Induction of urethral closure and inhibition of bladder contraction by continuous magnetic stimulation

Magnetic stimulation for female patients with stress urinary incontinence, a meta-analysis of studies with short-term follow-up

BACKGROUND

To determine the efficacy of magnetic stimulation (MS) in female patients with stress urinary incontinence (SUI) by performing a meta-analysis on peer-reviewed randomized controlled trails (RCTs).

METHODS

PubMed, Embase, and Cochrane library were retrieved for any peer-reviewed original articles in English. Databases were searched up to July 2018. Included studies investigated effects of MS on SUI. The data were analyzed by review manager 5.3 software (Cochrane Collaboration, Oxford, UK).

RESULTS

A total of 4 studies involving 232 patients were identified and included in present meta-analysis. Compared with the sham stimulation, the MS group had statistically significantly fewer leaks/3 days (MD = -1.42; 95%CI: -2.42 to -0.59; P = .007), less urine loss on pad test (g.)/24 h (MD = -4.99; 95%CI: -8.46 to -1.53; P = .005), higher QoL scores (MD = 0.42; 95%CI: 0.02-0.82; P = .009), and lower ICIQ scores (MD = -4.60; 95%CI: -5.02 to -4.19; P < .001). MS presented higher cure or improvement rate, with a statistically significant improvement in UDI and IIQ-SF scores compared to sham stimulation. No MS-related adverse effects were reported in study.

CONCLUSION

MS leads to an improvement in SUI without any reported safety concerns and an improvement in patient quality of life. The long-term outcome of this technique remains unclear and is the subject of ongoing research.

Effects of magnetic stimulation on urodynamic stress incontinence refractory to pelvic floor muscle training in a randomized sham-controlled study

OBJECTIVE

The aim of the present study was to evaluate the effect of magnetic stimulation on urodynamic stress incontinence refractory to pelvic floor muscle training in a randomized sham-controlled study.

METHODS

Female patients with urodynamic stress incontinence who had not been cured by pelvic floor muscle training were randomly assigned at a ratio of 2 : 1 to either active treatment or sham treatment for 10 weeks. The randomization was made using magnetic cards for individuals indicating active or sham stimulation. The primary endpoint was changes in the number of incontinence episodes/week, with secondary endpoints of the degree of incontinence (in g/day; determined using the pad test), the total score on the International Consultation on Incontinence Questionnaire - Short Form (ICIQ-SF), the ICIQ quality of life (QOL) score, and the abdominal leak point pressure (ALPP) on urodynamic study.

RESULTS

Although 39 patients were enrolled in the study, 9 dropped out, leaving a total patients for analysis (18 in the active treatment group, 12 in the sham treatment group). The number of incontinence episodes/week, the degree of incontinence, total ICIQ-SF score, ICIQ-QOL score, and ALPP were significantly improved after active treatment compared with baseline (all P < .05), but did not change significantly after sham treatment. There was a significant intergroup difference with regard to changes from baseline in the ICIQ-SF and ALPP in favor of the active treatment group (P < .05). There were no significant differences in any other parameters between the 2 groups. Treatment-related adverse events were not found in both groups.

CONCLUSION

Magnetic stimulation was effective in treating urodynamic stress incontinence.

Neuromodulation for the treatment of urinary incontinence

Neuromodulation has been reported to be effective for the treatment of stress and urgency urinary incontinence. The cure and improvement rates of pelvic floor neuromodulation in urinary incontinence are 30-50% and 60-90%, respectively. In clinical practice, vaginal, anal and surface electrodes are used for external, short-term stimulation, and sacral nerve stimulation for internal, chronic (long-term) stimulation. The effectiveness of neuromodulation has been verified in a randomized, placebo-controlled study. However, the superiority to other conservative treatments, such as pelvic floor muscle training has not been confirmed. A long-term effect has also been reported. In conclusion, pelvic floor exercise with adjunctive neuromodulation is the mainstay of conservative management for the treatment of stress incontinence. For urgency and mixed stress plus urgency incontinence, neuromodulation may therefore be the treatment of choice as an alternative to drug therapy.

Randomized, double-blind, sham-controlled evaluation of the effect of functional continuous magnetic stimulation in patients with urgency incontinence

AIMS

To evaluate the effect of functional continuous magnetic stimulation (FCMS) on urgency incontinence in randomized, sham-controlled manner.

METHODS

Thirty-nine patients with urgency incontinence, 16 males and 23 females (aged 66.0 +/- 16.5 years), who were refractory to pelvic floor muscle training (PFMT), were randomly assigned either to the treatment schedule performing 10-week active treatment, followed by 4-week non-treatment interval and then by 10-week sham treatment (A-S, n = 20) or to that performing the sham treatment first followed by 10-week active treatment (S-A, n = 19).

RESULTS

At 10 weeks, the number of leaks/week, the total score of the International Consultation on Incontinence-Questionnaire: Short Form (ICIQ-SF), and maximum cystometric capacity (MCC) were significantly improved as compared with the initial levels (P < 0.001, P < 0.001, and P = 0.003, respectively) in the former group, but not in the latter group. Four (20.0%) patients were cured in the A-S group, while no patient was cured in the S-A group. At the end of the A-S schedule (24 weeks of study), the effect of the active treatment was still maintained at a significantly improved level, as compared with the initial level. At the end of the S-A schedule, the number of leaks/week was significantly improved as compared with the initial level and with its 10-week level (P < 0.001 and P = 0.049, respectively), as well as ICIQ-SF total score (P = 0.001 and P = 0.006, respectively). MCC significantly increased from its initial level (P = 0.030).

CONCLUSION

Magnetic stimulation was effective on urgency incontinence in comparison to sham stimulation in this small patient group.

URODYNAMIC AND CLINICAL EVALUATION OF 91 FEMALE PATIENTS WITH URINARY INCONTINENCE TREATED WITH PERINEAL MAGNETIC STIMULATION: 1-YEAR FOLLOWUP

PURPOSE

We evaluate the perineal magnetic stimulation (PMS) effect on continence and quality of life in women with urinary incontinence.

MATERIALS AND METHODS

We prospective studied 91 women with demonstrable urinary incontinence treated with 16 sessions of PMS. Pretreatment and posttreatment evaluation was done by clinical history, physical examination, voiding diary, validated quality of life survey (I-QOL) and urodynamic study (UDS). Patients with no leakage after treatment were evaluated at 3, 6 and 12 months.

RESULTS

Mean patient age +/- SD was 60.5 +/- 10.1 years. Immediately after treatment the I-QOL score increased 35% (p <0.001), the number of pads daily decreased 40% (p <0.001), the number of leaks daily decreased 54% (p <0.001) and 34 patients (37%) became dry. Of the 91 patients 41 were evaluated before and after treatment by UDS. The average increase in vesical leak point pressure (VLPP) was 24.3% (p = 0.001) and initial VLPP in patients who became dry was greater than 80 cm H2O. After treatment 77% of patients with initial low pressure detrusor overactivity on UDS became free of this condition. One year after discontinuing PMS 94% of patients who became dry immediately after treatment had recurrence.

CONCLUSIONS

Immediately after 16 sessions of PMS women with urinary incontinence have significant improvement in the I-QOL score with decreased daily pad use and leakage episodes but 63% had failure. Therapy is more effective in patients with a VLPP of greater than 80 cm H2O. The beneficial effect is temporary with high and early recurrence after discontinuing treatment.

Functional magnetic stimulation of the spinal cord?a urodynamic study in healthy humans

AIMS

To study the effects of functional magnetic stimulation of the spinal cord in healthy subjects on somatic and autonomic pathways innervating the anal and the external urethral sphincter, bladder, bladder neck, and rectum.

METHODS

Eight healthy male volunteers gave their written informed consent and underwent functional magnetic stimulation of the thoracolumbar and sacral spinal cord. A two-channel microtip pressure transducer catheter was placed rectally measuring the abdominal and anal sphincter pressure. A three-channel microtip pressure transducer catheter was inserted into the urethra measuring the bladder, the bladder neck, and the external urethral sphincter pressure. A comprehensive protocol of single and repetitive magnetic stimulations was performed. Frequency, location, and duration of stimulation were varied while the intensity of stimulation was adapted to the maximum the subjects could tolerate. In four subjects, the degree of bladder filling was changed and the protocol was repeated when the subjects reported a full bladder and desire to void.

RESULTS

Continuous magnetic stimulation of the thoracolumbar spinal cord and the sacral roots applied with different frequencies (5, 15, 30, 60, 100 Hz) and different duration of stimulation (10, 30, 120 sec) evoked sphincter contraction of both anal and urethral sphincters. The stimulation could not evoke contractions of the bladder, the bladder neck, or the rectum. Also with filled bladder and present desire to void, the magnetic stimulation could not activate autonomic pathways innervating these structures.

CONCLUSIONS

Considering our results, we suggest that in individuals with preserved sensibility magnetic stimulation of the spinal cord with intensities below the pain threshold is ineffective in activating autonomic nerve fibres innervating bladder, bladder neck, and rectum.

Comparative study of the effects of magnetic versus electrical stimulation on inhibition of detrusor overactivity

OBJECTIVES

To perform a randomized comparative study investigating the urodynamic effects of functional magnetic stimulation (FMS) and functional electrical stimulation (FES) on the inhibition of detrusor overactivity.

METHODS

Thirty-two patients with urinary incontinence due to detrusor overactivity (15 men, 17 women; age 62. 3 +/- 16.6 years) were randomly assigned to two treatment groups (15 patients in the FMS group and 17 in the FES group). Stimulation was applied continuously at 10 Hz in both groups. For FMS, the magnetic stimulator unit was set on an armchair type seat and had a concave-shaped coil, so that the patients could sit during stimulation. For FES, a vaginal electrode was used in the women and a surface electrode on the dorsal part of the penis was used in the men. Cystometry was performed before and during the stimulation.

RESULTS

The bladder capacity at the first desire to void and the maximum cystometric capacity increased significantly during stimulation compared with prestimulation levels in both groups (P = 0.0054 and 0.0026, respectively, in the FMS group and P = 0.0015 and 0.0229, respectively, in the FES group). However, the increase in the maximum cystometric capacity was significantly (P = 0.0135) greater in the FMS group (114.2 +/- 124.1 mL or an increase of 105. 5% +/- 130.4% compared with the pretreatment level) than that in the FES group (32.3 +/- 56.6 mL or an increase of 16.3% +/- 33.9%). Detrusor overactivity was abolished in 3 patients in the FMS group but not in any patient in the FES group.

CONCLUSIONS

Although both treatments were effective, the inhibition of detrusor overactivity appeared greater in the FMS group than in the FES group.