(058) Acute Dorsal Genital Neuromodulation can Improve Subjective Arousal: A Pilot Study in Women With and Without Spinal Cord Injury
Authors: Bottorff E , Lane G , Moore M , Maymi-castrodad P , Rodriguez G , Gupta P , Bruns T 
Published: May 2023

Abstract

Introduction
Female sexual dysfunction (FSD) is a potentially life altering condition that impacts an estimated 40% of women. Unfortunately, the few treatment options available have limited success due to adverse events and an inability to improve subjective arousal. One potential treatment option, neuromodulation, has improved female sexual function index (FSFI) scores in small studies. The underlying mechanisms of how neuromodulation may improve FSD are not understood. We hypothesize that neuromodulation provides benefits by increasing genital blood flow.

Objective
Our primary objective is to determine if a single period of dorsal genital nerve stimulation (DGNS) or tibial nerve stimulation (TNS) directly causes a change in vaginal blood flow (VBF). Our secondary objective is to assess if subjective arousal increases during a single period of DGNS or TNS. These interventions will be compared among three cohorts of women: women with C6–T10 spinal cord injury (SCI), women with FSD (FSFI lubrication sub-score &lt; 4), and able-bodied women without FSD.

Methods
Participants attended two separate visits, one for each nerve target, randomly ordered and separated by 1–5 months. We are testing two experimental paradigms: without and with erotic audio-visual materials. The first experiments measured vaginal pulse amplitude (VPA) using a vaginal photoplethysmography transducer (VPP) before, during, and after 20 minutes of nerve stimulation. After data processing, we calculated average peak to peak (p2p) amplitudes for each time period and performed an ANOVA and post-hoc pairwise comparisons within each participant. For the second experiment we measured VPA during neutral and erotic videos both without stimulation and with stimulation. In both experiments we measured subjective arousal via a Likert-type scale at 4 timepoints and made comparisons across participants with a paired t-test. The first experiments are complete and data collection for the second experiments is ongoing.

Results
We recruited three participants in each cohort in the first experiments, with five participants completing both sessions. All participants saw significant changes in their p2p amplitude from before stimulation to after stimulation in DGNS trials (n = 3 increased, n = 4 decreased). Three of five participants had significant p2p increases in TNS trials and one participant had significant decreases. DGNS subject arousal scores increased significantly after stimulation, but TNS scores did not (Figure 1). Most participants reported genital sensations during DGNS (7 of 8) and TNS (3 of 6) sessions. Three participants have completed both visits in the second set of experiments, with similar trends.

Conclusions
Acute DGNS, but not TNS, increased subjective arousal across all participants. VPA responses to stimulation were heterogeneous and although most changes were significant, there may not be physiological or clinical relevance. It is possible that repeated stimulation sessions over time may enhance changes in VPA.

Disclosure
No