TRANSCUTANEOUS ELECTRICAL NERVE-STIMULATION AND TEMPORARY S3 NEUROMODULATION IN IDIOPATHIC DETRUSOR INSTABILITY

Purpose: We studied the effects of electrical stimulation on idiopathi c detrusor instability. Materials and Methods: Between January 1993 an d December 1994, 30 men and 41 women (mean age plus or minus standard deviation 48 +/- 16 years) underwent transcutaneous electrical nerve s timulation (TENS) of the S2-S3 dermatomes, and 13 men and 22 women (me an age 48 +/- 12 years) underwent S3 neuromodulation. Subjective asses sment was performed using a diary and symptom score of 0 to 14. Object ive outcome was analyzed with urodynamic studies. Results: Mean durati on of TENS was 3 +/- 1 weeks (range 2 to 4). Although there were no ma jor complications 31% of the patients reported local skin irritation. The overall urinary symptom scores improved from 10 +/- 2 (range 5 to 14) before the study to 7 +/- 3 (range 1 to 14) during stimulation. Ur odynamic analysis revealed significant (p < 0.05) improvements in tota l bladder capacity and voided volume, and decreases in the number and frequency of unstable contractions. Mean duration of S3 neuromodulatio n was 6 +/- 1 days (range 4 to 8 days). Four procedures failed due to electrode displacement in 3 cases and procedure intolerance in 1. Hemo rrhage from the puncture site occurred in 1 patient. Overall urinary s ymptom scores were 10 +/- 3 (range 5 to 14) before the study and 5 +/- 2 (range 2 to 10) during stimulation. Although symptomatic relief was more pronounced with S3 neuromodulation, no statistically significant differences were found regarding urinary symptoms compared to TENS. C onclusions: In patients with severe detrusor instability refractory to conservative treatments the use of TENS and S3 neuromodulation produc ed significant changes in urodynamic parameters and presenting symptom s. Our results appear to justify evaluation with neuromodulatory techn iques before definitive surgical intervention in these patients.