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. 2023 Apr 19;85(3):302-312.
doi: 10.1055/s-0043-57248. eCollection 2024 Jun.

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

Hakan Özalp  1 , Onur Özgüral  2 , Baran C Alpergin  2 , Ayşenur İnceoğlu  3 , Sibel Özalp  4 , Ercan Armağan  5 , Hadice Uçar  3 , Orhan Beger  3
Affiliations

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

Hakan Özalp et al. J Neurol Surg B Skull Base. .

Abstract

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%). Conclusion 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.

Keywords: Chiari malformation Type I; anterior clinoid process; anterior clinoidectomy; optic strut; pneumatization.

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Conflict of interest statement

Conflict of Interest None declared.

Figures

Fig. 1
Fig. 1
The photographs show the location of ACP and OS. ACP, anterior clinoid process; DS, dorsum sella; HF, hypophysial fossa; OS, optic strut; SS, sphenoid sinus.
Fig. 2
Fig. 2
The photographs show the parameters. a = ACP-A, b = ACP-L, c = ACP-W, d = Dis-ACP-OS, e = OS-L, and f = OS-W.
Fig. 3
Fig. 3
The photographs show the pneumatization degree of ACP. ( A ) No pneumatization, ( B ) Type 1, ( C ) Type 2, and ( D ) Type 3.
See this image and copyright information in PMC

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