Academia.edu no longer supports Internet Explorer.
To browse Academia.edu and the wider internet faster and more securely, please take a few seconds to upgrade your browser.
Background: Blast-explosion may cause traumatic brain injury (TBI), leading to post-concussion syndrome (PCS). In studies on military personnel, PCS symptoms are highly similar to those occurring in post-traumatic-stress-disorder (PTSD), questioning the overlap between these syndromes. In the current study we assessed PCS and PTSD in civilians following exposure to rocket attacks. We hypothesized that PCS symptomatology and brain connectivity will be associated with the objective physical exposure, while PTSD symptomatology will be associated with the subjective mental experience. Methods: 289 residents of explosion-sites have participated in the current study. Participants completed self-report of PCS and PTSD. The association between objective and subjective factors of blast and clinical outcomes was assessed using multivariate analysis. White-matter (WM) alterations and cognitive abilities were assessed in a sub-group of participants (n=46) and non-exposed controls (n=16). Non-pa...
BMC Psychiatry, 2023
Background Blast-explosion may cause traumatic brain injury (TBI), leading to post-concussion syndrome (PCS). In studies on military personnel, PCS symptoms are highly similar to those occurring in post-traumatic stress disorder (PTSD), questioning the overlap between these syndromes. In the current study we assessed PCS and PTSD in civilians following exposure to rocket attacks. We hypothesized that PCS symptomatology and brain connectivity will be associated with the objective physical exposure, while PTSD symptomatology will be associated with the subjective mental experience. Methods Two hundred eighty nine residents of explosion sites have participated in the current study. Participants completed self-report of PCS and PTSD. The association between objective and subjective factors of blast and clinical outcomes was assessed using multivariate analysis. White-matter (WM) alterations and cognitive abilities were assessed in a subgroup of participants (n = 46) and non-exposed controls (n = 16). Non-parametric analysis was used to compare connectivity and cognition between the groups. Results Blast-exposed individuals reported higher PTSD and PCS symptomatology. Among exposed individuals, those who were directly exposed to blast, reported higher levels of subjective feeling of danger and presented WM hypoconnectivity. Cognitive abilities did not differ between groups. Several risk factors for the development of PCS and PTSD were identified. Conclusions Civilians exposed to blast present higher PCS/PTSD symptomatology as well as WM hypoconnectivity. Although symptoms are sub-clinical, they might lead to the future development of a full-blown syndrome and should be considered carefully. The similarities between PCS and PTSD suggest that despite the different etiology, namely, the physical trauma in PCS and the emotional trauma in PTSD, these are not distinct syndromes, but rather represent a combined biopsychological disorder with a wide spectrum of behavioral, emotional, cognitive and neurological symptoms.
Military medicine, 2018
Traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD) are two of the signature injuries in military service members who have been exposed to explosive blasts during deployments to Iraq and Afghanistan. Acute stress disorder (ASD), which occurs within 2-30 d after trauma exposure, is a more immediate psychological reaction predictive of the later development of PTSD. Most previous studies have evaluated service members after their return from deployment, which is often months or years after the initial blast exposure. The current study is the first large study to collect psychological and neuropsychological data from active duty service members within a few days after blast exposure. Recruitment for blast-injured TBI patients occurred at the Air Force Theater Hospital, 332nd Air Expeditionary Wing, Joint Base Balad, Iraq. Patients were referred from across the combat theater and evaluated as part of routine clinical assessment of psychiatric and neuropsychological sy...
Frontiers in Psychology, 2021
Objective: The majority of combat-related head injuries are associated with blast exposure. While Veterans with mild traumatic brain injury (mTBI) report cognitive complaints and exhibit poorer neuropsychological performance, there is little evidence examining the effects of subconcussive blast exposure, which does not meet clinical symptom criteria for mTBI during the acute period following exposure. We compared chronic effects of combat-related blast mTBI and combat-related subconcussive blast exposure on neuropsychological performance in Veterans.Methods: Post-9/11 Veterans with combat-related subconcussive blast exposure (n = 33), combat-related blast mTBI (n = 26), and controls (n = 33) without combat-related blast exposure, completed neuropsychological assessments of intellectual and executive functioning, processing speed, and working memory via NIH toolbox, assessment of clinical psychopathology, a retrospective account of blast exposures and non-blast-related head injuries,...
Neuropsychology, 2014
Objective: To examine neuropsychological outcomes in veterans of Operations Enduring and Iraqi Freedom (OEF/OIF) with self-reported histories of blast exposure and determine the contribution of deployment-related mild traumatic brain injury (mTBI), and posttraumatic stress disorder (PTSD) and depression to performance. The effect of number of blast exposures and distance from the blast was also assessed. Method: OEF/OIF veterans who reported exposure to blast underwent structured interviews and were assigned to no-TBI (n ϭ 39), mTBI without loss of consciousness (LOC; n ϭ 53), or mTBI with LOC (n ϭ 35) groups. They were administered tests of executive function, memory, and motor function at least 6 months after the index event. Results: Neuropsychological outcomes did not differ as a function of mTBI group. Blast load and distance from the blast also did not affect neuropsychological performance. Both PTSD and depression symptoms were significantly associated with neuropsychological outcomes. Conclusions: A history of mTBI with or without LOC during deployment does not contribute to objective cognitive impairment in the chronic phase post injury. In contrast, PTSD and depression symptoms are associated with cognitive performance decrements. This finding is thought to reflect at least in part the impact of psychiatric distress on neuropsychological performance.
Applied Neuropsychology: Adult, 2014
The increased use of explosives in combat has resulted in a large number of returning veterans suffering from blast-related mild traumatic brain injury (mTBI) and self-reported complications. It remains unclear whether this increase in self-reported difficulties is unique to the blast mechanism or stressful preinjury environment and whether cognitivefunctioning deficits correspond with these difficulties in the postacute phase. This study examined the relationship between cognitive performance and self-reported psychological and somatic symptoms of blast-related mTBI compared with civilian mTBI, independent of comorbid posttraumatic stress disorder (PTSD) symptoms. Twelve veterans with blastrelated mTBI were compared to 18 individuals with civilian mTBI on cognitive tests and self-report questionnaires. Univariate analyses failed to reveal differences on any individual cognitive test. Further, veterans reported more psychological and somatic complaints. These self-reported difficulties were not significantly correlated with neuropsychological performance. Overall, preliminary results suggest that in the postacute phase, subjective complaints related to blast-related mTBI do not covary with objective cognitive performance. Additionally, cognitive outcomes from blast-related mTBI were similar to those of civilian forms of mTBI. Future studies should identify the cognitive and self-reported sequelae of blast-related mTBI independent of comorbid PTSD in a larger sample of veterans.
With the duration of combat operations that have been ongoing in Iraq and Afghanistan, the IED tactics used and technological safety advances the amounts of wounded soldiers have increased. This increase includes soldiers saved by medical techniques, advance in body armor and speed of first aid. Many injuries involve blasts and concurrent brain injury from exposure can have effects on their cognitive functioning and daily functioning. This study takes an overview of current neuropsychological evaluation results from 822 active duty military members. The sample contains 28 descripting variables including basic demographics, symptoms, blast profile, military ASVAB scores, and diagnosis of examining Neuropsychologist. This data also contains outcomes in 128 variables from 13 neuropsychological tests that were part of the blast battery. This battery was comprised of BAI, CVLT-II, COWAT, Groove Pegboard, Grip strength, Halstead-Reltan, Hayling and Brixton, MMPI, Stoop, TOMM, WAIS-III/WAI...
Human brain mapping, 2015
Although there is emerging data on the effects of blast-related concussion (or mTBI) on cognition, the effects of blast exposure itself on the brain have only recently been explored. Toward this end, we examine functional connectivity to the posterior cingulate cortex, a primary region within the default mode network (DMN), in a cohort of 134 Iraq and Afghanistan Veterans characterized for a range of common military-associated comorbidities. Exposure to a blast at close range (<10 meters) was associated with decreased connectivity of bilateral primary somatosensory and motor cortices, and these changes were not different from those seen in participants with blast-related mTBI. These results remained significant when clinical factors such as sleep quality, chronic pain, or post traumatic stress disorder were included in the statistical model. In contrast, differences in functional connectivity based on concussion history and blast exposures at greater distances were not apparent. ...
Military Medicine, 2015
Traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD) are frequently documented among the Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/OND) veterans. This study will investigate both combat exposure and PTSD as factors that may influence objective cognitive outcomes following blast-related mild TBI (mTBI). Participants included 54 OEF/OIF/OND veterans who had been exposed to blast and reported symptoms consistent with mTBI and 43 combat-deployed control participants who had no history of blast exposure or TBI. Raw scores from the Controlled Oral Word Association Test, Trail Making Test, Color-Word Interference Test, and Verbal Selective Reminding Test were used to measure cognitive functioning. All participants demonstrated adequate effort on the Word Memory Test. Demographics, injury characteristics, overall intellectual functioning, and total scores from the PTSD Checklist-Civilian Version (PCL-C) and Combat Exposure Scale (CES) were used as the predictors for each cognitive measure. History of mTBI was significantly associated with higher PCL-C and CES scores. Multivariable linear regression, however, showed no significant differences in cognitive performance between groups. The absence of effect of mTBI, PTSD, and combat exposure on cognitive functioning noted in this study may be partially explained by the inclusion of only those participants who passed performance validity testing.
Journal of the International Neuropsychological Society, 2012
This study explored whether remote blast-related MTBI and/or current Axis I psychopathology contribute to neuropsychological outcomes among OEF/OIF veterans with varied combat histories. OEF/OIF veterans underwent structured interviews to evaluate history of blast-related MTBI and psychopathology and were assigned to MTBI (n = 18), Axis I (n = 24), Co-morbid MTBI/Axis I (n = 34), or post-deployment control (n = 28) groups. A main effect for Axis I diagnosis on overall neuropsychological performance was identified (F(3,100) = 4.81; p = .004), with large effect sizes noted for the Axis I only (d = .98) and Co-morbid MTBI/Axis I (d = .95) groups relative to the control group. The latter groups demonstrated primary limitations on measures of learning/memory and processing speed. The MTBI only group demonstrated performances that were not significantly different from the remaining three groups. These findings suggest that a remote history of blast-related MTBI does not contribute to obje...
Journal of Military, Veteran and Family Health
LAY SUMMARY There has been increasing interest in understanding the impact of blast exposure on health and performance in military members and Veterans. This phenomenon has proven difficult to study because personnel diagnosed with blast-induced mild traumatic brain injury (mTBI) typically also exhibit emotional difficulties such as posttraumatic stress disorder (PTSD), likely because the events that led to mTBI in theatre were also emotionally traumatic. In turn, this comorbidity makes it difficult to tease apart symptoms uniquely due to blast-induced mTBI or PTSD. Researchers have therefore explored surrogate settings wherein the effects of blast exposure can be assessed in an operationally realistic, yet scientifically more controlled manner, such as breacher and sniper training. To that aim, researchers administered a measure of post-concussive symptomatology and two mental health scales to breachers and snipers, as well as sex- and age-matched military controls. The breachers a...
Journal of Head Trauma Rehabilitation, 2013
To understand the relations of mild traumatic brain injury (TBI), blast exposure, and brain white matter structure to severity of posttraumatic stress disorder (PTSD). Design: Nested cohort study using multivariate analyses. Participants: Fifty-two OEF/OIF veterans who served in combat areas between 2001 and 2008 were studied approximately 4 years after the last tour of duty. Main Measures: PTSD Checklist-Military; Combat Experiences Survey, interview questions concerning blast exposure and TBI symptoms; anatomical magnetic resonance imaging (MRI), and diffusion tensor imaging (DTI) scanning of the brain. Results: PTSD severity was associated with higher 1st percentile values of mean diffusivity on DTI (regression coefficient [r] = 4.2, P = .039), abnormal MRI (r = 13.3, P = .046), and the severity of exposure to combat events (r = 5.4, P = .007). Mild TBI was not significantly associated with PTSD severity. Blast exposure was associated with lower 1st percentile values of fractional anisotropy on DTI (odds ratio [OR] = 0.38 per SD; 95% confidence interval [CI], 0.15-0.92), normal MRI (OR = 0.00, 95% likelihood ratio test CI, 0.00-0.09), and the severity of exposure to traumatic events (OR = 3.64 per SD; 95% CI, 1.40-9.43). Conclusions: PTSD severity is related to both the severity of combat stress and underlying structural brain changes on MRI and DTI but not to a clinical diagnosis of mild TBI. The observed relation between blast exposure and abnormal DTI suggests that subclinical TBI may play a role in the genesis of PTSD in a combat environment.
Journal of the International Neuropsychological Society : JINS, 2018
This study investigated the relationship between close proximity to detonated blast munitions and cognitive functioning in OEF/OIF/OND Veterans. A total of 333 participants completed a comprehensive evaluation that included assessment of neuropsychological functions, psychiatric diagnoses and history of military and non-military brain injury. Participants were assigned to a Close-Range Blast Exposure (CBE) or Non-Close-Range Blast Exposure (nonCBE) group based on whether they had reported being exposed to at least one blast within 10 meters. Groups were compared on principal component scores representing the domains of memory, verbal fluency, and complex attention (empirically derived from a battery of standardized cognitive tests), after adjusting for age, education, PTSD diagnosis, sleep quality, substance abuse disorder, and pain. The CBE group showed poorer performance on the memory component. Rates of clinical impairment were significantly higher in the CBE group on select CVLT...
2008
A cross-sectional study of military personnel following deployment to conflicts in Iraq or Afghanistan ascertained histories of combat theater injury mechanisms and mild traumatic brain injury (TBI) and current prevalence of posttraumatic stress disorder (PTSD) and postconcussive symptoms. Associations among injuries, PTSD, and postconcussive symptoms were explored. In February 2005, a postal survey was sent to Iraq/Afghanistan veterans who had left combat theaters by September 2004 and lived in Maryland; Washington, DC; northern Virginia; and eastern West Virginia. Immediate neurologic symptoms postinjury were used to identify mild TBI. Adjusted prevalence ratios and 95% confidence intervals were computed by using Poisson regression. About 12% of 2,235 respondents reported a history consistent with mild TBI, and 11% screened positive for PTSD. Mild TBI history was common among veterans injured by bullets/shrapnel, blasts, motor vehicle crashes, air/water transport, and falls. Factors associated with PTSD included reporting multiple injury mechanisms (prevalence ratio ¼ 3.71 for three or more mechanisms, 95% confidence interval: 2.23, 6.19) and combat mild TBI (prevalence ratio ¼ 2.37, 95% confidence interval: 1.72, 3.28). The strongest factor associated with postconcussive symptoms was PTSD, even after overlapping symptoms were removed from the PTSD score (prevalence ratio ¼ 3.79, 95% confidence interval: 2.57, 5.59).
Alzheimer's & dementia (New York, N. Y.), 2017
This study examined whether World Trade Center (WTC)-related exposures and posttraumatic stress disorder (PTSD) were associated with cognitive function and whether WTC responders' cognition differed from normative data. A computer-assisted neuropsychological battery was administered to a prospective cohort study of 1193 WTC responders with no history of stroke or WTC-related head injuries. Data were linked to information collected prospectively since 2002. Sample averages were compared to published norms. Approximately 14.8% of sampled responders had cognitive dysfunction. WTC responders had worse cognitive function compared to normative data. PTSD symptom severity and working >5 weeks on-site was associated with lower cognition. Results from this sample highlight the potential for WTC responders to be experiencing an increased burden of cognitive dysfunction and linked lowered cognitive functioning to physical exposures and to PTSD. Future research is warranted to understand...
The Journal of Neuropsychiatry and Clinical Neurosciences, 1998
Veterans with chronic posttraumatic stress disorder were evaluated for a history of blast concussion, controlling for confounding conditions. Electroencephalograms were analyzed by discriminant function for traumatic brain injury. A difference was found in discriminant scores between veterans with and without blast concussion. More members of the blast group had attentional symptoms and attentional dysfunction. Combat veterans with a remote history of blast injury have persistent electroencephalographic features of traumatic brain injury as well as attentional problems. The authors hypothesize that these constitute a type of chronic postconcussive syndrome that has cognitive and mood symptoms overlapping those of posttraumatic stress disorder.
Frontiers in Neurology
The long-term effects of blast exposure are a major health concern for combat veterans returning from the recent conflicts in Iraq and Afghanistan. We used an optimized diffusion tensor imaging tractography algorithm to assess white matter (WM) fractional anisotropy (FA) in blast-exposed Iraq and Afghanistan veterans (n = 40) scanned on average 3.7 years after deployment/trauma exposure. Veterans diagnosed with a blast-related mild traumatic brain injury (mTBI) were compared to combat veterans with blast exposure but no TBI diagnosis. Blast exposure was associated with decreased FA in several WM tracts. However, total blast exposure did not correlate well with neuropsychological testing performance and there were no differences in FA based on mTBI diagnosis. Yet, veterans with mTBI performed worse on every neurocognitive test administered. Multiple linear regression across all blast-exposed veterans using a six-factor prediction model indicated that the amount of blast exposure accounted for 11-15% of the variability in composite FA scores such that as blast exposure increased, FA decreased. Education accounted for 10% of the variability in composite FA scores and 25-32% of FA variability in the right cingulum, such that as level of education increased, FA increased. Total blast exposure, age, and education were significant predictors of FA in the left cingulum. We did not find any effect of post-traumatic stress disorder on cognition or composite FA.
Journal of Neurotrauma, 2013
Breachers'' are a unique military and law enforcement population because they are routinely exposed to low-level blast (LLB) during training and operations. This repeated exposure has been associated with symptoms similar to that of sports concussion. This study examined effects of repeated exposure to LLB during an explosive entry course. Twenty-one members of the New Zealand Defence Force volunteered for this study. Serum samples, neurocognitive performance, and self-reported symptoms were periodically measured before, during, and after a 2-week course. Serum concentrations of three biomarkers, ubiquitin C-terminal hydrolase-L1, aII-spectrin breakdown product, and glial fibrillary acidic protein, were determined with sandwich enzyme-linked immunosorbent assays, and rank scores were derived using the area under the curve (relative to baseline) for each subject. Neurocognitive performance was measured with a computer-based test battery, and symptoms were assessed by paper-based inventory. There was a significant relationship ( p < 0.05) between composite biomarker and neurocognitive performance and between neurocognitive performance and symptoms. The individuals with the five highest (Top 5) and lowest (Bottom 5) composite biomarker scores were identified and compared using Wilcoxon's rank-sum test. The Top 5 had significantly longer reaction times and lower percent correct on neurocognitive performance and an increase in symptom reporting. The difference between individuals expressing the highest biomarker load during breacher training (Top 5) and those with the lowest biomarker load (Bottom 5) is reflected in neurocognitive performance deficits and self-reported symptoms. This suggests a measureable degree of brain perturbation linked to LLB exposure. Follow-up studies are underway to expand upon these results.
Journal of Trauma-injury Infection and Critical Care, 2008
Background: Although sustaining physical injury in theater increases service members' risk for posttraumatic stress disorder (PTSD), exposure to explosive munitions may increase the risk of mild traumatic brain injury (mTBI). We hypothesized a higher incidence of PTSD and mTBI in service members who sustained both burn and explosion injuries than in nonexplosion exposed service members. Methods: A retrospective review of PTSD and mTBI assessments was completed on burned service members between September 2005 and August 2006. Subjects were divided into cohort groups: (1) PTSD and mTBI, (2) PTSD and no mTBI, (3) mTBI and no PTSD, (4) no mTBI and no PTSD. Specific criteria used for group classification were based on subjects' total score on Posttraumatic Stress Disorder Checklist, Military version (PCL-M), clinical interview, and record review to meet American Congress of Rehabilitation Medicine criteria for mTBI. Descriptive analyses were used. Results: Seventy-six service members met the inclusion criteria. The incidence rate of PTSD was 32% and mTBI was 41%. Eighteen percent screened positive for PTSD and mTBI; 13% screened positive for PTSD, but not mTBI; 23% screened positive for mTBI but not PTSD; 46% did not screen positive for either PTSD or mTBI. Conclusion: Given the high incidence of these disorders in burned service members, further screening of PTSD and TBI appears warranted. Because symptom presentation in PTSD and mTBI is clinically similar in acute and subacute stages, and treatments can vary widely, further research investigating symptom profiles of PTSD and mTBI is warranted.
BMJ Neurology Open
ObjectivesThis study aims to describe which concussion subtype(s) result specifically from the explosions of theatre ballistic missiles (TBMs) blast waves, an extremely rare occurrence in modern warfare. We provide feedback from using the US military’s standard acute concussion screening tool, the Military Acute Concussion Examination version 2, in a deployed, chaotic, real-world environment.BackgroundIran launched 27 professionally manufactured TBMs into Iraq on 8 January 2020. Eleven detonated within Al Asad Air Base, exposing approximately 330 soldiers to TBM-blast waves. The concussion subtype(s) resultant from TBM blast-related concussion is not known.MethodsCase series from the Al Asad TBM-blast exposed cohort who evacuated to Landstuhl Regional Medical Center (LRMC), Germany up to 3 months following the attack and were diagnosed with concussion. Around 4 weeks, TBM-blast exposed individuals still present on Al Asad were screened with the Neurobehavioural Symptom Inventory (NS...
NeuroImage: Clinical
In the military, explosive blasts are a significant cause of mild traumatic brain injuries (mTBIs). The symptoms associated with blast mTBIs causes significant economic burdens and a diminished quality of life for many service members. At present, the distinction of the injury mechanism (blast versus non-blast) may not influence TBI diagnosis. However, using noninvasive imaging, this study reveals significant distinctions between the blast and non-blast TBI mechanisms. A cortical whole-brain thickness analysis was performed using structural highresolution T1-weighted MRI to identify the effects of blasts in persistent mTBI (pmTBI) subjects. A total of 41 blast pmTBI subjects were individually age-and gender-matched to 41 non-blast pmTBI subjects. Using FreeSurfer, cortical thickness was quantified for the blast group, relative to the non-blast group. Cortical thinning was identified within the blast mTBI group, in two clusters bilaterally. In the left hemisphere, the cluster overlapped with the lateral orbitofrontal, rostral middle frontal, medial orbitofrontal, superior frontal, rostral anterior cingulate and frontal pole cortices (p < 0.02, two-tailed, size = 1680 mm 2). In the right hemisphere, the cluster overlapped with the lateral orbitofrontal, rostral middle frontal, medial orbitofrontal, pars orbitalis, pars triangularis and insula cortices (p < 0.002, two-tailed, cluster size = 2453 mm 2). Self-report assessments suggest significant differences in the Post-Traumatic Stress Disorder Checklist-Civilian Version (p < 0.05, Bonferroni-corrected) and the Neurobehavioral Symptom Inventory (p < 0.01, uncorrected) between the blast and non-blast mTBI groups. These results suggest that blast may cause a unique injury pattern related to a reduction in cortical thickness within specific brain regions which could affect symptoms. No other study has found cortical thickness difference between blast and non-blast mTBI groups and further replication is needed to confirm these initial observations.
Loading Preview
Sorry, preview is currently unavailable. You can download the paper by clicking the button above.