Experimental Tinnitus Treatment With Transcranial Magnetic Stimulation

Experimental Tinnitus Treatment With Transcranial Magnetic Stimulation

There are numerous conditions that may benefit from TMS but they lack definitive data from clinical trials with sufficient scientific rigor, which includes large, multi-site, randomized sham-controlled trials. This is the status for a variety of psychiatric and neurological disorders such as tinnitus, central pain, movement disorders, stroke rehabilitation, obsessive compulsive disorders, anxiety, schizophrenia, and addiction. In certain instances there may be sufficient evidence supporting the treatment efficacy of TMS that it is reasonable to offer TMS as an off-label treatment, a term for clinical treatments that have not received FDA approval but may nonetheless be helpful for patients. In other cases there is such a paucity of clinical trial data that the use of therapeutic TMS is less appropriate as a clinical treatment that the patient is charged for out of pocket and may cost several thousand dollars, but is better suited for clinically-oriented research. This has the added benefit of potentially helping the patient and providing investigators with additional information from which to inform future clinical trials. In this study the investigators propose to use TMS to treat tinnitus, for which few other treatments currently exist. Tinnitus affects approximately 1% of the population and can be debilitating for patients. Recent studies have shown some promise in reducing symptoms through neuromodulation, but results are variable and more research is needed to improve treatment protocols. The investigators plan to contribute to this body of research by taking an evidence-based approach to test whether TMS is effective at reducing symptoms of tinnitus. Each subject's MRI will be used to perform neuronavigated TMS stimulations while documenting changes in symptom severity with self-report questionnaires and symptom severity scales. If it is determined that a stimulation protocol is effective, 1-2 weeks of daily treatments will be scheduled as part of that subject's personalized treatment plan.

1. Consent patients that have been referred to the Noninvasive Brain Stimulation Clinic at the University of Iowa.
2. Patients will complete the following before any treatments occur: Tinnitus Intake Questionnaire, Tinnitus Functional Index, Tinnitus Questionnaires, Iowa Tinnitus Primary Function, Clinical Global Improvement Scale.
3. Patients may undergo audiological assessment if they have not already been tested prior to the study.
4. Patients will be required to obtain an MRI prior to treatment to aid in neuronavigated stimulation unless there is have access to a previous clinical MRI for this purpose.
5. MRI images will be loaded into BrainSight or Localite, which are both frameless stereotactic systems for MRI-guided TMS localization. If no MRI is acquired, the subject's head will be transformed to MNI standard space within the software. Neuronavigation allows us to place specific stimulation targets onto each subjects's MRI. For this study, the investigators will be targeting left dorsolateral prefrontal cortex, auditory cortices, and auditory association cortices; all targets are placed anatomically by a neurologist. Infrared trackers on the subject's head and TMS coil allow for neuronavigated stimulation of anatomical targets on the cortex with millimeter precision.
6. The motor threshold of the subject will be assessed, which is the intensity of TMS required to elicit motor evoked potentials from the hand 50% of the time.
7. Subjects will be fitted with an EEG cap to record neural activity before, during, and after the initial test session.
8. Single TMS pulses or brief trains of repetitive TMS lasting a few seconds will be administered at 80 - 120% of motor threshold to targeted regions of the cerebral cortex and cerebellum. A typical experiment will last 30 minutes to 2 hours. The patients are told they can stop the experiment at any time.
9. After each stimulation, patients will be asked to rate any changes in symptom severity and whether any side effects were experienced (Tinnitus Questionnaires, Clinical Global Improvement Scale).
10. After the treatment session, the TMS pulse locations will be related to changes in symptom severity as measured by self-report. If any stimulation treatments were successful in reducing symptom severity, a treatment plan for that target will be discussed and follow-up treatments may be scheduled.
11. Follow up treatments will vary between patients but will typically consist of daily treatments for up to 4 weeks or until treatment response is sustained. The patient can withdraw from follow treatments at any time. Patients will be asked to complete the following at these visits: Tinnitus Functional Index, Tinnitus Questionnaires, Iowa Tinnitus Primary Function, Clinical Global Improvement Scale.

Inclusion Criteria:

• tinnitus diagnosis

Exclusion Criteria:

• have epilepsy or a family history of epilepsy
• have implanted metal in or near their head
• have any history of brain injury or stroke
• have a tinnitus handicap inventory score of <38 (less than moderate handicap)