White matter microstructural changes across the menstrual cycle: a differential tractography study.

purposeThis study explores white matter (WM) microstructural changes across different phases of the menstrual cycle (MC) in healthy women.

methodsUsing the publicly available Hormon Health Study dataset, we performed a differential tractography study on Q-space Trajectory Imaging sequences from 22 participants, assessing WM microstructural changes between three specific time points: (a) Menses phase (M-phase), (b) Ovulation phase (O-phase), and (c) Mid-Luteal phase (ML-phase). The difference between specific MC-phase scans were calculated by the scheme “phase - previous phase” of the MC in three distinct analyses: (a) Analysis 1 (O-phase – M-Phase); (b) Analysis 2 (ML-phase – O-phase); (c) Analysis 3 (M-phase – ML-phase). Quantitative anisotropy (QA), was employed to quantify changes in WM structure. A p-value corrected for false discovery rate (p-FDR) < 0.05 was used to identify statistically significant results.

resultsSignificant reductions in QA were widespread observed in Analysis 1 (O-phase – M-Phase; p-FDR = 0.00026802), and Analysis 2 (ML-phase – O-phase; p-FDR = 0.00000242), while increased QA values were observed in Analysis 3 (M-phase – ML-phase; p-FDR = 0.00002051).

conclusionThis study provides evidence of cyclic WM microstructural changes during the MC. These results may offer insights into the mechanisms underlying MC-related brain physiological and pathological changes.