A-16 Impact of Modifiable Mood and Health Factors on Cognitive Functioning among Veterans with History of Mild Traumatic Brain Injury

Predictors of Cognitive Functioning Among Veterans with Mild Traumatic Brain Injury

Objective: To examine the relationship between clinical characteristics and cognitive performance in service members and veterans with histories of blast-related mild traumatic brain injury (mTBI).Design: This study consisted of 40 Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) service members and veterans; 20 participants reported blast exposure and alteration of mental status consistent with mTBI and 20 participants denied blast exposure and had no history of traumatic brain injury (TBI), but could have experienced extra-cranial injuries. Measures of simple reaction time, processing speed, visual attention, working memory and mathematical processing were used to assess long-term effects of mTBI. Measures of post-traumatic stress symptom severity, pain intensity, sleep difficulty and subjective appraisal of cognition at time of testing were also obtained. Multivariate analyses were conducted with clinical characteristics and mTBI history as predictors of cognitive performance.Results: There was no evidence of an effect of mTBI history on cognitive performance in this sample. However, post-traumatic stress symptom severity was significantly related to two measures of cognitive performance.Conclusions: This study demonstrated the importance of considering the effects of current clinical symptoms (e.g. post-traumatic stress) as possibly having greater influence on current cognitive functioning than the effects of a remote history of mTBI.

Background and objective:Adults with a history of traumatic brain injury (TBI) often show deficits in executive function (EF), including the ability to inhibit, switch, and attend to task relevant information. Although performances differences between bilinguals and monolinguals have been observed in EF tasks, there is little research on the effect of TBI on EF in bilinguals. In this study, an ecologically valid standardized measure and experimental computerized tasks of EF were administered to Spanish-English bilingual adults with and without history of mild traumatic brain injury (mTBI).Method:Twenty-two bilinguals with a history of mTBI [mean age=20.1 years, SD=3.7; education=13.4 years, SD=0.7] and 20 control bilinguals [mean age=20.8 years, SD=3.6; education=13.7 years, SD=1.1], matched for age and education, completed language proficiency questionnaires, the Functional Assessment of Verbal Reasoning and Executive Strategies (FAVRES), English and Spanish language assessments, and a Flanker task (a test of inhibition).Results:Performance was analyzed using analyses of covariance. The results revealed that bilinguals with a history of mTBI performed worse on both the standardized assessment (FAVRES) and inhibition task. Interestingly, self-reported EF deficits were consistent with performance on these measures.Conclusion:The findings of this study provide useful information regarding assessment of EF deficits in bilinguals with a history mTBI. Computerized experimental tasks of EF may also prove useful in the assessment of EF in individuals with mTBI.

A-178 18F-Fluorodeoxyglucose Positron Emission Tomography Findings Are Not Related to Cognitive Functioning in Service Members with Remote History of Traumatic Brain Injury

Language control in bilingual adults with and without history of mild traumatic brain injury

Mental Health Does Not Moderate Compensatory Cognitive Training Efficacy for Veterans With a History of Mild Traumatic Brain Injury

In this study, we investigated history of traumatic brain injury with loss of consciousness in relation to cognitive functioning, subjective memory complaints, and brain structure in mid-life. This study included 2005 participants (mean age: 47.6 years, standard deviation: 5.0, women: 65%) from the Origins of Alzheimer's Disease Across the Life Course (ORACLE) study between 2017 and 2020. History of traumatic brain injury was defined as at least one lifetime self-reported brain injury with loss of consciousness. Associations of history of traumatic brain injury with (1) cognitive functioning (measured with the 15-Word Learning Test, Stroop Task, Letter-Digit Substitution Test, Word Fluency Test, Purdue Pegboard Test, and Design Organization Test), (2) current subjective memory complaints (present/absent, measured with a survey), and (3) brain structure (total brain volume, frontal and temporal lobe volume, gray matter volume, white matter volume, white matter hyperintensities volume, infarcts, and microbleeds, measured with brain magnetic resonance imaging [MRI]) were assessed using linear or logistical regression models and adjusted for relevant confounders. In total, 250 of 2005 (12%) participants reported a history of traumatic brain injury. Of those who reported the time post-injury (n = 173), most participants (n = 151, 87%) reported that it had occurred >10 years ago. We found no associations between history of traumatic brain injury and any of the cognitive tests. We did find that a history of traumatic brain injury was associated with having mid-life subjective memory complaints (odds ratio [OR]: 1.87; 95% confidence interval [CI]: 1.35, 2.58). This association was also present when investigating only those who reported an injury >10 years ago (OR:1.69; 95% CI: 1.15, 2.50). Additionally, the association was stronger in those with >30 min loss of consciousness (OR: 3.57; 95% CI: 1.48, 8.59) than in those with <30 min loss of consciousness (OR: 1.85; 95% CI: 1.25, 2.74), when compared with those without history of traumatic brain injury. Lastly, we found no associations between history of traumatic brain injury and any of the structural brain MRI outcomes. In conclusion, our study suggests that at least one lifetime traumatic brain injury with loss of consciousness in mid-life is associated with long-term subjective memory complaints, but not with cognitive functioning or brain structure.

Introduction: Clinical neuropsychological presentation of treatment-seeking Veterans with a remote history of mild traumatic brain injury (mTBI) is widely variable. This manuscript seeks to better characterize cognitive concerns in the post-acute phase following mTBI and to identify the neuropsychological profiles of a large sample of clinically referred Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/OND) Veterans with a history of mTBI and current cognitive complaints. We hypothesized that a minority of cases would exhibit valid and widespread neuropsychological deficits. Method: Retrospective chart reviews of neuropsychological testing and mental health symptoms and diagnoses were conducted on 411 clinically referred OEF/OIF/OND Veterans with a history of mTBI. Groups were created based on scores on performance validity measures and based on overall neuropsychological performance. Results: A total of 29.9% of the sample performed below normative expectations on at least one performance validity test (PVT). Of those Veterans performing adequately on PVTs, 60% performed within normal limits on virtually all neuropsychological measures administered, leaving only 40% performing below expectations on two or more measures. Mood and neurobehavioral symptoms were significantly elevated in Veterans performing below cutoff on PVTs compared to Veterans who performed within normative expectations or those with valid deficits. Neurobehavioral symptoms were significantly correlated with mental health symptom reports but not with injury variables. Conclusions: In summary, in a large sample of clinically referred Veterans with persistent cognitive complaints after mild TBI, a third demonstrated invalid clinical neuropsychological testing, and, of those performing at or above cutoff on PVTs, over half performed within normative expectations across most neuropsychological tests administered. Results highlight the importance of objective assessment of cognitive functioning in this population as subjective reports do not correspond to objective assessment in the majority of cases.

The long-term cognitive consequences of mild traumatic brain injury (mTBI) are poorly understood. Studies investigating cognitive performance in the chronic stage of injury in both hospital-based and population-based samples have revealed inconsistent findings. Importantly, population-based mTBI samples remain under-studied in the literature. This study investigated cognitive performance among individuals with a history of self-reported mTBI using a battery of cognitively demanding behavioural tasks. Importantly, more than half of the mTBI participants had experienced multiple mild head injuries. Compared to control participants (n = 49), participants with a history of mTBI (n = 30) did not demonstrate deficits in working memory, multitasking ability, cognitive flexibility, visuospatial ability, response inhibition, information processing speed or social cognition. There was moderate evidence that the mTBI group performed better than control participants on the visual working memory measure. Overall, these findings suggest that even multiple instances of mTBI do not necessarily lead to long-term cognitive impairment at the group level. Thus, we provide important evidence of the impact of chronic mTBI across a number of cognitive processes in a population-based sample. Further studies are necessary to determine the impact that individual differences in injury-related variables have on cognitive performance in the chronic stage of injury.

Objective:Olfaction is a critical sensory function and changes in the ability to detect smells could affect quality of life by diminishing appreciation of food, drink, and other aroma-based experiences, increase danger of hazardous exposures, and cause a loss of employment. Additionally, decrements in olfaction have been related to onset of some neurodegenerative conditions. Olfactory impairments in military populations are highly prevalent and often attributed to the long-term effects of mild traumatic brain injury (mTBI) and chronic psychiatric disorders. The main goal of this investigation was to examine olfactory function in a cohort of combat veterans using a quantitative smell test.Participants and Methods:Participants underwent a neurological examination using a revised version of the Neurological Outcome Scale for Traumatic Brain Injury. Olfactory function was examined using a set of essential oil vials with common odors. Based on the number of correctly identified odors, the following grading system was employed: no deficit; mild; moderate; severe deficit; and absence of smell detection. All study assessments were performed prior to March of 2020 (onset of COVID-19 pandemic). In addition, participants completed performance validity testing (PVT) and screening for ongoing substance misuse using the Alcohol Use Disorders Identification Test and Drug Abuse Screening Test-10. Lifetime history of brain injury, combat-related extracranial injuries, and deployment characteristics were assessed using structured interview. All available medical records were reviewed.Results:Participants were 38 veterans with a deployment-related mTBI who passed the PVT and did not have ongoing substance misuse issues. Olfactory examination revealed normosmia in 20 participants and various degrees of deficit in 18 (11= mild; 4=moderate; and 3=severe). The groups did not differ in demographics, post-injury interval, or current clinical (non-psychiatric) conditions. Participants with hyposmia frequently reported being exposed to a higher number of blasts and being positioned closer to the nearest primary blast, and more often endorsed a period of loss of consciousness after the most serious mTBI. In addition, they more often reported tympanic membrane perforation, extracranial injuries, and histories of both blast and blunt force mTBI. Comorbid diagnoses of posttraumatic stress disorder (PTSD), depression, chronic headaches, and pain were more common among these participants as well.Conclusions:Several blast exposure and specific injury-related characteristics increase the likelihood of long-term olfactory impairments, comorbid psychiatric conditions, and chronic pain among veterans with a history of deployment-related mTBI. Notably, none of the participants with hyposmia had a clinical diagnosis of olfactory dysfunction or were receiving service-connected disability for a loss of sense of smell at the time of their assessment. Multidisciplinary rehabilitation care provided to combat veterans with history of mTBI and/or PTSD should include olfactory examination using both quantitative and qualitative smell tests, education regarding the adversities related to loss of smell, management of current psychiatric symptoms, and follow-up assessments. The lack of a comparison group without a history of mTBI and the small sample size were the main limitations of this investigation.

Neurocognitive Intraindividual Variability in Veterans with Mild Traumatic Brain Injury History and Posttraumatic Stress Disorder.

We investigated whether a history of mild traumatic brain injury (mTBI), or concussion, has any effect on visual working memory (WM) performance. In most cases, cognitive performance is thought to return to premorbid levels soon after injury, without further medical intervention. We tested this assumption in undergraduates, among whom a history of mTBI is prevalent. Notably, participants with a history of mTBI performed worse than their colleagues with no such history. Experiment 1 was based on a change detection paradigm in which we manipulated visual WM set size from one to three items, which revealed a significant deficit at set size 3. In Experiment 2 we investigated whether feedback could rescue WM performance in the mTBI group, and found that it failed. In Experiment 3 we manipulated WM maintenance duration (set size 3, 500-1,500 ms) to investigate a maintenance-related deficit. Across all durations, the mTBI group was impaired. In Experiment 4 we tested whether retrieval demands contributed to WM deficits and showed a consistent deficit across recognition and recall probes. In short, even years after an mTBI, undergraduates perform differently on visual WM tasks than their peers with no such history. Given the prevalence of mTBI, these data may benefit other researchers who see high variability in their data. Clearly, further studies will be needed to determine the breadth of the cognitive deficits in those with a history of mTBI and to identify relevant factors that contribute to positive cognitive outcomes.

Cognitive functioning in individuals with Parkinson’s disease and traumatic brain injury: A longitudinal study

Case Report on the Effects of Cognitive Processing Therapy on Psychological, Neuropsychological, and Speech Symptoms in Comorbid PTSD and TBI

Radiofrequency electromagnetic field exposures and brain processes: ERPs and functional consequences of effects