Intravesical Electrical Stimulation Improves Abnormal Prefrontal Brain Activity in Patients With Underactive Bladder: A Possible Central Mechanism.

Purpose: The aim of this study was to explore the mechanisms of central brain action in patients with neurogenic underactive bladder (UAB) treated with intravesical electrical stimulation (IVES).

Methods: We prospectively recruited patients with neurogenic UAB who chose to receive IVES treatment and healthy subjects (HS). At baseline, the following data were obtained: a 72-hour voiding diary; measurements of postvoid residual urine (PVR), voiding efficiency (VE) and first sensation of bladder filling (FS); American Urological Association Symptom Index Quality of Life (AUA-SI-QOL) scores, and functional near-infrared spectroscopy scans of the prefrontal cortex in the voiding stage. All UAB patients were re-evaluated for these indices after completing 4 weeks of IVES. A >50% improvement in PVR was defined as successful IVES treatment. Prefrontal activity was analyzed using the NIRS_KIT software, corrected with the false discovery rate (P<0.05). Statistical analysis was performed using IBM SPSS Statistics ver. 22.0, and P<0.05 was considered statistically significant.

Results: Eighteen UAB patients and 16 HS were included. IVES treatment was successful in 11 UAB patients and failed in 7. The PVR, VE, 24-hour clean intermittent catheterization, FS volume, and AUA-SI-QOL scores of the UAB group significantly improved after successful IVES treatment. BA9 (right dorsolateral prefrontal cortex [DLPFC]) and BA10 (right frontal pole) were significantly activated after successful IVES, and no significant difference was found between the successful group and HS group after IVES. Before IVES, BA10 (right frontal pole) was significantly deactivated in the failed group compared with the successful group.

Conclusion: The possible central mechanism of IVES treatment for neurogenic UAB is that IVES reactivates the right DLPFC and right frontal pole.