Static and temporal dynamic changes in brain activity in patients with post-stroke balance dysfunction: a pilot resting state fMRI

Abstract

Objective: The aim of this study was to investigate the characteristics of brain activity changes in patients with post-stroke balance dysfunction and their relationship with clinical assessment, and to construct a classification model based on the extreme Gradient Boosting (XGBoost) algorithm to discriminate between stroke patients and healthy controls (HCs).

Methods: In the current study, twenty-six patients with post-stroke balance dysfunction and twenty-four HCs were examined by resting-state functional magnetic resonance imaging (rs-fMRI). Static amplitude of low frequency fluctuation (sALFF), static fractional ALFF (sfALFF), static regional homogeneity (sReHo), dynamic ALFF (dALFF), dynamic fALFF (dfALFF) and dynamic ReHo (dReHo) values were calculated and compared between the two groups. The values of the imaging metrics for the brain regions with significant differences were used in Pearson correlation analyses with the Berg Balance Scale (BBS) scores and as features in the construction of the XGBoost model.

Results: Compared to HCs, the brain regions with significant functional abnormalities in patients with post-stroke balance dysfunction were mainly involved bilateral insula, right fusiform gyrus, right lingual gyrus, left thalamus, left inferior occipital gyrus, left inferior temporal gyrus, right calcarine fissure and surrounding cortex, left precuneus, right median cingulate and paracingulate gyri, right anterior cingulate and paracingulate gyri, bilateral supplementary motor area, right putamen, and left cerebellar crus II. XGBoost results show that the model constructed based on static imaging features has the best classification prediction performance.

Conclusion: In conclusion, this study provided evidence of functional abnormalities in local brain regions in patients with post-stroke balance dysfunction. The results suggested that the abnormal brain regions were mainly related to visual processing, motor execution, motor coordination, sensorimotor control and cognitive function, which contributed to our understanding of the neuropathological mechanisms of post-stroke balance dysfunction. XGBoost is a promising machine learning method to explore these changes.

Keywords: amplitude of low frequency fluctuation; balance dysfunction; extreme gradient boosting; fractional amplitude of low frequency fluctuation; regional homogeneity; resting-state functional magnetic resonance imaging; stroke.

Figure 1

Statistically significant differences between groups are shown in a static amplitude of low frequency fluctuation (sALFF) map of the whole-brain with magnetic resonance imaging (MRI). The color bars indicate the T-value. FFG.R: right fusiform gyrus; IOG.L: left inferior occipital gyrus; LING.R: right lingual gyrus; ITG.L: left inferior temporal gyrus; INS.L: left insula; SFGmed.R: right superior frontal gyrus, medial; CAL.R: right calcarine fissure and surrounding cortex; ROL.L: left rolandic operculum; THA.L: left thalamus; ACG.R: right anterior cingulate and paracingulate gyri; DCG_R: right median cingulate and paracingulate gyri; SMA.R: right supplementary motor area; PCUN.L: left precuneus; SMA.L: left supplementary motor area.

Figure 2

Statistically significant differences between groups are shown in a dynamic amplitude of low frequency fluctuation (dALFF) map of the whole-brain with magnetic resonance imaging (MRI). The color bars indicate the T-value. ITG.L: left inferior temporal gyrus; IOG.L: left inferior occipital gyrus; LING.R: right lingual gyrus; FFG.R: right fusiform gyrus; INS.R: right insula; PUT.R: right lenticular nucleus; CAL.R: right calcarine fissure and surrounding cortex; INS.L: left insula; ACG.R: right anterior cingulate and paracingulate gyri; DCG.R: right median cingulate and paracingulate gyri; SMA.R: right supplementary motor area; PCUN.L: left precuneus.

Figure 3

Statistically significant differences between groups are shown in a static fractional amplitude of low frequency fluctuation (sfALFF) map of the whole-brain with magnetic resonance imaging (MRI). The color bars indicate the T-value. CC2.L: left cerebellar crus II; FFG.R: right fusiform gyrus; PCUN.L: left precuneus.

Figure 4

Statistically significant differences between groups are shown in a static regional homogeneity (sReHo) map of the whole-brain with magnetic resonance imaging (MRI). The color bars indicate the T-value. CAL.R: right calcarine fissure and surrounding cortex; PUT.R: right lenticular nucleus; DCG.R: right median cingulate and paracingulate gyri.

Figure 5

Statistically significant differences between groups are shown in a dynamic regional homogeneity (dReHo) map of the whole-brain with magnetic resonance imaging (MRI). The color bars indicate the T-value. PUT.R: right lenticular nucleus.