Extracorporeal magnetic innervation (EXMI) therapy in the treatment of urinary incontinence in women: results from a single center.

Abstract

To the Editor: Daily urinary incontinence is a common problem affecting millions of (mostly) older women. Numerous surgical and nonsurgical treatments have been proposed, depending on the type of incontinence; all have varying success rates. Several nonsurgical methods of treatment such as behavior modification, pharmacotherapy, and certain devices1,2 have been proposed. Pelvic floor muscle exercises3,4 and focused electrical stimulation5 are characterized as techniques that improve the function of the muscle complex thought to be involved with urinary continence and have been shown to be helpful in treating incontinence. However, these methods may have features that make them unacceptable to some women. Strong pulsing magnetic fields depolarize neural elements located in the field, resulting in muscle contraction. Repetitive contraction of normal skeletal muscle over prolonged periods results in increased strength, endurance, and circulation. If symptoms of urinary incontinence are improved with pelvic floor strengthening, it may be that strong magnetic field therapy applied properly to the perineum will result in symptom improvement. Our center evaluated the safety and efficacy of extracorporeal innervation therapy (ExMI) in women with urinary incontinence. Some of the patients presented in our study also took part in a multicenter trial.6 To enroll, incontinent women underwent a complete history, physical, multichannel urodynamic evaluation, urethroscopy, cystoscopy, standardized provocative pad test, and a perineal strength test. A validated quality of life questionnaire and urinary flow volume chart were obtained. With the exception of cystourethroscopy, all tests were repeated for comparison after the study. Patients sat fully clothed in a specially designed padded chair connected to a freestanding power supply that generated a powerful magnetic field. The patients' perineum was positioned on the central axis of the pulsing magnetic field for treatment. High intensity currents were rapidly turned on and off through the discharge of capacitors, generating a powerful magnetic field. Depolarization of motor neurons within the magnetic field caused by the induced electric field resulted in the release of neurotransmitters at the motor endplate, provoking a muscle contraction. The study consisted of two sessions of active treatment per week for 6 weeks, with each session lasting 20 minutes. Sixty-three women enrolled and 58 completed the entire 6-week course. Fifty-seven (98%), 18 (31%), 10 (17%), and 9 (16%) subjects had genuine stress urinary incontinence, mixed incontinence, detrusor instability (DI), and intrinsic sphincteric deficiency, respectively. One patient had DI only. The mean age and body mass index were 53.2 ± 10.5 years and 26.9 ± 4.8, respectively. Forty-four (76%) of the women had cystoceles, six (10%) had a previous anterior repair, and four (7%) had a previous Marshall-Marchetti-Krantz procedure for incontinence. Twenty-one women (36%) had previously had a hysterectomy, and 31 (53%) were taking hormone replacement therapy. Pad weight testing, number of pads used daily, and documented leak during Valsalva urodynamic testing demonstrated significant improvements after the 6-week treatment (P < .05). Maximum pressure during perineal meter testing increased from 35 ± 22 to 39 ± 25 mm Hg (P = .05). There was no difference in the incidence of hypermobile urethra before or after treatment. At the 8-week follow-up, symptoms of incontinence had improved in 51 (88%) of patients. Eight of 53 (15%) reported they were not using pads at 8 weeks, with the mean number of pads used per day decreased from 3.04 ± 1.3 to 1.83 ± 1.6 (mean decrease of 1.21 P < .05). At 12 and 24 weeks, 29 of 53 (55%) and 18 of 35 (51%), respectively, reported they were still satisfied with the results of their treatment. Before treatment, the mean quality of life score was 49; after all 12 treatments, the mean quality of life score rose to 70 (P < .001). This study evaluates a new nonsurgical method of treating urinary incontinence in women. The results of this study suggest there are definite objective and subjective benefits to this method of muscle strengthening when treating a group of incontinent women. Urinary incontinence is associated with loss of independence and quality of life. It is also an important cause of nursing home admissions, and many of these patients are not surgical candidates and must rely on absorbent pads or other devices to control their incontinence. Since there is absolutely no patient effort needed to participate in these treatments, the older incontinent woman may be an ideal candidate for treatment with this device.