The Effects of Chronic Exposure to Low-Level Blasts
| Status: | Recruiting |
|---|---|
| Conditions: | Healthy Studies, Neurology |
| Therapuetic Areas: | Neurology, Other |
| Healthy: | No |
| Age Range: | 18 - 60 |
| Updated: | 4/6/2019 |
| Start Date: | January 23, 2012 |
| Contact: | Alycia A Quick |
| Email: | alycia.quick@nih.gov |
| Phone: | (301) 496-5829 |
Experienced Breacher Study: Evaluation of the Effects From Chronic Exposure to Low-Level Blast
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.
- 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.
The purpose of this study is to evaluate the cognitive and neurophysiological effects of
chronic exposure to repeated low-level blast overpressure. Previous studies show converging
evidence for a neurophysiological effect from cumulative exposure to blast, which is
consistent with subjective reports of cognitive impairment by individuals trained to use
explosives to gain entry to structures (breachers). This study will expand on these findings
by examining a larger cohort of experienced breachers and artillery personnel who may be
incurring a cumulative effect of low-level blast exposure over the course of several years.
We will evaluate up to 20 participants from each of three groups: breachers, artillery
personnel, and unexposed individuals. Additionally, we will ask each of the above to bring a
close companion for a set of questionnaires and an interview to capture changes in
functioning that participants may not be able to self-assess. Participants will travel to the
NIH for evaluation of cognitive and neurophysiological measures. The procedures include
neuropsychological testing, blood analysis for biomarkers, vestibular and auditory testing,
and neuroimaging studies using diffusion tensor imaging, susceptibility weighted imaging,
perfusion imaging, functional magnetic resonance imaging, and, where there is evidence of a
sleep disorder, polysomnography. This study will be conducted in collaboration with the Naval
Medical Research Center (NMRC) and the Walter Reed Army Institute of Research (WRAIR) under a
Research Collaborative Agreement. The complementary DoD protocol will be reviewed by the DoD
IRB and includes this NIH protocol. The complementary DoD protocol includes data collection
at field settings, activity NIH is not engaged in and not described in this protocol.
chronic exposure to repeated low-level blast overpressure. Previous studies show converging
evidence for a neurophysiological effect from cumulative exposure to blast, which is
consistent with subjective reports of cognitive impairment by individuals trained to use
explosives to gain entry to structures (breachers). This study will expand on these findings
by examining a larger cohort of experienced breachers and artillery personnel who may be
incurring a cumulative effect of low-level blast exposure over the course of several years.
We will evaluate up to 20 participants from each of three groups: breachers, artillery
personnel, and unexposed individuals. Additionally, we will ask each of the above to bring a
close companion for a set of questionnaires and an interview to capture changes in
functioning that participants may not be able to self-assess. Participants will travel to the
NIH for evaluation of cognitive and neurophysiological measures. The procedures include
neuropsychological testing, blood analysis for biomarkers, vestibular and auditory testing,
and neuroimaging studies using diffusion tensor imaging, susceptibility weighted imaging,
perfusion imaging, functional magnetic resonance imaging, and, where there is evidence of a
sleep disorder, polysomnography. This study will be conducted in collaboration with the Naval
Medical Research Center (NMRC) and the Walter Reed Army Institute of Research (WRAIR) under a
Research Collaborative Agreement. The complementary DoD protocol will be reviewed by the DoD
IRB and includes this NIH protocol. The complementary DoD protocol includes data collection
at field settings, activity NIH is not engaged in and not described in this protocol.
- INCLUSION CRITERIA:
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
- Companions who are unable to travel to NIH may participate remotely ( off-site
companion )
EXCLUSION CRITERIA:
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
-Parallel to exclusion criteria for the breacher group, with the addition of exposure to
breaching blast (greater than 40 individual blasts) for the Artillery Group and exposure to
any blast (greater than 40 individual blasts) for the Unexposed Group.
COMPANION GROUP
We found this trial at
1
site
9000 Rockville Pike
Bethesda, Maryland 20892
Bethesda, Maryland 20892
Phone: 800-411-1222
Click here to add this to my saved trials
