Repeated ice water tests and electrical perception threshold determination to detect a neurologic cause of detrusor overactivity

OBJECTIVES To explore the added value of a repeated ice water test (IWT) and electrical perception threshold (EPT) measurement in the search for a neurologic cause of idiopathic detrusor overactivity (DOA). METHODS The IWT, if originally negative, was repeated up to three times, and EPT measurements were done in 63 patients with neurologic DOA, 117 patients with idiopathic DOA without outflow obstruction, and 30 women with stress urinary incontinence without DOA. RESULTS Although the IWT was positive in 46% of the neurologic patients if used once, this percentage became 86% when the IWT was repeated. In nonneurologic patients, one IWT was positive in only 7% and when repeated, the positive test rate increased to 24 %. IWT, even repeated, remained negative in the women with stress urinary incontinence. The EPTs were not significantly different between the neurologic and nonneurologic patients with a positive IWT, except after the third instillation. In those with negative IWTs, the EPTs were significantly different between the neurologic and nonneurologic patients, independent of the number of IWTs done. If the EPTs were compared within each group between those with positive and negative IWTs, the difference was not significant at the first IWT. However, the difference became statistically significant after two IWTs for the nonneurologic group and after three IWTs for both groups. CONCLUSIONS Our results have shown that repeating the IWT will increase its positivity. Combining the IWT and EPT will reinforce the results of both tests and can indicate more clearly the possibility of an unsuspected neurologic pathologic finding in patients with idiopathic DOA.