# Motor cortical neuromodulation in women with Interstitial Cystitis/Bladder Pain Syndrome: reducing pain by improving brain and muscle activity

> **NIH NIH R01** · UNIVERSITY OF SOUTHERN CALIFORNIA · 2020 · $363,000

## Abstract

PROJECT SUMMARY
Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS) is a common, chronic, and debilitating condition in women.
The underlying cause of IC/BPS remains unknown. We recently published the first functional magnetic
resonance imaging (fMRI) study comparing brain function in women with IC/BPS to healthy women. We found
that women with IC/BPS have altered resting activity in supplementary motor area (SMA). Specifically, these
changes appear in a part of SMA that we have shown to control pelvic floor muscle activity (“pelvic-SMA”). Our
results provide the first explanation for extensive published reports of increased pelvic floor muscle activity in
women with IC/BPS. We hypothesize that we are observing evidence of an important theory of chronic pain:
motor cortical changes occur that are initially beneficial to increase protective muscle activity but are ultimately
maladaptive and perpetuate pain. Our goal is to reduce pain by improving brain activity and pelvic muscle
activity (making them more similar to healthy individuals). Using non-invasive repetitive transcranial magnetic
stimulation (rTMS) directed at pelvic-SMA, we aim to determine if we can reduce pain (Aim 1), improve resting
brain activity (fMRI) and resting pelvic floor muscle electromyographic (EMG) activity in IC/BPS (Aim 2), and to
link the pain reductions to fMRI/EMG improvements to develop a causal mediation model of IC/BPS symptoms
(Aim 3). We will recruit 75 women with IC/BPS to participate in the study, and participants will be randomized
to 3 groups of 25 to test different rTMS paradigms: high-frequency (to increase excitability), low-frequency (to
decrease excitability), and sham (as a control). Our preliminary data suggest that high-frequency stimulation is
the best protocol since it improves resting pelvic-SMA activity while reducing pain and pelvic muscle activity.
These results are convergent with an independently-published preliminary study that suggests that 5
consecutive days of high-frequency stimulation can reduce IC/BPS pain relative to sham, even measured 3
weeks after the cessation of stimulation. We will extend these preliminary findings in the proposed work: in the
high-frequency and sham rTMS groups, we will study 5 consecutive days of stimulation with both shorter-term
outcome measures (associated with the first day of stimulation) and longer-term outcome measures (3 weeks
after the cessation of stimulation). In the low-frequency rTMS group, we will only examine shorter-term
outcome measures associated with a single session, since our preliminary data suggest that low-frequency
stimulation is active but perturbs pelvic-SMA and resting pelvic floor muscle activity away from values
associated with healthy controls and does not reduce pain. Our preliminary results agree with a large body of
literature suggesting that high-frequency rTMS applied to motor cortex is the best rTMS paradigm to reduce
pain. However, our proposed work has the potential to gr...

## Key facts

- **NIH application ID:** 10049147
- **Project number:** 1R01DK121724-01A1
- **Recipient organization:** UNIVERSITY OF SOUTHERN CALIFORNIA
- **Principal Investigator:** Jason J. Kutch
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $363,000
- **Award type:** 1
- **Project period:** 2020-08-15 → 2025-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10049147

## Citation

> US National Institutes of Health, RePORTER application 10049147, Motor cortical neuromodulation in women with Interstitial Cystitis/Bladder Pain Syndrome: reducing pain by improving brain and muscle activity (1R01DK121724-01A1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10049147. Licensed CC0.

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