Physiological Oscillations of Lateral Ventricular Volume Revealed by Fast fMRI: Effects of Aging and Vigilance

In 97 adults aged 35–82, lateral ventricular volume shows distinct low-frequency, respiratory, and cardiac oscillations, with respiratory and cardiac power accounting for 37.7% and 38.4% of total physiological spectral power.

• Why it matters: Ventricular motion may contribute to CSF displacement, but the physiological drivers of lateral ventricular dynamics—and how they change with aging and vigilance—are not well defined.
• What they did: Two fast resting-state fMRI scans were analyzed with automated ventricular segmentation to estimate time-resolved LVV; variability (standard deviation, coefficient of variation) and spectral power were compared across eyes-open wakefulness, eyes-closed wakefulness, and eyes-closed drowsiness.
• The result: Mean LVV increased with age (FDR-adjusted p = 0.010), while drowsiness increased LVV fluctuation magnitude (standard deviation FDR-adjusted p < 0.001; coefficient of variation FDR-adjusted p = 0.028) and raised low-frequency (FDR-adjusted p < 0.001) and respiratory power (FDR-adjusted p = 0.015) without changing mean LVV or cardiac power.