Specific Changes in Brain Activity During Urgency in Women with Overactive Bladder after Successful Sacral Neuromodulation: An fMRI Study.

J Urol. 2018 Apr 06;:

Authors: Weissbart SJ, Bhavsar R, Rao H, Wein AJ, Detre JA, Arya LA, Smith AL

Abstract
PURPOSE: The mechanism of sacral neuromodulation is poorly understood. We compared brain activity during urgency before and after sacral neuromodulation in women with overactive bladder and according to response to treatment.
MATERIALS AND METHODS: Women with refractory overactive bladder who elected for sacral neuromodulation were invited to undergo a functional magnetic resonance imaging exam before and after treatment. During the imaging exams, the bladder was filled until urgency was experienced. Regions of interest were identified a priori, and brain activity in these regions of interest was compared before and after treatment as well as according to treatment response. A whole brain exploratory analysis with an uncorrected voxel level threshold of p<0.001 was also conducted to identify additional brain regions that changed after sacral neuromodulation.
RESULTS: Among 12 women who underwent a pretreatment functional magnetic resonance imaging exam, seven were successfully treated with sacral neuromodulation and underwent a posttreatment exam. After sacral neuromodulation, brain activity decreased in the left anterior cingulate cortex, bilateral insula, left dorsolateral prefrontal cortex and bilateral orbitofrontal cortex (all p<0.05). There were no new brain regions with increased activity after sacral neuromodulation. Pretreatment brain activity levels in the bilateral anterior cingulate cortex, right insula, bilateral dorsolateral prefrontal cortex, right orbitofrontal cortex, right supplementary motor area, and right sensorimotor cortex were higher in women who underwent successful treatment (all p<0.05).
CONCLUSIONS: Brain activity during urgency changes after successful sacral neuromodulation. Sacral neuromodulation may be more effective in women with higher levels of pretreatment brain activity during urgency.

PMID: 29630979 [PubMed - as supplied by publisher]