Portable sacral magnetic stimulator shows no benefit in OAB

September 1, 2005

Trans-sacral magnetic stimulation using a portable device yielded no discernable benefits over a sham device in patients with overactive bladder in a study presented here yesterday. It remains unclear, said the authors, whether this failure is due to the particular manner in which the device delivered the magnetic field or whether magnetic stimulation in general is simply an ineffective treatment for this condition.

Trans-sacral magnetic stimulation using a portable device yielded no discernable benefits over a sham device in patients with overactive bladder in a study presented here yesterday. It remains unclear, said the authors, whether this failure is due to the particular manner in which the device delivered the magnetic field or whether magnetic stimulation in general is simply an ineffective treatment for this condition.

Encouraged by positive results with transcutaneous electrical nerve stimulation and implantable sacral neuromodulators, the researchers investigated whether they could achieve similar efficacy with a portable electromagnetic device that stimulates the S3 and S4 sacral nerve roots, said co-author Chahin Achtari, MD, a urogynecologist at Centre Hospitalier Universitaire Vaudois in Lausanne, Switzerland, who was a fellow at the Mercy Hospital for Women in Melbourne, Australia during his involvement in the study.

Sixty-three patients with OAB were randomized to treatment with the portable trans-sacral magnetic stimulation device or a placebo consisting of a sham device. Patients were instructed to use the device at home for 20 minutes daily over 12 weeks. Outcome measures included a 3-day voiding diary, 1-hour pad test, visual analog score for symptom impact, the King's Health Questionnaire, and the Australian Quality of Life Questionnaire.

Outcomes measured at 6 and 12 weeks revealed no difference between the two groups on any of the outcome parameters. There was no difference between the active and sham groups with respect to frequency, nocturia, or quality of life.

"We are going to analyze the results further," Dr. Achtari told Urology Times. "However, I don't think we are going to find any significant results based on what we can see now. There were some small [statistically insignificant] differences, and the next step would be to do a randomized, controlled trial on these small differences, but then you would probably need 500 patients to show that there is a small difference."