Pudendal Nerve Stimulation for Bowel Dysfunction in Complete Cauda Equina Syndrome

Objective: Pudendal nerve stimulation (PNS) aims to maximize afferent or efferent stimulation from the sacral plexus. Background: We hypothesized this may be a promising new treatment for patients with bowel dysfunction in complete cauda equina syndrome (CES). Methods: Thirteen patients with complete CES [8 constipation predominant (group 1) and 5 incontinence predominant (group 2)] had a 3-week trial of PNS. Patients who showed a 50% or more improvement in symptoms during the trial phase proceeded to permanent neurostimulator implantation. Results: Five (63%) of the 8 patients in group 1 showed a 50% or more improvement in bowel symptoms during the trial phase and were permanently implanted. The mean Cleveland Clinic constipation score, sense of incomplete evacuation (%), and straining during defecation (%) improved from 17 3.2 to 10 +/- 4.5, 94 +/- 18% to 30 +/- 35%, and 81 +/- 23% to 44 +/- 38%, respectively. All 5 patients in group 2 showed a 50% or more reduction in incontinent episodes during the trial phase. The mean St Mark's score, ability to defer defecation, and the number of incontinent episodes per week improved from 18 +/- 1.0 to 3.8 +/- 2.5, 2.2 +/- 1.8 to 11 +/- 5.5 minutes, and 9.4 +/- 10.7 to 0.4 +/- 0.5 episodes, respectively, per week. During a median follow-up of 12 (10-22) months of permanent implantation, one patient lost efficacy at 6 months due to lead migration and another required removal and reimplantation of the neurostimulator due to wound infection. Conclusions: PNS is an effective treatment in the short term for bowel dysfunction in some patients with complete CES.