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Ding D, Manohar S, Kador PF, Salvi R. Multifunctional redox modulator prevents blast-induced loss of cochlear and vestibular hair cells and auditory spiral ganglion neurons. Sci Rep 2024; 14:15296. [PMID: 38961203 PMCID: PMC11222375 DOI: 10.1038/s41598-024-66406-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Accepted: 07/01/2024] [Indexed: 07/05/2024] Open
Abstract
Blast wave exposure, a leading cause of hearing loss and balance dysfunction among military personnel, arises primarily from direct mechanical damage to the mechanosensory hair cells and supporting structures or indirectly through excessive oxidative stress. We previously reported that HK-2, an orally active, multifunctional redox modulator (MFRM), was highly effective in reducing both hearing loss and hair cells loss in rats exposed to a moderate intensity workday noise that likely damages the cochlea primarily from oxidative stress versus direct mechanical trauma. To determine if HK-2 could also protect cochlear and vestibular cells from damage caused primarily from direct blast-induced mechanical trauma versus oxidative stress, we exposed rats to six blasts of 186 dB peak SPL. The rats were divided into four groups: (B) blast alone, (BEP) blast plus earplugs, (BHK-2) blast plus HK-2 and (BEPHK-2) blast plus earplugs plus HK-2. HK-2 was orally administered at 50 mg/kg/d from 7-days before to 30-day after the blast exposure. Cochlear and vestibular tissues were harvested 60-d post-exposure and evaluated for loss of outer hair cells (OHC), inner hair cells (IHC), auditory nerve fibers (ANF), spiral ganglion neurons (SGN) and vestibular hair cells in the saccule, utricle and semicircular canals. In the untreated blast-exposed group (B), massive losses occurred to OHC, IHC, ANF, SGN and only the vestibular hair cells in the striola region of the saccule. In contrast, rats treated with HK-2 (BHK-2) sustained significantly less OHC (67%) and IHC (57%) loss compared to the B group. OHC and IHC losses were smallest in the BEPHK-2 group, but not significantly different from the BEP group indicating lack of protective synergy between EP and HK-2. There was no loss of ANF, SGN or saccular hair cells in the BHK-2, BEP and BEPHK-2 groups. Thus, HK-2 not only significantly reduced OHC and IHC damage, but completely prevented loss of ANF, SGN and saccule hair cells. The powerful protective effects of this oral MFRM make HK-2 an extremely promising candidate for human clinical trials.
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Affiliation(s)
- Dalian Ding
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY, 14214, USA
| | | | | | - Richard Salvi
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY, 14214, USA.
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Sonstroem A, Thapa S, Pigott K, Henry JA, Schultz J, Esquivel C, Carlson KF, Hullar TE, Reavis KM. Prevalence and Risk Factors of Self-reported Dizziness in Post-9/11 Service Members and Veterans. Mil Med 2023; 188:511-519. [PMID: 37948221 DOI: 10.1093/milmed/usad220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 03/14/2023] [Accepted: 05/31/2023] [Indexed: 11/12/2023] Open
Abstract
INTRODUCTION Dizziness is prevalent in the general population, but little is known about its prevalence in the U.S. military population. Dizziness is commonly associated with blast exposure and traumatic brain injury (TBI), but the potential independent contributions of blast and TBI have yet to be evaluated. This study's goal was to estimate the prevalence of dizziness among post-9/11 service members and Veterans and to examine independent and joint associations between military TBI history, blast exposure, and self-reported dizziness. MATERIALS AND METHODS The study sample consisted of service members (n = 424) and recently separated (< ∼2.5 years) Veterans (n = 492) enrolled in the Noise Outcomes in Service members Epidemiology (NOISE) Study. We examined associations between self-reported history of probable TBI and blast exposure and recent dizziness using logistic regression. Models were stratified by service member versus Veteran status and adjusted to account for potentially confounding demographic and military characteristics. RESULTS Overall, 22% of service members and 31% of Veterans self-reported dizziness. Compared to those with neither TBI nor blast exposure history, both service members and Veterans with TBI (with or without blast) were three to four times more likely to self-report dizziness. Those with blast exposure but no TBI history were not more likely to self-report dizziness. There was no evidence of an interaction effect between blast exposure and a history of TBI on the occurrence of dizziness. CONCLUSION Self-reported dizziness was prevalent in this sample of service members and Veterans. Probable TBI history, with or without blast exposure, was associated with dizziness, but blast exposure without TBI history was not. This suggests that treatment guidelines for TBI-related dizziness may not need to be tailored to the injury mechanism. However, future efforts should be directed toward the understanding of the pathophysiology of TBI on self-reported dizziness, which is fundamental to the design of treatment strategies.
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Affiliation(s)
- Anneka Sonstroem
- VA RR&D, National Center for Rehabilitative Auditory Research, VA Portland Health Care System, Portland, OR 97239, USA
- OHSU-PSU School of Public Health, Oregon Health & Science University, Portland, OR 97239, USA
| | - Samrita Thapa
- VA RR&D, National Center for Rehabilitative Auditory Research, VA Portland Health Care System, Portland, OR 97239, USA
- OHSU-PSU School of Public Health, Oregon Health & Science University, Portland, OR 97239, USA
| | - Kaylee Pigott
- VA RR&D, National Center for Rehabilitative Auditory Research, VA Portland Health Care System, Portland, OR 97239, USA
- Department of Communication Sciences and Disorders, Western Washington University, Bellingham, WA 98225, USA
| | - James A Henry
- VA RR&D, National Center for Rehabilitative Auditory Research, VA Portland Health Care System, Portland, OR 97239, USA
- Department of Otolaryngology, Oregon Health & Science University, Portland, OR 97239, USA
| | - James Schultz
- DoD Hearing Center of Excellence, Defense Health Agency, 59MDW/SG02O, Lackland AFB, TX 78236, USA
| | - Carlos Esquivel
- DoD Hearing Center of Excellence, Defense Health Agency, 59MDW/SG02O, Lackland AFB, TX 78236, USA
| | - Kathleen F Carlson
- VA RR&D, National Center for Rehabilitative Auditory Research, VA Portland Health Care System, Portland, OR 97239, USA
- OHSU-PSU School of Public Health, Oregon Health & Science University, Portland, OR 97239, USA
- VA HSR&D Center of Innovation, Center to Improve Veteran Involvement in Care, VA Portland Health Care System, Portland, OR 97239, USA
| | - Timothy E Hullar
- VA RR&D, National Center for Rehabilitative Auditory Research, VA Portland Health Care System, Portland, OR 97239, USA
- Department of Otolaryngology, Oregon Health & Science University, Portland, OR 97239, USA
| | - Kelly M Reavis
- VA RR&D, National Center for Rehabilitative Auditory Research, VA Portland Health Care System, Portland, OR 97239, USA
- OHSU-PSU School of Public Health, Oregon Health & Science University, Portland, OR 97239, USA
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Akin FW, Swan AA, Kalvesmaki A, Hall CD, Riska KM, Stressman KD, Nguyen H, Amuan M, Pugh MJ. Factors That Impact the Long-Term Outcome of Postconcussive Dizziness Among Post-9/11 Veterans. Am J Audiol 2023; 32:706-720. [PMID: 37040302 DOI: 10.1044/2023_aja-22-00150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2023] Open
Abstract
PURPOSE The primary aim of this study was to examine the factors associated with long-term outcomes of postconcussive disruptive dizziness in Veterans of the post-9/11 wars. METHOD For this observational cohort study, the Neurobehavioral Symptom Inventory-Vestibular subscale (NSI-V) score was used as an outcome measure for dizziness in 987 post-9/11 Veterans who indicated disruptive dizziness at an initial Veterans Health Administration Comprehensive Traumatic Brain Injury Evaluation (CTBIE). An NSI-V change score was calculated as the difference in the scores obtained at the initial CTBIE and on a subsequent survey. Differences in the NSI-V change scores were examined for demographics, injury characteristics, comorbidities, and vestibular and balance function variables, and multiple linear regression analyses were used to explore associations among the variables and the NSI-V change score. RESULTS The majority of Veterans (61%) demonstrated a decrease in the NSI-V score, suggesting less dizziness on the survey compared with the CTBIE; 16% showed no change; and 22% had a higher score. Significant differences in the NSI-V change score were observed for traumatic brain injury (TBI) status, diagnoses of post-traumatic stress disorder (PTSD), headache and insomnia, and vestibular function. Multivariate regressions revealed significant associations between the NSI-V change score and the initial CTBIE NSI-V score, education level, race/ethnicity, TBI status, diagnoses of PTSD or hearing loss, and vestibular function. CONCLUSIONS Postconcussive dizziness can continue for years following an injury. Factors associated with poor prognosis include TBI, diagnoses of PTSD or hearing loss, abnormal vestibular function, increased age, identification as a Black Veteran, and high school education level.
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Affiliation(s)
- Faith W Akin
- Vestibular and Balance Laboratory, James H. Quillen VA Medical Center, Mountain Home, TN
- Department of Audiology & Speech-Language Pathology, East Tennessee State University, Johnson City
| | - Alicia A Swan
- Department of Psychology, The University of Texas at San Antonio
- Polytrauma Rehabilitation Center, South Texas Veterans Health Care System, San Antonio
| | - Andrea Kalvesmaki
- Informatics, Decision-Enhancement, and Analytic Sciences (IDEAS) Center of Innovation, VA Salt Lake City Health Care System, UT
- Division of Epidemiology, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City
| | - Courtney D Hall
- Vestibular and Balance Laboratory, James H. Quillen VA Medical Center, Mountain Home, TN
- Physical Therapy Program, East Tennessee State University, Johnson City
| | - Kristal M Riska
- Department of Head and Neck Surgery & Communication Sciences, Duke University, Durham, NC
| | - Kara D Stressman
- Vestibular and Balance Laboratory, James H. Quillen VA Medical Center, Mountain Home, TN
| | - Huong Nguyen
- Informatics, Decision-Enhancement, and Analytic Sciences (IDEAS) Center of Innovation, VA Salt Lake City Health Care System, UT
- Division of Epidemiology, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City
| | - Megan Amuan
- Informatics, Decision-Enhancement, and Analytic Sciences (IDEAS) Center of Innovation, VA Salt Lake City Health Care System, UT
- Division of Epidemiology, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City
| | - Mary Jo Pugh
- Informatics, Decision-Enhancement, and Analytic Sciences (IDEAS) Center of Innovation, VA Salt Lake City Health Care System, UT
- Division of Epidemiology, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City
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Raciti FM, Morales Y, Snapp HA, Rajguru SM. A reliable and reproducible protocol for sound-evoked vestibular myogenic potentials in rattus norvegicus. Front Integr Neurosci 2023; 17:1236642. [PMID: 37731913 PMCID: PMC10508189 DOI: 10.3389/fnint.2023.1236642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 08/21/2023] [Indexed: 09/22/2023] Open
Abstract
Introduction Cervical vestibular evoked myogenic potentials (cVEMPs) provide an objective measure of the integrity of the sacculo-collic pathway leading to their widespread use as a clinical tool in the diagnostic vestibular test battery. Though the application of cVEMPs in preclinical models to assess vestibular function, as performed in relevant clinical populations, remains limited. The present study aimed to establish a rodent model of cVEMP with standardized methods and protocols, examine the neural basis of the responses, and characterize and validate important features for interpretation and assessment of vestibular function. Methods We compared air-conducted sound (ACS)-evoked VEMPs from the sternocleidomastoid muscles in naïve Brown Norway rats. A custom setup facilitated repeatable and reliable measurements which were carried out at multiple intensities with ACS between 1 and 16 kHz and over 7 days. The myogenic potentials were identified by the presence of a positive (P1)-negative (N1) waveform at 3-5 ms from the stimulus onset. Threshold, amplitude, and latency were compared with intensity- and frequency-matched responses within and between animals. Results cVEMP responses were repeatedly evoked with stimulus intensities between 50-100 dB SPL with excellent test-retest reliability and across multiple measurements over 7 days for all frequencies tested. Suprathreshold, cVEMP responses at 90 dB SPL for 6-10 kHz stimuli demonstrated significantly larger amplitudes (p < 0.01) and shorter latencies (p < 0.001) compared to cVEMP responses for 1-4 kHz stimuli. Latency of cVEMP showed sex-dependent variability, but no significant differences in threshold or amplitude between males and females was observed. Discussion The results provide a replicable and reliable setup, test protocol, and comprehensive characterization of cVEMP responses in a preclinical model which can be used in future studies to elucidate pathophysiological characteristics of vestibular dysfunctions or test efficacy of therapeutics.
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Affiliation(s)
- Federica M. Raciti
- Department of Otolaryngology, University of Miami, Miami, FL, United States
- Department of Biomedical Engineering, University of Miami, Miami, FL, United States
| | - Yasniary Morales
- Department of Otolaryngology, University of Miami, Miami, FL, United States
- Department of Biomedical Engineering, University of Miami, Miami, FL, United States
| | - Hillary A. Snapp
- Department of Otolaryngology, University of Miami, Miami, FL, United States
- Department of Biomedical Engineering, University of Miami, Miami, FL, United States
| | - Suhrud M. Rajguru
- Department of Otolaryngology, University of Miami, Miami, FL, United States
- Department of Biomedical Engineering, University of Miami, Miami, FL, United States
- Bruce W. Carter Department of Veterans Affairs Medical Center, Miami, FL, United States
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Pastras CJ, Gholami N, Jennings S, Zhu H, Zhou W, Brown DJ, Curthoys IS, Rabbitt RD. A mathematical model for mechanical activation and compound action potential generation by the utricle in response to sound and vibration. Front Neurol 2023; 14:1109506. [PMID: 37051057 PMCID: PMC10083375 DOI: 10.3389/fneur.2023.1109506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 03/01/2023] [Indexed: 03/28/2023] Open
Abstract
IntroductionCalyx bearing vestibular afferent neurons innervating type I hair cells in the striolar region of the utricle are exquisitely sensitive to auditory-frequency air conducted sound (ACS) and bone conducted vibration (BCV). Here, we present experimental data and a mathematical model of utricular mechanics and vestibular compound action potential generation (vCAP) in response to clinically relevant levels of ACS and BCV. Vibration of the otoconial layer relative to the sensory epithelium was simulated using a Newtonian two-degree-of-freedom spring-mass-damper system, action potential timing was simulated using an empirical model, and vCAPs were simulated by convolving responses of the population of sensitive neurons with an empirical extracellular voltage kernel. The model was validated by comparison to macular vibration and vCAPs recorded in the guinea pig, in vivo.ResultsTransient stimuli evoked short-latency vCAPs that scaled in magnitude and timing with hair bundle mechanical shear rate for both ACS and BCV. For pulse BCV stimuli with durations <0.8 ms, the vCAP magnitude increased in proportion to temporal bone acceleration, but for pulse durations >0.9 ms the magnitude increased in proportion to temporal bone jerk. Once validated using ACS and BCV data, the model was applied to predict blast-induced hair bundle shear, with results predicting acute mechanical damage to bundles immediately upon exposure.DiscussionResults demonstrate the switch from linear acceleration to linear jerk as the adequate stimulus arises entirely from mechanical factors controlling the dynamics of sensory hair bundle deflection. The model describes the switch in terms of the mechanical natural frequencies of vibration, which vary between species based on morphology and mechanical factors.
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Affiliation(s)
- Christopher J. Pastras
- Faculty of Science and Engineering, School of Engineering, Macquarie University, Sydney, NSW, Australia
| | - Nastaran Gholami
- Biomedical Engineering, University of Utah, Salt Lake City, UT, United States
| | - Skyler Jennings
- Communication Sciences and Neuroscience Program, University of Utah, Salt Lake City, UT, United States
| | - Hong Zhu
- University of Mississippi Medical Center, Jackson, MS, United States
| | - Wu Zhou
- University of Mississippi Medical Center, Jackson, MS, United States
| | - Daniel J. Brown
- School of Pharmacy and Biomedical Sciences, Curtin University, Bentley, WA, Australia
| | - Ian S. Curthoys
- Vestibular Research Laboratory, School of Psychology, The University of Sydney, Sydney, NSW, Australia
| | - Richard D. Rabbitt
- Biomedical Engineering, University of Utah, Salt Lake City, UT, United States
- Otolaryngology and Neuroscience Program, University of Utah, Salt Lake City, UT, United States
- *Correspondence: Richard D. Rabbitt,
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Paik CB, Pei M, Oghalai JS. Review of blast noise and the auditory system. Hear Res 2022; 425:108459. [PMID: 35181171 PMCID: PMC9357863 DOI: 10.1016/j.heares.2022.108459] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 02/03/2022] [Accepted: 02/07/2022] [Indexed: 11/22/2022]
Abstract
The auditory system is particularly vulnerable to blast injury due to the ear's role as a highly sensitive pressure transducer. Over the past several decades, studies have used a variety of animal models and experimental procedures to recreate blast-induced acoustic trauma. Given the developing nature of this field and our incomplete understanding of molecular mechanisms underlying blast-related auditory disturbances, an updated discussion about these studies is warranted. Here, we comprehensively review well-established blast-related auditory pathology including tympanic membrane perforation and hair cell loss. In addition, we discuss important mechanistic studies that aim to bridge gaps in our current understanding of the molecular and microstructural events underlying blast-induced cochlear, auditory nerve, brainstem, and central auditory system damage. Key findings from the recent literature include the association between endolymphatic hydrops and cochlear synaptic loss, blast-induced neuroinflammatory markers in the peripheral and central auditory system, and therapeutic approaches targeting biochemical markers of blast injury. We conclude that blast is an extreme form of noise exposure. Blast waves produce cochlear damage that appears similar to, but more extreme than, the standard noise exposure protocols used in auditory research. However, experimental variations in studies of blast-induced acoustic trauma make it challenging to compare and interpret data across studies.
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Affiliation(s)
- Connie B Paik
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, CA USA
| | - Michelle Pei
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, CA USA
| | - John S Oghalai
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, CA USA.
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Snapp HA, Schaefer Solle N, Millet B, Rajguru SM. Subclinical Hearing Deficits in Noise-Exposed Firefighters. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:11028. [PMID: 36078744 PMCID: PMC9518181 DOI: 10.3390/ijerph191711028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 08/24/2022] [Accepted: 08/30/2022] [Indexed: 06/15/2023]
Abstract
Noise-induced hearing loss (NIHL) is the most prevalent occupational disease in the world and firefighters are at increased risk of NIHL due to their frequent exposure to hazardous levels of noise during service. Adverse effects of NIHL include acceleration of age-related hearing loss and an increased risk of cognitive decline. A critical challenge in addressing NIHL is the delayed clinical presentation of symptoms and lack of sensitive tools for early detection. To study the early clinical symptoms of NIHL in this high-risk group, we collected hearing function data including behavioral audiometric thresholds and distortion product otoacoustic emissions (DPOAEs) in 176 firefighters during annual physical assessments. Results revealed significant deficits in cochlear outer hair cell function in the presence of normal audiograms. Additionally, 55% of firefighters self-reported changes in hearing, while 20% self-reported concerns about their balance. This study is the first to characterize DPOAEs in firefighters who display decreased DPOAE amplitudes with increasing years in the fire service. These effects were observed even when controlling for hearing loss and age and are suggestive of a link between hearing loss and occupational exposure to hazardous noise.
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Affiliation(s)
- Hillary A. Snapp
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA or
| | - Natasha Schaefer Solle
- Department of Medicine, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Barbara Millet
- Department of Interactive Media, University of Miami, Coral Gables, FL 33146, USA
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL 33146, USA
| | - Suhrud M. Rajguru
- Department of Otolaryngology, University of Miami Miller School of Medicine, Miami, FL 33136, USA or
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL 33146, USA
- RestorEar Devices LLC, Kirkland, WA 98033, USA
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Akin FW, Murnane OD, Hall CD, Riska KM, Sears J. Vestibular and balance function in veterans with chronic dizziness associated with mild traumatic brain injury and blast exposure. Front Neurol 2022; 13:930389. [PMID: 36119708 PMCID: PMC9481418 DOI: 10.3389/fneur.2022.930389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 08/15/2022] [Indexed: 11/13/2022] Open
Abstract
The purpose of this study was to examine vestibular and balance function in individuals with chronic dizziness associated with mTBI/blast. A prospective case-control study design was used to examine ocular motor, vestibular function, and postural stability in veterans with symptoms of dizziness and/or imbalance following an mTBI or blast exposure (n = 77) and a healthy control group (n = 32). Significant group differences were observed for saccadic accuracy, VOR gain during slow harmonic acceleration at 0.01 Hz, cervical vestibular evoked myogenic potentials asymmetry ratio, composite equilibrium score on the sensory organization test, total Dynamic Gait Index score, and gait. The frequency of test abnormalities in participants with mTBI/blast ranged from 0 to 70% across vestibular, ocular motor, and balance/gait testing, with the most frequent abnormalities occurring on tests of balance and gait function. Seventy-two percent of the mTBI/blast participants had abnormal findings on one or more of the balance and gait tests. Vestibular test abnormalities occurred in ~34% of the individuals with chronic dizziness and mTBI/blast, and abnormalities occurred more frequently for measures of otolith organ function (25% for cVEMP and 18% for oVEMP) than for measures of hSCC function (8% for SHA and 6% for caloric test). Abnormal ocular motor function occurred in 18% of the mTBI/blast group. These findings support the need for comprehensive vestibular and balance assessment in individuals with dizziness following mTBI/blast-related injury.
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Affiliation(s)
- Faith W. Akin
- Mountain Home Hearing and Balance Research Program, James H. Quillen VA Medical Center, Mountain Home, TN, United States
- Department of Audiology and Speech-Language Pathology, East Tennessee State University, Johnson City, TN, United States
- *Correspondence: Faith W. Akin
| | - Owen D. Murnane
- Mountain Home Hearing and Balance Research Program, James H. Quillen VA Medical Center, Mountain Home, TN, United States
- Department of Audiology and Speech-Language Pathology, East Tennessee State University, Johnson City, TN, United States
| | - Courtney D. Hall
- Mountain Home Hearing and Balance Research Program, James H. Quillen VA Medical Center, Mountain Home, TN, United States
- Physical Therapy Program, Department of Rehabilitative Sciences, East Tennessee State University, Johnson City, TN, United States
| | - Kristal M. Riska
- Department of Head and Neck Surgery & Communication Sciences, Duke University School of Medicine, Durham, NC, United States
| | - Jennifer Sears
- Mountain Home Hearing and Balance Research Program, James H. Quillen VA Medical Center, Mountain Home, TN, United States
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Wood NI, Hentig J, Hager M, Hill-Pearson C, Hershaw JN, Souvignier AR, Bobula SA. The Non-Concordance of Self-Reported and Performance-Based Measures of Vestibular Dysfunction in Military and Civilian Populations Following TBI. J Clin Med 2022; 11:jcm11112959. [PMID: 35683348 PMCID: PMC9181197 DOI: 10.3390/jcm11112959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/17/2022] [Accepted: 05/20/2022] [Indexed: 11/23/2022] Open
Abstract
As a predominately young, physically active, and generally healthy population, service members (SMs) with vestibular dysfunction (VD) following a TBI may not be accurately represented by the current civilian reference ranges on assessments of VD. This study enrolled SMs who were referred for vestibular rehabilitation following a mild/moderate TBI. The participants self-reported VD using the Activities-specific Balance Confidence (ABC) scale and the Dizziness Handicap Inventory (DHI) followed by evaluation of vestibular performance using computerized dynamic posturography sensory organizational test (CDP−SOT). Retrospective analysis of these outcomes comparing the study sample of SMs to the reported civilian samples revealed SMs self-reported lower VD with significantly higher balance confidence (ABC: 77.11 ± 14.61, p < 0.05) and lower dizziness (DHI: 37.75 ± 11.74, p < 0.05) than civilians. However, the SMs underperformed in performance-based evaluations compared to civilians with significantly lower CDP−SOT composite and ratio scores (COMP: 68.46 ± 13.46, p < 0.05; VIS: 81.36 ± 14.03, p < 0.01; VEST: 55.63 ± 22.28, p < 0.05; SOM: 90.46 ± 10.17, p < 0.05). Correlational analyses identified significant relationships between the ABC and CDP−SOT composite (r = 0.380, p < 0.01) and ratio scores (VIS: r = 0.266, p < 0.05; VEST: r = 0.352, p < 0.01). These results highlight the importance of recognizing and understanding nuances in assessing VD in SMs to ensure they have access to adequate care and rehabilitation prior to returning to duty.
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Affiliation(s)
- Nicholas I. Wood
- Evans Army Community Hospital, Fort Carson, CO 80913, USA; (N.I.W.); (C.H.-P.); (J.N.H.); (A.R.S.); (S.A.B.)
- Traumatic Brain Injury Center of Excellence, Fort Carson, CO 80913, USA;
- General Dynamics Information Technology, Falls Church, VA 22042, USA
| | - James Hentig
- Evans Army Community Hospital, Fort Carson, CO 80913, USA; (N.I.W.); (C.H.-P.); (J.N.H.); (A.R.S.); (S.A.B.)
- Traumatic Brain Injury Center of Excellence, Fort Carson, CO 80913, USA;
- General Dynamics Information Technology, Falls Church, VA 22042, USA
- Correspondence: ; Tel.: +1-(719)-258-0695
| | - Madison Hager
- Traumatic Brain Injury Center of Excellence, Fort Carson, CO 80913, USA;
| | - Candace Hill-Pearson
- Evans Army Community Hospital, Fort Carson, CO 80913, USA; (N.I.W.); (C.H.-P.); (J.N.H.); (A.R.S.); (S.A.B.)
- Traumatic Brain Injury Center of Excellence, Fort Carson, CO 80913, USA;
- General Dynamics Information Technology, Falls Church, VA 22042, USA
| | - Jamie N. Hershaw
- Evans Army Community Hospital, Fort Carson, CO 80913, USA; (N.I.W.); (C.H.-P.); (J.N.H.); (A.R.S.); (S.A.B.)
- Traumatic Brain Injury Center of Excellence, Fort Carson, CO 80913, USA;
- General Dynamics Information Technology, Falls Church, VA 22042, USA
| | - Alicia R. Souvignier
- Evans Army Community Hospital, Fort Carson, CO 80913, USA; (N.I.W.); (C.H.-P.); (J.N.H.); (A.R.S.); (S.A.B.)
| | - Selena A. Bobula
- Evans Army Community Hospital, Fort Carson, CO 80913, USA; (N.I.W.); (C.H.-P.); (J.N.H.); (A.R.S.); (S.A.B.)
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Mao B, Wang Y, Balasubramanian T, Urioste R, Wafa T, Fitzgerald TS, Haraczy SJ, Edwards-Hollingsworth K, Sayyid ZN, Wilder D, Sajja VSSS, Wei Y, Arun P, Gist I, Cheng AG, Long JB, Kelley MW. Assessment of auditory and vestibular damage in a mouse model after single and triple blast exposures. Hear Res 2021; 407:108292. [PMID: 34214947 PMCID: PMC8276524 DOI: 10.1016/j.heares.2021.108292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 05/17/2021] [Accepted: 06/02/2021] [Indexed: 12/18/2022]
Abstract
The use of explosive devices in war and terrorism has increased exposure to concussive blasts among both military personnel and civilians, which can cause permanent hearing and balance deficits that adversely affect survivors' quality of life. Significant knowledge gaps on the underlying etiology of blast-induced hearing loss and balance disorders remain, especially with regard to the effect of blast exposure on the vestibular system, the impact of multiple blast exposures, and long-term recovery. To address this, we investigated the effects of blast exposure on the inner ear using a mouse model in conjunction with a high-fidelity blast simulator. Anesthetized animals were subjected to single or triple blast exposures, and physiological measurements and tissue were collected over the course of recovery for up to 180 days. Auditory brainstem responses (ABRs) indicated significantly elevated thresholds across multiple frequencies. Limited recovery was observed at low frequencies in single-blasted mice. Distortion Product Otoacoustic Emissions (DPOAEs) were initially absent in all blast-exposed mice, but low-amplitude DPOAEs could be detected at low frequencies in some single-blast mice by 30 days post-blast, and in some triple-blast mice at 180 days post-blast. All blast-exposed mice showed signs of Tympanic Membrane (TM) rupture immediately following exposure and loss of outer hair cells (OHCs) in the basal cochlear turn. In contrast, the number of Inner Hair Cells (IHCs) and spiral ganglion neurons was unchanged following blast-exposure. A significant reduction in IHC pre-synaptic puncta was observed in the upper turns of blast-exposed cochleae. Finally, we found no significant loss of utricular hair cells or changes in vestibular function as assessed by vestibular evoked potentials. Our results suggest that (1) blast exposure can cause severe, long-term hearing loss which may be partially due to slow TM healing or altered mechanical properties of healed TMs, (2) traumatic levels of sound can still reach the inner ear and cause basal OHC loss despite middle ear dysfunction caused by TM rupture, (3) blast exposure may result in synaptopathy in humans, and (4) balance deficits after blast exposure may be primarily due to traumatic brain injury, rather than damage to the peripheral vestibular system.
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Affiliation(s)
- Beatrice Mao
- Section on Developmental Neuroscience, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Ying Wang
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Tara Balasubramanian
- Section on Developmental Neuroscience, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Rodrigo Urioste
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Talah Wafa
- Mouse Auditory Testing Core Facility, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Tracy S. Fitzgerald
- Mouse Auditory Testing Core Facility, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Scott J. Haraczy
- Section on Developmental Neuroscience, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Kamren Edwards-Hollingsworth
- Section on Developmental Neuroscience, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Zahra N. Sayyid
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Donna Wilder
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Venkata Siva Sai Sujith Sajja
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Yanling Wei
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Peethambaran Arun
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Irene Gist
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Alan G. Cheng
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Joseph B. Long
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Matthew W. Kelley
- Section on Developmental Neuroscience, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
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11
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Belding JN, Englert RM, Fitzmaurice S, Jackson JR, Koenig HG, Hunter MA, Thomsen CJ, da Silva UO. Potential Health and Performance Effects of High-Level and Low-Level Blast: A Scoping Review of Two Decades of Research. Front Neurol 2021; 12:628782. [PMID: 33776888 PMCID: PMC7987950 DOI: 10.3389/fneur.2021.628782] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 02/10/2021] [Indexed: 01/06/2023] Open
Abstract
Although blast exposure has been recognized as a significant source of morbidity and mortality in military populations, our understanding of the effects of blast exposure, particularly low-level blast (LLB) exposure, on health outcomes remains limited. This scoping review provides a comprehensive, accessible review of the peer-reviewed literature that has been published on blast exposure over the past two decades, with specific emphasis on LLB. We conducted a comprehensive scoping review of the scientific literature published between January 2000 and 2019 pertaining to the effects of blast injury and/or exposure on human and animal health. A three-level review process with specific inclusion and exclusion criteria was used. A full-text review of all articles pertaining to LLB exposure was conducted and relevant study characteristics were extracted. The research team identified 3,215 blast-relevant articles, approximately half of which (55.4%) studied live humans, 16% studied animals, and the remainder were non-subjects research (e.g., literature reviews). Nearly all (99.49%) of the included studies were conducted by experts in medicine or epidemiology; approximately half of these articles were categorized into more than one medical specialty. Among the 51 articles identified as pertaining to LLB specifically, 45.1% were conducted on animals and 39.2% focused on human subjects. Animal studies of LLB predominately used shock tubes to induce various blast exposures in rats, assessed a variety of outcomes, and clearly demonstrated that LLB exposure is associated with brain injury. In contrast, the majority of LLB studies on humans were conducted among military and law enforcement personnel in training environments and had remarkable variability in the exposures and outcomes assessed. While findings suggest that there is the potential for LLB to harm human populations, findings are mixed and more research is needed. Although it is clear that more research is needed on this rapidly growing topic, this review highlights the detrimental effects of LLB on the health of both animals and humans. Future research would benefit from multidisciplinary collaboration, larger sample sizes, and standardization of terminology, exposures, and outcomes.
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Affiliation(s)
- Jennifer N. Belding
- Defense Health Group, Leidos, San Diego, CA, United States
- Health and Behavioral Sciences Department, Naval Health Research Center, San Diego, CA, United States
| | - Robyn M. Englert
- Defense Health Group, Leidos, San Diego, CA, United States
- Health and Behavioral Sciences Department, Naval Health Research Center, San Diego, CA, United States
| | - Shannon Fitzmaurice
- Defense Health Group, Leidos, San Diego, CA, United States
- Health and Behavioral Sciences Department, Naval Health Research Center, San Diego, CA, United States
| | - Jourdan R. Jackson
- Defense Health Group, Leidos, San Diego, CA, United States
- Health and Behavioral Sciences Department, Naval Health Research Center, San Diego, CA, United States
| | - Hannah G. Koenig
- Defense Health Group, Leidos, San Diego, CA, United States
- Health and Behavioral Sciences Department, Naval Health Research Center, San Diego, CA, United States
| | - Michael A. Hunter
- Defense Health Group, Leidos, San Diego, CA, United States
- Health and Behavioral Sciences Department, Naval Health Research Center, San Diego, CA, United States
| | - Cynthia J. Thomsen
- Health and Behavioral Sciences Department, Naval Health Research Center, San Diego, CA, United States
| | - Uade Olaghere da Silva
- Health and Behavioral Sciences Department, Naval Health Research Center, San Diego, CA, United States
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12
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Stewart CE, Holt AG, Altschuler RA, Cacace AT, Hall CD, Murnane OD, King WM, Akin FW. Effects of Noise Exposure on the Vestibular System: A Systematic Review. Front Neurol 2020; 11:593919. [PMID: 33324332 PMCID: PMC7723874 DOI: 10.3389/fneur.2020.593919] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 09/28/2020] [Indexed: 11/13/2022] Open
Abstract
Despite our understanding of the impact of noise-induced damage to the auditory system, much less is known about the impact of noise exposure on the vestibular system. In this article, we review the anatomical, physiological, and functional evidence for noise-induced damage to peripheral and central vestibular structures. Morphological studies in several animal models have demonstrated cellular damage throughout the peripheral vestibular system and particularly in the otolith organs; however, there is a paucity of data on the effect of noise exposure on human vestibular end organs. Physiological studies have corroborated morphological studies by demonstrating disruption across vestibular pathways with otolith-mediated pathways impacted more than semicircular canal-mediated pathways. Similar to the temporary threshold shifts observed in the auditory system, physiological studies in animals have suggested a capacity for recovery following noise-induced vestibular damage. Human studies have demonstrated that diminished sacculo-collic responses are related to the severity of noise-induced hearing loss, and dose-dependent vestibular deficits following noise exposure have been corroborated in animal models. Further work is needed to better understand the physiological and functional consequences of noise-induced vestibular impairment in animals and humans.
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Affiliation(s)
- Courtney Elaine Stewart
- University of Michigan Department of Otolaryngology/Head-Neck Surgery, Kresge Hearing Research Institute, Ann Arbor, MI, United States.,VA Ann Arbor Healthcare System, Research Service, Ann Arbor, MI, United States
| | - Avril Genene Holt
- Department of Ophthalmology Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States.,John D. Dingell VA Medical Center, Molecular Anatomy of Central Sensory Systems Laboratory, Research Service, Detroit, MI, United States
| | - Richard A Altschuler
- University of Michigan Department of Otolaryngology/Head-Neck Surgery, Kresge Hearing Research Institute, Ann Arbor, MI, United States.,VA Ann Arbor Healthcare System, Research Service, Ann Arbor, MI, United States
| | - Anthony Thomas Cacace
- Department of Communication Sciences and Disorders, Wayne State University, Detroit, MI, United States
| | - Courtney D Hall
- Department of Rehabilitative Sciences, Doctor of Physical Therapy Program, East Tennessee State University, Johnson City, TN, United States.,Gait and Balance Research Laboratory, James H. Quillen VA Medical Center, Mountain Home, TN, United States
| | - Owen D Murnane
- Department of Audiology and Speech-Language Pathology, East Tennessee State University, Johnson City, TN, United States.,Vestibular Research Laboratory, James H. Quillen VA Medical Center, Mountain Home, TN, United States
| | - W Michael King
- University of Michigan Department of Otolaryngology/Head-Neck Surgery, Kresge Hearing Research Institute, Ann Arbor, MI, United States
| | - Faith W Akin
- Department of Audiology and Speech-Language Pathology, East Tennessee State University, Johnson City, TN, United States.,Vestibular Research Laboratory, James H. Quillen VA Medical Center, Mountain Home, TN, United States
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13
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Jafarzadeh S, Pourbakht A, Bahrami E. Vestibular Assessment in Patients with Persistent Symptoms of Mild Traumatic Brain Injury. Indian J Otolaryngol Head Neck Surg 2020; 74:272-280. [PMID: 36032895 PMCID: PMC9411379 DOI: 10.1007/s12070-020-02043-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 08/08/2020] [Indexed: 12/26/2022] Open
Abstract
Aim The estimated worldwide incidence of TBI is 10 million cases per year. Dizziness and imbalance are two common symptoms in mild TBI (mTBI). In about 10-15% of TBI patients, these symptoms remain for a long time and may show no recovery. These persistent symptoms may relate to different factors including vestibular abnormalities. The aim of this study is a vestibular assessment of patients with persistent symptoms of mTBI by different tests including computerized dynamic posturography. Materials and Methods 21 patients with mTBI evaluated in this study. Patients were civilians with persistent symptoms. TBI did cause by blunt force trauma (mainly from falling) in the past 6 months. They had normal neurologic and musculoskeletal assessments and no temporal bone fracture. Several auditory and vestibular evaluations were performed for each patient. They included: case history, otoscopy, pure tone and speech audiometry, tympanometry, vestibular bedside examination (spontaneous nystagmus, gaze, saccade, pursuit, Dix-Hallpike maneuver, side-lying maneuver, roll, and Romberg test), cervical Vestibular Myogenic Evoked Potential (c-VEMP), Computerized Dynamic Posturography (CDP) and Dizziness Handicap Inventory (DHI). Results Patients showed hearing loss in 10 (47.6%) and tinnitus in 4 (19.0%) cases. In ocular motor tests, patients had the most abnormal results in the pursuit test. 6 patients also had Benign Paroxysmal Positional Vertigo (BPPV) in the posterior canal. c-VEMP showed abnormal saccular function in 14 patients. In CDP, the composite scores were decreased relative to normal populations. Conclusion vestibular tests showed abnormal results in most patients. Vestibular abnormality could relate to persisting symptoms of mTBI patients.
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14
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Dickerson MR, Bailey ZS, Murphy SF, Urban MJ, VandeVord PJ. Glial Activation in the Thalamus Contributes to Vestibulomotor Deficits Following Blast-Induced Neurotrauma. Front Neurol 2020; 11:618. [PMID: 32760340 PMCID: PMC7373723 DOI: 10.3389/fneur.2020.00618] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 05/27/2020] [Indexed: 12/16/2022] Open
Abstract
Vestibular impairment has become a frequent consequence following blast-related traumatic brain injury (bTBI) in military personnel and Veterans. Behavioral outcomes such as depression, fear and anxiety are also common comorbidities of bTBI. To accelerate pre-clinical research and therapy developments, there is a need to study the link between behavioral patterns and neuropathology. The transmission of neurosensory information often involves a pathway from the cerebral cortex to the thalamus, and the thalamus serves crucial integrative functions within vestibular processing. Pathways from the thalamus also connect with the amygdala, suggesting thalamic and amygdalar contributions to anxiolytic behavior. Here we used behavioral assays and immunohistochemistry to determine the sub-acute and early chronic effects of repeated blast exposure on the thalamic and amygdala nuclei. Behavioral results indicated vestibulomotor deficits at 1 and 3 weeks following repeated blast events. Anxiety-like behavior assessments depicted trending increases in the blast group. Astrogliosis and microglia activation were observed upon post-mortem pathological examination in the thalamic region, along with a limited glia response in the amygdala at 4 weeks. These findings are consistent with a diffuse glia response associated with bTBI and support the premise that dysfunction within the thalamic nuclei following repeated blast exposures contribute to vestibulomotor impairment.
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Affiliation(s)
- Michelle R Dickerson
- Department of Biomedical Engineering and Mechanics, College of Engineering, Virginia Tech, Blacksburg, VA, United States
| | - Zachary Stephen Bailey
- Department of Biomedical Engineering and Mechanics, College of Engineering, Virginia Tech, Blacksburg, VA, United States
| | - Susan F Murphy
- Department of Biomedical Engineering and Mechanics, College of Engineering, Virginia Tech, Blacksburg, VA, United States.,Salem VA Medical Center, Salem, VA, United States
| | - Michael J Urban
- Department of Biomedical Engineering and Mechanics, College of Engineering, Virginia Tech, Blacksburg, VA, United States
| | - Pamela J VandeVord
- Department of Biomedical Engineering and Mechanics, College of Engineering, Virginia Tech, Blacksburg, VA, United States.,Salem VA Medical Center, Salem, VA, United States
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15
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Yu Y, Huang J, Tang X, Allison J, Sandlin D, Ding D, Pang Y, Zhang C, Chen T, Yin N, Chen L, Mustain W, Zhou W, Zhu H. Exposure to blast shock waves via the ear canal induces deficits in vestibular afferent function in rats. J Otol 2020; 15:77-85. [PMID: 32884557 PMCID: PMC7451608 DOI: 10.1016/j.joto.2020.01.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 01/09/2020] [Accepted: 01/15/2020] [Indexed: 12/11/2022] Open
Abstract
The ears are air-filled structures that are directly impacted during blast exposure. In addition to hearing loss and tinnitus, blast victims often complain of vertigo, dizziness and unsteady posture, suggesting that blast exposure induces damage to the vestibular end organs in the inner ear. However, the underlying mechanisms remain to be elucidated. In this report, single vestibular afferent activity and the vestibulo-ocular reflex (VOR) were investigated before and after exposure to blast shock waves (∼20 PSI) delivered into the left external ear canals of anesthetized rats. Single vestibular afferent activity was recorded from the superior branch of the left vestibular nerves of the blast-treated and control rats one day after blast exposure. Blast exposure reduced the spontaneous discharge rates of the otolith and canal afferents. Blast exposure also reduced the sensitivity of irregular canal afferents to sinusoidal head rotation at 0.5-2Hz. Blast exposure, however, resulted in few changes in the VOR responses to sinusoidal head rotation and translation. To the best of our knowledge, this is the first study that reports blast exposure-induced damage to vestibular afferents in an animal model. These results provide insights that may be helpful in developing biomarkers for early diagnosis of blast-induced vestibular deficits in military and civilian populations.
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Affiliation(s)
- Yue Yu
- Departmant of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS, USA
| | - Jun Huang
- Departmant of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS, USA
| | - Xuehui Tang
- Departmant of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS, USA
| | - Jerome Allison
- Departmant of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS, USA.,Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, MS, USA
| | - David Sandlin
- Program in Neuroscience, University of Mississippi Medical Center, Jackson, MS, USA
| | - Dalian Ding
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY, USA
| | - Yi Pang
- Department of Pediatric, University of Mississippi Medical Center, Jackson, MS, USA
| | - Chunming Zhang
- Department of Otolaryngology, First Affiliated Hospital, Shanxi Medical University, Taiyuan Shanxi, 030001, China
| | - Tianwen Chen
- Departmant of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS, USA
| | - Nathan Yin
- Departmant of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS, USA
| | - Lan Chen
- Departmant of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS, USA
| | - William Mustain
- Departmant of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS, USA
| | - Wu Zhou
- Departmant of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS, USA.,Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, MS, USA.,Department of Neurology, University of Mississippi Medical Center, Jackson, MS, USA
| | - Hong Zhu
- Departmant of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS, USA.,Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, MS, USA
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16
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Tuina Massage Improves Cognitive Functions of Hypoxic-Ischemic Neonatal Rats by Regulating Genome-Wide DNA Hydroxymethylation Levels. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2019; 2019:1282085. [PMID: 31772590 PMCID: PMC6854251 DOI: 10.1155/2019/1282085] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 09/05/2019] [Accepted: 09/30/2019] [Indexed: 12/31/2022]
Abstract
In addition to abnormalities of motor and posture, children with cerebral palsy (CP) often have intellectual disability. As a complementary and alternative traditional Chinese medicine (TCM) therapy, Chinese Tuina massage, also called Tuina in China, has been widely applied in clinical treatment for CP in China for a long time. However, the molecular basis for this still remains largely unknown. Recently, DNA hydroxymethylation has been shown to be sensitive to environment and plays critical roles in some neurological disorders, whereas the research focusing on the relationship between 5 hmC and Tuina therapy for cerebral palsy is deficient. In our study, we first observed that Tuina improved learning and memory functions of hypoxic-ischemic (HI) rat pups. Meanwhile, 5 hmC level of the temporal lobe cortex in the HI neonatal rat model is decreased significantly compared to that of the rats in control and Tuina groups. Then, we used the hMeDIP-Seq method to explore whether and how DNA hydroxymethylation is involved in Tuina therapy for cerebral palsy. Genomic annotation of DhMRs of HI group's hypo-hydroxymethylation to genes revealed enrichment in multiple neurodevelopmental signaling pathways. Moreover, we found the depletion of 5 hmC modifications in genes associated with neuronal development was accompanied by reduced mRNA levels of these genes. Taken together, our results indicate that Tuina may regulate the expression of neurodevelopment-related genes by changing the status of DNA hydroxymethylation, thereby improving learning and memory functions of cerebral palsy.
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