Overactive bladder syndrome (OAB) is a condition characterized by urinary urgency, with or without urinary incontinence, usually accompanied by increased frequency and nocturia. When pharmacological treatments fail to achieve an adequate response, alternative therapies such as transcutaneous tibial nerve stimulation (TTNS) are considered. 

Objetives: 
- Evaluate the response to treatment with TTNS  in women with OAB  who did not respond to medical treatment.
- Assess the number of sessions needed to determine the presence of a treatment response.
- Evaluate the degree of patient satisfaction.

A prospective descriptive study including 51 women diagnosed with OAB refractory to medical treatment. The patients received a 30-minute weekly TTNS session for 12 weeks. Before starting, they completed validated questionnaires: ICIQ-SF, OAB-8, and a 3-day Voiding Diary as baseline data. These questionnaires were repeated at weeks 6 and 12. Additionally, in the third week, they answered a subjective question regarding perceived improvement with treatment. At the end of the study, they completed a survey on satisfaction with the technique.

Statistically significant improvements were observed at the sixth week of treatment in the ICIQ-SF, OAB-8, and 3-day Voiding Diary in all parameters except for voided volume. Among the total patients, 12 reported no subjective improvement in the third week. A stratified analysis of these 12 patients showed no statistically significant differences from baseline results, leading to treatment discontinuation at week 6. A total of 39 patients completed the 12-week treatment. At week 12, statistically significant improvements were observed in all evaluated aspects except for voided volume. A total of 87.2% of patients reported being satisfied or very satisfied with the technique.

TTNS showed statistically significant improvements at 6 and 12 weeks, as assessed through the ICIQ-SF, OAB-8, and 3-day Voiding Diary questionnaires. According to our results, the third week could be established as a control point to determine whether to continue treatment based on the patient’s perception of improvement. Furthermore, this treatment demonstrated a high level of patient satisfaction.

TTNS demonstrated positive effects in improving symptoms of OAB in patients who did not respond to conventional medical treatment. The results show significant benefits from the sixth week of therapy, with high patient acceptance. Additionally, the evaluation at the third week could be key in early identification of patients who would benefit from continuing the treatment.