FR-taVNS Tinnitus Tria

Official title

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

Overview

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.

Detailed description

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.

Interventions

• Procedure True Foot Reflexology
  Once weekly, 20 min, 4 sessions over 1 month. Three phases: relaxation (diaphragm, brain, spine reflex zones, 3 min); inner-ear and autonomic regulation (inner ear, hypothalamus, cerebellum, brainstem, thyroid, adrenal zones, 10 min); circulation/detoxification (kidney, lymphatic zones, 7 min).
• Procedure Sham Foot Reflexology
  Light touch on non-specific foot areas (dorsum, anterior ankle, foot margins) without effective pressure.
• Device True ta-VNS
  Left tragus, cymba conchae, cavum conchae; 250 µs, 25 Hz, 0.5-5 mA individualized to tingling, 30 s on/off; once weekly, 20 min, 4 weeks. Device: Hong-Tai mid-frequency electrotherapy stimulator, model HT66B (TFDA license no. 000637), used off-label for auricular vagus nerve stimulation.
• Device Sham ta-VNS
  Left earlobe, 0.5 mA, otherwise identical parameters (250 µs, 25 Hz, 30 s on/off).
• Procedure True Auricular Acupressure
  Magnetic beads (1-2 mm) at left tragus, cymba conchae, cavum conchae; pressed 3×/day, \~30 s per point; changed every 2-3 days.
• Procedure Sham Auricular Acupressure
  Beads at left earlobe (non-vagal regions), same frequency/duration.
• Other Usual Care
  Standard tinnitus clinical care (pharmacologic and supportive); no study intervention.

Primary outcome measures

• Change in Tinnitus Handicap Inventory (THI) score [Time frame: T0 baseline, T1 week 2, T2 week 4, T3 week 8]
• Change in Tinnitus Functional Index (TFI) score [Time frame: T0 baseline, T1 week 2, T2 week 4, T3 week 8]

Secondary outcome measures (4)

• Change in Distress Thermometer (DT) [Time frame: T0 baseline, T1 week 2, T2 week 4, T3 week 8]
• Change in Pittsburgh Sleep Quality Index (PSQI) [Time frame: T0 baseline, T1 week 2, T2 week 4, T3 week 8]
• Change in Heart Rate Variability (HRV) [Time frame: T0 baseline, T1 week 2, T2 week 4, T3 week 8]
• Change in salivary cortisol concentration [Time frame: T0 baseline, T1 week 2, T2 week 4, T3 week 8]

Eligibility criteria

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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Treatment

Study locations

Taiwan · 1 center

• Hualien Tzu Chi Hospital, Department of Otorhinolaryngology — Hualien City

Publications

• Stegeman I, Velde HM, Robe PAJT, Stokroos RJ, Smit AL. Tinnitus treatment by vagus nerve stimulation: A systematic review. PLoS One. 2021 Mar 11;16(3):e0247221. doi: 10.1371/journal.pone.0247221. eCollection 2021. PMID 33705401
• Newman CW, Jacobson GP, Spitzer JB. Development of the Tinnitus Handicap Inventory. Arch Otolaryngol Head Neck Surg. 1996 Feb;122(2):143-8. doi: 10.1001/archotol.1996.01890140029007. PMID 8630207

Identifiers

NCT: NCT07711639 · Tzu Chi University

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗