Real-Time Changes in Brain Activity During Sacral Neuromodulation for Overactive Bladder: Beyond the Abstract

Sacral neuromodulation (SNM) is an effective treatment for refractory overactive bladder, as well as other lower urinary tract and gastrointestinal conditions. Its mechanism of action in treating overactive bladder has been hypothesized to involve altering neural activity in the sacral reflex arcs and influencing activity in brain structures related to voiding control. 

As this bothersome condition is suspected to result, in part, from aberrant signaling between the bladder and brain centers, it is felt that SNM helps restore normal communication between the two; similar to how noise-cancelling headphones enable music to be heard in a noisy environment. 

This study using functional magnetic resonance imaging (fMRI) is the first investigation to confirm in real-time that SNM influences brain activity. Furthermore, the changes in brain activity noted on fMRI occurred in structures known to be central to urinary function. When the SNM stimulus levels were adjusted from patients’ sensory thresholds to amplitudes above and below this level, the patterns of brain activity changes varied. In general, stronger stimuli led to activation of a number of brain regions, while sub-sensory stimuli was associated with a de-activation of important brain structures. 

Overall, this work confirms that SNM alters brain activity in women with overactive bladder who responded to the treatment. Further insight into both the condition and its treatment may be gained by further fMRI studies. 

Read the Abstract

Written By: Brad Gill MD, Javier Pizarro MD and Howard Goldman MD
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