JMIR Publications

ABSTRACT

Introduction: There is increasing evidence from animal and human studies that bimodal neuromodulation combining sound and electrical somatosensory stimulation can induce extensive brain changes and treat tinnitus. The main objectives of the proposed clinical study are to: (1) confirm the efficacy, safety and patient tolerability demonstrated in a previous large-scale study of bimodal auditory and trigeminal nerve stimulation (TENT-A1); (2) evaluate the therapeutic effects of adjusting stimulation parameters over time, and (3) determine the contribution of different features of bimodal stimulation in improving tinnitus outcomes. Methods and analysis: This study will be a prospective, randomised, double-blind, parallel-arm, comparative clinical trial of a 12-week treatment for tinnitus using a CE-marked device with a pre-post and 12-month follow-up design. Four treatment regimens will be investigated, in which each regimen consists of two different stimulation settings with the first setting presented during the first 6 weeks and the second setting presented during the second 6 weeks of treatment. The study will enrol 192 patients, split 80:80:16:16 across the four arms. Patients will be randomised to one of four arms and stratified to minimise baseline variability in four categories: two separate stratum for sound level tolerance (using loudness discomfort level as indicators for hyperacusis severity), high tinnitus symptom severity based on the Tinnitus Handicap Inventory (THI) and tinnitus laterality. The primary efficacy endpoints are within-arm changes in THI and Tinnitus Functional Index (TFI) as well as between-arm changes in THI after 6 weeks of treatment. Additional efficacy endpoints include within-arm or between-arm changes in THI after 6 or 12 weeks of treatment and in different subtypes of patients, as well as at post-treatment assessments at 6 weeks, 6 months and 12 months. Treatment safety, attrition rates and compliance rates will also be assessed and reported. Ethics and dissemination: This study protocol is approved by the Tallaght Hospital / St. James’s Hospital Joint Research Ethics Committee in Dublin, Ireland. Findings will be disseminated to relevant research, clinical, health service and patient communities through publications in peer-reviewed journals and presentations at scientific and clinical conferences. Trial registration number: The trial is registered on ClinicalTrials.gov (NCT03530306). The Sponsor is Neuromod Devices Limited in Dublin, Ireland.