Evidence for sex differences in morphological abnormalities in type I Chiari malformation

Area of Science:

• Neuroscience
• Radiology
• Genetics

Background:

• Individual differences in brain morphology presentation in Chiari I malformation (CMI) are not well understood.
• Sex is a key individual difference variable that may influence CMI's macro-level brain morphology.

Purpose of the Study:

• To investigate how patient sex influences case-control differences in brain morphology for Chiari I malformation.
• To compare morphometric abnormalities between male and female CMI patients and controls.

Main Methods:

• Utilized magnetic resonance images from the Chiari 1000 database for 104 participants (26 male CMI, 26 female CMI, 26 male controls, 26 female controls).
• Performed 24 morphometric measurements on mid-sagittal images using validated custom software (Morphpro).
• Conducted case-control comparisons separately by sex, matching controls by age and BMI, using t-tests, Cohen's d, and confidence intervals.

Main Results:

• Both male and female CMI groups showed similar trends of morphometric abnormalities, including reduced posterior cranial fossa (PCF) structure heights.
• Male CMI patients demonstrated greater reductions in PCF structure heights compared to female CMI patients, as indicated by Cohen's d effect sizes.

Conclusions:

• Macro-level morphometric abnormalities in Chiari I malformation are consistent between sexes.
• Despite higher CMI prevalence in females, male CMI patients may exhibit greater magnitude of morphometric abnormalities.
• Results highlight the importance of considering sex as an individual difference variable in CMI morphometric studies.