 

  6. 6.

    Bagci, A. M., S. H. Lee, N. Nagornaya, B. A. Green, and N. Alperin. Automated posterior cranial fossa volumetry by MRI: applications to Chiari malformation type I. AJNR Am. J. Neuroradiol. 34(9):1758–1763, 2013.

    CAS  Article  Google Scholar 

  7. 7.

    Barkovich, A. J., F. J. Wippold, J. L. Sherman, and C. M. Citrin. Significance of cerebellar tonsillar position on MR. AJNR Am J Neuroradiol. 7(5):795–799, 1986.

    CAS  PubMed  Google Scholar 

  8. 8.

    Boyles, A. L., D. S. Enterline, P. H. Hammock, D. G. Siegel, S. H. Slifer, L. Mehltretter, J. R. Gilbert, D. Hu-Lince, D. Stephan, U. Batzdorf, E. Benzel, R. Ellenbogen, B. A. Green, R. Kula, A. Menezes, D. Mueller, J. J. Oro, B. J. Iskandar, T. M. George, T. H. Milhorat, and M. C. Speer. Phenotypic definition of Chiari type I malformation coupled with high-density SNP genome screen shows significant evidence for linkage to regions on chromosomes 9 and 15. Am. J. Med. Genet. A. 140(24):2776–2785, 2006.

    Article  Google Scholar 

  9. 9.

    Chan, T. F., and L. A. Vese. Active contours without edges. IEEE Trans. Image Process. 10(2):266–277, 2001.

    CAS  Article  Google Scholar 

  10. 10.

    Dagtekin, A., E. Avci, E. Kara, D. Uzmansel, O. Dagtekin, A. Koseoglu, D. Talas, and C. Bagdatoglu. Posterior cranial fossa morphometry in symptomatic adult Chiari I malformation patients: comparative clinical and anatomical study. Clin Neurol Neurosurg. 113(5):399–403, 2011.

    Article  Google Scholar 

  11. 11.

    Dehghani, C., N. Pritchard, K. Edwards, A. W. Russell, R. A. Malik, and N. Efron. Fully automated, semiautomated, and manual morphometric analysis of corneal subbasal nerve plexus in individuals with and without diabetes. Cornea. 33(7):696–702, 2014.

    Article  Google Scholar 

  12. 12.

    Douglas, D.H., Peucker, T. K. Algorithms for the reduction of the number of points required to represent a digitized line or its caricature. Cartographica 10(2):112–122, 1973.

  13. 13.

    Dufton, J. A., S. Y. Habeeb, M. K. S. Heran, D. J. Mikulis, and O. Islam. Posterior fossa measurements in patients with and without Chiari I malformation. Can. J. Neurol. Sci. 38(3):452–455, 2011.

    Article  Google Scholar 

  14. 14.

    Elam, M. J., and J. A. Vaughn. Chiari Type I malformations in young adults: implications for the college health practitioner. J. Am. Coll. Health. 59(8):757–759, 2011.

    Article  Google Scholar 

  15. 15.

    Eppelheimer, M.S., J.R. Houston, J.R. Bapuraj, R. Labuda, D.M. Loth, A.M. Braun, N.J. Allen, S.H. Pahlavian, D. Biswas, A. Urbizu, B.A. Martin, C.O. Maher, P.A. Allen, and F. Loth. A retrospective 2D morphometric analysis of adult female Chiari Type I patients with commonly reported and related conditions. Front Neuroanat. 12, 2018.

  16. 16.

    Fischbein, R., J. R. Saling, P. Marty, D. Kropp, J. Meeker, J. Amerine, and M. R. Chyatte. Patient-reported Chiari malformation type I symptoms and diagnostic experiences: a report from the national Conquer Chiari Patient Registry database. Neurol. Sci. 36(9):1617–1624, 2015.

    Article  Google Scholar 

  17. 17.

    Hayakawa, K., Y. Konishi, T. Matsuda, M. Kuriyama, K. Konishi, K. Yamashita, R. Okumura, and D. Hamanaka. Development and aging of brain midline structures: assessment with MR imaging. Radiology. 172(1):171–177, 1989.

    CAS  Article  Google Scholar 

  18. 18.

    Heiss, J. D., N. Patronas, H. L. DeVroom, T. Shawker, R. Ennis, W. Kammerer, A. Eidsath, T. Talbot, J. Morris, E. Eskioglu, and E. H. Oldfield. Elucidating the pathophysiology of syringomyelia. J. Neurosurg. 91(4):553–562, 1999.

    CAS  Article  Google Scholar 

  19. 19.

    Hoogendam, Y. Y., J. N. van der Geest, F. van der Lijn, A. van der Lugt, W. J. Niessen, G. P. Krestin, A. Hofman, M. W. Vernooij, M. M. Breteler, and M. A. Ikram. Determinants of cerebellar and cerebral volume in the general elderly population. Neurobiol. Aging. 33(12):2774–2781, 2012.

    Article  Google Scholar 

  20. 20.

    Houston, J.R., M.S. Eppelheimer, S.H. Pahlavian, D. Biswas, A. Urbizu, B.A. Martin, J.R. Bapuraj, M. Luciano, P.A. Allen, and F. Loth. A morphometric assessment of type I Chiari malformation above the McRae line: A retrospective case-control study in 302 adult female subjects. J. Neuroradiol. 2017.

  21. 21.

    Houston, J.R., M.L. Hughes, M.C. Lien, B.A. Martin, F. Loth, M.G. Luciano, S. Vorster, and P.A. Allen. An electrophysiological study of cognitive and emotion processing in Type I Chiari malformation. Cerebellum. 2018.

  22. 22.

    Hwang, H. S., J. G. Moon, C. H. Kim, S. M. Oh, J. H. Song, and J. H. Jeong. The comparative morphometric study of the posterior cranial fossa : what is effective approaches to the treatment of Chiari malformation type 1? J. Korean Neurosurg. Soc. 54(5):405–410, 2013.

    Article  Google Scholar 

  23. 23.

    Jernigan, T. L., S. L. Archibald, C. Fennema-Notestine, A. C. Gamst, J. C. Stout, J. Bonner, and J. R. Hesselink. Effects of age on tissues and regions of the cerebrum and cerebellum. Neurobiol Aging. 22(4):581–594, 2001.

    CAS  Article  Google Scholar 

  24. 24.

    Karagoz, F., N. Izgi, and S. Kapijcijoglu Sencer. Morphometric measurements of the cranium in patients with Chiari type I malformation and comparison with the normal population. Acta Neurochir (Wien). 144(2):165–171; discussion 171, 2002.

  25. 25.

    Krishna, V., F. Sammartino, P. Yee, D. Mikulis, M. Walker, G. Elias, and M. Hodaie. Diffusion tensor imaging assessment of microstructural brainstem integrity in Chiari malformation Type I. J. Neurosurg. 125(5):1112–1119, 2016.

    Article  Google Scholar 

  26. 26.

    Lacy, M., S. E. Ellefson, S. DeDios-Stern, and D. M. Frim. Parent-reported executive dysfunction in children and adolescents with Chiari malformation type 1. Pediatr. Neurosurg. 51(5):236–243, 2016.

    Article  Google Scholar 

  27. 27.

    Lirng, J. F., J. L. Fuh, Y. Y. Chen, and S. J. Wang. Posterior cranial fossa crowdedness is related to age and sex: an magnetic resonance volumetric study. Acta Radiol. 46(7):737–742, 2005.

    CAS  Article  Google Scholar 

  28. 28.

    Luft, A. R., M. Skalej, J. B. Schulz, D. Welte, R. Kolb, K. Burk, T. Klockgether, and K. Voight. Patterns of age-related shrinkage in cerebellum and brainstem observed in vivo using three-dimensional MRI volumetry. Cereb. Cortex. 9(7):712–721, 1999.

    CAS  Article  Google Scholar 

  29. 29.

    Marin-Padilla, M., and T. M. Marin-Padilla. Morphogenesis of experimentally induced Arnold-Chiari malformation. J. Neurol. Sci. 50(1):29–55, 1981.

    CAS  Article  Google Scholar 

  30. 30.

    Meadows, J., M. Kraut, M. Guarnieri, R. I. Haroun, and B. S. Carson. Asymptomatic Chiari Type I malformations identified on magnetic resonance imaging. J. Neurosurg. 92(6):920–926, 2000.

    CAS  Article  Google Scholar 

  31. 31.

    Milhorat, T. H., M. W. Chou, E. M. Trinidad, R. W. Kula, M. Mandell, C. Wolpert, and M. C. Speer. Chiari I malformation redefined: clinical and radiographic findings for 364 symptomatic patients. Neurosurgery. 44(5):1005–1017, 1999.

    CAS  Article  Google Scholar 

  32. 32.

    Milhorat, T. H., M. Nishikawa, R. W. Kula, and Y. D. Dlugacz. Mechanisms of cerebellar tonsil herniation in patients with Chiari malformations as guide to clinical management. Acta Neurochir (Wien). 152(7):1117–1127, 2010.

    Article  Google Scholar 

  33. 33.

    Nishikawa, M., H. Sakamoto, A. Hakuba, N. Nakanishi, and Y. Inoue. Pathogenesis of Chiari malformation: a morphometric study of the posterior cranial fossa. J. Neurosurg. 86(1):40–47, 1997.

    CAS  Article  Google Scholar 

  34. 34.

    Noudel, R., N. Jovenin, C. Eap, B. Scherpereel, L. Pierot, and P. Rousseaux. Incidence of basioccipital hypoplasia in Chiari malformation type I: comparative morphometric study of the posterior cranial fossa. Clinical article. J. Neurosurg. 111(5):1046–1052, 2009.

    Article  Google Scholar 

  35. 35.

    Oldfield, E.H. Cerebellar tonsils and syringomyelia. J. Neurosurg. 97(5):1009–1010; discussion 1010, 2002.

  36. 36.

    Oldfield, E.H., K. Muraszko, T.H. Shawker, and N.J. Patronas. Pathophysiology of syringomyelia associated with Chiari I malformation of the cerebellar tonsils. Implications for diagnosis and treatment. J. Neurosurg. 80(1):3–15, 1994.

  37. 37.

    Ramer, U. An iterative procedure for the polygonal approximation of plane curves. Comput. Graph. Image Process. 1(3):244–256, 1972.

    Article  Google Scholar 

  38. 38.

    Rogers, J.M., G. Savage, and M.A. Stoodley. A Systematic review of cognition in Chiari I malformation. Neuropsychol. Rev. 2018.

  39. 39.

    Roller, L. A., B. B. Bruce, and A. M. Saindane. Demographic confounders in volumetric MRI analysis: is the posterior fossa really small in the adult Chiari 1 malformation? AJR Am J Roentgenol. 204(4):835–841, 2015.

    Article  Google Scholar 

  40. 40.

    Sekula, R.F., Jr., P.J. Jannetta, K.F. Casey, E.M. Marchan, L.K. Sekula, and C.S. McCrady. Dimensions of the posterior fossa in patients symptomatic for Chiari I malformation but without cerebellar tonsillar descent. Cereb. Fluid Res. 2:11, 2005.

  41. 41.

    Sgouros, S., M. Kountouri, and K. Natarajan. Posterior fossa volume in children with Chiari malformation Type I. J. Neurosurg. 105(2 Suppl):101–106, 2006.

    PubMed  Google Scholar 

  42. 42.

    Shaffer, N., B. A. Martin, B. Rocque, C. Madura, O. Wieben, B. J. Iskandar, S. Dombrowski, M. Luciano, J. N. Oshinski, and F. Loth. Cerebrospinal fluid flow impedance is elevated in Type I Chiari malformation. J. Biomech. Eng. 136(2):021012, 2014.

    Article  Google Scholar 

  43. 43.

    Shah, S. A., P. M. Doraiswamy, M. M. Husain, G. S. Figiel, O. B. Boyko, W. M. McDonald, E. H. Ellinwood, Jr, and K. R. Krishnan. Assessment of posterior fossa structures with midsagittal MRI: the effects of age. Neurobiol. Aging. 12(4):371–374, 1991.

    CAS  Article  Google Scholar 

  44. 44.

    Tastemur, Y., V. Sabanciogullari, I. Salk, M. Sonmez, and M. Cimen. The Relationship of the posterior cranial fossa, the cerebrum, and cerebellum morphometry with Tonsiller Herniation. Iran. J. Radiol. 14(1), 2017.

  45. 45.

    Urbizu, A., A. Ferré, M. A. Poca, A. Rovira, J. Sahuquillo, B. A. Martin, and A. Macaya. Cephalometric oropharynx and oral cavity analysis in Chiari malformation Type I: a retrospective case-control study. J Neurosurg. 126(2):626–633, 2017.

    Article  Google Scholar 

  46. 46.

    Urbizu, A., M. A. Poca, X. Vidal, A. Rovira, J. Sahuquillo, and A. Macaya. MRI-based morphometric analysis of posterior cranial fossa in the diagnosis of chiari malformation type I. J. Neuroimaging. 24(3):250–256, 2014.

    Article  Google Scholar 

  47. 47.

    Van Essen, D.C., K. Ugurbil, E. Auerbach, D. Barch, T.E. Behrens, R. Bucholz, A. Chang, L. Chen, M. Corbetta, S.W. Curtiss, S. Della Penna, D. Feinberg, M.F. Glasser, N. Harel, A.C. Heath, L. Larson-Prior, D. Marcus, G. Michalareas, S. Moeller, R. Oostenveld, S.E. Petersen, F. Prior, B.L. Schlaggar, S.M. Smith, A.Z. Snyder, J. Xu, E. Yacoub, and W.U.-M.H. Consortium. The Human Connectome Project: a data acquisition perspective. Neuroimage. 62(4):2222–2231, 2012.

  48. 48.

    Vega, A., F. Quintana, and J. Berciano. Basichondrocranium anomalies in adult Chiari type I malformation: a morphometric study. J. Neurol. Sci. 99(2–3):137–145, 1990.

    CAS  Article  Google Scholar 

  49. 49.

    Vurdem, U.E., N. Acer, T. Ertekin, A. Savranlar, and M.F. Inci. Analysis of the volumes of the posterior cranial fossa, cerebellum, and herniated tonsils using the stereological methods in patients with Chiari Type I malformation. Sci. World J. 2012.

  50. 50.

    Walhovd, K. B., L. T. Westlye, I. Amlien, T. Espeseth, I. Reinvang, N. Raz, I. Agartz, D. H. Salat, D. N. Greve, B. Fischl, A. M. Dale, and A. M. Fjell. Consistent neuroanatomical age-related volume differences across multiple samples. Neurobiol Aging. 32(5):916–932, 2011.

    Article  Google Scholar 

  51. 51.

    Yan, H., X. Han, M. Jin, Z. Liu, D. Xie, S. Sha, Y. Qiu, and Z. Zhu. Morphometric features of posterior cranial fossa are different between Chiari I malformation with and without syringomyelia. Eur Spine J. 25(7):2202–2209, 2016.

    Article  Google Scholar 

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The authors would like to acknowledge the contributions of Natalie Allen and Audrey Braun in the initial evaluation of the software. The authors would also like to acknowledge Phillip Vorster and Lauren Elicker for their help with consistency testing of CerePro2D. Funding was provided by Conquer Chiari.

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The authors declare that they have no conflict of interest.

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Correspondence to Dipankar Biswas.

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Associate Editor Andreas Anayiotos oversaw the review of this article.

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Biswas, D., Eppelheimer, M.S., Houston, J.R. et al. Quantification of Cerebellar Crowding in Type I Chiari Malformation. Ann Biomed Eng 47, 731–743 (2019). https://doi.org/10.1007/s10439-018-02175-z

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  • Morphology
  • MRI
  • Posterior cranial fossa
  • Tonsillar position
  • Cerebrospinal fluid