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Background: Visual stimuli are recognized to stimulate urinary urgency and urgency urinary incontinence (UUI). Current pathophysiology recognizes the importance of cortical control over micturition, but as clinicians lack any methodology to evaluate causal triggers, a MRI protocol for urologic use that explores the brain’s response to visual triggers in subjects with clinical symptoms of trigger-related UUI was developed. Methods: Using a 3 Tesla Philips Elition Scanner, structural T1 weighted images were acquired and used to define ~200 brain regions based on a validated brain atlas. Diffusion Tensor Imaging (DTI) and Myelin Water Fraction (MWF) scans were then obtained to investigate for myelin abnormalities. A functional MRI (fMRI) component followed, where, during scanning, patients were shown a defined random sequence of visual stimuli that consisted of subject-specific trigger images supplied by each subject, interspersed with neutral images. The fMRI study was performed after natural bladder filling. Results: N=10 subjects participated (6 asymptomatic controls and 4 with UUI). Debriefing confirmed that images within the sequence had triggered symptoms of UUI; tractography demonstrated robust structural connectivity between the anterior cingulate cortex and periaqueductal grey matter. Discussion: Conventional investigation of UUI lacks evaluative methodology for the impact of visual triggers on sensation of urgency and onset of incontinence, yet cortical control is recognized to be a major component of UUI in large numbers of the affected population. Conclusion: We describe the feasibility of a novel 1 hour 6 minute fMRI protocol for evaluation and quantification of the cortical mechanisms underlying visual triggers for UUI.
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