Mild Traumatic Brain Injury Symptoms Research Articles

Association of obesity with mild traumatic brain injury symptoms, inflammatory profile, quality of life and functional outcomes: a TRACK-TBI Study

ObjectivesObesity is associated with chronic inflammation, which may impact recovery from mild traumatic brain injury (mTBI). The objective was to assess the role of obesity in recovery of symptoms, functional...

Brain dynamics in triple-network interactions and its relation to multiple cognitive impairments in mild traumatic brain injury.

Traumatic brain injury (TBI) disrupt the coordinated activity of triple-network and produce impairments across several cognitive domains. The triple-network model posits a key role of the salience network (SN) that regulates interactions with the central executive network (CEN) and default mode network (DMN). However, the aberrant dynamic interactions among triple-network and associations with neurobehavioral symptoms in mild TBI was still unclear. In present study, we used brain network interaction index (NII) and dynamic functional connectivity to examine the time-varying cross-network interactions among the triple-network in 109 acute patients, 41 chronic patients, and 65 healthy controls. Dynamic cross-network interactions were significantly increased and more variable in mild TBI compared to controls. Crucially, mild TBI exhibited an increased NII as enhanced integrations between the SN and CEN while reduced coupling of the SN with DMN. The increased NII also implied much severer and multiple domains of cognitive impairments at both acute and chronic mild TBI. Abnormities in time-varying engagement of triple-network is a clinically relevant neurobiological signature of psychopathology in mild TBI. The findings provided align with and advance an emerging perspective on the importance of aberrant brain dynamics associated with highly disparate cognitive and behavioral outcomes in trauma.

Relationship Between Neighborhood Disadvantage and Mild Traumatic Brain Injury Symptoms.

To test the hypotheses that (1) higher neighborhood disadvantage is associated with greater injury-related symptom severity in civilians with mild traumatic brain injury (mTBI) and (2) neighborhood disadvantage remains predictive after controlling for other established predictors. Level 1 trauma center and affiliated academic medical center. N = 171 individuals with mTBI. Prospective cohort study. Rivermead Post Concussion Symptoms Questionnaire (RPQ) total score assessed less than 24 hours and at 2 weeks, 3 months, and 6 months postinjury. Linear mixed-effects models were used to assess the relationship between predictor variables and mTBI-related symptom burden (RPQ score). Neighborhood disadvantage was quantified by the Area Deprivation Index (ADI), a composite of 17 markers of socioeconomic position (SEP) scored at the census block group level. Individuals in the upper ADI quartile of the national distribution displayed higher RPQ symptoms than those in the lower 3 quartiles ( P < .001), with a nonsignificant ADI × visit interaction ( P = .903). In a multivariable model, the effect of ADI remained significant ( P = .034) after adjusting for demographics, individual SEP, and injury factors. Other unique predictors in the multivariable model were gender (gender × visit P = .035), health insurance type ( P = .017), and injury-related litigation ( P = .012). Neighborhood disadvantage as quantified by the ADI is robustly associated with greater mTBI-related symptom burden throughout the first 6 months postinjury. That the effect of ADI remained after controlling for demographics, individual SEP, and injury characteristics implies that neighborhood disadvantage is an important, understudied factor contributing to clinical recovery from mTBI.

Exploration of OT in Outpatient Adult Neurologic Concussion Rehabilitation Programs

Abstract Date Presented Accepted for AOTA INSPIRE 2021 but unable to be presented due to online event limitations. This descriptive, qualitative study describes the OT process used by expert practitioners for adults with persistent mild traumatic brain injury symptoms in outpatient concussion clinics. OTs are uniquely trained to return persons to their everyday activities, without requiring a military or sport background. This evidence empowers practitioners to advocate for the client and for the professional to be part of the rehabilitation team and raise the perceived value of the profession. Primary Author and Speaker: Mary Ann B. Roelke Contributing Authors: Vanessa Jewell

A Role for the Amygdala in Impairments of Affective Behaviors Following Mild Traumatic Brain Injury.

Mild traumatic brain injury (TBI) results in chronic affective disorders such as depression, anxiety, and fear that persist up to years following injury and significantly impair the quality of life for patients. Although a great deal of research has contributed to defining symptoms of mild TBI, there are no adequate drug therapies for brain-injured individuals. Preclinical studies have modeled these deficits in affective behaviors post-injury to understand the underlying mechanisms with a view to developing appropriate treatment strategies. These studies have also unveiled sex differences that contribute to the varying phenotypes associated with each behavior. Although clinical and preclinical studies have viewed these behavioral deficits as separate entities with unique neurobiological mechanisms, mechanistic similarities suggest that a novel approach is needed to advance research on drug therapy. This review will discuss the circuitry involved in the expression of deficits in affective behaviors following mild TBI in humans and animals and provide evidence that the manifestation of impairment in these behaviors stems from an amygdala-dependent emotional processing deficit. It will highlight mechanistic similarities between these different types of affective behaviors that can potentially advance mild TBI drug therapy by investigating treatments for the deficits in affective behaviors as one entity, requiring the same treatment.

Brain-Derived Neurotrophic Factor Val66Met Polymorphism and Internalizing Behaviors after Early Mild Traumatic Brain Injury.

Pediatric traumatic brain injury (TBI) can lead to adverse emotional, social, and behavioral consequences. However, outcome is difficult to predict due to significant individual variability, likely reflecting a complex interaction between injury- and child-related variables. Among these variables are genetically determined individual differences, which can modulate TBI outcome through their influence on neuroplasticity mechanisms. In this study, we examined the effect of Val66Met, a common polymorphism of the brain-derived neurotrophic factor gene known to be involved in neuroplasticity mechanisms, on behavioral symptoms of mild TBI (mTBI) sustained in early childhood. This work is part of a prospective, longitudinal cohort study of early TBI. The current sample consisted of 145 children between ages 18 and 60 months assigned to one of three participant groups: mild TBI, orthopedic injury, or typically developing children. Participants provided a saliva sample to detect the presence of the Val66Met polymorphism, and the Child Behavior Checklist was used to document the presence of behavioral symptoms at 6- and 18-months post-injury. Contrary to our initial hypothesis, at 6 months post-injury, non-carriers of the Val66Met polymorphism in the mTBI group presented significantly more internalizing symptoms (e.g., anxiety/depression and somatic complaints) than Val66Met carriers, who were similar to orthopedically injured and typically developing children. However, at 18 months post-injury, all children with mTBI presented more internalizing symptoms, independent of genotype. The results of the study provide evidence for a protective effect of the Val66Met polymorphism on internalizing behavior symptoms 6 months after early childhood mTBI.

Attention-Deficit/Hyperactivity Disorder Status and Sex Moderate Mild Traumatic Brain Injury Symptom Severity in Children and Adolescents: Implications for Clinical Management.

To investigate the impact of pediatric mild traumatic brain injury (mTBI), using a broad parent-reported measure, and to determine whether parent-ratings of mTBI symptoms are higher among those with premorbid attention-deficit/hyperactivity disorder (ADHD) and females. Retrospective case-control. Hospital-based sports medicine clinic. The retrospective chart review included 1346 (age: M = 13.11 years, SD = 2.6; 61.7% male) pediatric patients with (n = 209) and without (n = 1137) ADHD. Group membership (ADHD vs non-ADHD) and sex (male vs female). Baseline and current Post-Concussion Symptom Inventory-Parent Report Form (PCSI-P) Physical, Emotional, Cognitive, and Fatigue subscale scores. This study used a retrospective chart review; therefore, the hypotheses reported for the current study were formed after data were collected. Controlling for patient age and days from mTBI, patients with ADHD had significantly higher retrospective parent-reported pre-mTBI ratings of physical, emotional, and cognitive symptoms (ds = 0.17-0.62) and higher post-mTBI ratings across all 4 symptom domains (ds = 0.18-0.57) than those without ADHD. There was no group × time interaction for any of the PCSI-P subscales. Females overall had higher retrospective parent-reported pre-injury Fatigue and Emotional symptoms (ds = 0.13-0.19) and higher post-mTBI symptoms in all 4 PCSI-P symptom domains (ds = 0.23-0.35), relative to males. Attention-deficit/hyperactivity disorder-related postinjury exacerbations in parent-reported symptoms can be explained, in part, by elevated retrospective parent-reported ADHD-related pre-mTBI ratings. These results highlight the importance of assessing a patient's baseline symptoms post-mTBI. These data also indicate that ADHD status and sex should be considered when interpreting mTBI symptom severity during clinical evaluation of concussion.

Preinjury Psychological Factors and Case Formulation in Mild Traumatic Brain Injury Rehabilitation: A Case Report

Mild traumatic brain injury (TBI) accounts for the majority of TBIs. Most cases recover within 3 months and usual medical advice covers physical and cognitive rest, activity and fatigue management, and education. However, in some cases, symptoms can persist and there may be ongoing postconcussion difficulties. It is well established that pre- and postinjury psychological factors can contribute to cases of persistent postconcussion symptoms. However, there are few illustrative case examples in the published literature on mild TBI. This case example demonstrates the pivotal role that preinjury psychological factors can play in recovery from mild TBI, using an example of a 35-year-old woman with persistent mild TBI symptoms who had a limited response to previous brief treatment through a Concussion Clinic. Through the process of assessment and development of a psychological case formulation, preinjury psychological factors that had been barriers to recovery and prior rehabilitation efforts were identified. Rehabilitation counselors are equipped to (1) identify and address such barriers, (2) communicate this information to other rehabilitation professionals in the treatment team to facilitate a shared understanding of how factors might affect the client’s functioning and (3) contribute to team case formulation.

The effect of mild traumatic brain injury on the visual processing of global form and motion

ABSTRACTCortical visual processing involves the ventral stream (form perception) and the dorsal stream (motion perception). We assessed whether mild traumatic brain injury (TBI) differentially affects these two streams. Eleven adults with mild TBI (28 ± 9 yrs, 17 ± 5 months post injury) and 25 controls (25 ± 5 yrs) participated. Participants completed tests of global processing involving Glass patterns (form) and random dot kinematograms (motion), measurement of contrast thresholds for motion direction discrimination, a comprehensive vision screening and the Post-Concussion Symptom Inventory (PCSI). Our results showed that the mild TBI group had significantly higher (worse) global form (mean ± SD: TBI 25 ± 6%, control 21 ± 5%) and motion (TBI 14 ± 7%, control 11 ± 3%) coherence thresholds than controls. The magnitude of the mild TBI group deficit did not differ between the two tasks. Contrast thresholds for motion direction discrimination did not differ between the groups, but were positively correlated with PCSI score (r2 = 0.51. p = 0.01) in the mild TBI group. The mild TBI group had worse outcomes than controls for all clinical measurements of vision except distance visual acuity. In conclusion, mild TBI affects processing in both the dorsal and ventral cortical processing streams equally. In addition, spatiotemporal contrast sensitivity may be related to the symptoms of mild TBI.

Performance on the repeatable battery for the assessment of neuropsychological status in college students with mild traumatic brain injury

College students recovering from mild traumatic brain injury (MTBI) often experience a constellation of symptoms including cognitive and emotional difficulties. While these symptoms may interfere with academic performance, few students seek supportive services. Assessment of MTBI symptoms may be important to help identify students with symptoms that may interfere with academic performance and assist them in obtaining appropriate treatment and support services. The purpose of this study was to evaluate cognitive performance of college students with a history of MTBI on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) as well as symptoms of anxiety and depression. A total of seventy college students participated in this study. Participants were divided into two groups based on self-reported history of MTBI. Participants with a history of MTBI (n = 22) performed significantly higher (p < .05) on the RBANS Delayed Memory Index and endorsed significantly fewer (p < .05) trait anxiety symptoms on the State-Trait Anxiety Inventory (STAI) than students without a history of head injury (n = 48). Students with a history of MTBI displayed few impairments on the RBANS and are more likely to endorse fewer symptoms of trait anxiety (but not state anxiety or depression) than peers without a history of head injury.

Head trauma in sports - clinical characteristics, epidemiology and biomarkers.

Traumatic brain injury (TBI) is clinically divided into a spectrum of severities, with mild TBI being the least severe form and a frequent occurrence in contact sports, such as ice hockey, American football, rugby, horse riding and boxing. Mild TBI is caused by blunt nonpenetrating head trauma that causes movement of the brain and stretching and tearing of axons, with diffuse axonal injury being a central pathogenic mechanism. Mild TBI is in principle synonymous with concussion; both have similar criteria in which the most important elements are acute alteration or loss of consciousness and/or post-traumatic amnesia following head trauma and no apparent brain changes on standard neuroimaging. Symptoms in mild TBI are highly variable and there are no validated imaging or fluid biomarkers to determine whether or not a patient with a normal computerized tomography scan of the brain has neuronal damage. Mild TBI typically resolves within a few weeks but 10-15% of concussion patients develop postconcussive syndrome. Repetitive mild TBI, which is frequent in contact sports, is a risk factor for a complicated recovery process. This overview paper discusses the relationships between repetitive head impacts in contact sports, mild TBI and chronic neurological symptoms. What are these conditions, how common are they, how are they linked and can they be objectified using imaging or fluid-based biomarkers? It gives an update on the current state of research on these questions with a specific focus on clinical characteristics, epidemiology and biomarkers.

Detecting coached neuropsychological dysfunction: a simulation experiment regarding mild traumatic brain injury

Objective: Performance validity tests (PVTs) and symptom validity tests (SVTs) are often administered during neuropsychological evaluations. Examinees may be coached to avoid detection by measures of response validity. Relatively little research has evaluated whether graduated levels of coaching has differential effects upon PVT and SVT performance. Accordingly, the present experiment evaluated the effect of graduated levels of coaching upon the classification accuracy of commonly used PVTs and SVTs and the currently accepted criterion of failing two or more PVTs or SVTs. Method: Participants simulated symptoms associated with mild traumatic brain injury (TBI). One group was provided superficial information concerning cognitive, emotional, and physical symptoms. Another group was provided detailed information about such symptoms. A third group was provided detailed information about symptoms and guidance how to evade detection by PVTs. These groups were compared to an honest-responding group. Extending prior experiments, stand-alone and embedded PVT measures were administered in addition to SVTs. Results: The three simulator groups were readily identified by PVTs and SVTs, but a meaningful minority of those provided test-taking strategies eluded detection. The Word Memory Test emerged as the most sensitive indicator of simulated mild TBI symptoms. PVTs achieved more sensitive detection of simulated head injury status than SVTs. Conclusions: Individuals coached to modify test-taking performance were marginally more successful in eluding detection by PVTs and SVTs than those coached with respect to TBI symptoms only. When the criterion of failing two or more PVTs or SVTs was applied, only 5% eluded detection.

Is Age Associated With the Severity of Post–Mild Traumatic Brain Injury Symptoms?

Mild traumatic brain injury (mTBI) is a significant public health concern. Research has shown that mTBI is associated with persistent physical, cognitive, and behavioural symptoms, leading to significant direct and indirect medical costs. Our objective was to determine if age impacts the type and severity of post-mTBI symptoms experienced. Retrospective analysis of prospectively collected data at a level 1 tertiary care outpatient head injury clinic. Participants (N=167) were patients seen at the clinic following an mTBI. The Rivermead Post-Concussion Symptoms Questionnaire was used to assess symptom severity. In our sample, the mean age was 44±16 years with 51% males. Compared with other age groups, patients >66 years of age were significantly more likely to report an mTBI between 6 AM to 12 PM (69%). Middle-aged patients (36-55 years) were more likely to report higher severity of certain post-mTBI symptoms (headache, nausea and vomiting, irritability, poor concentration, sleep disturbance, blurry vision, light sensitivity, and taking longer to think) compared with patients >66 years of age. In general, middle-aged patients reported higher severity of post-mTBI symptoms compared with the oldest patients. Thus, there was a significant association between age and the severity of specific mTBI symptoms, which highlights the need for targeted management. Additional research is needed to understand the mechanisms that could be contributing to the higher symptom severity experienced by the middle-aged group.

Cognitive Rest and Graduated Return to Usual Activities Versus Usual Care for Mild Traumatic Brain Injury: A Randomized Controlled Trial of Emergency Department Discharge Instructions.

It is estimated that 15%-25% of patients with a mild traumatic brain injury (MTBI) diagnosed in the emergency department (ED) will develop postconcussive syndrome. The objective of this study was to determine if patients randomized to graduated return to usual activity discharge instructions had a decrease in their Post-Concussion Symptom Score (PCSS) 2 weeks after MTBI compared to patients who received usual care MTBI discharge instructions. This was a pragmatic, randomized trial of adult (18-64 years) patients of an academic ED (annual census 60,000) diagnosed with MTBI occurring within 24 hours of ED visit. The intervention group received cognitive rest and graduated return to usual activity discharge instructions, and the control group received usual care discharge instructions that did not instruct cognitive rest or graduated return. Patients were contacted by text message or phone 2 and 4 weeks post-ED discharge and asked to complete the PCSS, a validated, 22-item questionnaire, to determine if there was a change in their symptoms. Secondary outcomes included change in PCSS at 4 weeks, number follow-up physician visits, and time off work/school. A total of 118 patients were enrolled in the study (58 in the control group and 60 in the intervention). The mean (±SD) age was 35.2 (±13.7) years and 43 (36.4%) were male. There was no difference with respect to change in PCSS at 2 weeks (10.5 vs. 12.8; ∆2.3, 95% confidence interval [CI]= 7.0 to 11.7) and 4 weeks post-ED discharge (21.1 vs 18.3; ∆2.8, 95% CI= 6.9 to 12.7) for the intervention and control groups, respectively. The number of follow-up physician visits and time off work/school were similar when the groups were compared. Thirty-eight (42.2%) and 23 (30.3%) of patients in this cohort had ongoing MTBI symptoms (PCSS>20) at 2 and 4 weeks, respectively. Results from this study suggest graduated return to usual activity discharge instructions do not impact rate of resolution of MTBI symptoms 2 weeks after ED discharge. Given that patients continue to experience symptoms 2 and 4 weeks after MTBI, more investigation is needed to determine how best to counsel and treat patients with postconcussive symptoms.

Heart Rate Variability in Adolescents Following a Sport-Related Concussion

Sport-related concussion (SRC) or mild traumatic brain injury symptoms are usually resolved within 2 weeks after the injury, but a growing body of evidence suggests persistent deficits of the central nervous system months and years after the injury. A concussion could also alter the autonomic nervous system (ANS), which regulates heartbeat, blood pressure, respiration, thermoregulation and circadian rhythm. A simple and non-invasive way to evaluate ANS function is to measure heart rate variability (HRV). HRV, the variation of the beat-to-beat interval, is one of the physiological manifestations of the ANS. HRV was showed as a reliable marker of SNA dysfunction in patients who suffered from a traumatic brain injury. However, very few studies evaluated the effects of sport-related concussion on HRV and all of them only involved adults. Together, these studies suggest ANS alteration days to months after the injury. Nonetheless, the outcomes of concussion in youth regarding HRV and ANS remain unexplored and unknown. PURPOSE: Therefore, we sought to evaluate the influence of concussion on HRV in adolescents aged from 11 to 17 years. METHOD: To do so, we tested 30 hockey players with a history of concussion (HC) and 22 controls without a history of concussion (NHC). Time since injury was on average 25 months (±24,5). For each participant, we recorded the R-R interval with a chest strap heart rate monitor during all the session. After 5 minutes of sitting rest, the participants exercised on a cycle ergometer during 20 minutes between 60 and 70% of their theoretical maximal heart, following a gradual load increase. Then, there was a cool down for 2 minutes on the ergocycle and a rest period in sitting position for 10 minutes. We compared the HRV of the HC and the NHC during 4 minutes of the pre-exercise rest and 4 minutes of the post-exercise rest. RESULTS: We found no significant difference in any HRV measure of the temporal or frequency domains, neither did we find any difference in the non-parametric measures of HRV (p > 0.05). CONCLUSION: Our results suggest that, if there are ANS deficits in adolescents following a concussion, they do not manifest themselves under the conditions that we tested.

LO036: The influence of cognitive rest and graduated return to usual activities emergency department discharge instructions on symptoms of minor traumatic brain injury

Introduction: It is estimated 15-50% of patients with a mild traumatic brain injury (MTBI) diagnosed in the emergency department (ED) will develop post-concussive syndrome (PCS). Although expert consensus recommends cognitive rest and graduated return to usual activities, these interventions are not based on prospective clinical evidence. The objective of this study was to determine if patients randomized to graduated return to usual activity discharge instructions had a decrease in their Post-Concussion Symptom Score (PCSS) 2 weeks after MTBI compared to patients who received usual care MTBI discharge instructions. Methods: This was a pragmatic, randomized trial of adult (18-64 years) patients presenting to an academic ED (annual census 65,000) with chief complaint ‘head injury’ occurring within 24 hours of ED visit. Patients were contacted by text message or phone 2 weeks post ED discharge and again at 4 weeks and asked to complete a validated, 22 item questionnaire to determine if there was a change in their PCSS. Secondary outcomes included change in PCSS at 4 weeks, number follow-up physician visits, and time off work/school. Results: 118 patients were enrolled in the study (58 in the control group and 60 in the intervention). Mean (SD) age was 35.2 (13.7) years and 43 (36.4%) were male. There was no difference with respect to change in PCSS at 2 weeks (10.5 vs 12.8; Δ 2.3, 95% CI: 7.0, 11.7) and 4 weeks post-ED discharge (21.1 vs 18.3; Δ 2.8, 95% CI: 6.9, 12.7) for the intervention and control groups, respectively. The number follow-up physician visits and time off work/school was similar when the groups were compared. Conclusion: Results from this study suggest graduated return to usual activity discharge instructions do not impact rate of resolution of MTBI symptoms 2 weeks after ED discharge. Given patients continue to experience low to moderate symptoms 2 weeks after MTBI, more investigation is needed to determine how best to counsel and treat patients with post-concussive symptoms.

Exploring the physiological correlates of chronic mild traumatic brain injury symptoms.

We report on the results of a multimodal imaging study involving behavioral assessments, evoked and resting-state BOLD fMRI, and DTI in chronic mTBI subjects. We found that larger task-evoked BOLD activity in the MT+/LO region in extra-striate visual cortex correlated with mTBI and PTSD symptoms, especially light sensitivity. Moreover, higher FA values near the left optic radiation (OR) were associated with both light sensitivity and higher BOLD activity in the MT+/LO region. The MT+/LO region was localized as a region of abnormal functional connectivity with central white matter regions previously found to have abnormal physiological signals during visual eye movement tracking (Astafiev et al., 2015). We conclude that mTBI symptoms and light sensitivity may be related to excessive responsiveness of visual cortex to sensory stimuli. This abnormal sensitivity may be related to chronic remodeling of white matter visual pathways acutely injured.

Management of Mild Traumatic Brain Injury Symptoms in a 31-Year-Old Woman Using Cervical Manipulation and Acupuncture: A Case Report

ObjectiveThe objective was to describe chiropractic and acupuncture care of a patient with acute mild traumatic brain injury (mTBI) symptoms. Clinical FeaturesA 31-year-old woman had acute neck pain, headache, dizziness, nausea, tinnitus, difficulty concentrating, and fatigue following a fall. She was diagnosed at an urgent care facility with mTBI immediately following the fall. Pharmaceutical intervention had been ineffective for her symptoms. Intervention and OutcomeThe patient was treated with chiropractic adjustments characterized as high velocity, low amplitude thrusts directed to the cervical spine and local acupuncture points in the cervical and cranial regions. The patient received care for a total of 8 visits over 2.5 weeks with resolution of concussive symptoms. ConclusionThis patient with mTBI responded favorably to a conservative treatment protocol with the combination of chiropractic and acupuncture care.

Clinical Comparison of 99mTc Exametazime and 123I Ioflupane SPECT in Patients with Chronic Mild Traumatic Brain Injury

BackgroundThis study evaluated the clinical interpretations of single photon emission computed tomography (SPECT) using a cerebral blood flow and a dopamine transporter tracer in patients with chronic mild traumatic brain injury (TBI). The goal was to determine how these two different scan might be used and compared to each other in this patient population.Methods and FindingsTwenty-five patients with persistent symptoms after a mild TBI underwent SPECT with both 99mTc exametazime to measure cerebral blood flow (CBF) and 123I ioflupane to measure dopamine transporter (DAT) binding. The scans were interpreted by two expert readers blinded to any case information and were assessed for abnormal findings in comparison to 10 controls for each type of scan. Qualitative CBF scores for each cortical and subcortical region along with DAT binding scores for the striatum were compared to each other across subjects and to controls. In addition, symptoms were compared to brain scan findings. TBI patients had an average of 6 brain regions with abnormal perfusion compared to controls who had an average of 2 abnormal regions (p<0.001). Patient with headaches had lower CBF in the right frontal lobe, and higher CBF in the left parietal lobe compared to patients without headaches. Lower CBF in the right temporal lobe correlated with poorer reported physical health. Higher DAT binding was associated with more depressive symptoms and overall poorer reported mental health. There was no clear association between CBF and DAT binding in these patients.ConclusionsOverall, both scans detected abnormalities in brain function, but appear to reflect different types of physiological processes associated with chronic mild TBI symptoms. Both types of scans might have distinct uses in the evaluation of chronic TBI patients depending on the clinical scenario.

Predictors of psychiatric disorders in combat veterans

BackgroundMost previous research that has examined mental health among Operation Enduring Freedom and Operation Iraqi Freedom (OEF/OIF) combatants has relied on self-report measures to assess mental health outcomes; few studies have examined predictors of actual mental health diagnoses. The objective of this longitudinal investigation was to identify predictors of psychiatric disorders among Marines who deployed to combat in Iraq and Afghanistan.MethodsThe study sample consisted of 1113 Marines who had deployed to Iraq or Afghanistan. Demographic and psychosocial predictor variables from a survey that all Marines in the sample had completed were studied in relation to subsequent psychiatric diagnoses. Univariate and multivariate logistic regression were used to determine the influence of the predictors on the occurrence of psychiatric disorders.ResultsIn a sample of Marines with no previous psychiatric disorder diagnoses, 18% were diagnosed with a new-onset psychiatric disorder. Adjusting for other variables, the strongest predictors of overall psychiatric disorders were female gender, mild traumatic brain injury symptoms, and satisfaction with leadership. Service members who expressed greater satisfaction with leadership were about half as likely to develop a mental disorder as those who were not satisfied. Unique predictors of specific types of mental disorders were also identified.ConclusionsOverall, the study’s most relevant result was that two potentially modifiable factors, low satisfaction with leadership and low organizational commitment, predicted mental disorder diagnoses in a military sample. Additional research should aim to clarify the nature and impact of these factors on combatant mental health.