Can the ice-water test predict the outcome of intradetrusor injections of botulinum toxin in patients with neurogenic bladder dysfunction?

The aim of this project was to evaluate the ice-water test as a predictor of the response to intradetrusor botulinum toxin injection in patients with neurogenic detrusor overactivity. We retrospectively evaluated the urodynamic parameters in 22 patients with neurogenic bladder dysfunction and positive ice-water test. Maximum cystometric capacity (MCC), reflex volume (RV), maximum detrusor pressure during voiding (MVP) and bladder compliance (BC) were compared before and after intradetrusor injection of 300 units botulinum toxin and calculated as a quotient. The ice-water test was performed before the injection, and the maximum pressure rise and the time to maximum pressure were measured. Furthermore, the ratio between maximum pressure and time to reach maximum pressure was calculated as the velocity of pressure rise. Correlations between the ice-water test criteria and the quotients of the cystometric data before and after injection were determined by the Spearmen's Rho coefficient. The increase in MCC and RV after botulinum toxin A injection showed a small positive, but insignificant correlation of 0.25 and 0.2 to the velocity of pressure rise of the ice-water test. A small negative, but insignificant correlation was found in change of BC and MVP with -0.17 and -0.2, respectively. Based on our population the ice-water test cannot predict the efficacy of intradetrusor botulinum toxin injections in patients with neurogenic detrusor overactivity.