No effect of PTSD and other psychiatric disorders on cognitive functioning in veterans with mild TBI

Disentangling subjective symptom complaints and objective cognitive performance in veterans: Impact of posttraumatic stress disorder and lifetime traumatic brain injury burden

Self-reported histories of mild traumatic brain injury (mTBI) and posttraumatic stress disorder (PTSD) symptoms are prevalent among post-9/11 veterans. Both are associated with subjective and often overlapping symptom complaints, but variably with objective neuropsychological test performances. These outcomes are seldom explored in relation to lifetime mTBI burden. This cross-sectional study examined associations of PTSD and lifetime mTBI with subjective (persistent symptoms after concussion and cognitive complaints) and objective (performances across five cognitive domains) measures among 46 veterans. Within this sample, 20 veterans had Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) confirmed PTSD (PTSD+), whereas 26 demographically-similar participants did not meet criteria (PTSD-). The Boston Assessment of Traumatic Brain Injury-Lifetime (BAT-L) yielded total mTBI scores ranging from 0 to 8. Regressions showed PTSD was associated with increased subjective symptoms/cognitive complaints, along with reduced verbal fluency, visuospatial memory, and processing speed performances. Lifetime mTBI burden was associated with subjective symptoms, but not with objective cognitive test performance, after controlling for PTSD. No significant interactions were observed. Exploratory correlations suggested that all PTSD symptom clusters were generally associated with the subjective and objective measures. However, fewer significant associations emerged within the PTSD+/- groups separately, with each group yielding somewhat different patterns of relationships. PTSD and increasing mTBI burden are consistently associated with negative subjective symptoms, including cognitive complaints. Each condition likely explains some degree of unique variance in symptom reporting. PTSD is associated with poorer objective cognition on some tasks, including processing speed, executive functioning, and learning/memory. Implications are explored.

Effect of blast-related mTBI on the working memory system: a resting state fMRI study

Reduced working memory is frequently reported by Veterans with a history of blast-related mild traumatic brain injury (mTBI), but can be difficult to quantify on neuropsychological measures. This study aimed to improve our understanding of the impact of blast-related mTBI on the working memory system by using resting state functional magnetic resonance imaging (fMRI) to explore differences in functional connectivity between OEF/OIF/OND Veterans with and without a history of mTBI. Participants were twenty-four Veterans with a history of blast-related mTBI and 17 Veterans who were deployed but had no lifetime history of TBI. Working memory ability was evaluated with the Auditory Consonants Trigrams (ACT) task. Resting state fMRI was used to evaluate intrinsic functional connectivity from frontal seed regions that are known components of the working memory network. No significant group differences were found on the ACT, but the imaging analyses revealed widespread hyper-connectivity from the frontal seed regions in the Veterans with a history of mTBI relative to the deployed control group. Further, within the mTBI group, but not the control group, better performance on the ACT was associated with increased functional connectivity to multiple brain regions, including cerebellar components of the working memory network. These results were present after controlling for age, PTSD symptoms, and estimated premorbid IQ, and suggest that long-term alterations in the functional connectivity of the working memory network following blast-related mTBI may reflect a compensatory change that contributes to intact performance on an objective measure of working memory.

Posttraumatic Stress Disorder-Associated Cognitive Deficits on the Repeatable Battery for the Assessment of Neuropsychological Status in a Veteran Population

Background

Posttraumatic stress disorder (PTSD) is a frequent problem of veterans receiving care and is often associated with cognitive deficits. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) is a well-validated cognitive screening measure often used in the US Department of Veterans Affairs (VA), particularly in neurorehabilitation settings. However, the influence of PTSD on RBANS performance is unclear, particularly within a heterogeneous VA outpatient population in which PTSD and traumatic brain injury (TBI) may not be the primary focus of care.

Methods

Participants included 153 veterans with complex deployment-related health problems, including a diagnosis of PTSD (n = 98) and a history of TBI (n = 92). All veterans completed a targeted cognitive battery that included the Wechsler Test of Adult Reading, the Wechsler Adults Intelligence Scale, measure assessing processing speed, attention, and cognitive flexibility, and RBANS.

Results

A diagnosis of PTSD was associated with worse performance on the Story Recall subtest of the RBANS, but not on any other cognitive measures. A diagnosis of mild TBI, or co-occurring PTSD and TBI did not predict cognitive performance on any measures.

Conclusions

The RBANS best captured cognitive deficits associated with PTSD compared with a history of mild TBI or co-occurring mild TBI and PTSD. These findings may provide insight into the interpretation and attribution of cognitive deficits in the veteran population.

The Effects of Blast-Related Neurotrauma on Aurally Aided Visual Search While Standing and Walking

Service members (SMs) who have suffered mild traumatic brain injury due to blast exposure (b/TBI) often report post-concussive symptoms consistent with auditory, visual, or vestibular impairments even when they score within the normal range on traditional clinical tests of sensory function. One possible explanation for this discrepancy is that patients who score in the low normal range in more than one sensory modality may be severely impaired in tasks that require multisensory integration. This study evaluated unimodal and multimodal sensory performance in SMs with b/TBI and healthy controls by having them conduct four tasks while walking or standing in an immersive virtual environment: an Auditory Localization task (AL) where they moved a cursor to the perceived location of a sound; a Visual Discrimination task (VD) where they distinguished between two visual targets; an Aurally-Aided Visual Search Task (AAVS) where they used an auditory cue to locate and identify a visual target hidden in a field of visual distractors; and a Visual-Only Visual Search task (VOVS) where they located and identified a visual target in a field of distractors with no auditory cue. The results show the b/TBI and healthy control groups performed equivalently in the AL and VD tasks, but that the b/TBI group responded roughly 15% slower in the AAVS task and 50% slower in the VOVS task. Walking had no effect on performance in the visual-only tasks, but both groups responded faster while walking in the AL and AAVS tasks without any reduction in accuracy.

Impact of PTSD on post-concussive symptoms, neuropsychological functioning, and pain in post-9/11 veterans with mild traumatic brain injury

Prior work suggested that post-traumatic stress disorder (PTSD) worsens post-concussive symptoms (PCS), neuropsychological functioning, and pain-related outcomes in post-9/11 veterans. However, the impact of PTSD in the context of mild traumatic brain injury (mTBI) is not entirely clear. We evaluated possible differences among veterans with deployment-related mTBI with and without PTSD, and a comparison group. We hypothesized that veterans with comorbid mTBI and PTSD would report more PCS, perform worse on neuropsychological tasks, and report greater pain intensity and maladaptive pain coping relative to those without PTSD. Ninety (15 female, 75 male) post-9/11 veterans completed measures of psychiatric functioning, PCS, deployment-related mTBI, pain intensity, pain coping, and a brief neuropsychological evaluation. Veterans with comorbid mTBI and PTSD reported significantly higher PCS across domains, and greater pain intensity and maladaptive coping. They also performed more poorly on measures of recall, but not on measures of attention, encoding, or executive functioning. Findings suggest that PTSD results in greater PCS in the context of mTBI, and is associated with greater pain catastrophizing, worse recall, greater pain intensity, and greater illness-focused coping than in mTBI alone. PCS symptoms, recall, and pain coping may be of clinical importance for post-9/11 veterans with the "polytrauma triad."

Clinical and Magnetic Resonance Spectroscopic Imaging Findings in Veterans With Blast Mild Traumatic Brain Injury and Post-Traumatic Stress Disorder

OBJECTIVES

To compare magnetic resonance spectroscopic imaging (MRSI) findings from the hippocampal regions of military veterans with blast-related mild traumatic brain injury (blast mTBI) and post-traumatic stress disorder (PTSD) to those with PTSD only; and to examine the relationship of MRSI findings to cognitive and neuromotor impairment.

METHODS

35 military veterans-23 with blast mTBI and PTSD (blast mTBI/PTSD) and 12 with PTSD only participated in the study. Whole plane MRSI data including N-acetyl aspartate (NAA) and choline (Ch) were acquired at 7T for the hippocampus. Concurrent cognitive and neuromotor data were collected using established assessments. General linear models (GLMs) with Bonferroni correction were used to compare the two groups on NAA/Ch ratios across regions of the hippocampus. Spearman's correlations were used to examine correlations between NAA/Ch and cognitive and neuromotor impairment.

RESULTS

The NAA/Ch results for the left hippocampus were lower in the blast mTBI/PTSD group than the PTSD-only group. The blast mTBI/PTSD group also scored worse on the WAIS-IV-vocabulary. Significant correlations between NAA/Ch and neuromotor outcomes-including vestibular impairment-were supported.

CONCLUSIONS

Combined MRSI and cognitive and neuromotor data may help inform more objective and accurate diagnoses and effective treatments for patients with blast mTBI and PTSD.

Gender Differences in Neurocognitive Performance Among Children With Posttraumatic Stress Disorder and Mild Traumatic Brain Injury

Posttraumatic stress disorder (PTSD) and mild traumatic brain injury (mTBI) are frequent sequelae after motor vehicle accidents (MVAs). These two pathologies often have overlapping neurocognitive deficits across several domains, such as attention, memory, and executive functions. The present study was an effort to examine the contribution of gender to these overlapping symptoms. To this end, psychodiagnostic and neuropsychological data were collected on 61 children and adolescents 3 months following MVA. All participants were diagnosed with PTSD, and about half (n = 33) also received a diagnosis of mTBI. Analyses of variance revealed significant interactions between gender and mTBI (ηp2=.15), such that girls with mTBIs preformed significantly worse than noninjured girls on measures of executive functions (Cohen's d = 3.88) and sustained attention (Cohen's d = 3.24). Boys, on the other hand, did not differ significantly on any of those measures, irrespective of TBI injury status. Similarly, comparisons to the normative population revealed that, whereas boys showed impaired neurocognitive performances regardless of TBI status, impaired performances in girls were limited to those cases in which the girls were comorbid for PTSD and mTBI. It appears then that whereas PTSD alone might explain boys' reduced neurocognitive performance, among girls the comorbidity of PTSD and mTBI is required to account for performance deficits.

Elevated rates of memory impairment in military service-members and veterans with posttraumatic stress disorder

INTRODUCTION

Studies investigating the neurocognitive effects of posttraumatic stress disorder (PTSD) routinely find "deficits" in various cognitive domains. However, the rate of cognitive impairment in individuals with PTSD remains unclear, as studies have focused on null hypothesis testing (NHT) and inferring patterns of impairment rather than empirically determining the rate of cognitive impairment in this sample.

METHOD

This study examined rates of cognitive impairment using a domain-specific approach in non-treatment-seeking Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn service members and veterans with (n = 92) and without (n = 79) PTSD and without substance abuse/dependence who passed a performance validity measure and were matched on age, education, estimated IQ, and ethnicity. Chi-square analyses were used to compare the rate of cognitive impairment across groups based on normative scores using three cutoffs (-1, -1.5, and -2 SDs). NHT was also used to compare performances across groups.

RESULTS

Individuals with PTSD showed higher rates of impairment in memory (-1-SD cutoff) than controls, but equivalent rates of impairment in attention, processing speed, and executive functioning; no significant differences were found on NHT. Impairment in any domain was also more prevalent in PTSD (-1-, -1.5-, and -2-SD cutoffs). No differences were found on NHT or rates of impairment in individuals with PTSD with (n = 34) and without (n = 58) depression.

CONCLUSIONS

Patients with PTSD were more likely to meet criteria for memory impairment and to show impairment in any domain than controls. Patients with PTSD and comorbid depression were no more likely to be impaired in any cognitive domain or to have lower scores on individual cognitive tasks than patients with PTSD alone. Clinicians noting cognitive impairment in individuals with PTSD should exercise caution before ascribing that impairment to another etiology if deficits are limited to memory.

Brain Volume, Connectivity, and Neuropsychological Performance in Mild Traumatic Brain Injury: The Impact of Post-Traumatic Stress Disorder Symptoms

Post-traumatic stress disorder (PTSD) is commonly associated with mild traumatic brain injury (mTBI). To better understand their relationship, we examined neuroanatomical structures and neuropsychological performance in a sample of individuals with mTBI, with and without PTSD symptoms. Thirty-nine subjects with mTBI were dichotomized into those with (n = 12) and without (n = 27) significant PTSD symptoms based on scores on the PTSD Checklist. Using a region-of-interest approach, fronto-temporal volumes, fiber bundles obtained by diffusion tensor imaging, and neuropsychological scores were compared between the two groups. After controlling for total intracranial volume and age, subjects with mTBI and PTSD symptoms exhibited volumetric differences in the entorhinal cortex, an area associated with memory networks, relative to mTBI-only patients (F = 4.28; p = 0.046). Additionally, subjects with PTSD symptoms showed reduced white matter integrity in the right cingulum bundle (axial diffusivity, F = 6.04; p = 0.020). Accompanying these structural alterations, mTBI and PTSD subjects also showed impaired performance in encoding (F = 5.98; p = 0.019) and retrieval (F = 7.32; p = 0.010) phases of list learning and in tests of processing speed (Wechsler Adult Intelligence Scale Processing Speed Index, F = 12.23; p = 0.001; Trail Making Test A, F = 5.56; p = 0.024). Increased volume and white matter disruptions in these areas, commonly associated with memory functions, may be related to functional disturbances during cognitively demanding tasks. Differences in brain volume and white matter integrity between mTBI subjects and those with mTBI and co-morbid PTSD symptoms point to neuroanatomical differences that may underlie poorer recovery of mTBI subjects who experience PTSD symptoms. These findings support theoretical models of PTSD and its relationship to learning deficits.

The Effects of Mild Traumatic Brain Injury, Post-Traumatic Stress Disorder, and Combined Mild Traumatic Brain Injury/Post-Traumatic Stress Disorder on Returning Veterans

United States veterans of the Iraqi (Operation Iraqi Freedom [OIF]) and Afghanistan (Operation Enduring Freedom [OEF]) conflicts have frequently returned from deployment after sustaining mild traumatic brain injury (mTBI) and enduring stressful events resulting in post-traumatic stress disorder (PTSD). A large number of returning service members have been diagnosed with both a history of mTBI and current PTSD. Substantial literature exists on the neuropsychological factors associated with mTBI and PTSD occurring separately; far less research has explored the combined effects of PTSD and mTBI. The current study employed neuropsychological and psychological measures in a sample of 251 OIF/OEF veterans to determine whether participants with a history of mTBI and current PTSD (mTBI+PTSD) have poorer cognitive and psychological outcomes than participants with mTBI only (mTBI-o), PTSD only (PTSD-o), or veteran controls (VC), when groups are comparable on intelligence quotient, education, and age. The mTBI+PTSD group performed more poorly than VC, mTBI-o, and PTSD-o groups on several neuropsychological measures. Effect size comparisons suggest small deleterious effects for mTBI-o on measures of processing speed and visual attention and small effects for PTSD-o on measures of verbal memory, with moderate effects for mTBI+PTSD on the same variables. Additionally, the mTBI+PTSD group was significantly more psychologically distressed than the PTSD-o group, and PTSD-o group was more distressed than VC and mTBI-o groups. These findings suggest that veterans with mTBI+PTSD perform significantly lower on neuropsychological and psychiatric measures than veterans with mTBI-o or PTSD-o. The results also raise the possibility of mild but persisting cognitive changes following mTBI sustained during deployment.

Effect of posttraumatic stress on study time in a task measuring four component processes underlying text-level reading

PURPOSE

To investigate the effect of combat-related posttraumatic stress disorder (PTSD) on 4 components underlying text-level reading comprehension.

METHOD

A group of 17 veterans with PTSD and 17 matched control participants took part. An experimental task required participants to read and study 3-sentence paragraphs describing semantic features associated with real and unreal objects. Each paragraph was followed by true-false statements that assessed knowledge access, text memory, inference, and integration.

RESULTS

The results revealed that the PTSD group took significantly longer than the control group to study the paragraphs. Although there was no group difference in test statement accuracy, the PTSD group also took significantly longer to respond to the test statements.

CONCLUSIONS

Overall, the results provide evidence for the control theory of attention but suggest that more direct measures of task-irrelevant processing during text-level reading are needed. More important, the results begin to lay a foundation for developing not only diagnostic but also intervention strategies.

Factors Associated with Mild Traumatic Brain Injury in Veterans and Military Personnel: A Systematic Review

A history of mild traumatic brain injury (mTBI) is common among military members who served in Operations Enduring Freedom, Iraqi Freedom, and New Dawn (OEF/OIF/OND). We completed a systematic review to describe the cognitive, mental health, physical health, functional, social, and cost consequences of mTBI in Veteran and military personnel. Of 2668 reviewed abstracts, the 31 included studies provided very low strength evidence for the questions of interest. Cognitive, physical, and mental health symptoms were commonly reported by Veterans/military members with a history of mTBI. On average, these symptoms were not significantly more common in those with a history of mTBI than in those without, although a lack of significant mean differences does not preclude the possibility that some individuals could experience substantial effects related to mTBI history. Evidence of potential risk or protective factors moderating mTBI outcomes was unclear. Although the overall strength of evidence is very low due to methodological limitations of included studies, our findings are consistent with civilian studies. Appropriate re-integration services are needed to address common comorbid conditions, such as treatment for post-traumatic stress disorder, substance use disorders, headaches, and other difficulties that Veterans and members of the military may experience after deployment regardless of mTBI history. (JINS, 2014, 20, 1-13).

Neuropsychological effects of self-reported deployment-related mild TBI and current PTSD in OIF/OEF veterans

Current combat veterans are exposed to many incidents that may result in mild traumatic brain injury (mTBI) and/or posttraumatic stress disorder (PTSD). While there is literature on the neuropsychological consequences of PTSD only (PTSD-o) and mTBI alone (mTBI-o), less has been done to explore their combined (mTBI+PTSD) effect. The goal of this study was to determine whether Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF) veterans with mTBI+PTSD have poorer cognitive and psychological outcomes than veterans with PTSD-o, mTBI-o, or combat exposure-only. The final sample included 20 OIF/OEF veterans with histories of self-reported deployment mTBI (mTBI-o), 19 with current PTSD (PTSD-o), 21 with PTSD and self-reported mTBI (mTBI+PTSD), and 21 combat controls (CC) (no PTSD and no reported mTBI). Groups were formed using structured interviews for mTBI and PTSD. All participants underwent comprehensive neuropsychological testing, including neurocognitive and psychiatric feigning tests. Results of cognitive tests revealed significant differences in performance in the mTBI+PTSD and PTSD-o groups relative to mTBI-o and CC. Consistent with previous PTSD literature, significant differences were found on executive (switching) tasks, verbal fluency, and verbal memory. Effect sizes tended to be large in both groups with PTSD. Thus, PTSD seems to be an important variable affecting neuropsychological profiles in the post-deployment time period. Consistent with literature on civilian mTBI, the current study did not find evidence that combat-related mTBI in and of itself contributes to objective cognitive impairment in the late stage of injury.

Neuropsychological functioning of combat veterans with posttraumatic stress disorder and mild traumatic brain injury

This study examined the neuropsychological performance of 125 outpatient Operation Enduring Freedom/Operation Iraqi Freedom combat veterans with posttraumatic stress disorder (PTSD) and nonacute mild traumatic brain injury (TBI) (n = 66) and PTSD (n = 59) across multiple cognitive domains to determine whether mild TBI results in greater impairment among those with PTSD. Profile analyses revealed that veterans with PTSD and mild TBI did not differ significantly from those with just PTSD across domains, suggesting that comorbid mild TBI does not result in an additive effect. A norms-based comparison also revealed that neither group demonstrated impaired performance on any of the objective neuropsychological measures examined. However, both groups endorsed moderately elevated symptoms of depression and anxiety, indicating that comorbid psychopathology may contribute to subjective cognitive complaints.

Neuropsychological outcomes of U.S. Veterans with report of remote blast-related concussion and current psychopathology

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 objective cognitive impairment in the late stage of injury. Impairments, when present, are subtle and most likely attributable to PTSD and other psychological conditions. Implications for clinical neuropsychologists and future research are discussed. (JINS, 2012, 18, 1-11).

Impaired response inhibition in veterans with post-traumatic stress disorder and mild traumatic brain injury

Combat veterans with post-traumatic stress disorder (PTSD) can show impairments in executive control and increases in impulsivity. The current study examined the effects of PTSD on motor response inhibition, a key cognitive control function. A Go/NoGo task was administered to veterans with a diagnosis of PTSD based on semi-structured clinical interview using DSM-IV criteria (n = 40) and age-matched control veterans (n = 33). Participants also completed questionnaires to assess self-reported levels of PTSD and depressive symptoms. Performance measures from the patients (error rates and reaction times) were compared to those from controls. PTSD patients showed a significant deficit in response inhibition, committing more errors on NoGo trials than controls. Higher levels of PTSD and depressive symptoms were associated with higher error rates. Of the three symptom clusters, re-experiencing was the strongest predictor of performance. Because the co-morbidity of mild traumatic brain injury (mTBI) and PTSD was high in this population, secondary analyses compared veterans with PTSD+mTBI (n = 30) to veterans with PTSD only (n = 10). Although preliminary, results indicated the two patient groups did not differ on any measure (p > .88). Since cognitive impairments could hinder the effectiveness of standard PTSD therapies, incorporating treatments that strengthen executive functions might be considered in the future. (JINS, 2012, 18, 1-10).

Deployment-related TBI, persistent postconcussive symptoms, PTSD, and depression in OEF/OIF veterans

OBJECTIVE

A substantial proportion of the more than 2 million service members who have served in Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) have experienced a traumatic brain injury (TBI). Understanding the long-term impact of TBI is complicated by the nonspecific nature of postconcussive symptoms (PCSs) and the high rates of co-occurrence among TBI, posttraumatic stress disorder (PTSD), and depression. The goal of the present research was to examine the relations among TBI, persistent PCSs, and symptoms of PTSD and depression among returning OEF/OIF veterans.

METHOD

213 OEF/OIF veterans (87% male) completed a semistructured screening interview assessing deployment-related TBI and current, persistent PCSs. Participants also completed self-report measures of combat exposure and current symptoms of PTSD and depression.

RESULTS

Nearly half (46%) of sampled veterans screened positive for TBI, the majority of whom (85%) reported at least one persistent PCS after removing PCSs that overlapped with PTSD and depression. Veterans with deployment-related TBI reported higher levels of combat exposure and symptoms of PTSD and depression. Structural equation modeling was used to assess the fit of 3 models of the relationships among TBI, combat exposure, persistent PCSs, PTSD, and depression. Consistent with hypotheses, the best-fitting model was one in which the effects of TBI on both PTSD and depression were fully mediated by nonoverlapping persistent PCSs.

CONCLUSIONS

These findings highlight the importance of addressing persistent PCSs in order to facilitate the functional recovery of returning war veterans.

Neuropsychological sequelae of PTSD and TBI following war deployment among OEF/OIF veterans

Posttraumatic stress disorder (PTSD) and mild traumatic brain injury (mTBI) are highly prevalent among Veterans of the conflicts in Iraq and Afghanistan. These conditions are associated with common and unique neuropsychological and neuroanatomical changes. This review synthesizes neuropsychological and neuroimaging studies for both of these disorders and studies examining their co-occurrence. Recommendations for future research, including use of combined neuropsychological and advanced neuroimaging techniques to study these disorders alone and in concert, are presented. It is clear from the dearth of literature that addiitonal studies are required to examine and understand the impact of specific factors on neurocognitive outcome. Of particular relevance are temporal relationships between PTSD and mTBI, risk and resilience factors associated with both disorders and their co-occurrence, and mTBI-specific factors such as time since injury and severity of injury, utilizing comprehensive, yet targeted cognitive tasks.