Locke Jennifer A, Macnab Andrew, Garg Saurabh, McKeown Martin, Stothers Lynn
Department of Urologic Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
Department of Neurology, University of British Columbia, Vancouver, British Columbia, Canada.
Neurourol Urodyn. 2022 Jan;41(1):48-53. doi: 10.1002/nau.24824. Epub 2021 Oct 31.
Visual triggers have long been recognized clinically to stimulate urgency urinary incontinence (UUI). Current pathophysiology recognizes the importance of cortical control over micturition but there is no standardized methodology for clinicians to study the impact of visual triggers. Our aim was to develop an imaging protocol able to characterize the brain's response to personalized visual triggers, providing a methodology for evaluation on connectivity within the brain in patients with visually triggered urinary urgency.
A magnetic resonance imaging (MRI) methodology specific for urologic use was developed. A 3T-Elition Scanner was first used to acquire static structural images. These images were then used to define approximately 200 brain regions of interest (ROI) using a validated brain atlas. Then, real-time functional MRI (fMRI) scans were conducted during natural bladder filling, where study subjects were shown randomized block sequences of visual stimuli comprised of both subject-specific trigger images and neutral images. The fMRI scan data were merged to identify key ROI underlying UUI.
Dynamic fMRI scans were conducted in 10 subjects, 4 with trigger-induced UUI, 2 with trigger-induced urgency, and 4 with no urgency or leakage to visual triggers. No subjects with UUI history lost continence during imaging, but all four subjects reported sensations of urgency in response to their own subject-specific trigger images. The ROI identified were the periaqueductal gray, anterior cingulate gyrus, pons, and prefrontal cortex. We found increased activity in the prefrontal cortex and limbic system ROI in response to subject-specific visual triggers of UUI.
This information provides proof of principle for further exploration of subject-specific trigger image evaluation using fMRI to explore causation in patients with UUI.
视觉触发因素长期以来在临床上被认为会刺激急迫性尿失禁（UUI）。当前的病理生理学认识到皮质对排尿控制的重要性，但临床医生尚无标准化方法来研究视觉触发因素的影响。我们的目的是开发一种成像方案，能够表征大脑对个性化视觉触发因素的反应，为评估视觉触发型尿急患者的脑内连接性提供一种一种方法。
开发了一种专门用于泌尿外科的磁共振成像（MRI）方法。首先使用3T-Elition扫描仪获取静态结构图像。然后使用经过验证的脑图谱，利用这些图像定义大约200个脑感兴趣区域（ROI）。接着，在自然膀胱充盈期间进行实时功能MRI（fMRI）扫描，向研究对象展示由特定个体触发图像和中性图像组成的随机分组视觉刺激序列。将fMRI扫描数据合并以识别UUI潜在的关键ROI。
对10名受试者进行了动态fMRI扫描，其中4名有触发诱导型UUI，2名有触发诱导型尿急，4名对视觉触发因素无尿急或漏尿情况。没有UUI病史的受试者在成像过程中失禁，但所有4名受试者均报告在看到自己的特定个体触发图像时有尿急感。识别出的ROI包括导水管周围灰质、前扣带回、脑桥和前额叶皮质。我们发现，前额叶皮质和边缘系统ROI对UUI的特定个体视觉触发因素有增强的活动反应。
这些信息为进一步探索使用fMRI评估特定个体触发图像以探究UUI患者病因提供了原理证明。
