MRI Study of High Definition Transcranial Electrical Stimulation in Chronic Tinnitus (MRI HDtES-T)

Study Overview
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Brief Summary
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The purpose of this research is to understand how a neurostimulation technique, transcranial electrical stimulation (tES), affects brain function in adults with chronic subjective tinnitus measured with functional magnetic resonance imaging (fMRI). This study targets a specific kind of tES called transcranial direct current stimulation (tDCS), where a mild, constant current is passed between electrodes placed on the scalp.

Detailed Description
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This is an investigator-initiated MRI study of High Definition (HD) transcranial electrical stimulation (tES) in adults with chronic subjective tinnitus. HDtES is a mild, noninvasive form of brain stimulation using small electrodes to target a small part of the brain/cortex. Primary outcomes are changes in brain function and connectivity measured with MRI before and after a single 20-minute session of HDtES. Secondary outcomes are changes in tinnitus symptoms after 20-minutes of HDtES on 5 consecutive days.

Official Title
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MRI Study of High Definition Transcranial Electrical Stimulation in Chronic Tinnitus (MRI HDtES-T)

Conditions
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Tinnitus, Subjective

Intervention / Treatment
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* Device: Transcranial Direct Current Stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Ages between 18 and 75 Race/ethnicity: all races and ethnic groups Sex/Gender: all Capacity to provide informed consent Subjective tinnitus symptoms confirmed by patient self report meeting the following criteria: Present for at least one year prior to start of study Present (can be heard when consciously attended to) >50% of awake time Intrudes (is heard even when attempting to ignore/mask) >10% of awake time Has discussed tinnitus symptoms with clinician (i.e., physician, audiologist) to confirm low/no likelihood of physical or neurological origin of tinnitus symptoms (e.g., acoustic neuroma, Meniere's Disease, etc.), confirmed by patient self-report Stable standard or no pharmacological treatment regimen for tinnitus with no change in treatment 6 weeks prior to study start Exclusion Criteria: Ages below 18 (neurobiology is quite different in children vs. adults) Ages above 75 (cortical excitability changes with age) Tinnitus symptoms with known medial origin, including: Meniere's disease Pulsatile tinnitus Acoustic neuroma Spontaneous optoacoustic emissions Any other known medical origin Severe mood disorder (major depression or anxiety) Diagnosis of any medical condition potentially affecting brain function, including: neuropsychiatric or mental disorders (bipolar, post-traumatic stress disorder, etc.) severe mood disorders (major depression or anxiety) psychotic states or disorders developmental disorders neurological disorders, including mild cognitive impairment significant head injury significant history of alcohol/substance abuse or dependence active chronic pain condition (>1 year duration) other major medical conditions (e.g., cancer, stroke). MRI contraindications: metal or other implants that are not MR-safe claustrophobia pregnancy or suspected pregnancy tDCS contraindications*: skin conditions or injuries on the scalp hair extensions, wigs, braids, etc. that cannot be removed prior to the study metal implants or pacemakers (also contraindicated for MRI) Non-English speakers (due to written consent and questionnaires administered) Significant history of alcohol/substance abuse or dependence within last 12 months Neurostimulation or neuromodulation treatment longer than 20 minutes within the past 3 months Current medication use potentially affecting brain function, including decongestants, antihistamines, benzodiazepines or other anticonvulsants, or anti-psychotics.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Active<br> | Device: Transcranial Direct Current Stimulation<br>* Transcranial Direct Current Stimulation (tDCS) uses a mild electrical current to make small (or subtle) changes to how the brain works (or functions).<br>|
| Sham Comparator: Sham<br> | Device: Transcranial Direct Current Stimulation<br>* Transcranial Direct Current Stimulation (tDCS) uses a mild electrical current to make small (or subtle) changes to how the brain works (or functions).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in brain functional connectivity. | Functional MRI will measure changes in brain function during tDCS. Specifically, the investigators will measure change in functional connectivity of prefrontal cortex (% change in Fisher's z). | immediate | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in tinnitus symptoms | Symptoms of tinnitus will be measured before and after 5 sessions of tDCS using the Tinnitus Functional Index (TFI). Change in TFI scores will be used as a secondary outcome measure. Score range is 0-100, where low scores indicate low symptoms. | 1 week, 2 weeks, 1 month |