Approaches to Auditory Rehabilitation for Mild Traumatic Brain Injury

Study Overview
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Brief Summary
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Many soldiers returning from their recent service in Operation Iraqi Freedom/Operation Enduring Freedom (OIF/OEF) were exposed to blasts during combat. About 60% of blast-injured soldiers are diagnosed with traumatic brain injury (TBI), with approximately 18% having a mild TBI (mTBI). mTBI is associated with many symptoms, including memory problems, headaches, difficulty concentrating, increased anxiety, and, especially relevant here, reports of difficulty understanding speech in noisy environments and/or when people speak rapidly. While problems understanding rapid speech or speech in noise are associated with hearing loss, many of the OIF/OEF veterans with these complaints have clinically normal hearing. Although there is no physical damage to their ears, these veterans' hearing problems have a negative impact on their quality-of-life and functioning. Thus it is incumbent upon the VA to examine intervention approaches for veterans with normal/near-normal auditory sensitivity and significant complaints of difficulty hearing. Currently, there is no standard-of-care for these veterans other than providing information about hearing, hearing conservation, and the use of communication strategies. Two forms of rehabilitation likely to be more effective than such an informational-counseling approach are: (1) the use of personal miniaturized Frequency modulation (FM) systems, and (2) the provision of auditory training with Posit Science Brain Fitness Program (BFP). Personal FM systems increase the loudness of the speech signal relative to that of the unwanted noise, while the BFP training improves the ability to listen by taking advantage of the brain's ability to change (i.e., neural plasticity). In this study veterans will randomly be selected to receive one of four treatments: (1) FM use alone, (2) BFP training alone, (3) FM+BFP training combined, and (4) informational-counseling. The effectiveness of the interventions will be compared using self-report of hearing functioning on standard questionnaires. Results will contribute to the development of evidence-based intervention approaches for blast-exposed veterans with reported functional hearing difficulties and normal/near-normal auditory sensitivity.

Detailed Description
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The long-term goal of this study is to develop evidence-based auditory rehabilitation for veterans who have normal/near-normal peripheral auditory function and significant complaints of difficulty hearing. Many are veterans of the OIF/OEF conflicts who have been exposed to blast - the most common wounding etiology in these conflicts. Approximately 18% of blast-injured veterans are diagnosed with mild traumatic brain injury (mTBI). mTBI can result in post-concussive symptoms such as memory problems, difficulty concentrating, increased anxiety, and functional hearing difficulties in the presence of clinically-normal hearing sensitivity. Currently there is no standard-of-care auditory rehabilitation for veterans with normal/near-normal auditory sensitivity and complaints of difficulty hearing. At a minimum, the VA recommends provision of information about the auditory system, hearing conservation and use of communication strategies. Two interventions likely to be more efficacious are: (1) use of personal FM (frequency modulation) systems, and/or (2) auditory training. FM systems are effective for managing auditory problems in children with normal/near normal peripheral hearing. FM systems substantially improve the signal-to-noise ratio of speech in noisy and reverberant environments, theoretically making more resources available for higher level processing. Auditory training takes advantage of neural plasticity. The Posit Science Brain Fitness Program (BFP) is an auditory training program for adults that can improve temporal processing and working memory of older adults. Combining use of FM systems with auditory training has been shown to improve speech understanding and to decrease reported hearing abilities among adults with sensorineural hearing loss and functional hearing complaints. No study has systemically examined the relative efficacy of FM use and/or auditory training for veterans with mTBI and normal/almost normal hearing sensitivity. The effectiveness of these two intervention strategies will be examined in this study through a between-subjects randomized controlled clinical trial comparing the outcomes of: (1) FM use alone, (2) BFP alone, and (3) FM+BFP combined. All groups will also receive informational-counseling, as will (4) a control group. Outcomes will be measured subjectively through self-report of auditory competence. The results of the study will help to determine whether or not the use of FM systems or auditory training, either alone or combined, are efficacious interventions for blast-exposed veterans with reported functional hearing difficulties and normal/near-normal auditory sensitivity. Results will contribute to the development of evidence-based auditory rehabilitation for these veterans, moving VA closer to fulfilling its goal of providing excellence in patient care, veterans' benefits and customer satisfaction.

Official Title
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Evaluation of Approaches to Auditory Rehabilitation for Mild TBI

Conditions
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Traumatic Brain Injury

Intervention / Treatment
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* Device: FM system
* Behavioral: Auditory training


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participants will be OIF/OEF veterans with no exclusions based on age, ethnicity, or gender. To be included in the study participants will: Report difficulty understanding speech in difficult listening environments disproportionate to loss in hearing sensitivity, as defined by self-referral to the study Have hearing thresholds <= 65 decibels hearing loss (dB HL) at 0.5, 1.0, 2.0, 3.0 & 4.0 kilohertz (kHz) Cognitive abilities sufficient to participate in the study, as determined by an age and education-level appropriate score on the Mini Mental State Exam (MMSE; Folstein, Robins, & Helzer, 1983; Crum et al., 1993), English as a first language, Openness to using a personal FM system for a four-week period and/or to conducting auditory training over an eight-week period, as determined through interview. Exclusion Criteria: Asymmetric pure tone thresholds (left-right difference > 15 dB HL at frequencies of 500 through 4000 Hz), Presence of neurological, psychiatric or physical disorders, or co-morbid diseases that would prevent completion of the study as determined by chart review, Best corrected vision worse than 20/63 as measured with the Smith-Kettlewell Institute Low Luminance (SKILL) Card
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

Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: FM System<br>Provision of FM assistive device | Device: FM system<br>* Frequency modulation assistive device<br>|
| Experimental: Auditory Training<br>Provision of auditory training | Behavioral: Auditory training<br>* Participation in computerized auditory training program for eight weeks<br>|
| Experimental: FM System and Auditory Training<br>Provision of FM assistive device and auditory training | Device: FM system<br>* Frequency modulation assistive device<br>Behavioral: Auditory training<br>* Participation in computerized auditory training program for eight weeks<br>|
| No Intervention: Standard-of-Care<br>Standard-of-care informational counseling | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Competence Score From the Psychosocial Impact of Assistive Devices Scale (PIADS) | Assesses the impact a rehabilitative intervention has on perceived Competence (perceived functional capability, independence and performance). Responses are reported on a 7-point scale that ranges from -3 (maximum negative impact) to +3 (maximum positive impact). The mid-point, zero, indicates no impact or no perceived change | Immediately post-intervention between weeks 8 and 12 | 
| Stroop Color and Word Test | Measure of processing interference that assesses the ability to cope with cognitive stress and process complex input. It consists of a Word Page with color words printed in black ink, a Color Page with 'Xs' printed in color, and a Color-Word Page with words from the first page printed in colors from the second page (the color and the word do not match). The test-taker looks at each sheet and moves down the columns, reading words or naming the ink colors as quickly as possible within a time limit. Interference raw scores were converted into t-scores for analysis. T-score benefit was the analytic metric used. T-score benefit = post-intervention score minus baseline score | Baseline and Immediately post-intervention (between weeks 8 and 12). | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Hearing in Noise Test | Hearing In Noise Test assesses speech understanding in noise assessed. Sentences are presented in a background of noise. The signal to noise ratio is varied adaptively to obtained the signal to noise ratio at which participants can correctly repeat back 50% of sentences presented in speech-shaped noise is determined. A lower signal to noise ratio indicates better performance. | Immediately post-intervention between weeks 8 and 12. | 
| Staggered Spondaic Word Test | Dichotic listening test in which two spondaic words are presented, one to each ear of the listener, in an overlapping fashion such that the first syllable of the first word is presented in isolation, the second syllable of the first word is presented simultaneously with the first syllable of the second word, and the second syllable of the second word is presented in isolation. Total number of test spondee pairs = 40. | Immediately post-intervention between weeks 8 and 12. | 
| Digit Span Score Measure of Auditory Working Memory | The Digit Span subtest of the Wechsler Adult Intelligence Scale 3rd edition (WAIS-III) assessed auditory working memory. It consists of a Digit Span Forward task in which individuals to repeat numbers in the same sequence as they were presented verbally, and a Digit Span Backward task in which individuals repeat back the numbers in the reverse order to which they were heard. Data are summed to compute a Digit Span total score. Possible range of scores is 0 to 30, with higher scores indicating better performance. | Immediately post-intervention between weeks 8 and 12. | 
| Time Compressed Speech Test (TCST) | the TCST assessed speech recognition for speeded speech. Sentences are presented in the sound field in quiet at with 50% and 60% time compression. Participants repeat back each sentence after it is presented. | Immediately post-intervention between weeks 8 and 12. | 
| Cognitive Self Report Questionnaire (CSRQ). | CSRQ assesses self-reported cognitive difficulties in 8 domains: Attention, Executive function, Memory, Language, Vision, Hearing, Energy,and Satisfaction. Participants respond on a 3-point Likert scale whether they perceived they improved, remained the same, or got worse as a result of an intervention. Total score is computed by summing scores on each subscale. Range for total score = -64 to +64, with higher scores indicating fewer reported cognitive difficulties. | Immediately post-intervention between weeks 8 and 12. | 
| Speech, Spatial and Qualities of Hearing Scale-comparative (SSQ-C) | Three subscale questionnaire that examines reported change in auditory disability for Speech, Spatial hearing and Quality of sounds. Subjects respond on a scale of -5 ('much worse') to +5 (much better) to indicate the change in difficulties following an intervention they have hearing in specific situations, with a lower number indicating greater difficulty. Results are presented for average total SSQ-C score which can range from -5 to +5, with higher scores indicating greater improvement. | Immediately post-intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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traumatic brain injury, rehabilitation, auditory processing disorder