Cortical Brain Acute Neuroexcitation with Sacral Neuromodulation

Friday, October 25, 2024

9:55 AM – 10:05 AM EDT

Location: Liberty Ballroom (Meeting Level 4)

Figure 1. Averaged fNIRS signals by Brain Region comparing Sacral Neuromodulation device Deactivation (top) and Activation (bottom)

Figure 2. Averaged fNIRS signals in control regions with similar sensation of bladder fullness by brain region comparing one-minute segments.

Objectives: Sacral neuromodulation (SNM) has a proposed mechanism involving the afferent bladder nerve signals. fMRI studies have illustrated the PFC as a region involved in urgency and incontinence symptomatology which receives these afferent signals as part of its role in the decision to void. Functional near infrared spectroscopy (fNIRS) in a non-invasive technique for measuring cortical brain neuroexcitation. The objective of this study was to determine if fNIRS could detect differences in PFC neuroexcitation due to acute changes in SNM (On/Off) during natural bladder filling.

Methods: Female participants with medication-refractory urge urinary incontinence (UI) who had SNM implanted for at least 6 months underwent a two-fill natural hydration protocol and reported bladder sensation (0-100%) throughout using a Sensation Meter. During filling, continuous oxygenated hemoglobin concentration (O2Hb) was recorded. During the first fill, the SNM device was left On at baseline programming. During the second fill, the SNM devices were acutely changed from On-to-Off and Off-to-On in three minute cycles: prior to “first sensation,” after “first sensation,” and after “strong desire” as tolerated. The 24-channel fNIRS device targeted the PFC and channels were divided into brain regions: right (9), middle (6) and left (9). Signal processing for fNIRS included motion artifact removal, splicing, off-set correction, and low pass filtering. One-minute segments of O2Hb signals before and after acute modulation (On-Off) were selected and linear fit used to output slope. 2-minute control periods from the first fill were selected at a similar level of bladder sensation of fullness (0-100%) for comparison. Demographic characteristics and patient UI symptoms were collected using validated questionnaires (ICIq-OAB).

Results: Ten women (mean age: 58.415.1 years) completed the study. Median time from SNM implant was 17 [6.5,46] months and mean total ICIq-OAB score was 103.2. In all PFC brain regions, for the majority of cycles (70%), there was an alteration from baseline change in mean O2Hb over time (delta slope >0.5) with SNM device activation (Off-to-On), Figure 1 (Green to Red lines). This was contrary to deactivation of device (On-to-Off, Red to Green lines) where the majority of regions showed continuation of O2Hb signal pattern or rate of O2Hb change over time, Figure 1. The control segments showed stability of averaged O2Hb signal at similar sensation in all brain regions, Figure 2.

Conclusions: Acute changes in neuroexcitation of the prefrontal cortex can be identified with SNM device activation in female patients with UI using fNIRS. There is likely a persistent effect of the SNM stimulation when SNM is transitioned Off beyond the one-minute analysis period, requiring further investigation. These acute changes suggest SNM affects the PFC in the decision to void. This study shows that fNIRS methodology can potentially be used to objectively optimize SNM treatment efficacy.

Disclosure(s):

Linda Burkett, MD MSc: No financial relationships to disclose

Alice Strawn: No financial relationships to disclose

Mina Philipe Ghatas, Msc: No financial relationships to disclose

Luc Mortemousque: No financial relationships to disclose

Justin Dare: No financial relationships to disclose

Ryan W. Fogg, MD: No financial relationships to disclose

Brandon C. Wilson, MD: No financial relationships to disclose

Lynn Stothers, MD: No financial relationships to disclose

Adam P. Klausner, MD: BrightUro: Consultant/Advisory Board (Ongoing); VesiCorp: Stock-privately held company (Ongoing)

John E. Speich, PhD: No relevant disclosure to display

Presenting Author(s)

Linda Burkett, MD MSc (she/her/hers)

Assistant Professor
Virginia Commonwealth University
Richmond, Virginia, United States

Disclosure(s): No financial relationships to disclose

Co-Author(s)

Alice Strawn

Research Assistant
VCU
Richmond, Virginia, United States

Disclosure(s): No financial relationships to disclose
MG

Mina Philipe Ghatas, Msc

Research Engineer
Virginia Common Wealth University
Richmond, Virginia, United States

Disclosure(s): No financial relationships to disclose
LM

Luc Mortemousque (he/him/his)

Student
Virginia Commonwealth University School of Medicine
Richmond, Virginia, United States

Disclosure(s): No financial relationships to disclose
JD

Justin Dare (he/him/his)

Student
Virginia Commonwealth University School of Medicine
Fairfax Station, Virginia, United States

Disclosure(s): No financial relationships to disclose
RF

Ryan W. Fogg, MD

Resident Physician - Urology
Virginia Commonwealth University Health System
Richmond, Virginia, United States

Disclosure(s): No financial relationships to disclose
BW

Brandon C. Wilson, MD (he/him/his)

Urology Resident
Virginia Commonwealth University School of Medicine
Richmond, Virginia, United States

Disclosure(s): No financial relationships to disclose
LS

Lynn Stothers, MD

Professor of Urology
University of California Los Angeles
Los Angeles, California, United States

Disclosure(s): No financial relationships to disclose
AK

Adam P. Klausner, MD

Professor of Urology
Virginia Commonwealth University School of Medicine
Richmond, Virginia, United States

Disclosure(s): BrightUro: Consultant/Advisory Board (Ongoing); VesiCorp: Stock-privately held company (Ongoing)
JS

John E. Speich, PhD

Professor and Interim Chair
Virginia Commonwealth University
Richmond, Virginia, United States

Disclosure(s): No relevant disclosure to display