J Neurol Surg B Skull Base 2021; 82(03): 277-284
DOI: 10.1055/s-0039-1691832
Original Article

Pathogenesis and Classification of Chiari Malformation Type I Based on the Mechanism of Ptosis of the Brain Stem and Cerebellum: A Morphometric Study of the Posterior Cranial Fossa and Craniovertebral Junction

Misao Nishikawa
1   Department of Neurosurgery, Moriguchi-Ikuno Memorial Hospital Koudoukai Health System, Osaka, Japan
2   The Chiari Institute, North Shore University Hospital, New York, United States
3   Osaka City University Graduate School of Medicine, Neurosurgery, Osaka, Japan
,
Paolo A. Bolognese
2   The Chiari Institute, North Shore University Hospital, New York, United States
4   Chiari Neurosurgical Center, Long Island, New York, United States
,
Roger W. Kula
2   The Chiari Institute, North Shore University Hospital, New York, United States
4   Chiari Neurosurgical Center, Long Island, New York, United States
,
Hiromichi Ikuno
1   Department of Neurosurgery, Moriguchi-Ikuno Memorial Hospital Koudoukai Health System, Osaka, Japan
,
Kenji Ohata
3   Osaka City University Graduate School of Medicine, Neurosurgery, Osaka, Japan
› Author Affiliations

Abstract

Introduction We investigated the mechanism of ptosis of the brain stem and cerebellum (hindbrain) in Chiari malformation type I (CM-I) and classified CM-I according to pathogenesis, based on a morphometric study of the posterior cranial fossa (PCF) and craniovertebral junction (CVJ). We discuss the appropriate surgical treatment for hindbrain ptosis.

Materials and Methods We examined 500 patients with CM-I and 100 healthy control individuals. We calculated the volume of the PCF (VPCF) and measured the axial length of the enchondral parts of the occipital bone and hindbrain. As statistical analyses, for the multiple analyses, heavy palindromic tests were used. Using three independent objective parameters, we tried to classify CM-I.

Results Three independent subtypes were confirmed (CM-I types A, B, and C). CM-I type A (167 cases): normal VPCF, normal volume of the area surrounding the foramen magnum (VSFM), and normal occipital bone size; CM-I type B (178 cases): normal VPCF, small VSFM, and small occipital bone size; and CM-I type C (155 cases): small VPCF, small VSFM, and small occipital bone size.

Conclusions Morphometric analyses of PCF and CVJ were very useful for the investigation of the mechanism of hindbrain ptosis and classifying CM-I according to pathogenesis. CM-I type A included mechanisms other than hindbrain ptosis, for example, CVJ instability, tethered cord, and increased intracranial pressure. CM-I types B and C demonstrated underdevelopment of the occipital bone. For CM-I types B and C, posterior decompression should be performed. For CM-I type A, appropriate surgical management should be selected.



Publication History

Received: 07 October 2018

Accepted: 31 March 2019

Article published online:
30 September 2019

© 2019. Thieme. All rights reserved.

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany

 
  • References

  • 1 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 (01) 40-47
  • 2 Milhorat TH, Chou MW, Trinidad EM. et al. Chiari I malformation redefined: clinical and radiographic findings for 364 symptomatic patients. Neurosurgery 1999; 44 (05) 1005-1017
  • 3 Milhorat TH, Nishikawa M, Kula RW, Dlugacz YD. Mechanisms of cerebellar tonsil herniation in patients with Chiari malformations as guide to clinical management. Acta Neurochir (Wien) 2010; 152 (07) 1117-1127
  • 4 Stovner LJ, Bergan U, Nilsen G, Sjaastad O. Posterior cranial fossa dimensions in the Chiari I malformation: relation to pathogenesis and clinical presentation. Neuroradiology 1993; 35 (02) 113-118
  • 5 Badie B, Mendoza D, Batzdorf U. Posterior fossa volume and response to suboccipital decompression in patients with Chiari I malformation. Neurosurgery 1995; 37 (02) 214-218
  • 6 Noudel R, Gomis P, Sotorares G. et al. Posterior fossa volumetric increase after surgery for Chiari malformation type I: a quantitative study of the posterior cranial fossa. J Neurosurg 2011; 115: 647-658
  • 7 Karagöz F, Izgi N, Kapíjcíjoğlu Sencer S. Morphometric measurements of the cranium in patients with Chiari type I malformation and comparison with the normal population. Acta Neurochir (Wien) 2002; 144 (02) 165-171 , discussion 171
  • 8 Alperin N, Loftus JR, Oliu CJ. et al. Magnetic resonance imaging measures of posterior cranial fossa morphology and cerebrospinal fluid physiology in Chiari malformation type I. Neurosurgery 2014; 75 (05) 515-522 , discussion 522
  • 9 Speer MC, George TM, Enterline DS, Franklin A, Wolpert CM, Milhorat TH. A genetic hypothesis for Chiari I malformation with or without syringomyelia. Neurosurg Focus 2000; 8 (03) E12
  • 10 Fischl B, Salat DH, Busa E. et al. Whole brain segmentation: automated labeling of neuroanatomical structures in the human brain. Neuron 2002; 33 (03) 341-355
  • 11 Milhorat TH, Bolognese PA, Nishikawa M, McDonnell NB, Francomano CA. Syndrome of occipitoatlantoaxial hypermobility, cranial settling, and Chiari malformation type I in patients with hereditary disorders of connective tissue. J Neurosurg Spine 2007; 7 (06) 601-609
  • 12 Goel A, Jain S, Shah A. Radiological evaluation of 510 cases of basilar invagination with evidence of atlantoaxial instability (Group a basilar invagination). World Neurosurg 2018; 110: 533-543
  • 13 Goel A, Gore S, Shah A, Dharurkar P, Vutha R, Patil A. Atlantoaxial fixation for Chiari 1 formation in pediatric age group patients: report of treatment in 33 patients. World Neurosurg 2018; 111: e668-e677
  • 14 Goel A, Kaswa A, Shah A. Atlantoaxial fixation for treatment of Chiari formation and syringomyelia with no craniovertebral bone anomaly: report an experience with 57 cases. Acta Neurochir Suppl (Wien) 2019; 125: 101-110
  • 15 Milhorat TH, Bolognese PA, Nishikawa M. et al. Association of Chiari malformation type I and tethered cord syndrome: preliminary results of sectioning filum terminale. Surg Neurol 2009; 72 (01) 20-35
  • 16 Geddes DM, Cargill RS, LaPlaca MC. Mechanical stretch in neurons results in a strain rate and magnitude-dependent increasing in plasma membrane permeability. J Neurotrauma Rev 2003; 29: 251-264
  • 17 Cinalli G, Spennato P, Sainte-Rose C. et al. Chiari malformation in craniosynostosis. Childs Nerv Syst 2005; 21 (10) 889-901
  • 18 Leikola J, Haapamäki V, Karppinen A. et al. Morphometric comparison of foramen magnum in non-syndromic craniosynostosis patients with or without Chiari I malformation. Acta Neurochir (Wien) 2012; 154 (10) 1809-1813
  • 19 Whitton A, Hyzy SL, Britt C, Williams JK, Boyan BD, Olivares-Navarrete R. Differential spatial regulation of BMP molecules is associated with single-suture craniosynostosis. J Neurosurg Pediatr 2016; 18 (01) 83-91
  • 20 Taylor DG, Mastorakos P, Jane Jr JA, Oldfield EH. Two distinct populations of Chiari I malformation based on presence or absence of posterior fossa crowdedness on magnetic resonance imaging. J Neurosurg 2017; 126 (06) 1934-1940
  • 21 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 (05) 1050-1054 , discussion 1054–1055
  • 22 McLone DG, Dias MS. The Chiari II malformation: cause and impact. Childs Nerv Syst 2003; 19 (7-8): 540-550
  • 23 Hatta T. Development of neural tube. Nervous System in Children 2016; 41: 295-302
  • 24 Oaks J. Chiari malformation and syringomyelia. In Reagachary SS, Williams RH. eds. Principles of Neurosurgery. London: Mosby-Wolf; 1994. 9.1.18
  • 25 Sakamoto H, Nishikawa M, Hakuba A. et al. Expansive suboccipital cranioplasty for the treatment of syringomyelia associated with Chiari malformation. Acta Neurochir (Wien) 1999; 141 (09) 949-960 , discussion 960–961