Recent advances in neuroimaging of bladder, bowel and sexual function

Abstract

In this review, we summarize recent advances in the understanding of the neural control of the bladder, bowel and sexual function, in both men and women. Evidence of supraspinal areas controlling the storage of urine and micturition in animals, such as the pontine micturition centre, emerged in the early 20th century. Neurological stimulation and lesion studies in humans provided additional indirect evidence for additional bladder-related brain areas. Thereafter, functional neuroimaging in humans with PET and fMRI provided more direct evidence of the involvement of these brain areas. The areas involved in the storage and expulsion of urine also seem to be involved in the central control of storage and expulsion of feces. Furthermore, most knowledge on the brain control of sexual function is obtained from dynamic imaging in human volunteers. Relatively little is known about the dysfunctional central circuits in patients with pelvic organ dysfunction. fMRI has been the most widely used functional neuroimaging technique in the last decade to study the central control of bladder function, anorectal function and sexual function. The studies described in this review show which sensory and motor areas are involved, including cortical and subcortical areas. We propose the existence of a switch-like phenomenon located in the pons controlling micturition, defecation and orgasm.