Low-frequency oscillations measured in the periphery by NIRS were strongly correlated with those in the brain by BOLD fMRI, reflecting systemic physiological circulatory effects.
Observational
Do low-frequency oscillations measured in the periphery with NIRS correlate with BOLD fMRI signals in the brain in healthy volunteers?
Peripheral low-frequency oscillations measured by NIRS strongly correlate with central BOLD fMRI signals, indicating they reflect systemic circulatory effects and may serve as biomarkers for circulatory dysfunction.
Low-frequency oscillations (LFOs) in the range of 0.01-0.15 Hz are commonly observed in functional imaging studies, such as blood oxygen level-dependent functional magnetic resonance imaging (BOLD fMRI) and functional near-infrared spectroscopy (fNIRS). Some of these LFOs are nonneuronal and are closely related to autonomic physiological processes. In the current study, we conducted a concurrent resting-state fMRI and NIRS experiment with healthy volunteers. LFO data was collected simultaneously at peripheral sites (middle fingertip and big toes) by NIRS, and centrally in the brain by BOLD fMRI. The cross-correlations of the LFOs collected from the finger, toes, and brain were calculated. Our data show that the LFOs measured in the periphery (NIRS signals) and in the brain (BOLD fMRI) were strongly correlated with varying time delays. This demonstrates that some portion of the LFOs actually reflect systemic physiological circulatory effects. Furthermore, we demonstrated that NIRS is effective for measuring the peripheral LFOs, and that these LFOs and the temporal shifts between them are consistent in healthy participants and may serve as useful biomarkers for detecting and monitoring circulatory dysfunction.
Tong et al. (Mon,) conducted a observational in Healthy volunteers. Concurrent resting-state fMRI and NIRS was evaluated on Cross-correlations of low-frequency oscillations between peripheral sites and brain. Low-frequency oscillations measured in the periphery by NIRS were strongly correlated with those in the brain by BOLD fMRI, reflecting systemic physiological circulatory effects.