The Effects of Chronic Exposure to Low-Level Blasts

NCT01524822 | Completed

• 2 other identifiers: 12006512-N-0065
• Study Type: observational
• Target: 66
• Locations: 1 country
• Sites: 1

Brief Summary

Background: \- Repeated exposure to explosions may lead to changes in the way that people think or feel. Breachers (people trained to use explosives to get into buildings) are exposed to repeated blasts as part of their job. Researchers want to study how they might be affected by blast exposure. Breachers will be compared with other groups who have different levels of exposure to repeated blasts. Information will also be obtained from spouses or close companions. Objectives: \- To study the effects of repeated exposure to low-level blasts on thinking, memory, behavior, and brain function. Eligibility:

• Experienced military and civilian breachers, experienced active duty artillery operators, and active duty military without frequent blast exposure, 18 and 60 years of age.
• Spouses or close companions of these individuals. Design:
• Participants will be screened with a physical exam and medical history. Blood samples will be collected and a urine pregnancy test will be required of participants (not companions) before MRI scanning.
• Participants will spend up to 5-days as a NIH clinic outpatient, with about 6 hours of tests each day. Tests will include the following:
• Medical and professional history, with questions about exposures to blasts
• Tests of thinking, memory, and concentration
• Balance tests
• Hearing tests
• Imaging studies, such as magnetic resonance imaging, to look at the brain
• Overnight sleep study to monitor brain waves
• Blood samples
• Participants will return 1 year later for a 3-day followup visit. Some of the tests from before will be repeated. A spouse or close companion (if available) will be asked to complete questionnaires or have a telephone interview....

Conditions

Tramatic Brain Injury

Keywords

Military; Traumatic Brain Injury; Cognitive Testing; Neuroimaging; Natural History; Brain Function

Outcome Measures

Primary Outcomes (1)

• computer-based standardized testing, specifically the ANAM battery and the Simple Reaction Time (SRT) subtest within that battery

  The primary objective for this study is based on anecdotal report of blast-related symptomology and previous and ongoing studies with the breacher community, suggesting a relation between post-concussive symptomology and chronic exposure to low yield blast. Measures employed in this protocol are based on measures used in other protocols in this line of research, measures used inmilitary clinical practice for concussion, and measures outlined in literature as sensitive to brain injury. These include neuroimaging procedures (fMRI, DTI, SWI, and Gadolinium contrast), neurocognitive testing, and vestibular testing.

  10 years

Secondary Outcomes (1)

• blood draw and analysis for biomarkers of brain injury and tests of peripheral auditory functioning and polysomnography to address potential confounds.

  10 years

Study Arms (4)

Artillery personnel

exposure to a significant number of concussive evolutions, specifically, exposure to 400 or more within a career, will be considered experienced by the investigators.

Breachers

exposure to a significant number of breaching blasts, specifically, exposure to 400 breaching blasts or more within a career, will be considered experienced by the investigators

Companions

The criterion is met by a person who has both some historical knowledge of the participant and routine interactions outside a work environment.

Unexposed

People not exposed to repeated blasts

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)
• Sampling Method: Probability Sample

Study Population

120 total: 20 breachers, 20 artillery, 20 unexposed controls, and 60 companions

You may qualify if:

• EXPERIMENTAL GROUP: BREACHERS
• Active duty and veterans who have left active duty within the previous five years or civilian law enforcement personnel
• Ages 18 60 (age range for an active duty military population)
• At least 4 years of experience in the breaching profession and actively involved in breacher training and/or operations (minimum of annual exposure). An alternate criterion to years of breacher experience is exposure to a significant number of breaching blasts, specifically, exposure to 400 breaching blasts or more within a career, will be considered experienced by the investigators.
• EXPERIMENTAL GROUP 2: ARTILLERY
• Active duty and veterans who have left active duty within the previous five years
• Matched to the breacher group in terms of age, gender, and operational experience. Operational experience is defined as years of experience actively involved in artillery operations and/or number of artillery evolutions.
• At least 4 years experience with exposure to concussive environments not related to blast (minimum of annual exposure). An alternate criterion to years of experience is exposure to a significant number of concussive evolutions, specifically, exposure to 400 or more within a career, will be considered experienced by the investigators.
• CONTROL GROUP: UNEXPOSED
• Active duty and veterans who have left active duty within the previous five years
• Matched to the experimental group (breachers) in terms of age, gender, and operational experience. Operational experience is defined as years of experience actively involved in military or law enforcement operations with the condition that operations include direct mission engagement roles rather than support roles. Military deployment or law enforcement patrol are examples of direct mission engagement roles and shore logistics or office based call center are examples of support roles.
• COMPANION GROUP
• Spouse, close family member, or other living partner of an experimental or control group participant. The criterion is met by a person who has both some historical knowledge of the participant and routine interactions outside a work environment.
• Over 18 years of age
• Knowledge of the experimental or control group participant s daily functioning

You may not qualify if:

• BREACHERS
• History of moderate or more severe brain injury with loss of consciousness greater than 5 minutes
• Current diagnosis of other CNS disorder (mild to severe)
• Any cardiac, respiratory, or other medical condition that may affect cerebral metabolism
• MRI contraindications
• Metal in the body which would make having an MRI scan unsafe, such as pacemakers, medication pumps, aneurysm clips, metallic prostheses (including metal pins and rods, heart valves or cochlear implants), shrapnel fragments, permanent eye liner or small metal fragments in the eye
• Claustrophobia
• Inability to lie supine for up to 2 hours in the MRI scanner
• ARTILLERY \& UNEXPOSED
• COMPANION GROUP
• None

Sponsors & Collaborators

• National Institute of Neurological Disorders and Stroke (NINDS): lead
• Walter Reed Army Institute of Research (WRAIR): collaborator
• Naval Medical Research Center: collaborator

Study Sites (1)

National Institutes of Health Clinical Center

Bethesda, Maryland, 20892, United States

Location

Related Publications (3)

• Basford JR, Chou LS, Kaufman KR, Brey RH, Walker A, Malec JF, Moessner AM, Brown AW. An assessment of gait and balance deficits after traumatic brain injury. Arch Phys Med Rehabil. 2003 Mar;84(3):343-9. doi: 10.1053/apmr.2003.50034.

  PMID: 12638101 BACKGROUND

• Bonnet MH, Arand DL. EEG arousal norms by age. J Clin Sleep Med. 2007 Apr 15;3(3):271-4.

  PMID: 17561594 BACKGROUND

• El-Kashlan HK, Shepard NT, Asher AM, Smith-Wheelock M, Telian SA. Evaluation of clinical measures of equilibrium. Laryngoscope. 1998 Mar;108(3):311-9. doi: 10.1097/00005537-199803000-00002.

  PMID: 9504600 BACKGROUND

Related Links

• NIH Clinical Center Detailed Web Page

MeSH Terms

Conditions

Brain Injuries, Traumatic

Condition Hierarchy (Ancestors)

Brain Injuries; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Craniocerebral Trauma; Trauma, Nervous System; Wounds and Injuries

Study Officials

• Eric M Wassermann, M.D.

  National Institute of Neurological Disorders and Stroke (NINDS)

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: NIH
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 31, 2012
• First Posted: February 2, 2012
• Study Start: July 30, 2012
• Last Updated: March 17, 2023

Record last verified: 2023-03-14

Locations

US (1)