Altered Regional Homogeneity and Amplitude of Low-Frequency Fluctuations in Sub-acute Ischemic Stroke: A resting-state fMRI study

Abstract

Though sub-acute stroke patients have high recovery probability, the related neurological mechanism of recovery in the sub-acute stroke patients is unclear. The aim of this study was to investigate abnormal brain activation in patients with sub-acute stroke. In this study, four sub-acute ischemic stroke patients were recruited and conducted the scan of resting-state functional magnetic resonance imaging (rs-fMRI). The analysis of regional homogeneity (ReHo) and amplitude of low-frequency fluctuations (ALFF) were performed to reveal the changes in sub-acute stroke patients. Compared to the mean level of whole brain, decreased ReHo was mainly shown in the temporal lobe, precentral gyrus and putamen. Decreased ALFF was obtained mainly in cerebellum posterior lobe, precuneus, precentral gyrus, middle occipital gyrus, postcentral gyrus and frontal lobe, which were related to motor dysfunction in stroke. The positive correlation was detected between ALFF and ReHo in the grey matter level $(r = 0.4393, p< 0.001)$. Nevertheless, the correlation decreased in whole brain level $(r = 0.2327, p< 0.001)$, which means non-grey matter may have an impact on the correlation result. Our results suggested that ReHo and ALFF could reflect the changes of neurological function in sub-acute stroke.