[Sacral magnetic stimulation in overactive bladder syndrome: comparative analysis of protocols with a frequency of 1 and 5 Hz].

Peripheral magnetic stimulation (pMS) has shown its effectiveness in the treatment of lower urinary tract symptoms, such as symptoms of an overactive bladder (OAB). The perineal region (pelvic floor) and the sacral roots area (projection S3 of the root) are used as the locus of stimulation. The published literature presents protocols with different parameters of stimulation, while each of them reliably demonstrates clinical efficacy, however, no comparative studies have been found to select priority stimulation modes when analyzing available sources.

Objective: To compare the efficacy and safety of different frequency - 1 and 5 Hz - modes of sacral MS in patients with symptoms of OAB.

Material and methods: A single blind prospective randomized comparative clinical study included 59 patients with OAB symptoms. The patients were divided by simple randomization into the group 1 (n=30), which received MS 3 times a week for 5 weeks with a frequency of 1 Hz per sacral root area (S2-S4), and the group 2 (n=29), in which stimulation was performed at a frequency of 5 Hz, while the remaining parameters and duration of therapy were identical to group 1.

Results: Sacral pMS with different frequency modes (1 and 5 Hz) is reliably equally effective against the clinical symptoms of OAB, which is confirmed by the absence of significant intergroup differences. In patients receiving MS with a frequency of 5 Hz, there was a more pronounced increase in maximum cystometric capacity, normalization of the maximum and average urine flow velocity and regression of the residual urine volume (p<0.001, p=0.007, p=0.011 and p=0.012 compared with group 1). The greatest difference in indicators was observed in the increase in the maximum cystometric capacity - +31±25 ml at MS with a frequency of 1 Hz and +109±96 ml at MS with a frequency of 5 Hz (p<0.001). MS is a safe procedure and is well tolerated by patients.

Conclusion: pMS when exposed to the area of S2-S4 roots for 20 minutes 3 times a week with a course for 5 weeks is reliably effective against the clinical symptoms of OAB at different frequency modes (1 and 5 Hz). At the same time, MS with a frequency of 5 Hz may have an advantage over stimulation of 1 Hz in terms of its effect on urodynamic parameters (maximum cystometric capacity, peak and average urine flow velocity and residual urine volume), which may be associated with a large inhibitory effect on detrusor.