Low-level Blast Exposure
Conditions
Keywords
traumatic brain injury, concussion, magnetic resonance imaging, blast overpressure, low-level blast exposure, repeated blast exposure
Brief summary
The goal of this observational study is to learn about the impact of low-level blast exposure in U.S. Special Operations Forces personnel. The main questions it aims to answer are: What advanced brain imaging changes are related to clinical presentation after low-level blast exposure? What are the relationships between low-level blast exposure and common groups of symptoms after concussion? Participants will: * Undergo advanced brain imaging * Answer questionnaires * Complete clinical tests * Provide blood, urine, and saliva samples * Wear blast sensors
Detailed description
Participants in this observational study are active-duty U.S. Special Operations Forces personnel between the ages of 18 and 50. This study is designed to characterize the neurological and clinical effects associated with repeated low-level blast exposure (LLBE) in this population. Concerns have emerged that cumulative exposure to sub-concussive blast overpressure (BOP), even in the absence of a diagnosable concussion, may be associated with subtle changes in brain structure and function over time. Due to the nature of their operational and training environments, Special Operations Forces personnel may experience repeated LLBE and are therefore an important population for longitudinal investigation. Participation involves in-person assessments and data collection conducted over a period of approximately 4-5 years. The schedule of study activities includes baseline, daily, weekly, monthly, quarterly, and annual assessments. Baseline and annual study visits include advanced magnetic resonance imaging (MRI) and require travel to Walter Reed National Military Medical Center. Specifically, this study includes the use of the Microstructure Anatomy Gradient for Neuroimaging with Ultrafast Scanning (MAGNUS) 3.0 Tesla MRI. Throughout the study period, participants complete standardized questionnaires and clinical assessments and provide biological samples, including blood, urine, and saliva, at specified intervals. Participants also contribute measures on a daily, weekly, monthly, quarterly, and annual basis. They will wear blast sensors throughout their participation in the study. The total planned enrollment for the study is approximately 250 participants across multiple sites, with an estimated 60 participants enrolled at Fort Bragg, NC. Enrollment and follow-up are expected to occur over a 4-5 year period.
Interventions
None listed
Sponsors
Uniformed Services University of the Health Sciences
The Geneva Foundation
MIT Lincoln Laboratory
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
* Active duty * U.S. SOF personnel * 18-50 years old
Exclusion criteria
* Subjects will be excluded only if their participation will significantly interfere with validity of data collection or safety during the study (e.g., they have conditions that might result in harm or injury during research procedures). * Example: pregnancy (balance considerations) * Example: being unable to undergo MRI testing (i.e., they have non-MRI compatible devices, imbedded metal fragments such as shrapnel, and/or severe claustrophobia; these MRI contraindications will be screened using an MRI Safety Questionnaire)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Effective axonal radii mapping | At baseline and annually through study completion, an average of 5 years | The primary outcome measure in this study will be effective axonal radii (r\_eff) mapping derived from ultra-high performance diffusion magnetic resonance imaging using the MAGNUS system and its correlations to low-level blast exposure. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Ohio State University TBI Identification Method | At baseline and annually through study completion, an average of 5 years | The Ohio State University TBI Identification Method is a standardized approach for collecting an individual's comprehensive history of traumatic brain injuries through a structured interview lasting 3-5 minutes. |
| Concussion Clinical Profiles Screening | At baseline and annually through study completion, an average of 5 years | The Concussion Clinical Profiles Screening (CP Screen) tool will be used to measure the five concussion clinical subtypes (profiles) and two modifiers. The CP Screen is a 29-item post-concussion symptom inventory. Subjects rate the severity of 29 symptoms on a scale from 0 (None \[Not experiencing this symptom.\]) to 3 (Severe). The CP Screen total score is a sum of the 29 items (range 0 to 87, higher scores mean a worse outcome). Subscale scores range from 0 to 15 for vestibular, ocular-motor, anxiety/mood, and post-traumatic headache (migraine); 0 to 9 for cognitive; 0 to 12 for sleep; and 0 to 6 for cervical spine. |
| Neurobehavioral Symptom Inventory | At baseline and weekly through study completion, an average of 5 years | The Neurobehavioral Symptom Inventory (NSI) is a 22-item post-concussion symptom inventory. The NSI total score is a sum of the 22 items (range 0 to 88, higher scores mean a worse outcome). |
| Headache Impact Test | At baseline and weekly through study completion, an average of 5 years | The Headache Impact Test (HIT-6) is a 6-item assessment of the negative impact of headaches. The HIT-6 total score is a sum of the 6 items (range 36 to 78, higher scores mean a worse outcome). |
| modified Military Concussion Readiness Inventory for Dizziness and Balance | At baseline and quarterly through study completion, an average of 5 years | The modified Military Concussion Readiness Inventory for Dizziness and Balance (MCRI-DB) is a military-specific measure of the handicapping effects dizziness and imbalance (similar to the Dizziness Handicap Inventory). The modified MCRI-DB total score is a sum of the 25 items (range 0 to 100, higher scores mean a worse outcome). |
| Composite Autonomic Symptom Score (COMPASS) 31 | At baseline and annually through study completion, an average of 5 years | The Composite Autonomic Symptom Score (COMPASS) 31 is a 31-item self-reported evaluation that measures autonomic symptoms across six domains: orthostatic intolerance, vasomotor, secretomotor, gastrointestinal (combining constipation, diarrhea, and gastroparesis domains), bladder, and pupillomotor. The COMPASS-31 total score is a sum of the 31 items (range 0 to 100, higher scores mean a worse outcome). |
| Pittsburgh Sleep Quality Index | PSQI at baseline and annually through study completion, an average of 5 years | The Pittsburgh Sleep Quality Index (PSQI) is a 18-item self-reported evaluation of sleep quality to distinguish between "good" and "poor" sleepers, and identify significant sleep disturbances of various types. There are an additional five items for evaluating sleep quality, as reported by a bed partner/roommate. The PSQI total score is a sum of the 18 items (range 0 to 21, higher scores mean a worse outcome). |
| Brief Pittsburgh Sleep Quality Index | B-PSQI monthly through study completion (except at baseline and annually when the 18-item PSQI [see above] will be used), an average of 5 years | The Brief Pittsburgh Sleep Quality Index (B-PSQI) is a 6-item self-reported evaluation of sleep quality to distinguish between "good" and "poor" sleepers, and identify significant sleep disturbances of various types. The B-PSQI total score is a sum of the 6 items (range 0 to 21, higher scores mean a worse outcome). |
| STOP-Bang | At baseline and annually through study completion, an average of 5 years | The STOP-Bang questionnaire will be used as a screening instrument for obstructive sleep apnea. It uses a yes/no checklist for snoring, tiredness, observed apnea, high blood pressure, BMI, age, neck circumference, and gender (male sex). Scores on the STOP-Bang range from 0 to 8 (higher scores mean a worse outcome) with ≥3 indicating a positive screening. |
| Neck Disability Index | At baseline and annually through study completion, an average of 5 years | The Neck Disability Index (NDI) is a 10-item self-reported evaluation that measures how neck pain impacts daily life and the level of self-perceived disability in individuals with neck pain. The NDI total score is a sum of the 10 items (range 0 to 50, higher scores mean a worse outcome). |
| PTSD Checklist for DSM-5 (PCL-5) | At baseline and annually through study completion, an average of 5 years | The PTSD Checklist for DSM-5 (PCL-5) is a 20-item self-report instrument designed to evaluate the 20 symptoms of PTSD as outlined in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). The PCL-5 total score is a sum of the 20 items (range 0 to 80, higher scores mean a worse outcome). |
| General Anxiety Disorder (GAD-7) | At baseline and annually through study completion, an average of 5 years | The General Anxiety Disorder (GAD-7) is a 7-item assessment for identifying likely cases of generalized anxiety disorder. The GAD-7 total score is a sum of the 7 items (range 0 to 21, higher scores mean a worse outcome). |
| Patient Health Questionnaire (PHQ-9) | At baseline and annually through study completion, an average of 5 years | The Patient Health Questionnaire (PHQ-9) is a 9-item assessment for evaluating the presence and severity of depressive symptoms. The PHQ-9 total score is a sum of the 9 items (range 0 to 27, higher scores mean a worse outcome). |
| Quality of Life after Brain Injury (QOLIBRI) | At baseline and annually through study completion, an average of 5 years | The Quality of Life after Brain Injury (QOLIBRI) evaluates health-related quality of life in individuals following TBI, incorporating the individual's perspective on their health, functioning, and well-being. The QOLIBRI consists of 37 items divided into four scales: Cognition, Self, Daily Life and Autonomy, and Social Relationships. The QOLIBRI total score is a sum of the 37 items (range 0 to 100, higher scores mean a better outcome). |
| Caffeine Consumption Questionnaire - Revised | At baseline and weekly through study completion, an average of 5 years | The Caffeine Consumption Questionnaire - Revised is a six-page self-report measure to estimate caffeine consumption. This outcome measure can be scored in three ways: a conservative estimate using minimum caffeine concentration values, a mean estimate based on average concentrations, and a liberal estimate using maximum concentration values. |
| Supplement Frequency Questionnaire | At baseline and annually through study completion, an average of 5 years | The Supplement Frequency Questionnaire is a one-page survey that assesses supplement use across 16 categories over the past year. The 16 categories are: multivitamins (one-a-day, B-complex, antioxidant); vitamins A, C, E, B-12, and D; beta-carotene; folic acid; calcium; selenium; iron; zinc; fish oil/omega-3 fatty acids; and garlic. This outcome measure can be scored by calculating total nutrient intake for each nutrient from supplements by multiplying frequency × duration × default dose. |
| Alcohol Use Disorders Identification Test - Consumption (AUDIT-C) | At baseline and annually through study completion, an average of 5 years | The Alcohol Use Disorders Identification Test - Consumption (AUDIT-C) is a screening tool used to identify hazardous drinking and potential alcohol use disorders. The AUDIT-C total score is a sum of the 3 items (range 0 to 12, higher scores mean a worse outcome). |
| Penn State Cigarette Dependence Index | At baseline and annually through study completion, an average of 5 years | The Penn State Cigarette Dependence Index is a 10-item measure of nicotine dependence. The Penn State Cigarette Dependence Index total score is a sum of the 10 items (range 0 to 20, higher scores mean a worse outcome). |
| Penn State Electronic Cigarette Dependence Index | At baseline and annually through study completion, an average of 5 years | The Penn State Electronic Cigarette Dependence Index is a 10-item measure of nicotine dependence. The Penn State Electronic Cigarette Dependence Index total score is a sum of the 10 items (range 0 to 20, higher scores mean a worse outcome). |
| Penn State Nicotine Pouch Dependence Index | At baseline and annually through study completion, an average of 5 years | The Penn State Nicotine Pouch Dependence Index is a 10-item measure of nicotine dependence. The Penn State Nicotine Pouch Dependence Index total score is a sum of the 10 items (range 0 to 20, higher scores mean a worse outcome). |
| Military Acute Concussion Evaluation 2 (MACE2) | At baseline and annually through study completion, an average of 5 years | The Military Acute Concussion Evaluation 2 (MACE2) is the standard of care for concussion screening and diagnosis in the military, and consists of: description of incident (potentially concussive event); alteration of consciousness or memory; symptoms; history of concussion, headache disorder or migraine, depression, anxiety, or other behavioral health concerns; cognitive exam; neurological exam; and Vestibular/Ocular Motor Screening (VOMS; see below). The MACE2's multiple measurements will be aggregated to arrive at one reported value - positive or negative. |
| Military Acute Concussion Evaluation 2 (MACE2) with embedded Vestibular/Ocular Motor Screening (VOMS) | At baseline and annually through study completion, an average of 5 years | The Vestibular/Ocular Motor Screening (VOMS) is a brief clinical screening tool (\<5 minutes) for vestibular and ocular motor symptoms and impairment after concussion and consists of seven items: smooth pursuits, horizontal saccades, vertical saccades, near-point convergence (NPC), horizontal vestibulo-ocular reflex (VOR), vertical VOR, and visual motion sensitivity. The VOMS' multiple measurements will be aggregated to arrive at one reported value - positive or negative. |
| Sway mobile device application | At baseline and weekly through study completion, an average of 5 years | The Sway mobile device application (Sway Medical, Inc., Tulsa, OK) will be used to assess symptoms, cognition, and balance. Sway's multiple measurements will be aggregated to arrive at one reported value - positive or negative. |
| COncussion BALance Test (COBALT) | At baseline and quarterly through study completion, an average of 5 years | Subjects will undergo COncussion BALance Test (COBALT) (Bertec Corporation, Columbus, OH) testing. Each of the eight conditions in the manufacturer's research-only protocol will be performed for two 20-sec trials during which errors will be recorded by the clinician and sway velocity will be recorded by the force plate. The COBALT's multiple measurements will be aggregated to arrive at two reported values - sway velocity and number of errors. |
| King-Devick Test | At baseline and weekly through study completion, an average of 5 years | The King-Devick Test (King-Devick technologies, inc., Oak Brook, IL) is a short, timed assessment in which subjects rapidly read aloud single-digit numbers. |
| EYE-SYNC® | At baseline and annually through study completion, an average of 5 years | The EYE-SYNC® (NeuroSync, Inc., Holliston, MA) will be used to administer the Vestibular/Ocular Motor Screening, as well as pro-saccades and anti-saccades. |
| PLR®-4000 | At baseline and annually through study completion, an average of 5 years | The PLR®-4000 (NeurOptics, Inc., Irving, CA) will be used to measure pupil size and pupillary reactivity. Eight measurements from the device (maximum diameter, minimum diameter, percent change, latency of constriction, constriction velocity, maximum constriction velocity, dilation velocity, and time to reach 75% recovery) will be aggregated to arrive at one reported value - normal or abnormal (in comparison to published normative data). |
| Automated Neuropsychological Assessment Metrics (v4) Military Expanded | At baseline and annually through study completion, an average of 5 years | The Military Battery consists of Participant Information (military demographics), Sleepiness Scale, TBI Questionnaire, Mood Scale, Simple Reaction Time, Code Substitution - Learning, Procedural Reaction Time, Mathematical Processing, Matching to Sample, Code Substitution - Delayed, and Simple Reaction Time (Repeated) modules. The ANAM's multiple measurements will be aggregated to arrive at one reported value - normal or abnormal (in comparison to published normative data stratified by age \[5-year increments\], gender, race/ethnicity and education). |
| Wechsler Abbreviated Scale of Intelligence - Second Edition (WASI-II) | At baseline and annually through study completion, an average of 5 years | The Wechsler Abbreviated Scale of Intelligence - Second Edition (WASI-II) is a rapid (approximately 30-minute) assessment of cognitive functioning. A composite score, the Full Scale IQ-4 Subtest (FSIQ-4), ranges from "Very Superior" (≥130) to "Extremely Low/Impaired" (\<70) and higher scores mean a better outcome. |
| Videonystagmography (VNG) / oculomotor and vestibular function testing | At baseline and annually through study completion, an average of 5 years | Subjects will undergo videonystagmography (VNG) / oculomotor and vestibular function testing (smooth pursuit, horizontal and vertical saccades, caloric testing, ocular and cervical vestibular-evoked myogenic potentials \[oVEMP and cVEMP\]) performed by a Research Audiologist. The results of this battery of testing will be aggregated to arrive at one reported value - normal or abnormal (in comparison to published normative data). |
| Video Head Impulse (vHIT) | At baseline and annually through study completion, an average of 5 years | Subjects will undergo video Head Impulse Test (vHIT) testing with the ICS® Impulse (Natus; Middleton, WI). This is a standard clinical test of the semicircular canals. Vestibulo-ocular reflex gain will be determined using the ratio of the area under the curve of eye velocity relative to the area under the curve of head velocity (after saccade traces are removed) from onset to offset of head velocity. |
| Wireless Automated Hearing Test System (WAHTS) | At baseline and annually through study completion, an average of 5 years | Subjects will undergo Wireless Automated Hearing Test System (WAHTS) (WAHTS Hearing LLC; Lebanon, NH) portable, wireless audiometry testing. |
Countries
United States
Contacts
CONTACTTony T Yuan, PhD
CONTACTCarrie W Hoppes, PhD
STUDY_CHAIRVincent B Ho, MD
Uniformed Services University of the Health Sciences
PRINCIPAL_INVESTIGATORTony T Yuan, PhD
Uniformed Services University of the Health Sciences
Outcome results
None listed