Maintenance percutaneous tibial nerve stimulation in patients with multiple sclerosis led to sustained improvements in medically refractory lower urinary tract symptoms in a prospective, multicenter open-label trial.
All initial responders continued to respond after an average of 2 years of maintenance therapy, reported Dr. Claudio Gobbi of the Neurocentre of Southern Switzerland, Lugano, and his associates.
The prospective, multicenter open-label study recruited patients with multiple sclerosis who had lower urinary tract symptoms that had not responded to medical therapy. Symptom criteria included overactive bladder, incomplete voiding, hesitancy, poor or slow flow, prolonged and interrupted flow, and straining to void (J. Urol. 2014;191:697-702).
A total of 83 patients (mean age, 49 years; 62 women) completed 12 initial weekly sessions of percutaneous tibial nerve stimulation (PTNS). In all, 74 (89%) reported at least 50% improvement in lower urinary tract symptoms on the Patient Perception of Bladder Condition questionnaire.
These responders then underwent 30-minute PTNS maintenance sessions every 2, 3, or 4 weeks as needed. Most patients (60%) required treatment every 2 weeks, the researchers said.
After the 12 weekly PTNS treatments, most responders reported their bladder symptoms as moderately improved (based on a global response assessment), and mean treatment satisfaction was 70% (based on a visual analog scale). At 24 months’ follow-up, most patients described their symptoms as markedly improved, and mean treatment satisfaction was 82% (P less than .05).
The investigators also reported significant improvements over a 24-month period in measures of voiding and bladder diary parameters (including frequency of daytime urination, nocturia, and voided volume). Patients reported no relevant adverse effects of treatment.
Dr. Gobbi and his associates noted several caveats to their findings. The study probably lacked sufficient power to detect differences between subgroups, they said. The investigators also did not collect data on drinking habits or lifestyle modifications, each of which could have independently affected treatment outcomes. And the study included only patients who responded to and completed the initial treatment, which created a selection bias for patients willing to adhere to maintenance PTNS.
"Although the efficacy of PTNS was sustained for 2 years, the progressive neurologic course of MS with deteriorating bladder function may affect longer positive treatment outcomes," they added.
One author disclosed having financial interests or other relationships with Medtronic, Allergan, and Astellas. Dr. Gobbi and his other coauthors reported no conflicts of interest.