Conditional neuromodulation of neurogenic detrusor overactivity using transrectal stimulation in patients with spinal cord injury: A proof of principle study.

AIMS: A proof of principle study of a novel wearable device to control neurogenic detrusor over-activity in eight male spinal cord injured subjects using conditional neuromodulation. METHODS: Transrectal stimulation was delivered through the device in response to simultaneously recorded external anal sphincter (EAS) contraction as a marker for neurogenic detrusor overactivity (NDO). The effect of conditional neuromodulation on bladder capacity and maximum detrusor pressure was investigated in addition to reliability of dyssynergic sphincter contraction as a marker for NDO. RESULTS: Conditional neuromodulation through the novel device showed a statistically significant increase in bladder capacity and reduction in maximum detrusor pressure in six male subjects with spinal cord injury (SCI). EAS activity was a reliable surrogate for detection of NDO. CONCLUSIONS: It has been shown for the first time that conditional neuromodulation can be delivered and triggered via a single biocompatible device placed in the anal canal. The pudendal nerves lying in Alcock's canal were stimulated through the wall of the anal canal, and the dyssynergic activity of the EAS was used to detect NDO and trigger neuromodulation giving significant increases in bladder capacity and reduction in detrusor pressure in six male subjects with SCI.

The interaction of cortico-spinal pathways and sacral sphincter reflexes in subjects with incomplete spinal cord injury: a pilot study.

AIMS: To reveal the effectiveness of corticospinal drive in facilitating the pudendal reflex in the anal sphincter muscle, as a surrogate marker for the urethral sphincter, in incomplete spinal cord injury (iSCI). METHODS: Three neurologically normal subjects and twenty-six subjects with incomplete, supra-sacral spinal cord injuries and symptoms of a neuropathic bladder were recruited. Incontinence was assessed using the International Consultation on Incontinence Modular Questionnaire (ICIQ). Electromyographic activity of the external anal sphincter was recorded. The pudendo-anal reflex (PAR) was elicited by electrical stimulation of the dorsal penile nerve (DPN). Motor cortical excitation was achieved using transcranial magnetic stimulation (TMS). RESULTS: Preliminary findings in normal and iSCI subjects showed facilitation of the PAR by prior TMS with an optimal interval of 20-40 msec. Of 23 iSCI subjects, 12 showed facilitation to TMS applied 30 msec before DPN stimulation. Eight of the 12, and a further five iSCI subjects, had an anal sphincter MEP in response to TMS alone. There was a weak tendency (r(2) = 0.22, P = 0.03) for those with higher ICIQ values to have larger PAR responses but no significant difference in ICIQ scores between those with (ICIQ = 4.9 ± 4.0 mean ± SD) and those without (ICIQ = 7.2 ± 4.7) cortical facilitation of the PAR. CONCLUSIONS: Cortical TMS was effective in facilitating the PAR in some iSCI subjects. The presence of cortical facilitation of the PAR was not related to the degree of urinary continence.

A new artificial urinary sphincter with conditional occlusion for stress urinary incontinence: preliminary clinical results.

OBJECTIVES: To perform a preliminary clinical investigation to determine the safety and efficacy of a novel artificial urinary sphincter (AUS) with conditional occlusion for the treatment of stress urinary incontinence. METHODS: Male patients with urodynamically proven stress urinary incontinence after a prostatectomy were implanted with the novel AUS. They were followed up over a period of 12 months and the device tested for efficacy by using objective measurements of urinary leakage and continence. We derived a new measure for continence called the Continence Index. RESULTS: We have demonstrated that the patients receiving the new AUS showed a reduction of greater than 10-fold in mean daily leakage volume from 770.6 ml to 55.1 ml. There was an overall improvement in the Continence Index from 54% to 97%. CONCLUSIONS: The new AUS with conditional occlusion provides good continence rates and enables adjustment of regulating pressure in situ.