Treatment of Neurogenic Detrusor Overactivity: Early Versus Late Pudendal Nerve Stimulation in Spinal Cord Injury (SCI) Patients

Background: Although a small group, special attention has to be given to lower urinary tract (LUT) dysfunctions in spinal cord injury (SCI) patients, as they also suffer under a loss of motor-sensory function and autonomic regulation next to the severe deficiencies in bladder and bowel control. Autonomic dysregulation linked with LUT dysfunction can cause autonomic dysreflexia with life threatening increases in blood pressure and there is still no concept for an early rehabilitation of bladder function after SCI. Hypothesis: We assume that inadequate reorganization of nerve fibres in SCI is a reason for spastic bladder dysfunction and vegetative dysregulation and that this can be positively influenced by early neuromodulation. We hypothesized that bladder dysfunction as well as autonomic dysreflexia will be positively affected. Specific aims: Evaluation, if external pudendal nerve stimulation (EPS) can positively influence LUT rehabilitation in SCI patients and if early initiation of stimulation is more effective compared to late initiation (after spinal shock). Experimental design: Prospective multicentre study in 36 SCI patients (24 treatment subjects, 12 control subjects). EPS will be started either within 10 days after SCI (early stim group) or after cessation of spinal shock (late stim group). Effects on spastic bladder function and autonomic disinhibition will be assessed by urodynamics, vegetative tests, and by electrophysiological techniques. Expected value: If early EPS is effective and complete SCI patients benefit from this intervention; and if early onset of EPS has better and longer lasting effects than late onset stimulation, the findings will be of utmost relevance not only for bladder function but also to alleviate adverse phenomena such as autonomic dysreflexia. Neurostimulation may bear the opportunity to early reshape maladaptive neuroplasticity. This would be proof of an effective modulation and promotion of neuroplasticity, thus opening up n