Responses of functional brain networks to bladder control in healthy adults: a study using regional homogeneity combined with independent component analysis methods

Objective: A functional magnetic resonance imaging (fMRI) study was performed during urodynamic examination in healthy adults to determine the responses of functional brain networks to bladder control during urine storage. Methods: The brain imaging was performed in empty and full bladder states during urodynamic examination. First, we used independent component analysis (ICA) to obtain several resting state network masks, then the brain regions with significantly different regional homogeneity (ReHo) values between the two states were determined using a paired t test (p < 0.05; Gaussian random field correction [GRF]: voxel p < 0.01 and cluster p < 0.05) and presented in their corresponding resting state network (RSN) masks. Results: Data sets obtained from the remaining 20 subjects were analyzed after motion correction. Nine RSNs were identified by group-ICA, including the salience network (SN), default mode network (DMN), central executive network (CEN), dorsal attention network (dAN), auditory network (AN), sensorimotor network (SMN), language network (LN), visual network (VN), and cerebellum network (CN). The ReHo values were significantly increased (p < 0.05, GRF corrected) within the SN, DMN, and CEN in the full bladder state compared with the empty bladder state. Conclusion: Significant changes within the three functional brain networks were demonstrated when the bladder was full, suggesting that SN provides bladder sensation and DMN may provide self-reference, self-reflection, and decision-making about whether to void after assessment of the external environment, while CEN may provide support related to episodic memory, which provides new insight into the processing of bladder control and could serve as a premise to further explore the pathologic process underlying bladder dysfunction.