FR-taVNS Tinnitus Tria

Efficacy of Foot Reflexology and Transcutaneous Auricular Vagus Nerve Stimulation on Tinnitus in Non-Cancer Adult Populations

Tinnitus is a common neurosensory symptom affecting 12-30% of adults and is closely associated with anxiety, sleep disturbance, and autonomic dysregulation. Current pharmacologic treatments offer limited efficacy and notable side effects, prompting interest in non-pharmacological approaches. This randomized, single-blind, sham-controlled trial evaluates whether foot reflexology (FR), transcutaneous auricular vagus nerve stimulation (ta-VNS), and auricular acupressure (AA) improve tinnitus severity, psychological distress, sleep quality, and autonomic indicators (heart rate variability and salivary cortisol) in non-cancer adults with tinnitus, compared with usual care. Participants are randomized to a foot reflexology group, an auricular vagus nerve stimulation group (each with true and sham subgroups), or a usual-care control group, and are followed at baseline and weeks 2, 4, and 8.

This is a three-arm parallel, repeated-measures randomized controlled trial conducted in the otolaryngology outpatient and inpatient settings of Hualien Tzu Chi Hospital. Eligible non-cancer adults with tinnitus as the sole chief complaint and normal pure-tone thresholds are stratified by age and sex, then randomized by computer-generated random number tables to the FR group, the ta-VNS group, or the usual-care control group; the FR and ta-VNS groups are further randomized to true or sham subgroups. The foot reflexology intervention is delivered once weekly for 20 minutes over four sessions (one month) and comprises a relaxation phase, an inner-ear/autonomic regulation phase, and a circulation/detoxification phase; the sham condition applies light, non-specific touch. The ta-VNS intervention stimulates the left tragus, cymba conchae, and cavum conchae (pulse width 250 µs, 25 Hz, 0.5-5 mA individualized to a tingling sensation, 30 s on/off) once weekly for 20 minutes over four weeks; the sham condition stimulates the left earlobe at 0.5 mA. Auricular acupressure with magnetic beads is self-administered three times daily. Outcomes are assessed at T0 (baseline), T1 (week 2), T2 (week 4), and T3 (week 8). Data are analyzed with generalized estimating equation (GEE) models.

Inclusion Criteria:

• Age 18-75 years, conscious, able to communicate and comprehend, and able to complete questionnaires and comply with study procedures
• Tinnitus as the sole chief complaint, with pure-tone thresholds ≤25 dB HL bilaterally at 500, 1000, 2000, and 4000 Hz

Exclusion Criteria:

• Objective tinnitus, peripheral vestibular disease, central nervous or cardiovascular causes, or other organic ear pathology
• Open wounds or skin lesions of the foot or ear, lower-limb edema, history of deep vein thrombosis, or diabetes with most recent HbA1c >7.5%
• Cardiac pacemaker or other implanted electronic device, or other severe cardiovascular disease
• Foot reflexology or vagus nerve stimulation within the past 3 months
• Pregnant or breastfeeding women
• History of epilepsy or seizures
• Physically frail condition