Investigating the Neurobiology of Tinnitus
Condition: Tinnitus; Traumatic Brain Injury; Post Traumatic Stress Disorder
MeSH terms: Tinnitus; Brain Injuries; Brain Injuries, Traumatic; Stress Disorders, Traumatic; Stress Disorders, Post-Traumatic
Study type: Observational

Summary: 
      The investigators hypothesize that individual differences exist in resting-state cortical
      attention, control, sensory, and emotion networks prior to noise exposure and these
      differences predispose some to the development of bothersome tinnitus. Furthermore, the
      investigators hypothesize that these changes in functional connectivity of these vulnerable
      systems after noise exposure are responsible for tinnitus. The proposed study will use a
      case-control cohort study design. Cases will be those soldiers who develop tinnitus and
      controls will be those who do not. This will be the first prospective study of tinnitus and
      will provide important information about the neurobiology of tinnitus.

      If a cortical neural network etiology for bothersome tinnitus is confirmed, it will be an
      astounding, powerful, paradigm shifting model for the diagnosis, prevention and, most
      importantly, treatment of tinnitus. Furthermore, if a battery of neurocognitive tests can
      identify soldiers at risk for the development of tinnitus then appropriate primary prevention
      strategies can be introduced.

      There are three Specific Aims to this project.

      Specific Aim 1. To determine if soldiers who develop tinnitus display pre-deployment
      differences in a set of physical, functional, cognitive, vulnerability, perpetuating factors,
      pre-deployment neurocognitive scores, or neuroimaging features compared to soldiers who do
      not develop tinnitus ("control group").

      Specific Aim 2. To determine if particular scores on neurocognitive tests or neuroimaging
      features of functional/structural connectivity networks are associated with the development
      of tinnitus.

      Specific Aim 3. To identify a set of pre-deployment physical, functional, cognitive,
      vulnerability, and perpetuating factors, neurocognitive responses, and neuroimaging features
      that are associated with the development of tinnitus.

      The investigators plan to recruit 200 soldiers, between the ages of 18 and 30 years who do
      not have hearing loss or tinnitus and have never been deployed to military theater. The
      soldier participants will undergo a variety of tests before and after deployment, which will
      include a hearing test, neurocognitive tests (i.e., brain function tests), and a variety of
      novel radiologic imaging studies of the brain. One of these novel radiologic imaging studies
      is functional connectivity Magnetic Resonance Imaging, a proven methodology that monitors
      changes in brain activity and connections based on blood flow between different brain areas
      and levels of consumption of oxygen. This information is used to describe the condition of
      important neural networks responsible for such things as attention, mood, sensation, vision,
      hearing, and introspection or self-contemplation.
    


Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Active-duty or reserve United States military personnel between the ages of 18 and 30 of
        either sex, all races and ethnicity, who are scheduled for initial deployment to theater
        with a Military Occupational Specialty code (MOS) of 11B Infantryman, 11C Indirect Fire
        Infantryman, 19D Calvary Scout, or 19K Armor Crewman.