Article Impact Level: HIGH Data Quality: STRONG Summary of Stroke, STROKEAHA.124.048057. https://doi.org/10.1161/STROKEAHA.124.048057 Dr. Evgeniy I. Kreydin et al.
Points
- This cohort study investigated brain activity patterns during voluntary and involuntary bladder contractions in stroke survivors, using fMRI and urodynamics to focus on the neural mechanisms underlying urinary incontinence.
- The study found that volitional bladder emptying activated brain regions related to sensorimotor control and executive decision-making, such as the brainstem, cingulate cortex, prefrontal cortex, and motor areas in stroke survivors and healthy controls.
- In contrast, involuntary voiding events showed minimal cortical activation, suggesting that these events are largely independent of higher brain functions. Volitional bladder filling activated the salience network in both groups.
- The absence of salience network activation during involuntary bladder filling suggests that cortical involvement is absent in reflexive voiding, which may contribute to poststroke urinary incontinence in survivors.
- The study highlights the importance of the salience network in maintaining urinary continence. It suggests that targeting this network could offer potential interventions for improving lower urinary tract symptoms in stroke patients.
Summary
This cohort study aimed to investigate the brain activity patterns associated with volitional and involuntary bladder contractions in stroke survivors, focusing on understanding the neural mechanisms underlying urinary incontinence. The study enrolled 15 stroke survivors with urinary incontinence and 9 healthy controls. Functional magnetic resonance imaging (fMRI) and urodynamics captured 25 involuntary and 23 volitional bladder events in stroke survivors and 35 volitional voiding events in healthy controls. The study used general linear modeling to examine brain activity during these events and in the phases leading up to them. Statistical significance was set at P<0.005 with a minimum cluster size of 25 voxels.
The results revealed that during volitional bladder emptying, stroke survivors and healthy controls exhibited increased activation in brain regions associated with sensorimotor control and executive decision-making, such as the brainstem, cingulate cortex, prefrontal cortex, and motor areas. In contrast, involuntary voiding events showed minimal cortical activation, suggesting that these events are largely independent of higher brain functions. In both groups, bladder filling preceding volitional contractions activated the salience network, including the insula and anterior cingulate gyrus. However, this network was absent during bladder filling before involuntary contractions, indicating a lack of cortical involvement in these reflexive events.
These findings suggest that the salience network is critical in maintaining urinary continence in stroke survivors. The inability to activate this network may contribute to the pathophysiology of poststroke urinary incontinence. The study highlights the potential of targeting the salience network in interventions to improve lower urinary tract symptoms in stroke patients. This research opens the door for future therapies that may help restore volitional control over urinary function.
Link to the article: https://www.ahajournals.org/doi/10.1161/STROKEAHA.124.048057
References Kreydin, E. I., Abedi, A., Morales, L., Montero, S., Kohli, P., Ha, N., Chapman, D., Abedi, A., Ginsberg, D., Jann, K., Harvey, R. L., & Liu, C. Y. (2025). Neural mechanisms of poststroke urinary incontinence: Results from an fmri study. Stroke, STROKEAHA.124.048057. https://doi.org/10.1161/STROKEAHA.124.048057
