Is there a place for pudendal nerve maximal electrical stimulation for the treatment of detrusor hyperreflexia in spinal cord injury patients?

Abstract

The aim of the study is to determine whether pudendal nerve maximal electrical stimulation (MES) could represent an alternative treatment for detrusor hyperreflexia in spinal cord injury (SCI) patients. Six suprasacral SCI patients participated in the study. The treatment consisted of daily stimulation periods of 20 min, repeated five times a week, during 4 weeks, with continuous electrical stimulation of the penis or of the clitoris via bipolar surface electrodes (rectangular stimuli of 0.5 ms pulse duration, 5 Hz frequency), with the maximum tolerable stimulation strength (under the level of pain). In two patients, additional stimulation was administrated by means of an anal plug during the last 2 weeks. The stimulus strengths ranged from 35 to 99 mA (mean 54 mA). One patient stopped MES after 2 weeks. At the end of the treatment, neither the cystometric bladder capacities (153 ml vs 157 ml) nor the micturition charts had significantly improved for the five remaining patients. Only two patients experienced non lasting improvement of nocturia at some time of the treatment. In conclusion, we were not able to demonstrate the efficacy of MES in inhibiting detrusor hyperreflexia in SCI patients. To reach therapeutic effects, other parameters may be needed, such as higher stimulation strengths (currents above or equal to 99 mA) or other currents (such as interferential therapy). Chronic stimulation with external or implanted electrodes using lower currents may represent an alternative.