Findings with Bilateral Sacral Neurostimulation: Sixty-two PNE-Tests in Patients with Neurogenic and Idiopathic...

We performed bilateral PNE (peripheral nerve evaluation) tests to identify which diagnostic groups are the most likely to profit from bilateral sacral neuromodulation since the results published so far have been obtained exclusively on the basis of unilateral sacral root stimulation. In contrast to the original unilateral technique, we performed bilateral PNE test stimulation in 62 patients (36 with urinary retention symptoms and 26 with overactive detrusor; 21 with idiopathic and 41 with neurogenic bladder dysfunction) over 3-4 days. We used an advanced electrode, model #3057 (Medtronic, Inc. Minneapolis, MN). The stimulation amplitudes were adjusted individually for each side. Retrospectively, we analyzed our data according to diagnostic characteristics (retention vs. overactive bladder and neurogenic vs. idiopathic) of those patients who had positive PNE test results. The PNE test was successful in 32 patients (51.6%). Of these, 27 suffered from neurogenic bladder dysfunction; in five cases the cause was idiopathic. We conclude that bilateral PNE test stimulation with side-specific amplitude adjustment and the use of advanced PNE electrodes led to a positive PNE result in 51.6% of the patients, which is a substantially increased response rate compared to previous studies. Of the diagnostics groups, the group with neurogenic bladder dysfunctions showed the highest response rate.