Abstract：
OBJECTIVE: The study aims to analyze alterations in dynamic functional connectivity density (dFCD) and effective connectivity (dEC) patterns using functional magnetic resonance imaging (fMRI), hypothesizing that overactive bladder (OAB) patients will exhibit distinct dFCD and dEC patterns, reflecting altered neural communication underlying the OAB.
METHODS: Forty-three female OAB patients and 40 female healthy controls (HC) underwent resting-state fMRI. Sliding window correlation was used to calculate the variability of the dFCD. The changes in dFCD-based dEC between the two groups were examined using Granger causal analysis. To describe the time-varying Granger causality, a sliding-window approach was utilized to divide time courses into a group of windows. We adopted a k-means clustering method to cluster all matrices into discrete connectivity states.
RESULTS: Compared with HC, OAB females consistently had a dFCD (decreased) in the left anterior cingulate cortex (ACC) and left medial prefrontal cortex (mPFC) (p < 0.05, GRF corrected). In state 1, OAB patients had excitatory effective connections from bilateral ACC to left mPFC in comparison to HC. In state 2, there was an increase in dEC from the SMA to the mPFC. Participants with OAB showed significantly more inhibitory dorsolateral prefrontal cortex (dlPFC) connections between the left ACC and the right ACC in state 4, as well as an excitatory dEC connection between the right dlPFC and the left ACC in state 2 (p < 0.05, GRF corrected).
CONCLUSIONS: OAB patients demonstrate significant alterations in dFCD and dEC patterns, which may be indicative of the neural mechanisms involved in OAB pathophysiology.
METHODS: Forty-three female OAB patients and 40 female healthy controls (HC) underwent resting-state fMRI. Sliding window correlation was used to calculate the variability of the dFCD. The changes in dFCD-based dEC between the two groups were examined using Granger causal analysis. To describe the time-varying Granger causality, a sliding-window approach was utilized to divide time courses into a group of windows. We adopted a k-means clustering method to cluster all matrices into discrete connectivity states.
RESULTS: Compared with HC, OAB females consistently had a dFCD (decreased) in the left anterior cingulate cortex (ACC) and left medial prefrontal cortex (mPFC) (p < 0.05, GRF corrected). In state 1, OAB patients had excitatory effective connections from bilateral ACC to left mPFC in comparison to HC. In state 2, there was an increase in dEC from the SMA to the mPFC. Participants with OAB showed significantly more inhibitory dorsolateral prefrontal cortex (dlPFC) connections between the left ACC and the right ACC in state 4, as well as an excitatory dEC connection between the right dlPFC and the left ACC in state 2 (p < 0.05, GRF corrected).
CONCLUSIONS: OAB patients demonstrate significant alterations in dFCD and dEC patterns, which may be indicative of the neural mechanisms involved in OAB pathophysiology.
摘要：
目的：该研究旨在使用功能磁共振成像（fMRI）分析动态功能连接密度（dFCD）和有效连接（dEC）模式的变化，假设膀胱过度活动症（OAB）患者将表现出不同的dFCD和dEC模式，反映了OAB潜在的神经交流改变。
方法：43例女性OAB患者和40例女性健康对照（HC）接受静息状态fMRI检查。滑动窗口相关性用于计算dFCD的变异性。使用Granger因果分析检查两组之间基于dFCD的dEC的变化。为了描述时变的格兰杰因果关系，使用滑动窗口方法将时间课程划分为一组窗口。我们采用k-means聚类方法将所有矩阵聚类为离散的连通性状态。
结果：与HC相比，OAB女性在左前扣带回皮质（ACC）和左内侧前额叶皮质（mPFC）中始终存在dFCD（降低）（p<0.05，GRF校正）。在状态1中，与HC相比，OAB患者从双侧ACC到左侧mPFC具有兴奋性有效连接。在状态2中,dEC从SMA增加到mPFC。在状态4中，OAB参与者在左ACC和右ACC之间显示出明显更多的抑制性背外侧前额叶皮层（dlPFC）连接，在状态2中，右dlPFC和左ACC之间显示出兴奋性dEC连接（p<0.05，GRF校正）。
结论：OAB患者表现出dFCD和dEC模式的显著改变，这可能表明参与OAB病理生理学的神经机制。
方法：43例女性OAB患者和40例女性健康对照（HC）接受静息状态fMRI检查。滑动窗口相关性用于计算dFCD的变异性。使用Granger因果分析检查两组之间基于dFCD的dEC的变化。为了描述时变的格兰杰因果关系，使用滑动窗口方法将时间课程划分为一组窗口。我们采用k-means聚类方法将所有矩阵聚类为离散的连通性状态。
结果：与HC相比，OAB女性在左前扣带回皮质（ACC）和左内侧前额叶皮质（mPFC）中始终存在dFCD（降低）（p<0.05，GRF校正）。在状态1中，与HC相比，OAB患者从双侧ACC到左侧mPFC具有兴奋性有效连接。在状态2中,dEC从SMA增加到mPFC。在状态4中，OAB参与者在左ACC和右ACC之间显示出明显更多的抑制性背外侧前额叶皮层（dlPFC）连接，在状态2中，右dlPFC和左ACC之间显示出兴奋性dEC连接（p<0.05，GRF校正）。
结论：OAB患者表现出dFCD和dEC模式的显著改变，这可能表明参与OAB病理生理学的神经机制。
