Multimodal Therapy for Somatosensory Tinnitus

Background: Somatosensory tinnitus represents a clinically significant subgroup in which tinnitus is modulated by somatic manoeuvres (jaw movements, cervical rotation, trigger point palpation). The neuroanatomical basis involves convergence of somatosensory afferents from the TMJ and upper cervical spine (C1-C3) in the medullary nucleus spinalis nervi trigemini, with excitatory projections to the dorsal cochlear nucleus (DCN), leading to disinhibition of spontaneous neural activity perceived as tinnitus (Da Silva et al., 2023). Despite this evidence, multimodal treatment protocols specifically targeting somatosensory tinnitus remain largely absent from clinical practice in the Czech Republic.

Study Design: Single-centre randomized controlled trial with longitudinal follow-up and a crossover substudy on acute exercise effects. Stratified randomization by age group (18-35 / 36-50 / 51-70 years) and sex. Rotating block system: 4 blocks of \~27 participants; 8 weeks active intervention + 8 weeks pause per block.

Intervention: 8-week multimodal program comprising: (A) Physiotherapy - 16 sessions × 60 min: manual therapy of TMJ and cervical spine (myofascial techniques including intraoral TMJ techniques), neuromuscular exercise, proprioceptive training, home exercise program; (B) Exercise Program - 24 sessions × 60 min: combined aerobic (60-85% HRmax), resistance (40-80% 1RM), and breathing/relaxation training; 1× supervised/week + 2× home-based/week; (C) Psychological Support - 1× group psychoeducation session (90 min): cognitive-behavioral model of tinnitus distress, attention regulation, relaxation; weekly self-help materials; on-demand psychological support (max. 3× per 8 weeks).

Crossover Substudy: Repeated measures crossover design examining acute effects of 5 standardized conditions (low/high intensity aerobic exercise; low/high intensity resistance exercise; control rest) on tinnitus perception (VAS loudness and distress), with ≥48-72h washout between conditions.

Questionnaire Validation: Psychometric validation of Czech versions of THI, TFI, TCS, MTQ, CRF, TSCHQ, MDI, and WB questionnaires according to COSMIN guidelines, including reliability, validity, responsiveness, and MID determination.

Outcomes: Primary: THI change from baseline to 3, 12, and 24 months. Secondary: TFI, VAS/NRS, CGI, GAD-7, PHQ-9, PSQI, SF-36, WHO-5, cervical ROM, TMJ function (JFLS-20), NDI, CPET parameters (VO₂peak), body composition (BIA), muscle strength, autonomic regulation (BP, HR, PWV), and EEG spectral analysis (exploratory).

• Multimodal physiotherapy for TMJ and Cervical spine (Other), also known as physiotherapy, manual therapy: Manual therapy (mobilisations of TMJ and cervical spine C0-C7, myofascial techniques, intraoral TMJ techniques with gloves), neuromuscular exercise (CCFT with pressure biofeedback, scapular stabilisation, proprioceptive training), home exercise program. 16 sessions × 60 min over 8 weeks. Arms: Arm 1.
• Combined Exercise Program (Aerobic + Resistance + Breathing) (Behavioral), also known as physical therapy, motion: Structured 8-week combined exercise program: aerobic training (60-85% HRmax), progressive resistance training (40-80% 1RM), breathing and relaxation exercises (diaphragmatic breathing, box breathing, resonant breathing). 24 sessions × 60 min; 1× supervised/week + 2× home-based/week. Strict instructions to avoid the Valsalva manoeuvre. Arms: Arm 1.
• Tinnitus-Specific Psychological Support (Behavioral), also known as psychological approach: One group psychoeducation session (90 min): vicious cycle model of tinnitus distress, cognitive restructuring, attention regulation training, relaxation technique. Weekly self-help materials (worksheets, audio recordings, mindfulness). On-demand individual psychological support (max. 3 sessions per 8 weeks). Arms: Arm 1.

Primary outcomes

• Change in Tinnitus Handicap Inventory (THI) score [Baseline, 4 weeks, 8 weeks (end of intervention), 3 months, 12 months, and 24 months.]: The primary outcome is the change in tinnitus-related handicap measured by the Tinnitus Handicap Inventory (THI). The THI is a 25-item self-report questionnaire assessing the functional, emotional, and catastrophic impact of tinnitus on daily life. Total scores range from 0 to 100, where higher scores indicate greater tinnitus-related handicap. The primary analysis will compare the change in THI score from baseline between the multimodal intervention group and the control group.

Secondary outcomes

• Change in tinnitus loudness assessed by Visual Analogue Scale (VAS) [Baseline, 8 weeks, 3 months, 12 months, 24 months]: Change in perceived tinnitus loudness measured by the Visual Analogue Scale (VAS). The VAS is a single-item self-report scale ranging from 0 to 10, where 0 indicates no tinnitus loudness and 10 indicates the worst imaginable tinnitus loudness.
• Change in quality of life assessed by the Short Form Health Survey (SF-36) [Baseline, 4 weeks, 8 weeks, 3 months, 12 months, 24 months]: Change in health-related quality of life measured by the Short Form Health Survey (SF-36). The SF-36 is a 36-item self-report questionnaire assessing 8 domains of health-related quality of life. Scores range from 0 to 100 for each domain, where higher scores indicate better quality of life.
• Change in cervical range of motion assessed by goniometry [Baseline, 8 weeks, 3 months, 12 months, 24 months]: Change in active cervical range of motion measured by goniometry. Cervical range of motion will be assessed in all planes: flexion, extension, lateral flexion (left/right), and rotation (left/right). The unit of measure is degrees (°). Higher values indicate greater cervical mobility.
• Change in well-being assessed by the World Health Organization Five Well-Being Index (WHO-5) [Baseline, 4 weeks, 8 weeks, 3 months, 12 months, 24 months.]: Change in subjective well-being measured by the World Health Organization Five Well-Being Index (WHO-5). The WHO-5 is a 5-item self-report questionnaire. Scores range from 0 to 25, where higher scores indicate better well-being.
• Change in anxiety symptoms assessed by the Generalized Anxiety Disorder 7-item scale (GAD-7) [Baseline, 4 weeks, 8 weeks, 3 months, 12 months, 24 months.]: Change in anxiety symptoms measured by the Generalized Anxiety Disorder 7-item scale (GAD-7). The GAD-7 is a 7-item self-report questionnaire. Scores range from 0 to 21, where higher scores indicate more severe anxiety symptoms.
• Change in depressive symptoms assessed by the Patient Health Questionnaire (PHQ-9) [Baseline, 4 weeks, 8 weeks, 3 months, 12 months, 24 months.]: Change in depressive symptoms measured by the Patient Health Questionnaire (PHQ-9). The PHQ-9 is a 9-item self-report questionnaire. Scores range from 0 to 27, where higher scores indicate more severe depressive symptoms.
• Change in sleep quality assessed by the Pittsburgh Sleep Quality Index (PSQI) [Baseline, 4 weeks, 8 weeks, 3 months, 12 months, 24 months.]: Change in sleep quality measured by the Pittsburgh Sleep Quality Index (PSQI). The PSQI is a 19-item self-report questionnaire assessing sleep quality over the past month. Scores range from 0 to 21, where higher scores indicate poorer sleep quality.
• Change in temporomandibular joint range of motion assessed by direct measurement [Baseline, 8 weeks, 3 months, 12 months, 24 months.]: Change in temporomandibular joint (TMJ) range of motion measured by direct millimeter measurement using a ruler/caliper. Assessed parameters include maximum mouth opening, lateral mandibular movements (left/right), and protrusion. The unit of measure is millimeters (mm). Higher values indicate greater TMJ mobility.
• Change in cervical muscle tone assessed by algometry (pressure pain threshold) [Baseline, 8 weeks, 3 months, 12 months, 24 months.]: Change in cervical muscle tone measured by pressure algometry. Pressure pain threshold (PPT) will be assessed bilaterally at standardized trigger point locations in the cervical and craniocervical region (m. trapezius, m. sternocleidomastoideus, suboccipital muscles, m. levator scapulae). The unit of measure is kilopascals (kPa) or kilograms per square centimeter (kg/cm²). Higher values indicate lower muscle tenderness and better muscle tone.

Sex: All, ages: 18 Years to 70 Years, accepts healthy volunteers

Inclusion Criteria:

* Age 18-70 years (inclusive)
* Chronic subjective tinnitus present for ≥6 months
* Tinnitus Handicap Inventory (THI) score ≥18 points (indicating at least mild tinnitus handicap)
* Positive somatosensory modulation test: ability to reproducibly modulate tinnitus (change in loudness, pitch, or quality) through at least one of the following manoeuvres:
* Jaw movements (mouth opening, lateral excursion, protrusion, clenching)
* Neck movements (flexion, extension, rotation, lateral flexion)
* Pressure on specific head/neck muscles
* Eye movements or shoulder elevation
* Willing and able to attend all study sessions over 28 weeks
* Adequate cognitive capacity to understand study procedures and complete questionnaires in the Czech language
* Signed written informed consent

Exclusion Criteria:

* Audiological/ENT Exclusions:
* Objective or pulsatile tinnitus
* Active ear pathology requiring treatment:
* Acute otitis media or externa
* Chronic suppurative otitis media
* Cholesteatoma
* Meniere's disease with recent vertigo attacks (<3 months)
* Suspected retrocochlear pathology:
* Acoustic neuroma (vestibular schwannoma)
* Cerebellopontine angle tumor
* Neurological Exclusions:
* Neurological disease affecting brainstem or auditory pathways:
* Multiple sclerosis with brainstem involvement
* Stroke affecting auditory pathways
* Brain tumor
* Epilepsy or active seizure disorder
* Musculoskeletal Exclusions:
* Contraindications to manual therapy:
* Severe cervical spine instability
* Rheumatoid arthritis with atlantoaxial instability
* Down syndrome
* Vertebrobasilar insufficiency
* Severe osteoporosis with fracture risk
* Recent cervical spine surgery (<6 months)
* Recent head or neck trauma (<3 months)
* Ongoing physiotherapy or manual therapy for temporomandibular joint or cervical spine (<3 months prior to enrollment)
* Psychiatric Exclusions:
* Severe psychiatric disorder:
* Active psychosis
* Severe depression requiring inpatient treatment
* Acute suicidal ideation (PHQ-9 item 9 score ≥2)
* Active substance abuse disorder
* Other Exclusions:
* Pregnancy (due to modifications needed in physical examination and treatment)
* Ongoing litigation or compensation claims related to tinnitus or hearing loss
* Current participation in another interventional clinical trial
* Expected change of residence or long-term absence (>2 weeks) during the study period
* Unable or unwilling to comply with study procedures and attend all sessions