To investigate the short-term effects of bipolar radiofrequency applied to sacral nerves to treat neurogenic detrusor overactivity in patients with spinal cord injury.

Ten patients with spinal cord injury with neurogenic detrusor overactivity were recruited. These subjects were randomized to two groups: intervention (n=5) and control (n=5), members of which received conventional treatment. Voiding diary, International Consultation on Incontinence Questionnaire (ICIQ) and the urinary incontinence quality of life scale (IQOL) data were obtained and an urodynamic study (UDS) was performed before and after intervention. In the intervention group, percutaneous bipolar continuous radiofrequency (CRF) was performed on both the S2 and S3 nerves in each patient.

In a comparison of daily frequency and number of urinary incontinence and ICIQ and IQOL scores at baseline and at 1 and 3 months after intervention, all variables achieved a significant effect for time (p<0.05). Regarding UDS parameters, pre/post intervention differences between baseline and 3-month post-intervention for volume at maximal detrusor pressure during filling and reflex detrusor volume at first contraction were significantly different between the two groups (p<0.05). However, pre/post intervention differences in maximum cystometric capacity and maximum detrusor pressure during filling were not significant between the two groups (p>0.05).

Percutaneous bipolar CRF applied to sacral nerves might be an effective therapy for neurogenic overactive bladder that reduces urinary incontinence and improves quality of life.

To evaluate the effect of semiconditional electrical stimulation of the pudendal nerve afferents for the neurogenic detrusor overactivity in patients with spinal cord injury. Forty patients (36 males, 4 males) with spinal cord injury who had urinary incontinence and frequency, as well as felt bladder contraction with bladder filling sense or autonomic dysreflexic symptom participated in this study.

Patients with neurogenic detrusor overactivity were subdivided into complete injury and incomplete injury groups by ASIA classification and subdivided into tetraplegia and paraplegia groups by neurologic level of injury. Bladder function, such as bladder volumes infused to the bladder until the first occurrence of neurogenic detrusor overactivity (V_ini) and the last contraction suppressed by electrical stimulation (V_max) was measured by water cystometry (CMG) and compared with the results of each subgroup.

Among the 40 subjects, 35 patients showed neurogenic detrusor overactivity in the CMG study. Among these 35 patients, detrusor overactivity was suppressed effectively by pudendal nerve afferent electrical stimulation in 32 patients. The infusion volume until the occurrence of the first reflex contraction (V_ini) was 99.4±80.3 ml. The volume of saline infused to the bladder until the last contraction suppressed by semiconditional pudendal nerve stimulation (V_max) was 274.3±93.2 ml, which was significantly greater than V_ini. In patients with good response to the pudendal nerve afferent stimulation, the bladder volume significantly increased by stimulation in all the patients.

In this study, semiconditional electrical stimulation on the dorsal penile afferent nerve could effectively inhibit neurogenic detrusor overactivity and increase bladder volume in patients with spinal cord injury.