Functional MRI in neuro-urology: A narrative review

Abstract

Neuro-imaging has given urologists a new tool to investigate the neural control of the lower urinary tract. Using functional magnetic resonance imaging (fMRI), it is now possible to understand which areas of the brain contribute to the proper function of the storage and voiding of the lower urinary tract. This field of research has evolved from simple anatomical descriptions to elucidating the complex micturition network. A keyword search of the Medline database was conducted by two reviewers for relevant studies from January 1, 2010, to August 2022. Of 2047 peer-reviewed articles, 49 are included in this review. In the last decade, a detailed understanding of the brain-bladder network has been described, elucidating a dedicated network, as well as activated areas in the brainstem, cerebellum, and cortex that share reproducible connectivity patterns. Research has shown that various urological diseases can lead to specific changes in this network and that therapies used by urologists to treat lower urinary tract symptoms (LUTS) are also able to modify neuronal activity. This represents a set of potential new therapeutic targets for the management of the lower urinary tract symptoms (LUTS). fMRI technology has made it possible to identify subgroups of responders to various treatments (biofeedback, anticholinergic, neuromodulation) and predict favourable outcomes. Lastly, this breakthrough understanding of neural control over bladder function has led to treatments that directly target brain regions of interest to improve LUTS. One such example is the use of non-invasive transcranial neuromodulation to improve voiding symptoms in individuals with multiple sclerosis.

Keywords: Bas appareil urinaire; Bladder; Brain mapping; Cartographie cérébrale; Functional MRI; IRM fonctionnelle; Lower urinary tract; Neuro-urology; Vessie.