Psychiatric distress caused by PTSD may increase attention toward tinnitus, as well as perceived loudness and discomfort. It is important to understand how tinnitus-related distress and PTSD negatively interact together, in order to develop more effective therapeutic approaches. Understanding symptoms and neurobiological mechanisms using functional magnetic resonance imaging (fMRI), can lead to the necessary knowledge to develop effective interventions for individuals who suffer from both conditions.
Tinnitus and posttraumatic stress disorder (PTSD) are two of the most common service-connected disabilities for active-duty Service Members and Veterans. Tinnitus and PTSD are highly co-morbid, yet distinct disorders. Tinnitus is an auditory disorder in which an illusory auditory percept is experienced, usually as ringing, buzzing, or whooshing sounds, despite no external objective noise source. On the other hand, PTSD is a trauma-related disorder, and is identified by intrusions of the traumatic event, avoidance of reminders, negative alterations in cognition and mood, and hypervigilance or hyperarousal. Similarities between tinnitus and PTSD have been documented among Cambodian refugees, as well as among U.S. Veteran samples. Moreover, the latest neuroimaging data from a recent clinical trial indicated that the auditory-vigilance network was the most dysregulated among active-duty service members with PTSD, compared to combat controls and civilian controls. Due to similar symptoms between tinnitus-related distress and PTSD, and similar dysregulated resting-state brain networks, it remains important to more fully understand how these two distinct disorders may be related. This study will be the first to prospectively examine the overt emotional, behavioral, and cognitive symptoms related to tinnitus-related distress and PTSD, and the overlapping functional connectivity between tinnitus and PTSD. Investigators will examine the overlapping symptoms and neurobiological mechanisms by conducting audiometric and psychological assessments and resting-state functional magnetic resonance imaging (fMRI) among 120 participants (30 with tinnitus and PTSD, 30 with only PTSD, 30 with only tinnitus, and 30 healthy controls). Participants will be recruited from the Frank Tejeda PTSD Clinic and the Audiology Clinic within the South Texas VA Health Care System, and the Hearing Center of Excellence at Lackland Air Force Base. Canonical correlations will be conducted to examine the symptom overlap between tinnitus and PTSD (Aim 1). Investigators aim to neurobiologically characterize tinnitus and PTSD, both separately and conjointly, by conducting fMRI (Aim 2). Investigators also aim to apply modeling to psychometric and neurofunctional data to identify specific regions of the auditory-vigilance network associated with distress related to tinnitus and PTSD. Understanding the shared cognitive, emotional, and behavioral symptoms and neurobiology associated with tinnitus and PTSD will help clinicians and researchers fully understand tinnitus and PTSD independently and conjointly. Results will lead to the identification of neurobiological markers for tinnitus and PTSD, identification of a different phenotype for individuals with both conditions, and development of behavioral and neuro-modulatory therapies that can reduce distress and impairment.
We will acquire BOLD fMRI images in an unstimulated state using an extended time-series (300 whole-brain volumes over \~ 60-75 min). These data are a main outcome. Data will be processed on an ongoing basis to ensure integrity, and includes controlling for white matter, cerebral spinal fluid, and movement.
The CAPS-5 is a semi-structured interview, conducted by an independent evaluator, that measures DSM-5 symptoms of PTSD. Presence of at least one intrusion symptom, one avoidance symptom, two cognition and mood symptoms, and two arousal symptoms for 1 month or more are required to reach the diagnostic threshold.
UT Health San Antonio
San Antonio, Texas, United States
Resting-State Functional MRI
We will acquire BOLD fMRI images in an unstimulated state using an extended time-series (300 whole-brain volumes over \~ 30 min) and assess for activation within the Auditory Vigilance Network. These data are a main outcome. Data were be processed on an ongoing basis to ensure integrity, and includes controlling for white matter, cerebral spinal fluid, and movement. BOLD levels were transformed to Z-scores, a statistical measure that conveys how many standard deviations the data points are away from the dataset. A Z-score of 0 represents the population mean. For each of the regions reported in the Auditory Vigilance Network, each positive point represents one standard deviation above the population mean. These positive Z-scores represent more brain activation within these regions.
Time frame: 30 minutes of acquired data
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Study Type
OBSERVATIONAL
Enrollment
64
Tympanometry will be conducted to assess ear canal volume (cm cubed), maximum pressure (daPa) peak compliance (ml), and type (A, AD, AS, B, B-High, C) for each ear) at 226-Hz admittance.
Tinnitus acoustic assessment (for tinnitus participants only): Tinnitus ear (left, right, bilateral), pitch matched frequency (Hz) and loudness matched intensity (dB) will be conducted. When available, the tinnitus acoustic assessment only will be repeated at the RII, on the same day and prior to the fMRI scan, to demonstrate reproducibility of results.
Otoscopy is a clinical procedure used to examine structures of the ear, particularly the external auditory canal, tympanic membrane, and middle ear
Pure tone air- and bone-conduction threshold will be conducted to evaluate audiometry and masking levels in both ears, from 250 Hz. To 16000 Hz.
Speech testing will be conducted in both ears, which will include speech reception threshold, speech reception threshold masking level, word recognition presentation level, and word recognition masking level.
Loudness discomfort levels will be tested in both right and left ears, from 500Hz to 4000Hz and speech reception threshold.
Quick Speech in Noise Test (QuickSIN) is a quick method for clinicians to quantify a patient's ability to hear in noise (1 minute).
Distortion-Product Otoacoustic Emissions (DPOAE) is an automated evaluation of cochlear function. A sensitive microphone is placed in the ear canal via a probe assembly with a disposable ear-tip attached to perform and record the measurements. DPOAEs will be elicited at multiple frequencies in both ears (10 min).