Transdermal posterior tibial nerve laser therapy is not effective in women with interstitial cystitis

Interstitial cystitis (IC) is a debilitating condition which causes irritative bladder symptoms, pain and a decrease in health status. The pathophysiology is poorly understood so therapeutic options are diverse. Percutaneous posterior tibial nerve stimulation is an effective treatment and pulsed transdermal laser stimulation is an established technique for pain management. We evaluated the efficacy of transdermal laser stimulation of the posterior tibial nerve for patients with IC.

Women meeting the National Institutes of Health National Institute for Diabetes and Digestive and Kidney Diseases criteria for IC were prospectively recruited and randomized to treatment (29) or placebo (27) cohorts in a double-blind trial. At home the patient performed laser therapy daily for 30 seconds over the SP6 acupuncture point for 12 weeks. Measures at baseline and at 84-day followup included the 7-day voiding diary, the Interstitial Cystitis Problem Index, Interstitial Cystitis Symptom Index and RAND 36-Item Health Survey questionnaires.

There were no significant differences between the treatment and control cohorts on any of the measures. However, there was a significant decrease between baseline and 12-week followup in the amount voided, symptom problems and severity, and on all 8 SF-36 scales. There was no significant effect of fluid intake.

This study demonstrated no difference between the active and sham device. However, it is interesting that treatment and control cohorts experienced similar improvements, suggesting that the control cohort improvements may have been due to participants' belief that they were receiving active treatment from the stimulator. These findings provide support for investigating placebo effects in randomized trials.