Analysis of the Prechiasmatic Sulcus in Chiari Malformation Type I

World Neurosurg. 2023 Jul:175:e1149-e1157. doi: 10.1016/j.wneu.2023.04.083. Epub 2023 Apr 26.


Objective: To assess morphologic features of the prechiasmatic sulcus (PS) in Chiari malformation type I (CM-I).

Methods: Computed tomography images were obtained in patients with CM-1 (mean age: 21.26 ± 16.46 years; sex: 25 females and 17 males) and 58 healthy control subjects (mean age: 28.12 ± 22.60 years; sex: 29 females and 29 males). The following parameters were measured to determine the anatomy of the PS: planum length, sulcal length, sulcal angle (SA), and interoptic distance. Considering sulcal length and SA measurements, 4 types of PS were identified: narrow-steep-groove (NSG), narrow-flat-groove (NFG), wide-steep-groove, and wide-flat-groove.

Results: SA was greater in the CM-I group (32.80 ± 18.21°) compared with the control group (23.05 ± 14.53°) (P = 0.004), but the other parameters were similar in both groups. Distribution ranking of PS types was as follows: NFG (31%) > NSG (26.20%) > wide-steep-groove (23.80%) > wide-flat-groove (19%) in the CM-I group; wide-flat-groove (37.90%) > wide-steep-groove (20.70%) = NFG (20.70%) = NSG (20.70%) in the control group. Distribution rate of PS types relative to both groups showed that the classification system was not affected by CM-I (P = 0.226).

Conclusions: SA value was approximately 25% greater in the CM-I group than in the control group; thus, CM-I patients had more vertical groove. The percentage of narrow-type (NSG + NFG) PS in the CM-I group was higher than in the control group.

Keywords: Chiari malformation type I; Prechiasmatic sulcus; Sellar region; Sphenoid sinus.

MeSH terms

  • Adolescent
  • Adult
  • Arnold-Chiari Malformation* / diagnostic imaging
  • Arnold-Chiari Malformation* / surgery
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Male
  • Middle Aged
  • Tomography, X-Ray Computed / methods
  • Young Adult