Effects Of Functional Magnetic Stimulation At Different Frequencies On Urination Function In Patients With Urinary Retention After Spinal Cord Injury

Objective To observe the effect of functional magnetic stimulation of sacral 3 nerve root on the recovery of urination function in patients with urinary retention after spinal cord injury.Methods In this study,forty-five patients with neurogenic bladder after spinal cord injury were selected according to the inclusion criteria.According to the random number table method,they were randomly divided into 5Hz group,20 Hz group and sham group,with 15 cases in each group.Finally,one patient in the 5Hz group dropped out for personal reasons,and a total of 44 patients completed the study.All patients in the three groups were given FMS on the basis of conventional bladder function intervention,and the stimulation site and course in the three groups were the same(S3 nerve root region,20min/ day,5 days/week,a total of four consecutive weeks).Before treatment and after 4weeks treatment,patients were assessed for bladder pressure volume,electromyography(EMG),and a detailed urine diary was recorded during treatment.Results Before the treatment,there were no significant differences in bladder safe volume,residual urine volume,bladder pressure,mean daily catheterization times,mean daily urination times and mean single urination volume among the three groups in terms of bladder pressure volume assessment and urination diary(P>0.05).After the treatment,the above clinical indicators in the 5Hz group and the 20 Hz group were significantly improved compared with those before treatment(P<0.05),while there were no significant differences in the sham group before and after the treatment(P>0.05).After the treatment,the above clinical indicators in the 5Hz group and 20 Hz group were significantly different from those in the sham group(P<0.05);There were also significant differences in residual urine volume,mean daily urination times and mean single urination volume between the20 Hz group and the 5Hz group(P<0.05).In terms of electrophysiological indexes,there were no significant differences in the latency and the wave amplitude of H reflex,the latency and extraction rate of F wave between the three groups before the treatment(P>0.05);After the treatment,the above electrophysiological indexes in 5Hz group and 20 Hz group were significantly improved compared with those before the treatment(P<0.05),while there were no significant differences in the sham group before and after the treatment(P>0.05).After the treatment,electrophysiological indexes of 5Hz group and20 Hz group were significantly different from those of the sham group(P<0.05);The latency and amplitude of H reflex were also significantly different between the 20 Hz group and the 5Hz group(P<0.05),there were no significant differences in the latency and extraction rate of F wave(P>0.05).Conclusion Both the 5Hz FMS and the 20 Hz FMS of S3 nerve roots combined with routine rehabilitation training can improve the urination function of patients with urinary retention after spinal cord injury,and the treatment effect of 20 Hz group is significantly better than that of 5Hz group.