Sacral nerve stimulation reduces elevated urinary nerve growth factor levels in women with symptomatic detrusor overactivity.

OBJECTIVES:To investigate changes in urinary nerve growth factor (uNGF) in women with symptomatic detrusor overactivity (DO) following peripheral nerve evaluation (PNE) for sacral neuromodulation vs controls. STUDY DESIGN:There were 23 subjects with overactive bladder symptoms and DO who failed management with anticholinergics and 22 controls consented to participate in this prospective pilot study. Urine specimens were collected from controls at baseline for evaluation of uNGF and creatinine. Subjects were evaluated at baseline and 5 days after a trial of sacral nerve stimulation referred to as a PNE. Each visit included urine collection for uNGF and, Incontinence Quality of Life Questionnaire, Urinary Distress Inventory Questionnaire, postvoid residual volume, and a 3-day voiding diary. uNGF levels were measured by enzyme-linked immunosorbent assay and expressed as uNGF pg/creatinine mg. RESULTS:Subjects with DO had significantly higher baseline uNGF levels (corrected for creatinine) compared with controls (19.82 pg/mg vs 7.88 pg/mg, P < .002). Seventeen DO subjects underwent PNE and were evaluated at the end of the testing period. There was a significant improvement in quality of life scores for subjects after PNE compared with baseline (Urinary Distress Inventory Questionnaire: 7.0 vs 13.7, P < .001; Incontinence Quality of Life Questionnaire: 87.3 vs 52.8, P < .0001). Concordantly, uNGF levels significantly decreased from 17.23 pg/mg to 9.24 pg/mg (P < .02) after PNE. CONCLUSION:uNGF levels decrease with symptomatic response in DO subjects undergoing PNE. DO subjects had significantly higher uNGF at baseline vs controls, and uNGF levels significantly decreased after only 5 days of sacral nerve stimulation. These findings support a larger study to validate the use of uNGF as an objective tool to assess therapeutic outcome in patients undergoing PNE for sacral neuromodulation.