AUA 2018: Association Between Overactive Bladder Severity and Bold fMRI Brain Activity

San Francisco, CA ( Overactive bladder (OAB) is a common urological condition characterized by the sense of urinary urgency and has been shown to detrimentally affect quality of life. Prior studies using functional magnetic resonance imaging (fMRI) have demonstrated altered patterns of brain activity in women with OAB compared to healthy controls. Steven Weissbart, MD of Stony Brook University Hospital presented his research at the University of Pennsylvania to assess whether brain activity patterns are further altered with increased severity of OAB symptoms.

In this prospective study funded by the SUFU neuromodulation grant, twelve women with refractory OAB underwent fMRIs during bladder filling. Exclusion criteria included patients with neurogenic causes, pregnant or nursing patients, patients with claustrophobia, and patients who had a previously placed medical device or foreign body in which MRIs were contraindicated. 

At the start of the study, subjects completed the ICIQ-FLUTS questionnaire, assessing filling/storage symptoms, voiding symptoms, and incontinence symptoms. All patients then underwent blood-oxygen-level dependent (BOLD) fMRI brain imaging. During the fMRI study, subjects experienced multiple cycles of bladder filling via an infusion pump and were asked to signal their experience of urinary urgency by pressing a response button. Brain activity during urgency was compared to brain activity without urgency and was measured in brain regions known to be involved in the micturition cycle (anterior cingulate cortex (ACC), posterior cingulate cortex (PCC), insula, thalamus, frontal cortex, and pons). 

Median ICIQ-FLUTS storage, voiding, and incontinence subscale scores were 8.5 (IQR 4), 5 (IQR 3.5), and 10.5 (IQR 8), respectively, and the median bladder volume during urinary urgency was 112mL (IQR 85). Women with more severe baseline storage symptoms on the ICIQ-FLUTS had significantly greater increases in brain activity during urgency in the right and left ACC, as well as the right insula (p<0.05).  Women with more severe baseline incontinence were found to have less brain activity during urgency in the left ACC (p=0.04).

The authors concluded that brain activity during urgency appears to be correlated with the severity of OAB symptoms, given that there were greater increases in brain activity in the right ACC, left ACC, and right insula in patients reporting more severe filling/storage symptoms. The data from their study suggests that patients with more severe OAB may experience an even greater increase in afferent signaling. Future research is needed to investigate whether women with OAB and urgency incontinence have different brain activity patterns than those with OAB and no associated incontinence.

Presented by: Steven Weissbart, MD, Stony Brook University Hospital, Stony Brook, NY 

Co-Authors: Rupal Bhavsar, University of Pennsylvania, Philadelphia, PA, Alan Wein, MD, Phd (Hon), University of Pennsylvania, Philadelphia, PA , Lily Arya, MD, University of Pennsylvania, Philadelphia, PA, Ariana Smith, MD, University of Pennsylvania, Philadelphia, PA

Written by:  Judy Choi, MD, Assistant Professor, Department of Urology, University of California, Irvine @judymchoi at the 2018 AUA Annual Meeting - May 18 - 21, 2018 – San Francisco, CA USA