To determine if women with overactive bladder (OAB) requiring 3rd line therapy demonstrate greater central sensitization, indexed by temporal summation to heat pain stimuli, than those with OAB.
We recruited 39 adult women with OAB from the Urology clinic who were planning to undergo interventional therapy for medication refractory OAB with either onabotulinumtoxinA bladder injection or sacral neuromodulation and 55 women with OAB, either newly seen in our Urology clinic or responding to advertisements for study participation. Participants underwent quantitative sensory testing using a thermal temporal summation protocol. The primary study outcome was the degree of temporal summation, as reflected in the magnitude of positive slope of the line fitted to the series of 10 stimuli at a 49°C target temperature. We compared the degree of temporal summation between study groups using linear regression.
Women in the group undergoing 3rd line therapy demonstrated significantly higher standardized temporal summation slopes compared to those in the nontreatment group (beta = 1.57, 95% confidence interval = .18 - 2.96, t = 2.25, p = .027). On exploratory analyses, a history of incontinence surgery or hysterectomy were factors associated with significantly greater temporal summation.
In this study, the degree of temporal summation was elevated in women undergoing 3rd line OAB therapy compared to women with OAB not undergoing 3rd line therapy. These findings suggest there may be pathophysiologic differences, specifically in afferent nerve function and processing, in some women with OAB.
The Journal of urology. 2018 May 07 [Epub ahead of print]
W Stuart Reynolds, Casey Kowalik, Joshua Cohn, Melissa Kaufman, Alan Wein, Roger Dmochowski, Stephen Bruehl
Department of Urologic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee. Electronic address: ., Department of Urologic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee., Department of Urology, Einstein Healthcare Network, Pennsylvania., Division of Urology, Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania., Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, Tennessee.