Effects of Transcutaneous Electrical Nerve Stimulation at Two Frequencies on Urinary Incontinence in Poststroke Patients

The objective of this study was to compare the effects of two frequencies of transcutaneous electrical nerve stimulation (TENS) on urinary incontinence caused by stroke.Eighty-one patients with poststroke urinary incontinence were recruited and randomized into the following three groups with a 1:1 ratio: a 20-Hz TENS group, a 75-Hz TENS group, and a no-treatment control group (n = 27 per group). TENS currents were biphasic square waves with pulse durations of 150 μsecs and pulse frequencies of 20 Hz or 75 Hz and were applied for 30 mins once per day for 90 days. The positive electrodes were placed in the region of the second sacral level on opposite sides of the vertebral column; the negative electrodes were placed on the inside of the middle and lower third of the junction between the posterior superior iliac spine and the ischial node. Overactive Bladder Symptom Scores, Barthel Index, urodynamic values, and voiding diary parameters were assessed before and after 90 days.The patients treated with 20 Hz had superior Overactive Bladder Symptom Scores, Barthel Index totals, urodynamic values, and voiding diary parameters (P < 0.05). In the 75-Hz group, values were statistically improved compared with the no-treatment group (P < 0.05), but the results were significantly inferior to those of the 20-Hz group (P < 0.05).Twenty-hertz TENS improved incontinence symptoms and promoted activities of daily living better than 75-Hz TENS. These results will aid future research regarding TENS parameters.