This study investigates the role of autonomic parameters, specifically skin sympathetic nerve activity (SKNA), as potential biomarkers for differentiating between patients with Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS) with Hunner lesions and those without, utilizing our novel non-invasive neuECG method, and to investigate their implications for clinical management.

In this prospective study, we enrolled new patients diagnosed with IC/BPS who were scheduled for cystoscopic hydrodistension. Autonomic function was evaluated in the morning before the hydrodistension using neuECG, a technique that simultaneously analyzes SKNA and heart rate variability (HRV). Additionally, bladder diary entries and findings from the hydrodistension were documented.

A total of 10 patients with Hunner lesions and 43 patients without Hunner lesions were analyzed. As shown in Figure 1, patients with Hunner lesions exhibited significantly decreased maximal voiding volume (based on patients' voiding diaries) and bladder capacity under hydrodistension. The baseline SKNA was notably higher in patients with Hunner lesions (p<0.001), as well as during the recovery phase (p<0.001). Furthermore, 80% of patients with Hunner lesions demonstrated altered skin sympathetic responses compared to 35% of those without Hunner lesions (p<0.001). In terms of HRV, the root mean square of the successive differences (RMSSD) during stress was significantly higher in the Hunner group (p=0.034).

Our findings indicate that significantly higher SKNA levels are present in patients with Hunner lesions compared to those without. Moreover, IC/BPS patients with Hunner lesions show a greater prevalence of altered skin sympathetic responses. This study highlights the potential role of autonomic parameters as biomarkers for differentiating between IC/BPS patients with and without Hunner lesions and aids in understanding the underlying mechanisms of the disease.