Soft tissue density within the foramen magnum, a predictor for surgical intervention in pediatric patients with Chiari malformation type I

View More View Less
  • 1 Division of Neurosurgery, Arkansas Children’s Hospital; and
  • 2 Department of Neurosurgery, University of Arkansas for Medical Sciences, Little Rock, Arkansas
Restricted access

Purchase Now

USD  $45.00

JNS + Pediatrics - 1 year subscription bundle (Individuals Only)

USD  $505.00

JNS + Pediatrics + Spine - 1 year subscription bundle (Individuals Only)

USD  $600.00
Print or Print + Online

OBJECTIVE

Chiari malformation type I (CMI) is diagnosed as herniation of the cerebellar tonsils by at least 5 mm below the foramen magnum. However, the degree of tonsillar herniation is a poor predictor of the need for decompression surgery. Exploration for an alternative morphological predictor for surgical intervention could provide greater insight into the development of an appropriate treatment plan for these patients. To investigate this issue, the authors calculated the soft tissue density within the foramen magnum as a measure of impaction of the cerebellar tonsils. Soft tissue density within the foramen magnum and degree of tonsillar herniation were then assessed for their correlation with the need for surgical intervention.

METHODS

The authors conducted a retrospective, longitudinal chart review of pediatric patients with CMI. Those who had undergone surgical intervention were considered symptomatic and those who had been treated conservatively, as asymptomatic. Soft tissue density was found by dividing the soft tissue occupancy of the foramen magnum (brainstem and cerebellar tonsils) by the total area of the bony foramen magnum. The predictive value of these two measurements for the need of surgery was determined.

RESULTS

Of the 465 patients seen for CMI at the authors’ institution between July 1, 2011, and May 31, 2017, 80 underwent surgical intervention and 385 were asymptomatic. The average tissue density was significantly greater in the surgical group than in the asymptomatic group (83.3% and 78.6%, respectively, p < 0.0001). The average tonsillar descent for surgical patients was 10.8 mm compared to 9.8 mm for asymptomatic patients (p = 0.140). The point-biserial correlation coefficient was assessed, and soft tissue density was found to positively correlate with the need for surgical intervention (rpb = 0.199, p = 0.0001), whereas tonsillar herniation did not correlate with the need for surgery (rpb = 0.083, p = 0.115). Additionally, the degree of tonsillar herniation did not correlate with soft tissue density (r = 0.09), indicating that soft tissue density is an independent morphological parameter.

CONCLUSIONS

The study findings suggest that the need for surgical intervention in CMI patients is positively correlated with increasing soft tissue density within the foramen magnum, whereas the degree of tonsillar herniation did not show a correlation with the need for surgical intervention. Additionally, soft tissue density is a factor independent of the degree of tonsillar herniation. Further investigation of tissue density within the foramen magnum is needed in the hope of discovering a clinically applicable parameter that would indicate a need for surgical intervention in patients with CMI.

ABBREVIATIONS CMI = Chiari malformation type I; ICC = intraclass correlation coefficient.

JNS + Pediatrics - 1 year subscription bundle (Individuals Only)

USD  $505.00

JNS + Pediatrics + Spine - 1 year subscription bundle (Individuals Only)

USD  $600.00

Contributor Notes

Correspondence Gregory Albert: University of Arkansas for Medical Sciences, Little Rock, AR. galbert2@uams.edu.

INCLUDE WHEN CITING Published online October 2, 2020; DOI: 10.3171/2020.6.PEDS19744.

Disclosures The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

  • 1

    Tubbs RS, Lyerly MJ, Loukas M, The pediatric Chiari I malformation: a review. Childs Nerv Syst. 2007;23(11):12391250.

  • 2

    Hekman KE, Aliaga L, Straus D, Positive and negative predictors for good outcome after decompressive surgery for Chiari malformation type 1 as scored on the Chicago Chiari Outcome Scale. Neurol Res. 2012;34(7):694700.

    • Search Google Scholar
    • Export Citation
  • 3

    Klekamp J, Batzdorf U, Samii M, Bothe HW. The surgical treatment of Chiari I malformation. Acta Neurochir (Wien). 1996;138(7):788801.

    • Search Google Scholar
    • Export Citation
  • 4

    Pomeraniec IJ, Ksendzovsky A, Awad AJ, Natural and surgical history of Chiari malformation Type I in the pediatric population. J Neurosurg Pediatr. 2016;17(3):343352.

    • Search Google Scholar
    • Export Citation
  • 5

    Aguiar PH, Tella OI Jr, Pereira CU, Chiari type I presenting as left glossopharyngeal neuralgia with cardiac syncope. Neurosurg Rev. 2002;25(1-2):99102.

    • Search Google Scholar
    • Export Citation
  • 6

    Elta GH, Caldwell CA, Nostrant TT. Esophageal dysphagia as the sole symptom in type I Chiari malformation. Dig Dis Sci. 1996;41(3):512515.

    • Search Google Scholar
    • Export Citation
  • 7

    Zolty P, Sanders MH, Pollack IF. Chiari malformation and sleep-disordered breathing: a review of diagnostic and management issues. Sleep. 2000;23(5):637643.

    • Search Google Scholar
    • Export Citation
  • 8

    Bao C, Yang F, Liu L, Surgical treatment of Chiari I malformation complicated with syringomyelia. Exp Ther Med. 2013;5(1):333337.

  • 9

    Panigrahi M, Reddy BP, Reddy AK, Reddy JJ. CSF flow study in Chiari I malformation. Childs Nerv Syst. 2004;20(5):336340.

  • 10

    Cuthbert S, Blum C. Symptomatic Arnold-Chiari malformation and cranial nerve dysfunction: a case study of applied kinesiology cranial evaluation and treatment. J Manipulative Physiol Ther. 2005;28(4):e1e6.

    • Search Google Scholar
    • Export Citation
  • 11

    Rekate HL, Nadkarni TD, Teaford PA, Wallace D. Brainstem dysfunction in chiari malformation presenting as profound hypoglycemia: presentation of four cases, review of the literature, and conjecture as to mechanism. Neurosurgery. 1999;45(2):386391.

    • Search Google Scholar
    • Export Citation
  • 12

    Tsara V, Serasli E, Kimiskidis V, Acute respiratory failure and sleep-disordered breathing in Arnold-Chiari malformation. Clin Neurol Neurosurg. 2005;107(6):521524.

    • Search Google Scholar
    • Export Citation

Metrics