Treatment of detrusor-sphincter dyssynergia by pudendal nerve block in patients with spinal cord injury

Objective: To study the effects of pudendal nerve block with phenol on detrusor-sphincter dyssynergia in patients with spinal cord injury (SCI). Design: Before-after trial performed by using a consecutive sample. Setting: Rehabilitation hospital affiliated with a medical school. Patients: Twenty-two male SCI patients (mean age, 46.3±11.9y; mean duration postinjury, 2.7y) with voiding dysfunction resulting from external urethral sphincter hypertonicity. Intervention: Pudendal nerve block with 5% phenol solution under the guidance of electric stimulator. Main Outcome Measures: Outcomes were measured using (1) postvoid residual volume, maximal detrusor pressure, leak point pressure, bladder volume at the first uninhibited contraction, maximal bladder capacity, and urethral pressure profile; (2) rectoanal rest and squeeze pressures; and (3) quality of life measures for urination, quantified by the Quality of Life Index (QLI). Changes in bowel habit or autonomic dysreflexia were recorded. Results: The mean decrease in postvoid residual volume was 242.8mL (mean decrease, 66%) after treatment (P<.001). The mean reduction in leak point pressure and maximal detrusor pressure were 37.1cmH2O and 43.3cmH2O, respectively (P<.05). The mean QLI significantly improved from -.74±.38 to .42±.47 (P<.001). The rectoanal pressures showed no significant difference. No complaints of fecal incontinence or other complications were noted after treatment. Conclusion: Pudendal nerve block performed by using 5% phenol solution was safe, easy to perform, and effective as a treatment for detrusor-sphincter dyssynergia in selected patients with SCI.