Contextual Effects of Traumatic Brain Injury on the Connectome: Differential Effects of Deployment- and Non-Deployment-Acquired Injuries.

OBJECTIVE: To identify differential effects of mild traumatic brain injury (TBI) occurring in a deployment or nondeployment setting on the functional brain connectome. SETTING: Veterans Affairs Medical Center. PARTICIPANTS: In total, 181 combat-exposed veterans of the wars in Iraq and Afghanistan ( n = 74 with deployment-related mild TBI, average time since injury = 11.0 years, SD = 4.1). DESIGN: Cross-sectional observational study. MAIN MEASURES: Mid-Atlantic MIRECC (Mid-Atlantic Mental Illness Research, Education, and Clinical Center) Assessment of TBI, Clinician-Administered PTSD Scale, connectome metrics. RESULTS: Linear regression adjusting for relevant covariates demonstrates a significant ( P < .05 corrected) association between deployment mild TBI with reduced global efficiency (nonstandardized ß = -.011) and degree of the K-core (nonstandardized ß = -.79). Nondeployment mild TBI was significantly associated with a reduced number of modules within the connectome (nonstandardized ß = -2.32). Finally, the interaction between deployment and nondeployment mild TBIs was significantly ( P < .05 corrected) associated with increased mean (nonstandardized ß = 9.92) and mode (nonstandardized ß = 14.02) frequency at which connections occur. CONCLUSIONS: These results demonstrate distinct effects of mild TBI on the functional brain connectome when sustained in a deployment versus nondeployment context. This is consistent with findings demonstrating differential effects in other areas such as psychiatric diagnoses and severity, pain, sleep, and cognitive function. Furthermore, participants were an average of 11 years postinjury, suggesting these represent chronic effects of the injury. Overall, these findings add to the growing body of evidence, suggesting the effects of mild TBI acquired during deployment are different and potentially longer lasting than those of mild TBI acquired in a nondeployment context.

Research Letter: Blast Exposure and Brain Volume.

OBJECTIVE: To determine whether blast exposure is associated with brain volume beyond posttraumatic stress disorder (PTSD) diagnosis and history of traumatic brain injury (TBI). SETTING: Veterans Affairs Medical Center. PARTICIPANTS: One hundred sixty-three Iraq and Afghanistan combat veterans, 86.5% male, and 68.10% with a history of blast exposure. Individuals with a history of moderate to severe TBI were excluded. MAIN MEASURES: Clinician-Administered PTSD Scale (CAPS-5), Mid-Atlantic MIRECC Assessment of TBI (MMA-TBI), Salisbury Blast Interview (SBI), and magnetic resonance imaging. Maximum blast pressure experienced from a blast event represented blast severity. METHODS: Hierarchical regression analysis evaluated effects of maximum pressure experienced from a blast event on bilateral volume of hippocampus, anterior cingulate cortex, amygdala, orbitofrontal cortex, precuneus, and insula. All analyses adjusted for effects of current and lifetime PTSD diagnosis, and a history of deployment mild TBI. RESULTS: Maximum blast pressure experienced was significantly associated with lower bilateral hippocampal volume (left: ΔR2 = 0.032, P < .001; right: ΔR2 = 0.030, P < .001) beyond PTSD diagnosis and deployment mild TBI history. Other characteristics of blast exposure (time since most recent exposure, distance from closest blast, and frequency of blast events) were not associated with evaluated volumes. CONCLUSION: Exposure to a blast is independently associated with hippocampal volume beyond PTSD and mild TBI; however, these effects are small. These results also demonstrate that blast exposure in and of itself may be less consequential than severity of the exposure as measured by the pressure gradient.

Distress Tolerance and Symptom Severity as Mediators of Symptom Validity Failure in Veterans With PTSD.

OBJECTIVE: Performance validity tests (PVTs) and symptom validity tests (SVTs) are necessary in clinical and research contexts. The extent to which psychiatric distress contributes to failure on these tests is unclear. The authors hypothesized that the relation between posttraumatic stress disorder (PTSD) and validity would be serially mediated by distress tolerance and symptom severity. METHODS: Participants included 306 veterans, 110 of whom met full criteria for current PTSD. PVTs included the Medical Symptom Validity Test (MSVT) and b Test. The Structured Inventory of Malingered Symptomatology (SIMS) was used to measure symptom validity. RESULTS: MSVT failure was significantly and directly associated with PTSD severity (B=0.05, CI=0.01, 0.08) but not distress tolerance or PTSD diagnosis. b Test performance was not significantly related to any variable. SIMS failure was significantly associated with PTSD diagnosis (B=0.71, CI=0.05, 1.37), distress tolerance (B=-0.04, CI=-0.07, -0.01), and symptom severity (B=0.07, CI=0.04, 0.09). The serial mediation model significantly predicted all SIMS subscales. CONCLUSIONS: PTSD severity was associated with failing a memory-based PVT but not an attention-based PVT. Neither PVT was associated with distress tolerance or PTSD diagnosis. SVT failure was associated with PTSD diagnosis, poor distress tolerance, and high symptomatology. For veterans with PTSD, difficulty managing negative emotional states may contribute to symptom overreporting. This may reflect exaggeration or an inability to tolerate stronger negative affect, rather than a "cry for help."

Brain Volume in Veterans: Relationship to Posttraumatic Stress Disorder and Mild Traumatic Brain Injury.

OBJECTIVE: Clarify associations between diagnosis of posttraumatic stress disorder (PTSD) and deployment traumatic brain injury (TBI) on salient regional brain volumes in returning combat veterans. PARTICIPANTS: Iraq and Afghanistan era combat veterans, N = 163, 86.5% male. MAIN MEASURES: Clinician-administered PTSD Scale (CAPS-5), Mid-Atlantic MIRECC Assessment of TBI (MMA-TBI), magnetic resonance imaging. METHODS: Hierarchical regression analyses evaluated associations and interactions between current and lifetime PTSD diagnosis, deployment TBI, and bilateral volume of hippocampus, anterior cingulate cortex, amygdala, orbitofrontal cortex, precuneus, and insula. RESULTS: Deployment TBI was associated with lower bilateral hippocampal volume (P = .007-.032) and right medial orbitofrontal cortex volume (P = .006). Neither current nor lifetime PTSD diagnosis was associated with volumetric outcomes beyond covariates and deployment TBI. CONCLUSION: History of deployment TBI is independently associated with lower volumes in hippocampus and medial orbitofrontal cortex. These results support TBI as a potential contributing factor to consider in reduced cortical volume in PTSD.

Sequelae of Blast Events in Iraq and Afghanistan War Veterans using the Salisbury Blast Interview: A CENC Study.

Objective: To comprehensively characterize blast exposure across the lifespan and relationship to TBI.Participants: Post-deployment veterans and service members (N = 287).Design: Prospective cohort recruitment.Main Measures: Salisbury Blast Interview (SBI).Results: 94.4% of participants reported at least one blast event, 75% reported a pressure gradient during a blast event. Participants reported an average of 337.7 (SD = 984.0) blast events (range 0-4857), 64.8% occurring during combat. Across participants, 19.7% reported experiencing a traumatic brain injury (TBI) during a blast event. Subjective ratings of blast characteristics (wind, debris, ground shaking, pressure, temperature, sound) were significantly higher when TBI was experienced and significantly lower when behind cover. Pressure had the strongest association with resulting TBI (AUC = 0.751). Pressure rating of 3 had the best sensitivity (.54)/specificity (.87) with TBI. Logistic regression demonstrated pressure, temperature and distance were the best predictors of TBI, and pressure was the best predictor of primary blast TBI.Conclusion: Results demonstrate the ubiquitous nature of blast events and provide insight into blast characteristics most associated with resulting TBI (pressure, temperature, distance). The SBI provides comprehensive characterization of blast events across the lifespan including the environment, protective factors, blast characteristics and estimates of distance and munition.

Ultrasound Visualization of Torsional Anatomic Changes From External Rotation of the Anterior Shoulder.

The sonographic appearance of soft tissue can be altered with movement. This can be related to both position change as well as torsional stress. The objective of this article is to demonstrate sonographic anatomy of the anterior shoulder as it moves into full external rotation. METHODS: Ultrasound images were obtained in a healthy human subject. Conventional imaging locations were selected that are typically utilized to assess musculoskeletal and peripheral nerve anatomy as well as perform therapeutic injections. The transducer was centered over each region to obtain both short- and long-axis views. A pair of sonographic images was recorded for both imaging planes at each site: the first in anatomic neutral and second in full external rotation. In addition, a video recording was made at each site to track the movement of the muscles and nerves during external rotation. RESULTS: The rotator interval including the intertubercular groove and biceps brachii long head moves far laterally when viewed in short axis, and it becomes out of plane when viewed in long axis. The subscapularis is relatively poorly visualized with the shoulder in neutral position, but the tendon and more distal aspect of the muscle are well visualized in full external rotation. The pectoralis major tendon insertion is well visualized in long axis with the shoulder in both neutral position and full external rotation. Movement of the humerus and the pectoralis major insertion are seen with shoulder rotation. The muscle appears to tighten and lengthen. The pectoralis major muscle is also seen in greater detail in external rotation. The cord level of the brachial plexus is also visualized at the infraclavicular portion of the anterior shoulder. The medial, posterior, and lateral cords are visualized in relation to the axillary artery. The relative position of the cords is only minimally altered with external rotation; however, the overlying pectoralis minor is tightened, and its influence can be visualized. DISCUSSION: External rotation has a considerable effect on the sonographic appearance of the anterior shoulder. Targets used for therapeutic injections, such as the bicipital groove, rotate out of clear view. Some chemodenervation targets, such as the muscle of the subscapularis, can only be accessed with the shoulder in full external rotation. Full external rotation of the shoulder also places torsional stress on some of the anterior shoulder structures, such as the pectorals, which can provide diagnostic clues in certain pathologic conditions. CONCLUSION: Movement into external rotation changes the sonographic appearance of the anatomic relationships of the anterior shoulder. Knowledge of these torsional changes can have both diagnostic and therapeutic implications.

Torsional Anatomy of the Lower Limb: The Appearance of Anatomy in Hemispastic Position.

OBJECTIVE: The aim of the study was to determine whether there are relevant anatomical variations to the typical injection sites for antispasticity procedures in the lower limb. METHODS: Sonographic images were obtained at traditional injection locations for spasticity in the lower limb. Images were recorded in neutral and contracted postures. Doppler imaging was obtained for sites that contained vasculature. The images were analyzed, and schematics were created that highlighted relevant findings. RESULTS: The adductor longus in commonly used injection sites was close to vasculature making accidental injection of the latter a higher risk. The sciatic nerve was vulnerable to injections at the proximal biceps femoris injection side if injected too deeply. Hamstring injection sites can be adjusted to the midline to improve accuracy. The proximity of the tibial nerve to the flexor hallucis longus and the deep fibular nerve to the extensor hallucis longus puts these nerves at risk for accidental injection. DISCUSSION: Contracted posture results in altered positions of lower extremity muscles that could lead to inadvertent neurovascular injection or decreased efficacy with injections. Findings in this study may be helpful for planning and executing injections to reduce spasticity in the lower extremity. CONCLUSIONS: Sonographic imaging allows a better localization of muscles associated with spasticity and can instruct the clinician to alter usual injection pathways. This article documents visual evidence that previous assumptions for injection strategies require updating.

Behavioral and Health Outcomes Associated With Deployment and Nondeployment Acquisition of Traumatic Brain Injury in Iraq and Afghanistan Veterans.

OBJECTIVE: To characterize behavioral and health outcomes in veterans with traumatic brain injury (TBI) acquired in nondeployment and deployment settings. DESIGN: Cross-sectional assessment evaluating TBI acquired during and outside of deployment, mental and behavioral health symptoms, and diagnoses. SETTING: Veterans Affairs Medical Centers. PARTICIPANTS: Iraq and Afghanistan veterans who were deployed to a warzone (N=1399). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Comprehensive lifetime TBI interview, Structured Clinical Interview for DSM-IV Disorders, Combat Exposure Scale, and behavioral and health measures. RESULTS: There was a main effect of deployment TBI on depressive symptoms, posttraumatic stress symptoms, poor sleep quality, substance use, and pain. Veterans with deployment TBI were also more likely to have a diagnosis of bipolar, major depressive, alcohol use, and posttraumatic stress disorders than those who did not have a deployment TBI. CONCLUSIONS: TBIs acquired during deployment are associated with different behavioral and health outcomes than TBI acquired in nondeployment environments. The presence of TBI during deployment is associated with poorer behavioral outcomes, as well as a greater lifetime prevalence of behavioral and health problems in contrast to veterans without deployment TBI. These results indicate that problems may persist chronically after a deployment TBI and should be considered when providing care for veterans. Veterans with deployment TBI may require treatment alterations to improve engagement and outcomes.

Longitudinal changes in neuroimaging and neuropsychiatric status of post-deployment veterans: a CENC pilot study.

PRIMARY OBJECTIVE: The purpose of this study was to evaluate preliminary data on longitudinal changes in psychiatric, neurobehavioural, and neuroimaging findings in Iraq and Afghanistan combat veterans following blast exposure. RESEARCH DESIGN: Longitudinal observational analysis. METHODS AND PROCEDURES: Participants were invited to participate in two research projects approximately 7 years apart. For each project, veterans completed the Structured Clinical Interview for DSM-IV Disorders and/or the Clinician-Administered PTSD Scale, Neurobehavioral Symptom Inventory, and magnetic resonance imaging (MRI). MAIN OUTCOMES AND RESULTS: Chi-squared tests indicated no significant changes in current psychiatric diagnoses, traumatic brain injury (TBI) history, or blast exposure history between assessment visits. Wilcoxon signed-rank tests indicated significant increases in median neurobehavioural symptoms, total number of white matter hyperintensities (WMH), and total WMH volume between assessment visits. Spearman rank correlations indicated no significant associations between change in psychiatric diagnoses, TBI history, blast exposure history, or neurobehavioural symptoms and change in WMH. CONCLUSION: MRI WMH changes were not associated with changes in psychiatric diagnoses or symptom burden, but were associated with severity of blast exposure. Future, larger studies might further evaluate presence and aetiology of long-term neuropsychiatric symptoms and MRI findings in blast-exposed populations.

Procedure-Oriented Torsional Anatomy of the Hand for Spasticity Injection.

OBJECTIVES: To provide musculoskeletal ultrasound (MSKUS) images of hand anatomy in the position of hemiparetic flexion as a reference for spasticity injections. After a stroke, spasticity can result in anatomic distortion of the hand. Spasticity may require treatment with botulinum toxin or phenol injections. Anatomic distortion may decrease the accuracy of injections. Standard anatomic references are of limited utility because they are not in this spastic hemiparetic position. There presently is no anatomic reference in the literature for these spastic postures. This study is part three of a series examining torsional anatomy of the body. DESIGN: Ultrasound (US) images were obtained in a healthy subject. The muscles examined included the lumbricals and the flexor pollicis brevis. A marker dot was placed at each dorsal and palmar anatomic injection site for these muscles. The US probe was placed on these dots to obtain a cross-sectional view. A pair of US images was recorded with and without power Doppler imaging: the first in anatomic neutral and second in hemiparetic spastic positions. In addition, a video recording of the movement of the muscles during this rotation was made at each site. RESULTS: On the palmar view, the lumbricals rotated medially. On dorsal view, the lumbricals can be seen deep to the dorsal interossei muscles, with spastic position, and they become difficult to identify. The flexor pollicis brevis (FPB) muscle contracts with torsion, making abductor pollicis brevis (APB) predominately in view. DISCUSSION: The anatomic location of the lumbrical muscles makes them difficult to inject even with ultrasound guidance. However, recognizing the nearby digital vasculature allows for improved identification of the musculature for injection purposes. The FPB muscle also can be identified by its adjacent radial artery lateral to the flexor pollicus longus tendon. CONCLUSION: Normal anatomy of hand can become distorted in spastic hemiparesis. Diagnostic ultrasound is able to discern these anatomic locations if the sonographer is competent in recognizing the appearance of normal anatomy and is skilled in resolving the visual changes that occur in spastic hemiparesis. The authors hope this series of images will increase the accuracy, safety, and efficacy of spasticity injections in the hand.

Procedure-oriented torsional anatomy of the proximal arm for spasticity injection.

UNLABELLED: This is the first in a series of papers related to the new concept of "torsional" anatomy. The objective of this article is to provide musculoskeletal ultrasound (MSKUS) anatomy of the upper arm in the position of hemispastic flexion as a reference relevant to needle procedures. METHODS: The MSKUS images were obtained in a healthy human subject. A pair of MSKUS images was recorded for each level: the first in anatomic neutral and second in hemispastic position. RESULTS: At the proximal 1/3 level of the upper arm, the pectoralis major rotated out of view. At the middle of the upper arm, the biceps rotated medially, and the brachialis rotated from far lateral to the middle of the screen. At the distal 1/3 level of the upper arm, the radial nerve rotated more anteriorly. At the distal 1/6 level of the upper arm, the biceps shifted and was replaced by the brachialis and brachioradialis. The radial nerve also rotated more anteriorly and superficially. DISCUSSION: With torsion, it is possible that intended muscle targets, such as the pectoralis, are missed, and unintended targets, such as the radial nerve, are accidentally injected in the upper arm. CONCLUSIONS: It is hoped that this series of images will increase the accuracy and safety of needle placement for spasticity and nerve block injections in the proximal upper arm.

Procedure-oriented sectional anatomy of the foot.

This is the seventh and last in a series of studies related to procedure-oriented joint anatomy. This article reviews the anatomy of the foot and its relationship to procedures in the clinical setting with or without ultrasound guidance. Anatomically correct axial schematics allow injections to be envisioned relative to clinically important anatomy for common forefoot procedures. Cross-sectional schematics for the ankle were drawn as they appear in imaging projections. The levels and planes of cross section were selected to highlight important anatomic landmarks for injection. It is hoped that these schematics allow for safer and more accurate needle procedures in the foot area.

Procedure Oriented Torsional Anatomy of the Forearm for Spasticity Injection.

UNLABELLED: : This is the second in a series of articles related to the concept of "torsional" anatomy. The objective of this article is to provide musculoskeletal ultrasound (MSKUS) anatomy of the forearm in the position of hemispastic flexion as a reference relevant to needle procedures. METHODS: The MSKUS images were obtained in a healthy human subject. Marker dots were placed over common injection sites in the forearm for spasticity. The MSKUS probe was centered over each dot to obtain a cross-sectional view. A pair of MSKUS images was recorded for each site: the first in anatomic neutral and second in hemiparetic spastic position. The images were compared side to side. In addition, a video recording was made at each site to track the movement of the muscles and nerves during internal rotation. RESULTS: The pronator teres (PT) rotated medially and the brachialis and biceps tendon rotated in view. In addition, the median nerve became more superficial. The flexor carpi radialis rotated medially and was replaced by PT and the median nerve. The flexor carpi ulnaris and flexor digitorum profundus rotated medially and were replaced by the flexor carpi radialis, PT and median nerve. The flexor digitorum superficialis was replaced by the brachioradialis, extensor carpi radialis brevis, and radial nerve. The brachioradialis was replaced by the extensor carpi radialis brevis and extensor digitorum communis. DISCUSSION: Intended muscle targets rotate out of view and injection range. These are replaced by other muscles and nerves that could inadvertently be injected. This potentially could result in both increased complications and decreased efficacy of the procedure. CONCLUSIONS: It is hoped that this series of images will increase the accuracy and safety of needle placement for spasticity injections in the forearm.

White matter compromise in veterans exposed to primary blast forces.

OBJECTIVE: Use diffusion tensor imaging to investigate white matter alterations associated with blast exposure with or without acute symptoms of traumatic brain injury (TBI). PARTICIPANTS: Forty-five veterans of the recent military conflicts included 23 exposed to primary blast without TBI symptoms, 6 having primary blast with mild TBI, and 16 unexposed to blast. DESIGN: Cross-sectional case-control study. MAIN MEASURES: Neuropsychological testing and diffusion tensor imaging metrics that quantified the number of voxel clusters with altered fractional anisotropy (FA) radial diffusivity, and axial diffusivity, regardless of their spatial location. RESULTS: Significantly lower FA and higher radial diffusivity were observed in veterans exposed to primary blast with and without mild TBI relative to blast-unexposed veterans. Voxel clusters of lower FA were spatially dispersed and heterogeneous across affected individuals. CONCLUSION: These results suggest that lack of clear TBI symptoms following primary blast exposure may not accurately reflect the extent of brain injury. If confirmed, our findings would argue for supplementing the established approach of making diagnoses based purely on clinical history and observable acute symptoms with novel neuroimaging-based diagnostic criteria that "look below the surface" for pathology.