J Neurol Surg B Skull Base
DOI: 10.1055/s-0043-57248
Original Article

Assessment of the Anterior Clinoid Process and Optic Strut in Chiari Malformation Type I: A Computed Tomography Study

Hakan Özalp
1   Department of Neurosurgery, Istanbul Medipol University Faculty of Medicine, İstanbul, Turkey
Onur Özgüral
2   Department of Neurosurgery, Ankara University Faculty of Medicine, Ankara, Turkey
2   Department of Neurosurgery, Ankara University Faculty of Medicine, Ankara, Turkey
Ayşenur İnceoğlu
3   Department of Anatomy, Gaziantep University Faculty of Medicine, Gaziantep, Turkey
Sibel Özalp
4   Department of Medical Laboratory Techniques, Istanbul Medipol University School of Vocation, İstanbul, Turkey
Ercan Armağan
5   Department of Neurosurgery, Silivri Anadolu Hospital, İstanbul, Turkey
Hadice Uçar
3   Department of Anatomy, Gaziantep University Faculty of Medicine, Gaziantep, Turkey
3   Department of Anatomy, Gaziantep University Faculty of Medicine, Gaziantep, Turkey
› Author Affiliations


Objective This study aimed to evaluate morphological features of the anterior clinoid process (ACP) and the optic strut (OS) in Chiari malformation Type I (CM-I).

Methods The study universe consisted of computed tomography images of 41 CM-I patients and 45 normal subjects. Comparison of the parameters for CM-I and the control group was performed with the Student's t-test. A “p < 0.05” was accepted as the significance level.

Results ACP length was smaller in CM-I than the control group (p < 0.001). In contrast to ACP length, ACP angle (p < 0.001), OS length (p = 0.022), and the distance between ACP and OS (p = 0.020) were found greater in CM-I in comparison to the control group (p < 0.05). ACP width (p = 0.233) and OS width (p = 0.376) were similar in both groups. ACP pneumatization in CM-I group was found as 12.20%, whereas in the control group as 8.90%. Two different types about the pneumatization were identified in CM-I group (Type 1: 4.9% and Type 2: 7.3%), whereas three different types in the control group (Type 1: 3.3%, Type 2: 4.4%, and Type 3: 1.1%). Relative to ACP, three different types about OS position were identified in CM-I group (Type C: 31.70%, Type D: 64.60%, and Type E: 3.70%) and the control group (Type C: 7.80%, Type D: 64.40%, and Type E: 27.80%).

Conclusions Shorter ACP, wide-angled ACP, longer OS, and more anteriorly located OS were found in CM-I group compared with the normal group. Our findings showed that the pneumatization of ACP was not affected by CM-I.

Ethical Approval

The Clinical Research Ethics Committee of Ankara University approved this retrospective CT work ethically (confirmation date September 22, 2022, no. 108-521-22).

Informed Consent

Approval from the Institutional Review Board was obtained and in keeping with the policies for a retrospective review; informed consent was not required.

Author Contributions

Conceptualization: H.Ö., O.Ö., E.A., S.Ö.; methodology: H.Ö., S.Ö., O.Ö., E.A.; data collection: O.Ö., B.C.A.; analysis and interpretation of results: H.U., Aİ, O.B.; writing original draft: H.Ö., O.B., H.U., Aİ; critical revision of the manuscript: H.Ö., O.Ö., O.B.; approval of the final version of the manuscript: all authors.

Publication History

Received: 23 January 2023

Accepted: 27 March 2023

Article published online:
19 April 2023

© 2023. Thieme. All rights reserved.

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany

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