Frequency-dependent changes in the amplitude of low-frequency fluctuations in subcortical ischemic vascular disease (SIVD): A resting-state fMRI study

- SIVD has abnormal intrinsic neural oscillations in widely cortical areas.
- The abnormal intrinsic neural oscillations in SIVD are related to specific frequency bands.
- Frequency domain analyses of resting-state BOLD signals may provide a useful means to study the pathophysiology and physiology of SIVD.

Resting-state functional magnetic resonance imaging (RS-fMRI) allowed researchers to detect intrinsic brain activity during rest and has been considered an analytical tool for evaluation of dementia. Previously, subcortical ischemic vascular disease (SIVD) has been found decreased amplitude low-frequency fluctuations (ALFF) in a widely frequency range (0.01-0.08 Hz) in the bilateral precuneus and increased ALFF values in the bilateral anterior cingulate cortex (ACC), left insula and hippocampus, which showed significant correlations with the cognitive performance. In this study we analyzed the ALFF of 30 patients with SIVD in two different frequency bands (slow-5: 0.01-0.027 Hz; slow-4: 0.027-0.073 Hz). In the slow-5 band, SIVD patients compared with controls exhibited significant higher ALFF in the bilateral anterior cingulate cortex, right putamen and right supplementary motor area, while lower ALFF in the right precuneus and right angular gyrus. A close correlation was found between the ALFF value of the right angular gyrus and ADL scores. In the slow-4 band, SIVD patients only exhibited increased ALFF in the bilateral anterior cingulate cortex, right putamen, left fusiform gyrus, and no correlation with cognitive scores was found. Our data demonstrate that SIVD patients have widespread abnormal intrinsic neural oscillations, which are dependent on specific frequency bands. ALFF of right angular gyrus at slow-5 band is more specific for SIVD and may be a useful tool to help SIVD diagnosis.