Does Muscle Pain Induce Alterations in the Pelvic Floor Motor Unit Activity Properties in Interstitial Cystitis/Bladder Pain Syndrome? A High-Density sEMG-Based Study

Several studies have shown interstitial cystitis/bladder pain syndrome (IC/BPS), a chronic condition that poses challenges in both diagnosis and treatment, is associated with painful pelvic floor muscles (PFM) and altered neural drive to these muscles. However, its pathophysiology could also involve other alterations in the electrical activity of PFM motor units (MUs). Studying these alterations could provide novel insights into IC/BPS and help its clinical management. This study aimed to characterize PFM activity at the MU level in women with IC/BPS and pelvic floor myalgia using high-density surface electromyography (HD-sEMG). Signals were recorded from 15 patients and 15 healthy controls and decomposed into MU action potential (MUAP) spike trains. MUAP amplitude, firing rate, and magnitude-squared coherence between spike trains were compared across groups. Results showed that MUAPs had significantly lower amplitudes during contractions on the patients’ left PFM, and delta-band coherence was significantly higher at rest on their right PFM compared to controls. These findings suggest altered PFM tissue and neuromuscular control in women with IC/BPS and pelvic floor myalgia. Our results demonstrate that HD-sEMG can provide novel insights into IC/BPS-related PFM dysfunction and biomarkers that help identify subgroups of IC/BPS patients, which may aid their diagnosis and treatment.

Monica Albaladejo-Belmonte,1 Michael Houston,2 Nicholas Dias,2 Theresa Spitznagle,3 Henry Lai,4 Yingchun Zhang,2,5,6,7 and Javier Garcia-Casado,1

  1. Centro de Investigación e Innovación en Bioingeniería (CI2B), Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain
  2. Department of Biomedical Engineering, University of Houston, Houston, TX 77204, USA
  3. Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO 63108, USA
  4. Division of Urologic Surgery, Departments of Surgery and Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA
  5. Department of Biomedical Engineering, University of Miami, Coral Gables, FL 33146, USA
  6. Desai Sethi Urology Institute, University of Miami, 1120 NW 14th Street, Miami, FL 33136, USA
  7. Miami Project to Cure Paralysis, University of Miami, 1095 NW 14th Terrace #48, Miami, FL 33136, USA
Source: Albaladejo-Belmonte M., Houston M., Dias N. et al. Does Muscle Pain Induce Alterations in the Pelvic Floor Motor Unit Activity Properties in Interstitial Cystitis/Bladder Pain Syndrome? A High-Density sEMG-Based Study. Sensors 2024, 24(23), 7417; https://doi.org/10.3390/s24237417.