Transcutaneous electrical nerve stimulation in the treatment of neurological patients with urinary symptoms

To determine whether transcutaneous electrical nerve stimulation (TENS) benefits patients with urinary symptoms caused by neurological diseases.

Patients with urinary symptoms from any kind of neurological disease were prospectively recruited between October 1996 and July 1998. Before attending the first assessment patients were asked to complete a week's diary recording the frequency of micturition, incontinence episodes, and frequency of pad and clothes changing. At the first assessment the patients completed the Frimodt-Moller urinary symptom questionnaire, and quality-of-life scales including the Nottingham Health Profile and Short-Form 36. Demographic and disability data (Barthel Index and Frenchay Aphasia Screening Test) were recorded, and patients underwent a neurological examination and urodynamic studies. The placing of electrode pads on the sacral dermatomes 2.5 cm either side of and 2.5 cm above the natal cleft was demonstrated, and the patient instructed to use TENS for 90 min twice a day. The current strength applied was set to that which the patient could tolerate, at a square-wave of 20 Hz and 200-micros duration. Six weeks later the patients were further assessed, where the diary exercise, questionnaires and urodynamics were repeated. In all, 44 patients (13 men and 33 women, mean age 50.8 years) were recruited.

The commonest disease was multiple sclerosis and the commonest impairments para/tetraplegia or hemiplegia. There was no change in the neurological status of the 34 patients completing the study. Irritative voiding symptoms were significantly decreased (0.68-0.61, P = 0.003) and diaries also showed significant improvements in the 24 h frequency of micturition (P = 0.01), incontinence episodes (P = 0.04) and clothes changes (P = 0.02). Urodynamics showed detrusor hyper-reflexia in most patients. The only significant changes after TENS were an increased postvoid residual volume (from a mean of 134 mL to 160 mL, P = 0.03) and an increase in the volume leaked during the urodynamic study with TENS on (from a mean of 4.7 mL to 12 mL, P = 0.003). There were no significant changes in the quality-of-life scores. Of the 34 patients completing the study, half still reported a benefit from TENS at 1 year, although some patients found it took 3-4 weeks to work.

TENS applied to the sacral dermatomes of neurological patients with urinary symptoms had a minimal effect on urodynamic data but significantly improved irritative urinary symptoms, 24-h urinary frequency, incontinence and clothes changing. The lack of effect on quality-of-life measures probably reflects the lack of sensitivity in the tools used in this group of patients. We therefore recommend using TENS in this often problematical group of patients.