Low-Frequency TENS in Women With Behavioral Dysphonia: Preliminary Data From a Randomized Clinical Trial.

PURPOSE: To verify the effectiveness of low-frequency transcutaneous electrical nerve stimulation (TENS) simultaneously applied to the performance of vocal exercises in women with behavioral dysphonia.

METHODS

This is a randomized, blinded clinical trial (Register Number: RBR-5k95vs). Twelve adult women with vocal nodules, randomly divided into three groups (G1: 4 participants - 12 sessions - application of placebo TENS simultaneously to the execution of vocal exercises; G2: 5 participants - 12 sessions - application of low-frequency TENS (frequency at 10 Hz, 200 μs duration phase, motor threshold, with electrodes placed on the thyroid cartilage lamina, bilaterally); and G3: 3 participants - 12 sessions - application of low-frequency TENS (same condition as G2) simultaneously to the execution of vocal exercises), participated in this study. The therapies were performed for 30 minutes in each session, twice a week. The participants were evaluated regarding vocal quality through acoustic voice analysis (fundamental frequency, Cesptral Peak Prominence-Smoothed (CPPs), alpha ratio, L1-L0, Acoustic Breathiness Index (ABI), and Acoustic Vocal Quality Index (AVQI)), vocal economy through electroglottography, and vocal self-assessment using the Voice-Related Quality of Life (V-RQOL) protocol. Assessments were performed before and immediately after voice therapy. Data were analyzed using the two-way repeated-measures ANOVA (variance analysis) test to compare assessment times and intervention groups.

RESULTS

It was observed that G2 presented a reduction in the ABI acoustic parameter after the intervention and an increase in the values of the CPPs and L1-L0 parameter and in the scores of the physical and total V-RQOL domains. There were no differences for the other outcomes in relation to time and group.

CONCLUSION

Preliminary results indicate that low-frequency TENS applied alone can reduce ABI parameter values and improve voice-related quality of life in dysphonic women.