Abstract.

Background and Purpose. Relatively little is known about the influence of individual difference variables on the presentation of macro-level brain morphology in Type I Chiari malformation (CMI). The goal of the present study is to examine how case-control differences in Chiari are affected by patient sex.

Materials and Methods. Patient-provided MR images were acquired through the Chiari1000 database. Twenty-four morphometric measurements were taken using mid-sagittal images of 104 participants (26 male CMI, 26 female CMI, 26 male control, 26 female control) using internally-developed and validated custom software, Morphpro. Casecontrol comparisons were conducted separately by sex using age and BMI-match healthy control participants. Probability-based t-tests, effect sizes (Cohen’s d), and confidence intervals were used to compare casecontrol differences separately by sex.

Results. Male and female case-control comparisons yielded largely the same trends of CMI-related morphometrics abnormalities. Both groups yielded reductions in PCF structure heights. However, there was evidence for greater PCF structure height reductions in male CMI patients as measured by Cohen’s d.

Conclusion. Case-control differences indicated strong consistency in the morphometric abnormalities of CMI malformation in males and females. However, despite the higher prevalence rates of CMI in females, the results from the present study suggest that male morphometric abnormalities may be greater in magnitude. These findings also provide insight into the inconsistent findings from previous morphometric studies of CMI and emphasize the importance of controlling for individual differences when conducting case-control comparisons in CMI.

Contributors.

James R. Houston, Natalie J. Allen, Maggie S. Eppelheimer, Jayapalli Rajiv Bapuraj, Philip A. Allen, Sarel Vorster, Mark G. Luciano, Francis Loth

Publication.

The Neuroradiology Journal