**5. Therapeutic effect of magnetic therapy**

#### **5.1 Effect on urinary incontinence**

Urinary incontinence (UI) is a common urinary disease and is usually defined as involuntary urine leakage due to weakening of the urethral sphincter and pelvic floor muscles without the need for urination [5]. According to the International Continence Association (ICS), urinary incontinence affects more than 200 million people worldwide, primarily women. Half of women may not report UI, perhaps because of embarrassment, lack of knowledge about treatments, and the belief that UI is normal with age. Urinary incontinence can be divided into (i) stress incontinence (ii) urge incontinence (iii) mixed incontinence, which is a combination of the two types. Stress urinary incontinence accounts for 29–75% of women, urge incontinence accounts for 7–33% of the population, and mixed urinary incontinence accounts for 14–61% of the population. Men may also develop urinary incontinence due to urethral sphincter deficiency after radical prostatectomy, adversely affecting the patient's quality of life [6]. Controlling urinary incontinence is also an important issue for extending healthy life expectancy. It is known that the prevalence of urinary incontinence increases with age in the elderly. A large database analysis in Northern California found that the risk of admission to a long-term care facility after diagnosis of urinary incontinence was twice as high for women and 3.2 times for men, and increased the risk of hospitalization [7].

Various research reports have been published on the therapeutic effect of magnetic stimulation on stress urinary incontinence (SUI). In a randomized, double-blind, sham controlled trial of 120 female patients with SUI, the treatment group received magnetic stimulation twice a week for a total of 16 times over a two-month period. When the primary endpoint is a decrease in the score of ICIQ-UI SF (International Consultation on Incontinence Questionnaire for Urinary Incontinence-Short Form) by 5 points as the therapeutic response, the therapeutic response in the magnetic therapy group is 3.46 times that in the placebo group. The total score of ICIQ-UI SF decreased significantly. There was also a consistent significant improvement in score between 1 and 2 months, indicating that 8-week PMS was more effective than 4-week. An additional year of follow-up suggested that the effect was long-lasting [8]. In a pilot study comparing 52 randomized patients with SUI, the treatment group showed lower myostatin levels and improved UI severity ratings (The Revised Urinary Incontinence Scale) and depression severity (Beck Depression Inventory) before and after treatment [9]. In a randomized, sham-controlled trial of 30 female SUI patients resistant to pelvic floor muscle training, magnetic stimulation significantly improved ICIQ-SF and the abdominal leak point pressure (ALPP) in the treatment group compared to baseline, with significant differences between groups (P < 0.05). In addition, self-efficacy beliefs (GSES) improved in the magnetic therapy group, and the authors reported that there were effects of magnetic therapy on both physical and psychosocial aspects [10]. In a randomized controlled trial of three groups of women with SUI: a pelvic floor muscle training and extracorporeal magnetic therapy group and a control group, the two treatment groups showed a decrease in depressive symptoms (BDI-II) and significant improvements in an improvement in urinary incontinence severity (RUIS) and several quality of life items (KHQ). Moreover, GSES improved in the extracorporeal magnetic therapy group [11]. A study was also conducted to evaluate the effect of sacral magnetic stimulation (SMS) on functional and urodynamic improvement in patients 45–75 years of age with refractory SUI. This study was a sham-controlled, double-blind, parallel study with a

#### *Therapeutic Effect of Magnetic Stimulation Therapy on Pelvic Floor Muscle Dysfunction DOI: http://dx.doi.org/10.5772/intechopen.99728*

follow-up of 4.5 months [12]. Compared to the sham group, the experimental group showed significant improvement in Urge-Urinary Distress Inventory and Overactive Bladder Questionnaire (OAB-q) scores after the intervention and also at follow-up. In addition, there were significant increases in bladder capacity, urethral functional length, and pressure transmission ratio after the intervention. The response to SMS was greater in patients with severe SUI than in patients with mild symptoms, confirming the effectiveness of SMS in the treatment of SUI. In another study, a total of 75 patients with stress urinary incontinence were subjected to repetitive magnetic stimulation of 15 Hz. at the sacral root at 50% intensity output for 30 minutes with a duration of 5 seconds per minute. As a result, an obvious increase in urethral closing pressure and a significant increase in bladder capacity after stimulation were observed in the sacral stimulation group. In addition, the number of urine leaks and urine volume in the pad test were significantly decreased in the active stimulation group than in the sham stimulation group, and the QOL score was also significantly improved. The improvement rate of the active stimulation group was 74%, which was significantly higher than that of the sham stimulation group (32%) [13]. A randomized controlled trial investigating the shortand long-term effects of repetitive magnetic stimulation on the sacral root observed an improvement in the quality of life of patients with abdominal stress urinary incontinence at one week after stimulation [14].

Some studies have reported therapeutic effects on urge and mixed urinary incontinence. In a multicenter, randomized, single-blind, controlled trial of 151 women with urge incontinence with overactive bladder, armchair-type magnetic stimulators were used to stimulate magnetically twice a week for 25 minutes. As a result, the number of urine leaks / week according to the bladder diary was significantly improved in the treatment group, and the urgency within 24 hours and the average excretion amount were also significantly improved. In addition, the change in total OABSS from baseline was significantly lower in the treatment group than in the sham group, and the change in mean IPSS-QOL score was also significantly lower in the treatment group [3]. A retrospective study conducted in Italy examined the effects of magnetic therapy on 20 men and women with stress incontinence, urge incontinence, and mixed incontinence. The treatment was performed using a functional magnetic stimulator and a magnetic coil installed under the seating surface of the chair. During treatment, the patient was instructed to sit in a chair so that the perineum was centered on the coil and that muscle contractions (pelvic floor and sphincter contractions) were felt during stimulation. Patients were treated for 20 minutes / session, twice a week for 3 weeks (6 times in total). The stimulation frequency was fixed at 10 Hz for 10 minutes and at 35 Hz for another 10 minutes, and the activity time and rest time were 6 seconds each. As a result, micturition frequency and nocturia were significantly reduced before and after treatment, and bladder capacity was significantly increased [15]. A study of 82 female patients with various urinary incontinences in Slovenia received 10 magnetic stimuli over a 4-week period. As a result, in urge incontinence and mixed incontinence, the frequency of urinary incontinence, the number of daily urinary incontinence, and the decrease in the number of urination were statistically observed [16].

#### *5.1.1 Postoperative urinary incontinence of prostate cancer*

Prostate cancer is the number one cancer in Europe and the United States that affects men. Surgery and radiation therapy are used for localized prostate cancer. Although surgical invasion has been significantly reduced due to the spread of surgical robot Da Vinci technique in recent years, postoperative stress urinary incontinence caused by removal of the prostate reduces the patient's QOL. In a multicenter study in the United States, 46% of patients required a urinary incontinence pad 6 months after surgery, and urinary incontinence often persists long after surgery [17]. In a

previous study, 10 patients who had been suffering from urinary incontinence for more than 12 months after radical prostatectomy were treated with magnetic therapy for 20 minutes, twice a week for 2 months. The pulsed field frequency was 10 Hz for 10 minutes, followed by a second treatment at 50 Hz for 10 minutes. As objective and subjective evaluations, a micturition diary, a 1-hour pad weight test, and a quality of life survey were performed 1, 2, 3, and 6 months after the start of treatment. As a result, 30% of patients became dry and 30% showed improvement. In the 1-hour pad weight test, the average pad weight decreased from 25 to 10.3 g, and the QOL score improved significantly 2 months after treatment. In addition, the number of urine leaks per day decreased from 5.0 before treatment to 1.9 after treatment [18]. Although robotic surgery has improved the degree of urinary incontinence, 14% of patients in our department still use two or more urinary incontinence pads/day after 6 months post surgery. In order to improve this annoying complication after surgery, our facility is currently actively adopting magnetic therapy.
