MRI Study of Noninvasive Transcranial Electrical Stimulation in Tinnitus

Northwestern University

Status and phase

Completed

Early Phase 1

Conditions

Tinnitus, Subjective

Treatments

Device: Transcranial electrical stimulation (tES)

Study type

Interventional

Funder types

Other

NIH

Identifiers

NCT03544359

STU00207056

R21DC015880 (U.S. NIH Grant/Contract)

Details and patient eligibility

About

The purpose of this research is to understand how a neuromodulation technique, transcranial electrical stimulation (tES), affects brain function in adults with chronic tinnitus measured with functional magnetic resonance imaging (fMRI). We hypothesize that multiple sessions of tES (5 consecutive days) will modulate:

Overall activity and local connectivity within brain regions near tES electrodes, and
Functional connectivity within brain networks associated with brain regions near tES electrodes.

In exploratory analyses, we also measure the extent to which the hypothesized changes listed above a related to changes in tinnitus symptoms after tES.

Full description

Chronic subjective tinnitus is a common and sometimes disabling condition, with few effective treatments and no cure. Tinnitus is thought to involve dysfunction in central brain networks subsequent to peripheral injury or interference; thus, neurostimulation therapies that directly target central circuits are receiving growing interest. Of these, noninvasive transcranial electrical stimulation (tES) is an attractive option, due to its relative affordability, mobility, and favorable safety profile. A growing number of studies have demonstrated that tES of temporal/auditory cortex is effective at transiently reducing tinnitus symptoms, including tinnitus loudness and tinnitus distress. However, the results of previous clinical trials are variable, and a mechanistic understanding of tES and its therapeutic effects remains elusive. The main goal of this research is to lay the groundwork for improved, patient-centered approaches to noninvasive neurostimulation therapy for chronic tinnitus. To accomplish this long-term goal, this study will determine how the intrinsic activity and connectivity of auditory networks are affected during simultaneous tES-fMRI of auditory cortex, specifically in those patients who experience reduced tinnitus symptoms after 5 consecutive days of tES. Though the primary goal of the proposed research is to optimize tES for the treatment of tinnitus, these studies will also provide a wealth of information regarding tinnitus pathophysiology and the mechanisms of tES more generally, which is being investigated for the treatment of a wide variety of brain disorders and injuries.

Enrollment

20 patients

Sex

All

Ages

18 to 65 years old

Volunteers

No Healthy Volunteers

Inclusion criteria

Ages between 18 and 65
Race/ethnicity: all races and ethnic groups
Sex/Gender: all
Capacity to provide informed consent
Subjective tinnitus symptoms for at least one year prior (confirmed by patient self-report)
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 (e.g., SSRI or SNRI) 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 65 (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
Diagnosis of any medical condition potentially affecting brain function, including: neuropsychiatric or mental disorders, mood disorders (bipolar disorder, anxiety, PTSD), psychotic states or disorders, developmental disorders, neurological disorders, including mild cognitive impairment, significant head injury, significant history of alcohol/substance abuse or dependence, chronic pain (>1 year duration)
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) *Please note that history of seizures or epilepsy, stroke, and brain injury are not safety concerns for tES use, and may be inclusion criteria for other tES studies. However, individuals with history of these conditions will be excluded here because these conditions are not a focus of the current study (see above).
Non-English speakers (due to written consent and questionnaires administered)
other major medical conditions (e.g., cancer, stroke).
Significant history of alcohol/substance abuse or dependence within last 12 months
Neurostimulation or neuromodulation treatment for any reason within the past 3 months
Current medication use potentially affecting brain function, including decongestants, antihistamines, benzodiazepines or other anticonvulsants, anti-psychotics, or antidepressants.
Prisoners will not participate in this study.