Examining Bladder Control Using Magnetic Resonance Imaging (MRI) and Diffusion Tensor Imaging (DTI)

One devastating manifestation of overactive bladder is urgency incontinence. Although urgency incontinence is a common problem with profound clinical, social and psychological consequences, little is understood about its underlying cause. The involuntary detrusor overactivity (DO) often associated with the disease points to a possible abnormality in voluntary control of the spinobulbospinal voiding reflex by a higher order neuronal network. Recent functional MRI (fMRI) and PET studies have identified increased brain activity during bladder filling and voiding in normal subjects from higher order cognitive control centers. In addition, there are now data to suggest that interactions between these brain areas, which include the pontine micturition center (PMC), periaqueductal gray (PAG), thalamus, insula, dorsal anterior cingulate and prefrontal cortex, may be abnormal in patients with urgency incontinence. Despite these encouraging findings, we do not yet know how these regions are interacting with each other, or to other, unknown but important, regions in the brain. Nor do we know how this interaction might play a role in this disease process. Expanding our knowledge of how these regions are integrated to achieve continence and, importantly, what aspects of this complex circuitry are atypical in patients with urge incontinence is key to our future therapeutic endeavors. With this in mind, the goal of this study is to better characterize the functional integration (i.e. functional connectivity) of the brain's control networks in relation to typical and atypical bladder function. We aim to identify distinct differences in the brain's functional and anatomic topography in women with and without urgency incontinence. Our approach not only has the potential to advance our understanding of the higher level pathophysiology of this disease process, but could also lead to novel more centrally acting therapeutic approaches for treatment of urgency incontinence.