History Of Mild Traumatic Brain Injury Research Articles

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

Both posttraumatic stress disorder (PTSD) and history of traumatic brain injury (TBI) are prevalent conditions in military veterans, frequently co-occur in this population, and have substantial symptom overlap. Cognitive processing therapy (CPT) is an empirically supported treatment for PTSD but questions have arisen about its efficacy for individuals with a history of TBI, particularly those experiencing cognitive or other neurologic symptoms. Research examining the generalizability of CPT to veterans with both PTSD and a history of TBI has been limited. We describe the use of CPT with a veteran who presented with PTSD, a history of mild TBI, subjective cognitive complaints, objective cognitive deficits, and speech disturbance (stuttering). This case study demonstrates that CPT can effectively and significantly reduce core PTSD symptoms as well as cognitive symptoms and speech disturbances in this comorbid presentation.

Poor sleep predicts subacute postconcussion symptoms following mild traumatic brain injury

ABSTRACTThe primary objective was to determine if poor sleep predicts postconcussion symptoms in the subacute period after mild traumatic brain injury (TBI). The impact of poor sleep pre- and post-injury was examined. The research design was cross-sectional. After screening to detect response invalidity, 61 individuals with a self-reported history of mild TBI 1-to-6 months prior answered an online fixed order battery of standardized questionnaires assessing their sleep (current and preinjury) and persistent postconcussion symptoms (Neurobehavioral Symptom Inventory, minus sleep, and fatigue items). The sleep measures were the Insomnia Severity Index, Epworth Sleepiness Scale, a single Likert-scale pre-injury sleep quality rating, and two PROMIS™ measures (sleep-related impairment and sleep disturbance). After controlling for the effects of preinjury sleep quality and demographics, the combination of the sleep measures made a significant contribution to the outcome (F[8,58] = 4.013, p = .001, ). Only current sleep-related impairment (ß = .60, p < .05) made a significant and unique contribution to neurobehavioral symptoms. Preinjury sleep was not a predictor (ß = −.19, p > .05), although it contributed 3% of the variance in NSI scores after controlling for demographics. Sleep-related impairment is a modifiable factor. As a significant contributor to neurobehavioral symptoms, treatment for post-injury sleep-related impairment warrants further attention.

Valsalva maneuver unveils central baroreflex dysfunction with altered blood pressure control in persons with a history of mild traumatic brain injury.

BackgroundPatients with a history of mild TBI (post-mTBI-patients) have an unexplained increase in long-term mortality which might be related to central autonomic dysregulation (CAD). We investigated whether standardized baroreflex-loading, induced by a Valsalva maneuver (VM), unveils CAD in otherwise healthy post-mTBI-patients.MethodsIn 29 healthy persons (31.3 ± 12.2 years; 9 women) and 25 post-mTBI-patients (35.0 ± 13.2 years, 7 women, 4–98 months post-injury), we monitored respiration (RESP), RR-intervals (RRI) and systolic blood pressure (BP) at rest and during three VMs. At rest, we calculated parameters of total autonomic modulation [RRI-coefficient-of-variation (CV), RRI-standard-deviation (RRI-SD), RRI-total-powers], of sympathetic [RRI-low-frequency-powers (LF), BP-LF-powers] and parasympathetic modulation [square-root-of-mean-squared-differences-of-successive-RRIs (RMSSD), RRI-high-frequency-powers (HF)], the index of sympatho-vagal balance (RRI LF/HF-ratios), and baroreflex sensitivity (BRS). We calculated Valsalva-ratios (VR) and times from lowest to highest RRIs after strain (VR-time) as indices of parasympathetic activation, intervals from highest systolic BP-values after strain-release to the time when systolic BP had fallen by 90 % of the differences between peak-phase-IV-BP and baseline-BP (90 %-BP-normalization-times), and velocities of BP-normalization (90 %-BP-normalization-velocities) as indices of sympathetic withdrawal.We compared patient- and control-parameters before and during VM (Mann-Whitney-U-tests or t-tests; significance: P < 0.05).ResultsAt rest, RRI-CVs, RRI-SDs, RRI-total-powers, RRI-LF-powers, BP-LF-powers, RRI-RMSSDs, RRI-HF-powers, and BRS were lower in patients than controls. During VMs, 90 %-BP-normalization-times were longer, and 90 %-BP-normalization-velocities were lower in patients than controls (P < 0.05).ConclusionsReduced autonomic modulation at rest and delayed BP-decrease after VM-induced baroreflex-loading indicate subtle CAD with altered baroreflex adjustment to challenge. More severe autonomic challenge might trigger more prominent cardiovascular dysregulation and thus contribute to increased mortality risk in post-mTBI-patients.

Deep white matter hyperintensities affect verbal memory independent of PTSD symptoms in veterans with mild traumatic brain injury

Objective: Although white matter hyperintensity (WMH) pathology has been observed in the context of traumatic brain injury (TBI), the contribution of this type of macrostructural damage to cognitive and/or post-concussive symptomatology (PCS) remains unclear.Methods: Sixty-eight Veterans (mTBI = 46, Military Controls [MCs] = 22) with and without history of mild TBI (mTBI) underwent structural MRI and comprehensive cognitive and psychiatric assessment. WMH volume was identified as deep (DWMH) or periventricular (PVWMH) on fluid-attenuated inversion recovery (FLAIR) images.Results: Group analyses revealed that mTBI history was not associated with increased WMH pathology (p’s > 0.05). However, after controlling for post-traumatic stress disorder (PTSD) and intracranial volume, DWMH was associated with reduced short-and long-delayed memory performance within the mTBI group (p’s < 0.05). Additionally, after adjusting for PTSD and time since injury, regression analyses revealed that WMH was not associated with self-reported ratings of PCS (p’s > 0.05) in the mTBI group.Conclusions: The results demonstrate that, in relatively young Veterans with mTBI, DWMH differentially and negatively affects memory performance above and beyond the effects of PTSD symptoms. The findings may help to clarify prior mixed results as well as offer focused treatment implications for Veterans with history of neurotrauma and evidence of macrostructural white matter damage.

Ongoing daytime behavioural problems in university students following childhood mild traumatic brain injury.

Sleep is often disrupted in traumatic brain injury (TBI) and may be related to persistent behaviour problems; however, little is known about this relationship in young adults. This study explored associations between TBI, behavioural problems and sleep disturbances in 247 university students (197 non-TBI, 47 mild TBI, two moderate TBI, one severe TBI) aged 18-25 years, who completed validated measures for behaviour, sleep quality and history of TBI. Because of small group numbers, participants reporting moderate to severe TBI were excluded from the analyses. Results indicated that students with mild TBI reported higher levels of daytime dysfunction, somatic complaints, withdrawal, other behavioural complaints and internalizing behaviours compared with students with no TBI history. A correlational analysis indicated a moderate relationship between the above significant variables. Our results suggest that university students with a history of mild TBI are more likely to experience certain ongoing daytime behavioural problems, which are likely to negatively influence their academic functioning in tertiary education. This study highlights the importance of research on long-term problems following mild TBI in young adults aged 18-25 years--an age group often overlooked within the literature.

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

Both posttraumatic stress disorder (PTSD) and history of traumatic brain injury (TBI) are prevalent conditions in military veterans, frequently co-occur in this population, and have substantial symptom overlap. Cognitive processing therapy (CPT) is an empirically supported treatment for PTSD but questions have arisen about its efficacy for individuals with a history of TBI, particularly those experiencing cognitive or other neurologic symptoms. Research examining the generalizability of CPT to veterans with both PTSD and a history of TBI has been limited. We describe the use of CPT with a veteran who presented with PTSD, a history of mild TBI, subjective cognitive complaints, objective cognitive deficits, and speech disturbance (stuttering). This case study demonstrates that CPT can effectively and significantly reduce core PTSD symptoms as well as cognitive symptoms and speech disturbances in this comorbid presentation.

Intermittent Autonomic Disorders and Emotion: A Two-way Street?

Background: Long-term mortality is increased in patients with a history of traumatic brain injury (TBI). Pathophysiology is unknown but might be related to central autonomic dysfunction compromising cardiovascular control. In patients with a history of mild TBI, we found compromised cardiovascular responses to parasympathetic challenge by eyeball-pressure-stimulation (EPS). We hypothesize that EPS also yields abnormal responses in patients with a history of moderate-severe TBI. Methods: In 51 patients with a history of moderate-severe-TBI (32.71 ± 10.49 years, 43.12 ± 33.35 months post-injury, GCS 9.29 ± 4.49), and 30 controls (29.13 ± 9.77 years), we recorded respiration, RR-intervals (RRI), systolic and diastolic blood-pressure (BPsys, BPdia), before and during monocular EPS (120 seconds; 30 mmHg), using an ophthalmologic ocular-pressuredevice. We calculated spectral-powers of mainly sympathetic low (LF: 0.04-0.15Hz) and parasympathetic high (HF: 0.15-0.5Hz) frequency RRI-fluctuations, sympathetically mediated LF-powers of BPsys, normalized RRI-LF- (LFnu-RRI-) powers, normalized RRI-HFpowers (HFnu-RRI-powers), and RRI-LF/HF-ratios. We compared parameters between groups before and during EPS by RANOVA with post-hoc analysis (significance: p b 0.05). Results: At rest, LF-BPsyspowers were lower in patients than controls (11.31 ± 13.23 vs. 15.16 ± 9.56, p = 0.011). During EPS, only controls significantly increased RRIs and HFnu-RRI-powers, and decreased LF-RRI-powers, LFnu-RRI-powers, RRI-LF/HF-ratios, and LF-BPsys-powers. In postTBI-patients, EPS only increased BPsys (132.00 ± 13.13 vs. 129.22 ± 14.52 mmHg, p b 0.001) but changed no other parameter. Conclusions: Already at rest, autonomic BP-modulation is compromised in moderate-severe post-TBI-patients. During EPS, moderate-severe post-TBI-patients fail to activate parasympathetic cardiovascular

Factors related to satisfaction with life in veterans with mild traumatic brain injury.

Satisfaction with life (SWL) is an important measure of outcome in rehabilitation. Previous research suggests that those with a history of traumatic brain injury (TBI), even mild TBI, report lower levels of life satisfaction when compared with the noninjured population. Although is it possible that TBI has a direct effect on SWL, various medical and psychosocial factors commonly affecting those recovering from TBI likely contribute to SWL. The present study aimed to identify factors related to SWL in 95 veterans of Operation Enduring Freedom (OEF), Operation Iraqi Freedom (OIF), and Operation New Dawn (OND) with a history of mild TBI. Regression analyses indicated that headache impact, pain interference, sleep quality, posttraumatic stress symptom severity, and social support were all significantly related to SWL. However, when secondary analyses were conducted including posttraumatic stress symptom severity as a covariate before the entry of other predictors, only sleep quality and social support remained significantly associated with SWL. These results indicate the importance of properly identifying and treating symptoms of posttraumatic stress in veterans with a history of mTBI, as posttraumatic stress symptoms appear to be strongly related to SWL in those with a history of mild TBI. Optimizing sleep quality and social support may also be important in improving SWL.

Evaluation of a hybrid treatment for Veterans with comorbid traumatic brain injury and posttraumatic stress disorder: Study protocol for a randomized controlled trial

Comorbidity of posttraumatic stress disorder (PTSD) and history of traumatic brain injury (TBI) is high among Veterans of Operation Iraqi Freedom/Enduring Freedom/New Dawn (OIF/OEF/OND). Cognitive processing therapy (CPT) is empirically supported for the treatment of PTSD, but it is not specifically designed to accommodate the memory, attention, or problem solving deficits that are experienced by many Veterans with comorbid PTSD and TBI. Compensatory cognitive rehabilitation, including cognitive symptom management and rehabilitation therapy (CogSMART), is effective for cognitive deficits stemming from a variety of etiologies, including TBI. We have integrated components of CogSMART into CPT in order to address the unique challenges faced by Veterans with ongoing cognitive complaints related to PTSD and a history of mild TBI. Here we describe an ongoing randomized controlled trial investigating the efficacy of our novel hybrid treatment, SMART-CPT, as compared to standard CPT, for OIF/OEF/OND Veterans with PTSD and a history of mild to moderate TBI. We describe the development of this hybrid treatment as well as implementation of the randomized controlled trial.

Treatment of persistent post-concussive symptoms after mild traumatic brain injury: a systematic review of cognitive rehabilitation and behavioral health interventions in military service members and veterans.

Increased prevalence of traumatic brain injury (TBI) has been associated with service members and veterans who completed combat deployments in support of Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF). Management of persistent post-concussive symptoms (PCS) has been a challenge to healthcare providers throughout the Military and Veterans Healthcare Systems, as well as civilian healthcare providers, due in part to the chronic nature of symptoms, co-occurrence of behavioral health disorders such as depression, Posttraumatic Stress Disorder (PTSD), and substance use disorders, and fear of a potential stigma associated with psychiatric diagnoses and behavioral health treatment(s). This systematic review examined non-pharmacologic behavioral health interventions and cognitive rehabilitation interventions for PCS in military service members and veterans with a history of mild TBI (mTBI). Six electronic databases were searched with specific term limitations, identifying 121 citations. Ultimately, 19 articles met criteria for inclusion in this systematic review. Studies were broadly categorized into four subtypes: psychoeducational interventions, cognitive rehabilitation, psychotherapeutic approaches, and integrated behavioral health interventions for PCS and PTSD. The review provides an update of the empirical evidence for these four types of interventions for PCS in active duty service members and veterans. Recommendations for future research are discussed, including the need to expand and improve the limited evidence basis on how to manage persistent post-concussive symptoms in this population.

Prolonged Exposure Therapy With Veterans and Active Duty Personnel Diagnosed With PTSD and Traumatic Brain Injury.

The present study used archival clinical data to analyze the delivery and effectiveness of prolonged exposure (PE) and ancillary services for posttraumatic stress disorder (PTSD) among Operation Enduring Freedom, Operation Iraqi Freedom, and Operation New Dawn veterans (N = 69) with histories of mild to severe traumatic brain injury (TBI). Data from standard clinical assessments of veterans and active duty personnel treated in both inpatient and outpatient programs at 2 Department of Veteran Affairs medical centers were examined. Symptoms were assessed with self-report measures of PTSD (PTSD Checklist) and depression (Beck Depression Inventory-II) before and throughout therapy. Mixed linear models were utilized to determine the slope of reported symptoms throughout treatment, and the effects associated with fixed factors such as site, treatment setting (residential vs. outpatient), and TBI severity were examined. Results demonstrated significant decreases in PTSD, B = -3.00, 95% CI [-3.22, -2.78]; t(210) = -13.5; p < .001, and in depressive symptoms, B = -1.46, 95% CI [-1.64, -1.28]; t(192) = -8.32; p < .001. The effects of PE treatment did not differ by clinical setting and participants with moderate to severe injuries reported more rapid gains than those with a history of mild TBI. The results provide evidence that PE may well be effective for veterans with PTSD and TBI.

Measuring executive function in control subjects and TBI patients with question completion time (QCT).

Questionnaire completion is a complex task that places demands on cognitive functions subserving reading, introspective memory, decision-making, and motor control. Although computerized questionnaires and surveys are used with increasing frequency in clinical practice, few studies have examined question completion time (QCT), the time required to complete each question. Here, we analyzed QCTs in 172 control subjects and 31 patients with traumatic brain injury (TBI) who completed two computerized questionnaires, the 17-question Post-Traumatic Stress Disorder (PTSD) Checklist (PCL) and the 25-question Cognitive Failures Questionnaire (CFQ). In control subjects, robust correlations were found between self-paced QCTs on the PCL and CFQ (r = 0.82). QCTs on individual questions correlated strongly with the number of words in the question, indicating the critical role of reading speed. QCTs increased significantly with age, and were reduced in females and in subjects with increased education and computer experience. QCT z-scores, corrected for age, education, computer use, and sex, correlated more strongly with each other than with the results of other cognitive tests. Patients with a history of severe TBI showed significantly delayed QCTs, but QCTs fell within the normal range in patients with a history of mild TBI. When questionnaires are used to gather relevant patient information, simultaneous QCT measures provide reliable and clinically sensitive measures of processing speed and executive function.

Comparing the Neuropsychological Test Performance of Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) Veterans with and without Blast Exposure, Mild Traumatic Brain Injury, and Posttraumatic Stress Symptoms.

To compare neuropsychological test performance of Veterans with and without mild traumatic brain injury (MTBI), blast exposure, and posttraumatic stress disorder (PTSD) symptoms. We compared the neuropsychological test performance of 49 Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) Veterans diagnosed with MTBI resulting from combat blast-exposure to that of 20 blast-exposed OEF/OIF Veterans without history of MTBI, 23 OEF/OIF Veterans with no blast exposure or MTBI history, and 40 matched civilian controls. Comparison of neuropsychological test performance across all four participant groups showed a complex pattern of mixed significant and mostly nonsignificant results, with omnibus tests significant for measures of attention, spatial abilities, and executive function. The most consistent pattern was the absence of significant differences between blast-exposed Veterans with MTBI history and blast-exposed Veterans without MTBI history. When blast-exposed Veteran groups with and without MTBI history were aggregated and compared to non-blast-exposed Veterans, there were significant differences for some measures of learning and memory, spatial abilities, and executive function. However, covariation for severity of PTSD symptoms eliminated all significant omnibus neuropsychological differences between Veteran groups. Our results suggest that, although some mild neurocognitive effects were associated with blast exposure, these neurocognitive effects might be better explained by PTSD symptom severity rather than blast exposure or MTBI history alone.

In vivo characterization of chronic traumatic encephalopathy using [F-18]FDDNP PET brain imaging

Chronic traumatic encephalopathy (CTE) is an acquired primary tauopathy with a variety of cognitive, behavioral, and motor symptoms linked to cumulative brain damage sustained from single, episodic, or repetitive traumatic brain injury (TBI). No definitive clinical diagnosis for this condition exists. In this work, we used [F-18]FDDNP PET to detect brain patterns of neuropathology distribution in retired professional American football players with suspected CTE (n = 14) and compared results with those of cognitively intact controls (n = 28) and patients with Alzheimer's dementia (AD) (n = 24), a disease that has been cognitively associated with CTE. [F-18]FDDNP PET imaging results in the retired players suggested the presence of neuropathological patterns consistent with models of concussion wherein brainstem white matter tracts undergo early axonal damage and cumulative axonal injuries along subcortical, limbic, and cortical brain circuitries supporting mood, emotions, and behavior. This deposition pattern is distinctively different from the progressive pattern of neuropathology [paired helical filament (PHF)-tau and amyloid-β] in AD, which typically begins in the medial temporal lobe progressing along the cortical default mode network, with no or minimal involvement of subcortical structures. This particular [F-18]FDDNP PET imaging pattern in cases of suspected CTE also is primarily consistent with PHF-tau distribution observed at autopsy in subjects with a history of mild TBI and autopsy-confirmed diagnosis of CTE.

Traumatic Brain Injury and Psychogenic Seizures in Veterans

To evaluate a proposed seizure etiology of traumatic brain injury (TBI) as a risk factor for psychogenic nonepileptic seizures (PNESs), the effect of reported TBI severity on the diagnosis of PNES versus epileptic seizures (ESs), and the potential moderating role of posttraumatic stress disorder (PTSD). Veterans with a diagnosis of PNES or ES during epilepsy monitoring at a Veterans Affairs Medical Center. Retrospective review of seizure type, proposed seizure etiology, TBI severity, and PTSD. Both PNES and ES groups were compared for TBI history and severity, and prior diagnosis of PTSD. Traumatic brain injury was the proposed seizure etiology for 57% of 67 PNES patients versus 35% of 54 ES patients (P < .05). It was mild in 87% of PNES patients and 37% of ES patients (P < .001). Posttraumatic stress disorder increased the likelihood of diagnosing PNES versus ES in Veterans with mild TBI as the proposed seizure etiology. Veterans with PNES commonly cite a TBI as the cause for seizures. Mild TBI was strongly associated with PNES versus ES. Posttraumatic stress disorder may moderate the development of PNES in Veterans with a history of mild TBI. Clinicians caring for Veterans with seizures may use these results in selecting patients for early diagnostic evaluation.

A factor analysis and exploration of attitudes and beliefs toward complementary and conventional medicine in veterans.

Although Veterans utilize complementary and alternative medicine (CAM) at rates comparable with civilians, little is known about Veterans' attitudes and beliefs toward CAM. Measures to increase such knowledge may help to identify treatment preferences, particularly among those with signature conditions from the recent conflicts [ie, traumatic brain injury (TBI), posttraumatic stress disorder (PTSD)]. This exploratory study aimed to: (1) determine the factors of the Complementary, Alternative, and Conventional Medicine Attitudes Scale (CACMAS); and to utilize the resulting factors to describe (2) attitudes and beliefs toward CAM; (3) their association with TBI, PTSD, and history of self-directed violence. Patterns of CAM use were also obtained. Factor analysis. Observational study. Participants were 97 Veterans seeking care at a Mountain State Veterans Affairs Medical Center. Participants completed the CACMAS, clinical interviews, and self-report measures during a single visit. CACMAS factors identified were: acceptability of (1) CAM and (2) conventional medicine; (3) mind-body integration; and (4) belief in CAM. Acceptability of CAM was significantly associated with history of mild TBI (mTBI) or PTSD symptom severity. Veterans endorsed a wide range of CAM use. Veterans in this sample were open to CAM and conventional medicine, believed in CAM, and believed that treatments should incorporate the mind and body. Veterans with a history of mTBI or PTSD symptoms may be more accepting of CAM. Understanding Veterans' beliefs and attitudes regarding CAM may help providers deliver patient-centered treatments, particularly among those with conditions for which evidence-based interventions are limited (eg, mTBI).

Impaired practice effects following mild traumatic brain injury: An event-related potential investigation

Background: The negative effects of mild traumatic brain injury (mTBI) on attention are well established. Effects of practice on neuropsychological test performance have also been long recognized and more recently linked to electrophysiological indices of information processing.Objective: The current study examined the behavioural and electrophysiological impact of mTBI on consistent practice of a neuropsychological test of attention.Research design: Prospective cohort study.Methods: Adult participants with a history of mild TBI (n = 10; time since injury > 2 months, mean = 15.2 months) and healthy matched controls (n = 10) completed the Paced Auditory Serial Addition Task (PASAT) at four separate sessions. Event-related potentials (ERPs) were simultaneously recorded.Results: Accuracy of PASAT performance in both groups improved significantly with practice. In healthy controls behavioural improvements were associated with significant attenuation of a frontally distributed ERP component marker of executive attention. These executive attention demands did not appear to ease with consistent practice in the mTBI group, who also endorsed more concussion-related symptoms.Conclusions: These preliminary results suggest sustained mental effort is required to achieve ‘normal’ performance levels following mTBI and support the use of practice-related, ERP indices of recovery from mTBI as a sensitive correlate of persistent post-concussion symptoms.

Degraded temporal processing after traumatic brain injury

Hearing complaints are common following traumatic brain injury (TBI) even in the absence of peripheral auditory impairment. Study goals were to explore the mechanisms which underlie this complaint. Adult listeners with a history of mild TBI or concussion were compared to young and age-matched controls. All listeners had normal or near-normal audiometric thresholds. Listeners with TBI reported difficulty understanding speech in noise. We hypothesized that hearing complaints after TBI are related to damage to neural pathways resulting in degraded temporal resolution. A battery of psychophysical tasks were used to test this hypothesis, specifically: monaural temporal fine structure, to evaluate temporal coding of unresolved harmonics; binaural temporal fine structure, to evaluate temporal coding of a low-frequency sinusoid; interaural coherence, to evaluate sensitivity to the similarity of a correlated broadband noise; and masking level difference, to evaluate the ability to take advantage of interaural phase for tone detection in noise. Results showed individual differences in temporal processing ability among listeners with a history of TBI. Test scores varied from normal to significantly impaired, despite normal audiometry. These results suggest that auditory temporal processing may be related to difficulty understanding speech in noise after TBI. [Work supported by NIH.]

Concordance of clinician judgment of mild traumatic brain injury history with a diagnostic standard.

The concordance of Department of Veterans Affairs (VA) clinician judgment of mild traumatic brain injury (mTBI) history with American Congress of Rehabilitation Medicine (ACRM)-based criteria was examined for Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF) Veterans. In order to understand inconsistencies in agreement, we also examined the associations between evaluation outcomes and conceptually relevant patient characteristics, deployment-related events, current self-reported health symptoms, and suspected psychiatric conditions. The Veteran sample comprised 14,026 OIF/OEF VA patients with deployment-related mTBI history (n = 9,858) or no history of mTBI (n = 4,168) as defined by ACRM-based criteria. In the majority of cases (76.0%), clinician judgment was in agreement with the ACRM-based criteria. The most common inconsistency was between clinician judgment (no) and ACRM-based criteria (yes) for 21.3% of the patients. Injury etiology, current self-reported health symptoms, and suspected psychiatric conditions were additional factors associated with clinician diagnosis and ACRM-based criteria disagreement. Adherence to established diagnostic guidelines is essential for accurate determination of mTBI history and for understanding the extent to which mTBI symptoms resolve or persist over time in OIF/OEF Veterans.

Too hard to control: compromised pain anticipation and modulation in mild traumatic brain injury

Mild traumatic brain injury (MTBI) is a vulnerability factor for the development of pain-related conditions above and beyond those related to comorbid traumatic and emotional symptoms. We acquired functional magnetic resonance imaging (fMRI) on a validated pain anticipation task and tested the hypotheses that individuals with a reported history of MTBI, compared with healthy comparison subjects, would show increased brain response to pain anticipation and ineffective pain modulation after controlling for psychiatric symptoms. Eighteen male subjects with a reported history of blast-related MTBI related to combat, and eighteen healthy male subjects with no reported history of MTBI (healthy controls) underwent fMRI during an event-related experimental pain paradigm with cued high or low intensity painful heat stimuli. No subjects in either group met diagnostic criteria for current mood or anxiety disorder. We found that relative to healthy comparison subjects, after controlling for traumatic and depressive symptoms, participants with a reported history of MTBI showed significantly stronger activations within midbrain periaqueductual grey (PAG), right dorsolateral prefrontal cortex and cuneus during pain anticipation. Furthermore, we found that brain injury was a significant moderator of the relationship between anticipatory PAG activation and reported subjective pain. Our results suggest that a potentially disrupted neurocognitive anticipatory network may result from damage to the endogenous pain modulatory system and underlie difficulties with regulatory pain processing following MTBI. In other words, our findings are consistent with a notion that brain injury makes it more difficult to control acute pain. Understanding these mechanisms of dysfunctional acute pain processing following MTBI may help shed light on the underlying causes of increased vulnerability for the development of pain-related conditions in this population.