Neuropsychiatric Problems After Traumatic Brain Injury: Unraveling the Silent Epidemic

Association Between Traumatic Brain Injury and Psychopathic Traits Among Justice-Involved Adolescents

Traumatic brain injury (TBI) is a global public health problem and is highly prevalent among justice-involved populations. Pediatric TBI is linked with long-term negative outcomes and is correlated with substance use, criminal behavior, psychiatric disorders, and disruptions in neurocognition. These same TBI correlates are evident among youth with psychopathic traits. Given ongoing neurobiological and social development in adolescence, understanding the link between psychopathic traits and TBI in justice-involved youth is critical. A sample of 263 male adolescents were recruited from a maximum-security juvenile justice facility. Using a structural equation modeling (SEM) framework, measurement invariance of psychopathic traits (TBI ±) was tested, and psychopathy scores were accounted for in terms of TBI variables (severity, age of first TBI, total number), participant's age, IQ, substance use, and internalizing psychopathology. There was evidence of strong invariance across TBI status and those with TBI had higher affective and impulsive lifestyle psychopathic traits than adolescents without TBI. The SEM indicated that TBI severity was associated with lower IQ scores, which in turn were associated with increased lifestyle/antisocial (Factor 2) psychopathic traits. Total number of TBIs was associated with higher substance use, which was associated with both increased interpersonal/affective (Factor 1) and Factor 2 psychopathic traits. These TBI variables also had indirect associations with psychopathic traits through IQ and substance use. The findings indicate that TBI is associated with psychopathic traits and suggest that disturbances in cognition and substance use may be treatment targets for youth with TBI and psychopathic traits.

Effects of Repetitive Mild Traumatic Brain Injury on Corticotropin-Releasing Factor Modulation of Lateral Habenula Excitability and Motivated Behavior

Mild traumatic brain injury (mTBI) is a significant health burden due to mTBI-related chronic debilitating cognitive and psychiatric morbidities. Recent evidence from our laboratory suggests a possible dysregulation within reward/motivational circuit function at the level of a subcortical structure, the lateral habenula (LHb), where we demonstrated a causal role for hyperactive LHb in mTBI-induced motivational deficits in self-care grooming behavior in young adult male mice when exposed to mTBI injury during late adolescence (at ~8 weeks old). Here we extended this observation by further characterizing neurobehavioral effects of this repetitive closed head injury model of mTBI in both young adult male and female mice on LHb excitability, corticotropin releasing factor (CRF) modulation of LHb activity, and behavioral responses of motivation to self-care behavior, and approach versus avoidance behavior in the presence of a social- or threat-related stimulus. We show that mTBI increases LHb spontaneous tonic activity in female mice similar to what we previously observed in male mice as well as promoting LHb neuronal hyperexcitability and hyperpolarization-induced LHb bursting in both male and female mice. Interestingly, mTBI only increases LHb intrinsic excitability in male mice coincident with higher levels of the hyperpolarization-activated cation currents (HCN/Ih) and reduces levels of the M-type potassium currents while potentiating M-currents without altering intrinsic excitability in LHb neurons of female mice. Since persistent dysregulation of brain CRF systems is suggested to contribute to chronic psychiatric morbidities and that LHb neurons are highly responsive to CRF, we then tested whether LHb CRF subsystem becomes engaged following mTBI. We found that in vitro inhibition of CRF receptor type 1 (CRFR1) within the LHb normalizes mTBI-induced enhancement of LHb tonic activity and hyperexcitability in both sexes, suggesting that an augmented intra-LHb CRF-CRFR1-mediated signaling contributes to the overall LHb hyperactivity following mTBI. Behaviorally, mTBI diminishes motivation for self-care grooming in female mice as in male mice. mTBI also alters defensive behaviors in the looming shadow task by shifting the innate defensive behaviors towards more passive action-locking rather than escape behaviors in response to an aerial threat in both male and female mice as well as prolonging the latency to escape responses in female mice. While, this model of mTBI reduces social preference in male mice, it induces higher social novelty seeking during the novel social encounters in both male and female mice. Overall, our study provides further translational validity for the use of this preclinical model of mTBI for investigation of mTBI-related reward circuit dysfunction and mood/motivation-related behavioral deficits in both sexes while uncovering a few sexually dimorphic neurobehavioral effects of this model that may differentially affect young males and females when exposed to this type of mTBI injury during late adolescence.

Behavioral Interventions Can Improve Brain Injury-Induced Deficits in Behavioral Flexibility and Impulsivity Linked to Impaired Reward-Feedback Beta Oscillations

Traumatic brain injury (TBI) affects a large population, resulting in severe cognitive impairments. Although cognitive rehabilitation is an accepted treatment for some deficits, studies in patients are limited in ability to probe physiological and behavioral mechanisms. Therefore, animal models are needed to optimize strategies. Frontal TBI in a rat model results in robust and replicable cognitive deficits, making this an ideal candidate for investigating various behavioral interventions. In this study, we report three distinct frontal TBI experiments assessing behavior well into the chronic post-injury period using male Long-Evans rats. First, we evaluated the impact of frontal injury on local field potentials recorded simultaneously from 12 brain regions during a probabilistic reversal learning (PbR) task. Next, a set of rats were tested on a similar PbR task or an impulsivity task (differential reinforcement of low-rate behavior [DRL]) and half received salient cues associated with reinforcement contingencies to encourage engagement in the target behavior. After intervention on the PbR task, brains were stained for markers of activity. On the DRL task, cue relevance was decoupled from outcomes to determine if beneficial effects persisted on impulsive behavior. TBI decreased the ability to detect reinforced outcomes; this was evident in task performance and reward-feedback signals occurring at beta frequencies in lateral orbitofrontal cortex (OFC) and associated frontostriatal regions. The behavioral intervention improved flexibility and increased OFC activity. Intervention also reduced impulsivity, even after cues were decoupled, which was partially mediated by improvements in timing behavior. The current study established a platform to begin investigating cognitive rehabilitation in rats and identified a strong role for dysfunctional OFC signaling in probabilistic learning after frontal TBI.

Cognitive and Motor Function Effects of Antipsychotics in Traumatic Brain Injury: A Systematic Review of Pre-Clinical Studies

Traumatic brain injury (TBI) survivors often suffer from agitated behaviors and will most likely receive pharmacological treatments. Choosing an optimal and safe treatment that will not interfere with neurological recovery remains controversial. By interfering with dopaminergic circuits, antipsychotics may impede processes important to cognitive recovery. Despite their frequent use, there have been no large randomized controlled studies of antipsychotics for the management of agitated behaviors during the acute TBI recovery period. We conducted a systematic review and meta-analysis of pre-clinical studies evaluating the effects of antipsychotics post-TBI on both cognitive and motor recovery. MEDLINE and Embase databases were searched up to August 2, 2023. Pre-clinical studies evaluating the effects of antipsychotics on cognitive and motor functions post-TBI were considered. Risk of bias was evaluated with the Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE) tool. We identified 15 studies including a total of 1188 rodents, mostly conducted in male Sprague-Dawley rats using cortical impact injury. The analysis revealed no consistent effect of haloperidol on motor functions, but risperidone was associated with a significant impairment in motor function on day 5 post-injury (7.05 sec; 95% confidence interval [CI]: 1.47, 12.62; I2 = 92%). Other atypical antipsychotics did not result in impaired motor function. When evaluating cognitive function, haloperidol- (23.00 sec; 95% CI: 17.42-28.59; I2 = 7%) and risperidone-treated rats (24.27 sec; 95% CI: 16.18-32.36; I2 = 0%) were consistently impaired when compared to controls. In studies evaluating atypical antipsychotics, no impairments were observed. Clinicians should avoid the regular use of haloperidol and risperidone, and future human studies should be conducted with atypical antipsychotics.

Guiding patients with traumatic brain injury through the instrumental activities of daily living with the RehaGoal App: a feasibility study

PURPOSE

Individuals with traumatic brain injuries (TBI) often experience executive function impairments that impact activities of daily living. Assistive technologies can help overcome these disabilities and Goal Management Training (GMT) provides an effective therapeutic approach for treating such impairments. To capture the benefits of GMT with assistive technology we developed the RehaGoal App. In this study, we investigate whether combining a modified GMT (mGMT) with the RehaGoal App is feasible in terms of study design, and preliminary evaluation of the attainment of self-defined goals. We also examine if the app produces useful metrics data, tests its usability, and gauges its potential for improving goal attainment.

METHODS

We used a case study design to evaluate four individuals with impairments in executive functions after TBI. They underwent an 8-week mGMT and RehaGoal App intervention to achieve a self-defined goal. To investigate the intervention's feasibility, we collected Goal Attainment Scale (GAS) scores at two-time points, neuropsychological data at study start, System Usability Scale (SUS) scores at study end, and metrics data throughout the study period.

RESULTS

Participant retention and compliance rates were high. All participants improved on GAS. Metrics data was collected successfully and revealed different participant usage behaviours. Overall, the SUS scores of the participants indicated excellent app usability.

CONCLUSIONS

The intervention was feasible but the study design should be modified. Preliminary evaluation of GAS, SUS, and metrics data provided useful insights on user behaviour, app usability, and its role in achieving self-defined goals. The app received overall positive participant ratings.IMPLICATION FOR REHABILITATIONMetric data can be useful as it can give therapists additional opportunities to gain more information about the realization of intervention tasks between the therapy sessions allowing them to use this information to adjust therapy elements.RehaGoal App in combination with a modified GMT may be able to support participants with impairment in executive functions in completing the task of daily living.The study shows that the RehaGoal App is feasible in rehabilitation for a small sample size and that it may be scaled up in the future larger randomized controlled trial.

Disinhibited and angry: Investigating the relationship between social disinhibition and the components of aggression following severe TBI

Social disinhibition and aggression share many similarities. But unlike with aggression, research evidence about social disinhibition following severe traumatic brain injury (TBI) is limited and treatments are missing. Establishing the association between aggression and social disinhibition would facilitate a better conceptualization of these disorders. This study aimed to determine the relationship between social disinhibition and aggression following severe TBI.In this case-control study, 25 individuals with severe TBI and 25 control participants completed the Buss-Perry Aggression Questionnaire (BPAQ), Frontal Systems Behaviour Scale (FrSBe), and Social Disinhibition Interview (SDI).Hierarchical multiple regression analyses revealed that, when controlling for covariates, the inclusion of BPAQ Anger in the model led to a 13% increase in proportion of explained variance of social disinhibition (Adjusted R2 increased from .243 to .363, p < .005). BPAQ Anger was not a significant predictor of SDI scores. Similarly, BPAQ Physical aggression scores did not contribute to the prediction of FrSBe Disinhibition or SDI scores.In conclusion, higher levels of self-reported anger (but no other components of aggression) are associated with higher levels of self-reported social disinhibition. While these findings have potential implications for the treatment of social disinhibition, further research into the possible relationship with aggression should be conducted.

Behavioral deficits after mild traumatic brain injury by fluid percussion in rats

Mild traumatic brain injury (TBI) can lead to various disorders, encompassing cognitive and psychiatric complications. While pre-clinical studies have long investigated behavioral alterations, the fluid percussion injury (FPI) model still lacks a comprehensive behavioral battery that includes psychiatric-like disorders. To address this gap, we conducted multiple behavioral tasks over two months in adult male Wistar rats, focusing on mild FPI. Statistical analyses revealed that both naive and sham animals exhibited an increase in sweet liquid consumption over time. In contrast, the TBI group did not show any temporal changes, although mild FPI did induce a statistically significant decrease in sucrose consumption compared to control groups during the chronic phase. Additionally, social interaction tasks indicated reduced contact time in TBI animals. The elevated plus maze task demonstrated an increase in open-arm exploration following fluid percussion. Nonetheless, no significant differences were observed in the acute and chronic phases for the forced swim and light-dark box tasks. Evaluation of three distinct memory tasks in the chronic phase revealed that mild FPI led to long-term memory deficits, as assessed by the object recognition task, while the surgical procedure itself resulted in short-term spatial memory deficits, as evaluated by the Y-maze task. Conversely, working memory remained unaffected in the water maze task. Collectively, these findings provide a nuanced characterization of behavioral deficits induced by mild FPI.

Early deficits in dentate circuit and behavioral pattern separation after concussive brain injury

Traumatic brain injury leads to cellular and circuit changes in the dentate gyrus, a gateway to hippocampal information processing. Intrinsic granule cell firing properties and strong feedback inhibition in the dentate are proposed as critical to its ability to generate unique representation of similar inputs by a process known as pattern separation. Here we evaluate the impact of brain injury on cellular decorrelation of temporally patterned inputs in slices and behavioral discrimination of spatial locations in vivo one week after concussive lateral fluid percussion injury (FPI) in mice. Despite posttraumatic increases in perforant path evoked excitatory drive to granule cells and enhanced ΔFosB labeling, indicating sustained increase in excitability, the reliability of granule cell spiking was not compromised after FPI. Although granule cells continued to effectively decorrelate output spike trains recorded in response to similar temporally patterned input sets after FPI, their ability to decorrelate highly similar input patterns was reduced. In parallel, encoding of similar spatial locations in a novel object location task that involves the dentate inhibitory circuits was impaired one week after FPI. Injury induced changes in pattern separation were accompanied by loss of somatostatin expressing inhibitory neurons in the hilus. Together, these data suggest that the early posttraumatic changes in the dentate circuit undermine dentate circuit decorrelation of temporal input patterns as well as behavioral discrimination of similar spatial locations, both of which could contribute to deficits in episodic memory.

Repeated Mild Traumatic Brain Injury and JZL184 Produce Sex-Specific Increases in Anxiety-Like Behavior and Alcohol Consumption in Wistar Rats

Alcohol use disorder (AUD) is highly comorbid with traumatic brain injury (TBI). Previously, using a lateral fluid percussion model (LFP) (an open-head injury model) to generate a single mild to moderate traumatic brain injury (TBI) we showed that TBI produces escalation in alcohol drinking, that alcohol exposure negatively impacts TBI outcomes, and that the endocannabinoid degradation inhibitor (JZL184) confers significant protection from behavioral and neuropathological outcomes in male rodents. In the present study, we used a weight drop model (a closed-head injury model) to produce repeated mild TBI (rmTBI; three TBIs separated by 24 hours) in male and female rats to examine the sex-specific effects on anxiety-like behavior and alcohol consumption, and whether systemic treatment with JZL184 would reverse TBI effects on those behaviors. In two separate studies, adult male and female Wistar rats were subjected to rmTBI or sham procedure using the weight drop model. Physiological measures of injury severity were collected from all animals. Animals in both studies were allowed to consume alcohol using an intermittent 2-bottle choice procedure (12 pre-TBI sessions and 12 post-TBI sessions). Neurological severity and neurobehavioral scores (NSS and NBS, respectively) were tested 24 hours after the final injury. Anxiety-like behavior was tested at 37-38 days post-injury in Study 1-, and 6-8-days post-injury in Study 2. Our results show that females exhibited reduced respiratory rates relative to males with no significant differences between Sham and rmTBI, no effect of rmTBI or sex on righting reflex, and increased neurological deficits in rmTBI groups in both studies. In Study 1, rmTBI increased alcohol consumption in female but not male rats. Male rats consistently exhibited higher levels of anxiety-like behavior than females. The rmTBI did not affect anxiety-like behavior 37-38 days post-injury. In Study 2, rmTBI once again increased alcohol consumption in female but not male rats, and repeated systemic treatment with JZL184 did not affect alcohol consumption. Also in Study 2, rmTBI increased anxiety-like behavior in males but not females and repeated systemic treatment with JZL184 produced an unexpected increase in anxiety-like behavior 6-8 days post-injury. In summary, rmTBI increased alcohol consumption in female rats, systemic JZL184 treatment did not alter alcohol consumption, and both rmTBI and systemic JZL184 treatment increased anxiety-like behavior 6-8 days post-injury in males but not females, highlighting robust sex differences in rmTBI effects.

Mediating effects of impulsivity and alexithymia in the association between traumatic brain injury and aggression in incarcerated males

Studies suggest both alexithymia and impulsivity (partially) explain aggressive behavior in traumatic brain injury (TBI) patients, but none of these studies use both questionnaire and performance-based measures as recommended, nor simultaneously investigate both impulsivity and alexithymia. The available studies therefore likely miss part of the constructs of alexithymia and impulsivity, and do not comprehensively assess the mediating effects of both constructs in the relationship between TBI and aggression. A sample of N = 281 incarcerated individuals were recruited from Dutch penitentiary institutions, and completed the Buss Perry Aggression Questionnaire (aggression), BIS-11 (impulsivity) and Toronto Alexithymia Scale-20 (alexithymia) questionnaires, as well as a stop-signal task and an emotion recognition paradigm. Several multiple mediation analyses were conducted using structural equation modelling, to assess the viability of a causal theoretical model of aggression. The final planned models were the original models with a good fit with the data (comparative fit index > 0.95, root mean square error of approximation and Standardized root mean square residual < 0.05), and results indicate that only questionnaire-based impulsivity mediated the relationship between TBI and aggression. TBI was unrelated to alexithymia, stop-signal or emotion recognition performance. Aggression was predicted by both alexithymia and impulsivity, but not by the performance measures. Post hoc analyses shows that alexithymia moderates the relationship between impulsivity and aggression. These results imply that aggressive incarcerated individuals showing impulsive behavior should be screened for TBI, since TBI is often overlooked or misdiagnosed, and indicate that both impulsivity and alexithymia are potential focus points for aggression reduction treatment in TBI patients.

The Renin Angiotensin System as a Therapeutic Target in Traumatic Brain Injury

Traumatic brain injury (TBI) is a major public health problem, with limited pharmacological options available beyond symptomatic relief. The renin angiotensin system (RAS) is primarily known as a systemic endocrine regulatory system, with major roles controlling blood pressure and fluid homeostasis. Drugs that target the RAS are used to treat hypertension, heart failure and kidney disorders. They have now been used chronically by millions of people and have a favorable safety profile. In addition to the systemic RAS, it is now appreciated that many different organ systems, including the brain, have their own local RAS. The major ligand of the classic RAS, Angiotensin II (Ang II) acts predominantly through the Ang II Type 1 receptor (AT1R), leading to vasoconstriction, inflammation, and heightened oxidative stress. These processes can exacerbate brain injuries. Ang II receptor blockers (ARBs) are AT1R antagonists. They have been shown in several preclinical studies to enhance recovery from TBI in rodents through improvements in molecular, cellular and behavioral correlates of injury. ARBs are now under consideration for clinical trials in TBI. Several different RAS peptides that signal through receptors distinct from the AT1R, are also potential therapeutic targets for TBI. The counter regulatory RAS pathway has actions that oppose those stimulated by AT1R signaling. This alternative pathway has many beneficial effects on cells in the central nervous system, bringing about vasodilation, and having anti-inflammatory and anti-oxidative stress actions. Stimulation of this pathway also has potential therapeutic value for the treatment of TBI. This comprehensive review will provide an overview of the various components of the RAS, with a focus on their direct relevance to TBI pathology. It will explore different therapeutic agents that modulate this system and assess their potential efficacy in treating TBI patients.

Early Deficits in Dentate Circuit and Behavioral Pattern Separation after Concussive Brain Injury

Traumatic brain injury leads to cellular and circuit changes in the dentate gyrus, a gateway to hippocampal information processing. Intrinsic granule cell firing properties and strong feedback inhibition in the dentate are proposed as critical to its ability to generate unique representation of similar inputs by a process known as pattern separation. Here we evaluate the impact of brain injury on cellular decorrelation of temporally patterned inputs in slices and behavioral discrimination of spatial locations in vivo one week after concussive lateral fluid percussion injury (FPI) in mice. Despite posttraumatic increases in perforant path evoked excitatory drive to granule cells and enhanced ΔFosB labeling, indicating sustained increase in excitability, the reliability of granule cell spiking was not compromised after FPI. Although granule cells continued to effectively decorrelate output spike trains recorded in response to similar temporally patterned input sets after FPI, their ability to decorrelate highly similar input patterns was reduced. In parallel, encoding of similar spatial locations in a novel object location task that involves the dentate inhibitory circuits was impaired one week after FPI. Injury induced changes in pattern separation were accompanied by loss of somatostatin expressing inhibitory neurons in the hilus. Together, these data suggest that the early posttraumatic changes in the dentate circuit undermine dentate circuit decorrelation of temporal input patterns as well as behavioral discrimination of similar spatial locations, both of which could contribute to deficits in episodic memory.

Hinge craniotomy versus standard decompressive hemicraniectomy: an experimental preclinical comparative study

INTRODUCTION

Decompressive craniectomy (DC) is the most common surgical procedure to manage increased intracranial pressure (ICP). Hinge craniotomy (HC), which consists of fixing the bone operculum with a pivot, is an alternative method conceived to avoid some DC-related complications; nonetheless, it is debated whether it can provide enough volume expansion. In this study, we aimed to analyze the volume and ICP obtained with HC using an experimental cadaver-based preclinical model and compare the results to baseline and DC.

METHODS

Baseline conditions, HC, and DC were compared on both sides of five anatomical specimens. Volume and ICP values were measured with a custom-made system. Local polynomial regression was used to investigate volume differences.

RESULTS

The area of the bone opercula resulting from measurements was 115.55 cm2; the mean supratentorial volume was 955 mL. HC led to intermediate results compared to baseline and DC. At an ICP of 50 mmHg, HC offers 130 mL extra space but 172 mL less than a DC. Based on local polynomial regression, the mean volume difference between HC and the standard craniotomy was 10%; 14% between DC and HC; both are higher than the volume of brain herniation reported in the literature in the clinical setting. The volume leading to an ICP of 50 mmHg at baseline was less than the volume needed to reach an ICP of 20 mmHg after HC (10.05% and 14.95% from baseline, respectively).

CONCLUSIONS

These data confirm the efficacy of HC in providing sufficient volume expansion. HC is a valid intermediate alternative in case of potentially evolutionary lesions and non-massive edema, especially in developing countries.

JZL184 increases anxiety-like behavior and does not reduce alcohol consumption in female rats after repeated mild traumatic brain injury

Alcohol use disorder (AUD) is highly comorbid with traumatic brain injury (TBI). Previously, using a lateral fluid percussion model (LFP) (an open model of head injury) to generate a single mild to moderate traumatic brain injury (TBI), we showed that TBI produces escalation in alcohol drinking, that alcohol exposure negatively impacts TBI outcomes, and that the endocannabinoid degradation inhibitor (JZL184) confers significant protection from behavioral and neuropathological outcomes in male rodents. In the present study, we used a weight drop model (a closed model of head injury) to produce a repeated mild TBI (rmTBI, 3 TBIs, spaced by 24 hours) to examine the sex-specific effects on alcohol consumption and anxiety-like behavior in rats, and whether systemic treatment with JZL184 would reverse TBI effects on those behaviors in both sexes. In two separate studies, adult male and female Wistar rats were subjected to rmTBI or sham using the weight drop model. Physiological measures of injury severity were collected from all animals. Animals in both studies were allowed to consume alcohol using an intermittent 2-bottle choice procedure (12 pre-TBI sessions and 12 post-TBI sessions). Neurological severity and neurobehavioral scores (NSS and NBS, respectively) were tested 24 hours after the final injury. Anxiety-like behavior was tested at 37-38 days post-injury in Study 1, and 6-8 days post-injury in Study 2. Our results show that females exhibited reduced respiratory rates relative to males with no significant differences between Sham and rmTBI, no effect of rmTBI or sex on righting reflex, and increased neurological deficits in rmTBI groups in both studies. In Study 1, rmTBI increased alcohol consumption in female but not male rats. Male rats consistently exhibited higher levels of anxiety-like behavior than females. rmTBI did not affect anxiety-like behavior 37-38 days post-injury. In Study 2, rmTBI once again increased alcohol consumption in female but not male rats, and repeated systemic treatment with JZL184 did not affect alcohol consumption. Also in Study 2, rmTBI increased anxiety-like behavior in males but not females and repeated systemic treatment with JZL184 produced an unexpected increase in anxiety-like behavior 6-8 days post-injury. In summary, rmTBI increased alcohol consumption in female rats, systemic JZL184 treatment did not alter alcohol consumption, and both rmTBI and sub-chronic systemic JZL184 treatment increased anxiety-like behavior 6-8 days post-injury in males but not females, highlighting robust sex differences in rmTBI effects.

AI-Based Decision Support System for Traumatic Brain Injury: A Survey

Traumatic brain injury (TBI) is one of the major causes of disability and mortality worldwide. Rapid and precise clinical assessment and decision-making are essential to improve the outcome and the resulting complications. Due to the size and complexity of the data analyzed in TBI cases, computer-aided data processing, analysis, and decision support systems could play an important role. However, developing such systems is challenging due to the heterogeneity of symptoms, varying data quality caused by different spatio-temporal resolutions, and the inherent noise associated with image and signal acquisition. The purpose of this article is to review current advances in developing artificial intelligence-based decision support systems for the diagnosis, severity assessment, and long-term prognosis of TBI complications.

Traumatic Brain Injury and Psychopathic Traits in Justice-Involved Adult Women

Studies have documented associations between traumatic brain injury (TBI) and mental disorders. The relationship between psychopathic personality and TBI remains poorly understood, though both are associated with similar characteristics (e.g., low empathy, aggression, disturbances in social/moral behavior). Yet, it is not clear whether assessment of psychopathic features is influenced by presence versus absence of TBI, and which aspects of TBI may be associated with psychopathic traits. This study examined the psychopathy-TBI association in justice-involved women (N = 341) with structural equation modeling. We tested if measurement invariance of psychopathic traits was evident among those with versus without TBI and which TBI variables (number, severity, age at first TBI) predicted psychopathic features in conjunction with symptoms of psychopathology, IQ, and age. Results provided evidence of measurement invariance, and more women with TBI, compared to those without, met criteria for psychopathy. Younger age of TBI and TBI severity predicted interpersonal-affective psychopathic features.

S100B, Actor and Biomarker of Mild Traumatic Brain Injury

Mild traumatic brain injury (mTBI) accounts for approximately 80% of all TBI cases and is a growing source of morbidity and mortality worldwide. To improve the management of children and adults with mTBI, a series of candidate biomarkers have been investigated in recent years. In this context, the measurement of blood biomarkers in the acute phase after a traumatic event helps reduce unnecessary CT scans and hospitalizations. In athletes, improved management of sports-related concussions is also sought to ensure athletes’ safety. S100B protein has emerged as the most widely studied and used biomarker for clinical decision making in patients with mTBI. In addition to its use as a diagnostic biomarker, S100B plays an active role in the molecular pathogenic processes accompanying acute brain injury. This review describes S100B protein as a diagnostic tool as well as a potential therapeutic target in patients with mTBI.

DCC/netrin-1 regulates cell death in oligodendrocytes after brain injury

Hallmark pathological features of brain trauma are axonal degeneration and demyelination because myelin-producing oligodendrocytes (OLs) are particularly vulnerable to injury-induced death signals. To reveal mechanisms responsible for this OL loss, we examined a novel class of "death receptors" called dependence receptors (DepRs). DepRs initiate pro-death signals in the absence of their respective ligand(s), yet little is known about their role after injury. Here, we investigated whether the deleted in colorectal cancer (DCC) DepR contributes to OL loss after brain injury. We found that administration of its netrin-1 ligand is sufficient to block OL cell death. We also show that upon acute injury, DCC is upregulated while netrin-1 is downregulated in perilesional tissues. Moreover, after genetically silencing pro-death activity using DCCD1290N mutant mice, we observed greater OL survival, greater myelin integrity, and improved motor function. Our findings uncover a novel role for the netrin-1/DCC pathway in regulating OL loss in the traumatically injured brain.

Multi-site, multi-country randomized clinical trial of an acute traumatic brain injury caregiver transition assistance program in Latin America

BACKGROUND

Individuals with traumatic brain injury (TBI) in Latin America experience high levels of disability and extremely poor functional outcomes, and their informal caregivers play a key role in their rehabilitation and care.

OBJECTIVE

To improve TBI rehabilitation through stronger informal caregiving, this study developed and evaluated an evidence-based and culturally appropriate Transition Assistance Program (TAP) for informal caregivers of individuals with TBI in Latin America, specifically targeting the time period before and after the transition from hospital to home.

METHODS

A sample of 89 people with a new TBI and their primary informal caregiver (n = 178) was recruited from two hospitals in Mexico City, Mexico, and in Cali, Colombia. Caregivers were randomly assigned to either the TAP group or to a control group receiving the standard care provided by the hospital. Caregivers completed measures of depression and burden, and individuals with TBI completed measures of depression and self-perceived burden on caregivers before hospital discharge and at 2- and 4-month follow ups.

RESULTS

Caregivers in the TAP group reported significantly lower burden than those in the control group and marginally lower depression. Individuals with TBI whose caregivers had been in the TAP group reported significantly lower depression than those whose caregivers had been in the control group, and a non-significant but lower self-perceived burden on their caregivers.

CONCLUSION

The results suggest that the TAP has strong potential to benefit both TBI caregivers and individuals with TBI during the transition from acute TBI hospitalization to home in Latin America, generally showing small-or medium-sized effects on key outcomes.

Involvement of Lateral Habenula Dysfunction in Repetitive Mild Traumatic Brain Injury-Induced Motivational Deficits

Affective disorders including depression (characterized by reduced motivation, social withdrawal, and anhedonia), anxiety, and irritability are frequently reported as long-term consequences of mild traumatic brain injury (mTBI) in addition to cognitive deficits, suggesting a possible dysregulation within mood/motivational neural circuits. One of the important brain regions that control motivation and mood is the lateral habenula (LHb), whose hyperactivity is associated with depression. Here, we used a repetitive closed-head injury mTBI model that is associated with social deficits in adult male mice and explored the possible long-term alterations in LHb activity and motivated behavior 10-18 days post-injury. We found that mTBI increased the proportion of spontaneous tonically active LHb neurons yet decreased the proportion of LHb neurons displaying bursting activity. Additionally, mTBI diminished spontaneous glutamatergic and GABAergic synaptic activity onto LHb neurons, while synaptic excitation and inhibition (E/I) balance was shifted toward excitation through a greater suppression of GABAergic transmission. Behaviorally, mTBI increased the latency in grooming behavior in the sucrose splash test suggesting reduced self-care motivated behavior following mTBI. To show whether limiting LHb hyperactivity could restore motivational deficits in grooming behavior, we then tested the effects of Gi (hM4Di)-DREADD-mediated inhibition of LHb activity in the sucrose splash test. We found that chemogenetic inhibition of LHb glutamatergic neurons was sufficient to reverse mTBI-induced delays in grooming behavior. Overall, our study provides the first evidence for persistent LHb neuronal dysfunction due to an altered synaptic integration as causal neural correlates of dysregulated motivational states by mTBI.

A single closed head injury in male adult mice induces chronic, progressive white matter atrophy and increased phospho-tau expressing oligodendrocytes

Traumatic brain injury (TBI) acutely damages the brain; this injury can evolve into chronic neurodegeneration. While much is known about the chronic effects arising from multiple mild TBIs, far less is known about the long-term effects of a single moderate to severe TBI. We found that a single moderate closed head injury to mice induces diffuse axonal injury within 1-day post-injury (DPI). At 14 DPI, injured animals have atrophy of ipsilesional cortex, thalamus, and corpus callosum, with bilateral atrophy of the dorsal fornix. Atrophy of the ipsilesional corpus callosum is accompanied by decreased fractional anisotropy and increased mean and radial diffusivity that remains unchanged between 14 and 180 DPI. Injured animals show an increased density of phospho-tau immunoreactive (pTau+) cells in the ipsilesional cortex and thalamus, and bilaterally in corpus callosum. Between 14 and 180 DPI, atrophy occurs in the ipsilesional ventral fornix, contralesional corpus callosum, and bilateral internal capsule. Diffusion tensor MRI parameters remain unchanged in white matter regions with delayed atrophy. Between 14 and 180 DPI, pTau+ cell density increases bilaterally in corpus callosum, but decreases in cortex and thalamus. The location of pTau+ cells within the ipsilesional corpus callosum changes between 14 and 180 DPI; density of all cells increases including pTau+ or pTau- cells. >90% of the pTau+ cells are in the oligodendrocyte lineage in both gray and white matter. Density of thioflavin-S+ cells in thalamus increases by 180 DPI. These data suggest a single closed head impact produces multiple forms of chronic neurodegeneration. Gray and white matter regions proximal to the impact site undergo early atrophy. More distal white matter regions undergo chronic, progressive white matter atrophy with an increasing density of oligodendrocytes containing pTau. These data suggest a complex chronic neurodegenerative process arising from a single moderate closed head injury.

A descriptive analysis of pharmacological management of aggression and/or agitation in patients with traumatic brain injury in a Southwest Virginia inpatient population

WHAT IS KNOWN AND OBJECTIVE

Traumatic brain injury (TBI) is a major cause of disability, and it has been associated with agitation and aggression. In a previous study, we reviewed the literature to identify evidence-based pharmacological agents for treatment of agitation in TBI. Based on the results of our previous study that summarizes the findings of several systematic reviews, the use of haloperidol and benzodiazepines is not supported by the available evidence while the use of amantadine, beta blockers, antiepileptics and methylphenidate is supported by the limited available evidence. In this study, we describe the psycho-pharmacological agents that were administered to patients with agitation and/or aggression in the context of TBI in inpatient facilities of a private, non-profit health care system in southwest Virginia. We will also compare the psycho-pharmacological agents ordered before and after psychiatric consultation.

METHODS

Adult patients who were admitted to Carilion Clinic's inpatient facilities from March 30, 2013, to March 30, 2018, had a diagnosis of TBI, and received psychiatric consultation for agitation and/or aggression were enrolled in this study. A retrospective review of electronic medical records was conducted by researchers and data were collected on the following measures: ordered psycho-pharmacological agents, frequency, dosing and duration of orders, whether each administered psycho-pharmacological agent was started before or after psychiatric consultation, and psycho-pharmacological agents prescribed upon discharge.

RESULTS AND DISCUSSION

About 68% of patients were started on benzodiazepines and/or typical antipsychotics and 23% of patients were subsequently discharged on these medication categories. Only 23% of patients were ordered to receive medications supported by the evidence such as amantadine, beta blockers or antiepileptics. The percentage of patient-days with an order to receive typical antipsychotics significantly decreased following psychiatric consultation (p = 0.0056), but the percentage of patient-days with an order to receive benzodiazepines significantly increased following psychiatric consultation (p = 0.0001). This finding remained statistically significant after excluding patients with active or unclear alcohol/benzodiazepine withdrawal (p < 0.0001).

WHAT IS NEW AND CONCLUSION

This study demonstrates the widespread use of typical antipsychotics and benzodiazepines in the management of agitation in TBI and the importance of multidisciplinary collaboration, research and education of providers to improve patient care.

The sensitivity of the IOP-29 and IOP-M to coached feigning of depression and mTBI: An online simulation study in a community sample from the United Kingdom

Assessing the credibility of symptoms is critical to neuropsychological assessment in both clinical and forensic settings. To this end, the Inventory of Problems-29 (IOP-29) and its recently added memory module (Inventory of Problems-Memory; IOP-M) appear to be particularly useful, as they provide a rapid and cost-effective measure of both symptom and performance validity. While numerous studies have already supported the effectiveness of the IOP-29, research on its newly developed module, the IOP-M, is much sparser. To address this gap, we conducted a simulation study with a community sample (N = 307) from the United Kingdom. Participants were asked to either (a) respond honestly or (b) pretend to suffer from mTBI or (c) pretend to suffer from depression. Within each feigning group, half of the participants received a description of the symptoms of the disorder to be feigned, and the other half received both a description of the symptoms of the disorder to be feigned and a warning not to over-exaggerate their responses or their presentation would not be credible. Overall, the results confirmed the effectiveness of the two IOP components, both individually and in combination.

Sleep from acute to chronic traumatic brain injury and cognitive outcomes

STUDY OBJECTIVES

Traumatic brain injuries (TBIs) cause persistent cerebral damage and cognitive deficits. Because sleep may be a critical factor for brain recovery, we characterized the sleep of patients with TBI from early hospitalization to years post-injury and explored the hypothesis that better sleep during hospitalization predicts more favorable long-term cognitive outcomes.

METHODS

We tested patients with moderate-to-severe TBI in the hospitalized (n = 11) and chronic (n = 43) stages using full-night polysomnography, with 82% of the hospitalized group being retested years post-injury. Hospitalized patients with severe orthopedic and/or spinal cord injury (n = 14) and healthy participants (n = 36) were tested as controls for the hospitalized and chronic TBI groups, respectively. Groups had similar age and sex and were compared for sleep characteristics, including slow waves and spindles. For patients with TBI, associations between sleep during hospitalization and long-term memory and executive function were assessed.

RESULTS

Hospitalized patients with TBI or orthopedic injuries had lower sleep efficiency, higher wake after sleep onset, and lower spindle density than the chronic TBI and healthy control groups, but only hospitalized patients with brain injury had an increased proportion of slow-wave sleep. During hospitalization for TBI, less fragmented sleep, more slow-wave sleep, and higher spindle density were associated to more favorable cognitive outcomes years post-injury, while injury severity markers were not associated with these outcomes.

CONCLUSION

These findings highlight the importance of sleep following TBI, as it could be a strong predictor of neurological recovery, either as a promoter or an early marker of cognitive outcomes.

LDC7559 Exerts Neuroprotective Effects by Inhibiting GSDMD-dependent Pyroptosis of Microglia in Mice with Traumatic Brain Injury

Pyroptosis is considered one of a critical factor in the recovery of neurological function following traumatic brain injury. Brain injury activates a molecular signaling cascade associated with pyroptosis and inflammation, including NLRP3, inflammatory cytokines, caspase-1, gasdermin D (GSDMD), and other pyroptosis-related proteins. In this study, we explored the neuroprotective effects of LDC7559, a GSDMD inhibitor. Briefly, LDC7559, siRNA-GSDMD (si-GSDMD), or equal solvent was administrated to mice with a lipopolysaccharide + nigericin (LPS + Nig) model in vitro or with controlled cortical impact brain injury. The findings revealed that inflammation and pyroptosis levels were decreased by LDC7559 or si-GSDMD treatment both in vitro and in vivo. Immunofluorescence staining, brain water content, hematoxylin and eosin staining, and behavioral investigations suggested that LDC7559 or si-GSDMD inhibited microglial proliferation, ameliorated cerebral edema, reduced brain tissue loss, and promoted brain function recovery. Taken together, LDC7559 may inhibit pyroptosis and reduce inflammation by inhibiting GSDMD, thereby promoting the recovery of neurological function.

Chronic cerebral aspects of long COVID, post-stroke syndromes and similar states share their pathogenesis and perispinal etanercept treatment logic

The chronic neurological aspects of traumatic brain injury, post‐stroke syndromes, long COVID‐19, persistent Lyme disease, and influenza encephalopathy having close pathophysiological parallels that warrant being investigated in an integrated manner. A mechanism, common to all, for this persistence of the range of symptoms common to these conditions is described. While TNF maintains cerebral homeostasis, its excessive production through either pathogen‐associated molecular patterns or damage‐associated molecular patterns activity associates with the persistence of the symptoms common across both infectious and non‐infectious conditions. The case is made that this shared chronicity arises from a positive feedback loop causing the persistence of the activation of microglia by the TNF that these cells generate. Lowering this excess TNF is the logical way to reducing this persistent, TNF‐maintained, microglial activation. While too large to negotiate the blood‐brain barrier effectively, the specific anti‐TNF biological, etanercept, shows promise when administered by the perispinal route, which allows it to bypass this obstruction.

Minocycline fails to treat chronic traumatic brain injury-induced impulsivity and attention deficits

Traumatic brain injury (TBI) impacts millions worldwide and can cause lasting psychiatric symptoms. Chronic neuroinflammation is a characteristic of post-injury pathology and is also associated with psychiatric conditions such as ADHD and bipolar disorder. Therefore, the current study sought to determine whether TBI-induced impulsivity and inattention could be treated using minocycline, an antibiotic with anti-inflammatory properties. Rats were trained on the five-choice serial reaction time task (5CSRT), a measure of motor impulsivity and attention. After behavior was stable on the 5CSRT, rats received either a bilateral frontal TBI or sham procedure. Minocycline was given at either an early (1 h post-injury) or chronic (9 weeks post-injury) timepoint. Minocycline was delivered every 12 h for 5 days (45 mg/kg, i.p.). Behavioral testing on the 5CSRT began again after one week of recovery and continued for 12 more weeks, then rats were transcardially perfused. Impulsivity and inattention were both substantially increased following TBI. Minocycline had no therapeutic effects at either the early or late time points. TBI rats had increased lesion volume, but minocycline did not attenuate lesion size. Additionally, microglia count measured by IBA-1⁺ cells was only increased acutely after TBI, and minocycline did not differentially change the number of microglia in TBI rats. Despite this, minocycline had clear effects on the gut microbiome. Based on the results of this study, minocycline may have limited efficacy for post-injury psychiatric-like symptoms.

Military traumatic brain injury: a challenge straddling neurology and psychiatry

Military psychiatry, a new subcategory of psychiatry, has become an invaluable, intangible effect of the war. In this review, we begin by examining related military research, summarizing the related epidemiological data, neuropathology, and the research achievements of diagnosis and treatment technology, and discussing its comorbidity and sequelae. To date, advances in neuroimaging and molecular biology have greatly boosted the studies on military traumatic brain injury (TBI). In particular, in terms of pathophysiological mechanisms, several preclinical studies have identified abnormal protein accumulation, blood-brain barrier damage, and brain metabolism abnormalities involved in the development of TBI. As an important concept in the field of psychiatry, TBI is based on organic injury, which is largely different from many other mental disorders. Therefore, military TBI is both neuropathic and psychopathic, and is an emerging challenge at the intersection of neurology and psychiatry.

A Prognostic Model for Predicting One-Month Outcomes among Emergency Department Patients with Mild Traumatic Brain Injury and a Presenting Glasgow Coma Scale of Fifteen

The lack of well-performing prognostic models for early prognostication of outcomes remains a major barrier to improving the clinical care of patients with mild traumatic brain injury (mTBI). We aimed to derive a prognostic model for predicting incomplete recovery at 1-month in emergency department (ED) patients with mTBI and a presenting Glasgow Coma Scale (GCS) score of 15 who were enrolled in the HeadSMART (Head Injury Serum Markers for Assessing Response to Trauma) study. The derivation cohort included 355 participants with complete baseline (day-of-injury) and follow-up data. The primary outcome measure was the Glasgow Outcome Scale Extended (GOSE) at 1-month and incomplete recovery was defined as a GOSE <8. At 1-month post-injury, incomplete recovery was present in 58% (n = 205) of participants. The final multi-variable logistic regression model included six variables: age in years (odds ratio [OR] = 0.98; 95% confidence interval [CI]: 0.97-1.00), positive head CT (OR = 4.42; 95% CI: 2.21-9.33), history of depression (OR = 2.59; 95% CI: 1.47-4.69), and self-report of moderate or severe headache (OR = 2.49; 95% CI: 1.49-4.18), difficulty concentrating (OR = 3.17; 95% CI: 1.53-7.04), and photophobia (OR = 4.17; 95% CI: 2.08-8.92) on the day-of-injury. The model was validated internally using bootstrap resampling (1000 resamples), which revealed a mean over-optimism value of 0.01 and an optimism-corrected area under the curve (AUC) of 0.79 (95% CI: 0.75-0.85). A prognostic model for predicting incomplete recovery among ED patients with mTBI and a presenting GCS of 15 using easily obtainable clinical and demographic variables has acceptable discriminative accuracy. External validation of this model is warranted.

Targeting Oxidative Stress with Antioxidant Duotherapy after Experimental Traumatic Brain Injury

We assessed the effect of antioxidant therapy using the Food and Drug Administration-approved respiratory drug N-acetylcysteine (NAC) or sulforaphane (SFN) as monotherapies or duotherapy in vitro in neuron-BV2 microglial co-cultures and validated the results in a lateral fluid-percussion model of TBI in rats. As in vitro measures, we assessed neuronal viability by microtubule-associated-protein 2 immunostaining, neuroinflammation by monitoring tumor necrosis factor (TNF) levels, and neurotoxicity by measuring nitrite levels. In vitro, duotherapy with NAC and SFN reduced nitrite levels to 40% (p < 0.001) and neuroinflammation to -29% (p < 0.001) compared with untreated culture. The treatment also improved neuronal viability up to 72% of that in a positive control (p < 0.001). The effect of NAC was negligible, however, compared with SFN. In vivo, antioxidant duotherapy slightly improved performance in the beam walking test. Interestingly, duotherapy treatment decreased the plasma interleukin-6 and TNF levels in sham-operated controls (p < 0.05). After TBI, no treatment effect on HMGB1 or plasma cytokine levels was detected. Also, no treatment effects on the composite neuroscore or cortical lesion area were detected. The robust favorable effect of duotherapy on neuroprotection, neuroinflammation, and oxidative stress in neuron-BV2 microglial co-cultures translated to modest favorable in vivo effects in a severe TBI model.

Depression in Older Adults 12 Months Following Traumatic Brain Injury: A TRACK-TBI Study

OBJECTIVE

To investigate depression at 12 months following traumatic brain injury (TBI) in older compared with younger adults.

DESIGN

Prospective longitudinal cohort study of persons with medically documented mild, moderate, and severe TBI at 12 months post-injury.

SETTING

Eighteen participating Level One trauma centers in the U.S.

PARTICIPANTS

1,505 participants with TBI and primary outcome data at 12-month follow-up.

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURE

Patient Health Questionnaire-9 (PHQ-9).

RESULTS

PHQ-9 total scores were significantly lower for older adults (age≥65)(M = 3.2) as compared with younger adults (age<65)(M = 5.0) (B = -1.63, p < .001), indicating less depressive symptoms in older adults. Age did not interact with education, sex, race/ethnicity, psychiatric history, substance use, or GCS severity to impact PHQ-9 scores. Of the 29% of older adults who endorsed symptoms consistent with depression, 14% were classified as minor depression and 15% as major depression. The odds of older adults falling in the major depression vs. no depression group was significantly lower (decreased by 56%) as compared with younger adults (OR = 0.44, p =.001).

CONCLUSIONS

At 12-months post-TBI, older adults endorse lower depressive symptoms than their younger counterparts and are less likely to experience major depression; however, over one-fourth of older adults endorsed symptoms consistent with depression, warranting evaluation and treatment.

Epidemiology of traumatic brain injury based on clinical symptoms amongst inhabitants of the Southwest Region of Cameroon: a community-based study

BACKGROUND

The majority of studies investigating the epidemiology of traumatic brain injury (TBI) in sub-Saharan Africa are primarily hospital-based, missing fatal, mild, and other cases of TBI that do not present to formal care settings. This study aims to bridge this gap in data by describing the epidemiology of TBI in the Southwest Region of Cameroon.

METHODS

This was a cross-sectional community-based study. Using a three-stage cluster sampling, local research assistants surveyed households with a pre-tested questionnaire to identify individuals with symptoms of TBI in nine health districts in the Southwest Region of Cameroon from 2016 to 2017.

RESULTS

Data gathered on 8,065 individuals revealed 78 cases of suspected TBI. Road traffic injury (RTI) comprised 55% of subjects' mechanism of injury. Formal medical care was sought by 82.1% of subjects; three subjects died at the time of injury. Following injury, 59% of subjects reported difficulty affording basic necessities and 87.2% of subjects were unable to perform activities of their primary occupation.

CONCLUSIONS

This study postulates an incidence of TBI in Southwest Cameroon of 975.57 per 100,000 individuals, significantly greater than prior findings. A large proportion of TBI is secondary to RTI.

Pharmacotherapy for Treatment of Cognitive and Neuropsychiatric Symptoms After mTBI

OBJECTIVES

Cognitive and neuropsychiatric symptoms are extremely common following mild traumatic brain injury (TBI), also known as concussion. Although most patients will recovery rapidly, a significant minority go on to experience persistent symptoms. There are currently no FDA-approved medications for treatment of cognitive and neuropsychiatric problems in the context of mild TBI, yet a number of agents are prescribed "off-label" for these complaints. Rigorous trials are lacking, but there are a number of open-label studies, and some small randomized controlled trials that support the safety and possible efficacy of pharmacotherapies in this population. Clinical trials conducted in samples with more severe brain injuries can also serve as a guide.

METHODS

Review of the literature.

RESULTS & CONCLUSIONS

There is the most support in the literature for the neurostimulant methylphenidate for treatment of mild TBI-related cognitive dysfunction, and the selective serotonin reuptake inhibitor, sertraline, for the treatment of postinjury depression. There is clearly a need for more well-designed studies to guide clinicians in selecting the appropriate medication and dose. Without clear guidance from the literature, a cautious approach of starting low and titrating slowly is recommended.

Pharmacological Treatment of Agitation and/or Aggression in Patients With Traumatic Brain Injury: A Systematic Review of Reviews

OBJECTIVE

To systematically review the available literature on the pharmacological management of agitation and/or aggression in patients with traumatic brain injury (TBI), synthesize the available data, and provide guidelines.

DESIGN

Systematic review of systematic reviews.

MAIN MEASURES

A literature review of the following websites was performed looking for systematic reviews on the treatment of agitation and/or aggression among patients with TBI: PubMed, CINAHL, DynaMed, Health Business Elite, and EBSCO (Psychology and behavioral sciences collection). Two researchers independently assessed articles for meeting inclusion/exclusion criteria. Data were extracted on year of publication, reviewed databases, dates of coverage, search limitations, pharmacological agents of interest, and a list of all controlled studies included. The included controlled studies were then examined to determine potential reasons for any difference in recommendations.

RESULTS

The literature review led to 187 citations and 67 unique publications after removing the duplicates. Following review of the title/abstracts and full texts, a total of 11 systematic reviews were included. The systematic reviews evaluated the evidence for safety and efficacy of the following medications: amantadine, amphetamines, methylphenidate, antiepileptics, atypical and typical antipsychotics, benzodiazepines, β-blockers, and sertraline.

CONCLUSIONS

On the basis of the results of this literature review, the authors recommend avoiding benzodiazepines and haloperidol for treating agitation and/or aggression in the context of TBI. Atypical antipsychotics (olanzapine in particular) can be considered as practical alternatives for the as-needed management of agitation and/or aggression in lieu of benzodiazepines and haloperidol. Amantadine, β-blockers (propranolol and pindolol), antiepileptics, and methylphenidate can be considered for scheduled treatment of agitation and/or aggression in patients with TBI.

Prevalence of depression and anxiety disorders following mild traumatic brain injury

BACKGROUND

Previous studies have identified an association between traumatic brain injuries and the development of psychiatric disorders in general. However, these studies were subject to limitations that demonstrate the need for a study of a large, clearly defined mild traumatic brain injury (mTBI) population within an integrated healthcare system.

OBJECTIVE

To determine the prevalence and relative risk of postinjury affective disorders over 4 years following mTBI.

DESIGN

Cohort study of mTBI cases and matched controls, over a 4-year period.

SETTING

An integrated healthcare delivery system in California.

PATIENTS

A total of 9428 adult health plan members diagnosed with mTBI from 2000-2007 and enrolled in the year before injury, during which no TBI was ascertained. Control participants included 18,856 individuals selected based on the following criteria: Two unexposed health plan members per each mTBI-exposed patient were randomly selected and individually matched for age, gender, race/ethnicity, and medical comorbidities.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

A diagnosis of affective disorder (depressive, anxiety, and adjustment disorders) in the 4 years after mTBI or the reference date, determined according to the International Classification of Diseases, Ninth Revision, Clinical Modification as well as the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision.

RESULTS

Affective disorders were most prominent during the first 12 months with 23% following mTBI and 14% in the control group. Four-year aggregate adjusted odds ratios for having an affective disorder following mTBI were 1.2 (95% CI: 1.1, 1.2; p < .001) and 1.5 (95% CI: 1.5, 1.6; p < .001) for patients with and without prior affective disorders, respectively.

CONCLUSION

mTBI was associated with a significantly increased risk of having subsequent affective disorders. Screening for and addressing affective disorders at earlier stages following the injury is an important step to avoid persisting conditions that may pose a barrier to full recovery.

Legacies of Neurosurgery and its Implications on Global Neurosurgery Today

Trephination, the practice of boring a hole in ones skull, is one of the oldest surgical procedures performed by and on man. Fossil records show evidence of trephined skulls on separate continents throughout ancient history. Even more remarkably, fossils show that ancient humans actually survived the procedure, some more than once. Ancient mythologies and texts provide context to the fossil record, indicating that trephination was performed some of the time for medical indications, including traumatic head injury and intractable neurological conditions. In modern day, traumatic brain injury accounts for a significant percentage of the overall global burden of disease and its incidence is disproportionately increasing in low-and-middle-income countries. In critical situations neurosurgical intervention may be indicated. The burr hole procedure, or trephination, was identified as an essential surgical procedures that all first-level hospitals should be able to perform; however, there exists a dramatic lack of access to neurosurgical specialists and care globally, especially among low-and-middle-income countries. Task-shifting/sharing is one paradigm that may be used effectively to broaden access to this life-saving procedure but it is at the moment a contested practice.

Insulin-like Growth Factors may be Markers of both Traumatic Brain Injury and Fear-Related Stress

Insulin-like growth factors (IGF) are potent neurotrophic and neurorepair factors that were recently proposed as biomarkers of traumatic brain injury (TBI) and associated psychiatric comorbidities, in particular post-traumatic stress disorder (PSTD). We tested the hypothesis that the IGF system is differentially deregulated in the acute and early chronic stages of TBI, and under acute stress. Plasma and brain IGF1 and IGF2 levels were evaluated in mice 3 weeks and 3 days after a controlled cortical impact (CCI)-induced mild-to-moderate TBI. The effects of conditioned fear on IGF levels and its interaction with TBI (TBI followed, 3 weeks later, by fear-inducing procedures) were also evaluated. In the plasma, IGF1 decreased 3 weeks post-TBI only (-9%), whereas IGF2 remained unaffected. In the brain, IGF1 increased only in the cortex and hippocampus at 3 weeks post-TBI (up to +650%). At 3 days, surpringly, this increase was more diffuse and more important in sham (craniotomized) animals. Additionally, IGF2 immunostaining in brain ventricles was reorganized in TBI animals at both post-TBI stages. Conditioned fear exposure did not influence the effects of early chronic TBI on plasma IGF1 levels, but reduced plasma IGF2 (-6%) levels. It also dampened the effects of TBI on brain IGF systems, but brain IGF1 level and IGF2 tissue distribution remained statistically different from controls under these conditions. In co-exposed animals, DNA methylation increased at the hippocampal Igf1 gene promoter. These results show that blood IGF1 and IGF2 are most reduced in the early chronic phase of TBI and after exposure to a stressful event, and that the brain IGF system is up-regulated after TBI, and more so in the acute phase.

Pattern of Neuronal and Axonal Damage, Glial Response, and Synaptic Changes in Rat Cerebellum within the First Week following Traumatic Brain Injury

We examined damage and repair processes in the rat cerebellum within the first week following moderate traumatic brain injury (TBI) induced by lateral fluid percussion injury (LFPI) over the left parietal cortex. Rats were killed 1, 3, or 7 days after the injury or sham procedure. Fluoro-Jade B staining revealed 2 phases of neurodegenerative changes in the cell bodies and fibers: first, more focal, 1 day after the LFPI, and second, widespread, starting on post-injury day 3. Purkinje cell loss was detected in posterior lobule IX 1 day following LFPI. Apoptosis was observed in the cerebellar cortex, on days 1 and 7 following LFPI, and was not caspase- or apoptosis-inducing factor (AIF)-mediated. AIF immunostaining indicated axonal damage in the cerebellar white matter tracts 3- and 7-days post-injury. Significant astrocytosis and microgliosis were noticed on day 7 following LFPI at the sites of neuronal damage and loss. Immunohistochemical labeling with the presynaptic markers synaptophysin and growth-associated protein-43 revealed synaptic perturbations already on day 1 that were more pronounced at later time points following LFPI. These results provide new insights into pathophysiological alterations in the cerebellum and their mechanisms following cerebral TBI.

Is Helping Really Helping? Health-Related Quality of Life after TBI Predicting Caregiver Depression Symptom Trajectories in Latin America

Previous research connecting health-related quality of life (HRQoL) in people with traumatic brain injury (TBI) and caregiver mental health has primarily been conducted cross-sectionally in the U.S. and Western Europe. This study, therefore, examined how HRQoL in individuals immediately after their TBI predicts longitudinal caregiver depression symptom trajectories in Latin America. A sample of 109 patients with an acute TBI and 109 caregivers (total n = 218) was recruited from three hospitals in Mexico City, Mexico, and in Cali and Neiva, Colombia. TBI patients reported their HRQoL while they were still in hospital, and caregivers reported their depression symptoms at the same time and at 2 and 4 months later. Hierarchal linear models (HLM) found that caregiver depression symptom scores decreased over time, and lower patient mental health and pain-related quality of life at baseline (higher pain) predicted higher overall caregiver depression symptom trajectories across the three time points. These findings suggest that in Latin America, there is an identifiable relationship between psychological and pain-related symptoms after TBI and caregiver depression symptom outcomes. The results highlight the importance of early detection of caregiver mental health needs based in part upon patient HRQoL and a culturally informed approach to rehabilitation services for Latin American TBI caregivers.

Therapeutic benefits of pharmacologic and nonpharmacologic treatments for depressive symptoms after traumatic brain injury: a systematic review and network meta-analysis

BACKGROUND

Depression is a common morbidity after traumatic brain injury. This network meta-analysis investigated the efficacy and tolerability of pharmacologic and nonpharmacologic interventions for depression after traumatic brain injury.

METHODS

We extracted randomized controlled trials examining pharmacologic or nonpharmacologic interventions with placebo- or active-controlled designs from PubMed, the Cochrane Library and ScienceDirect, from inception to October 30, 2018. We based study selection and extraction of a predefined list of variables on the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines, and conducted meta-analysis procedures using random effects modelling. Primary outcomes were changes in depressive symptom severity after pharmacologic or nonpharmacologic treatment; the secondary outcome was tolerability, reflected in overall patient dropout rates.

RESULTS

Our analysis of 27 randomized controlled trials (10 pharmacologic, total n = 483, mean age = 37.9 yr; 17 nonpharmacologic, total n = 1083, mean age = 38.0 yr) showed that methylphenidate had significantly superior efficacy compared to placebo or control (standardized mean difference -0.91, 95% confidence interval [CI] -1.49 to -0.33). Sertraline was associated with significantly lower tolerability (i.e., a higher dropout rate) compared to placebo or control (odds ratio 2.65, 95% CI 1.27 to 5.54). No nonpharmacologic treatment was more effective than the others, and we found no significant differences in tolerability (i.e., dropout rates) among the nonpharmacologic treatments.

LIMITATIONS

Heterogeneity in participant characteristics (e.g., comorbidities), study designs (e.g., trial duration) and psychopathology assessment tools, as well as small trial numbers for some treatment arms, could have been confounders.

CONCLUSION

The present network meta-analysis suggests that methylphenidate might be the best pharmacologic intervention for depressive symptoms related to traumatic brain injury. None of the nonpharmacologic interventions was associated with better improvement in depressive symptoms than the others or than control conditions. None of the pharmacologic or nonpharmacologic treatments had inferior tolerability compared to placebo or controls except for sertraline, which had significantly lower tolerability than placebo.

Reactive pericytes in early phase are involved in glial activation and late-onset hypersusceptibility to pilocarpine-induced seizures in traumatic brain injury model mice

In this study, among neurovascular unit (NVU) cells, we focused on pericyte reactivity in mice subjected to controlled cortical impact (CCI) to understand how traumatic brain injury (TBI) causes uncoordinated crosstalk in the NVU and alters neuronal activity. Histological analyses of brain pericytes, microglia and astrocytes were performed for up to 28 days after CCI in the injured ipsilateral hippocampus. To evaluate altered neuronal activity caused by CCI, we measured seizure susceptibility to a sub-threshold dose of pilocarpine on postoperative day 7, 14, 21 and 28. Platelet-derived growth factor receptor (PDGFR) β immunoreactivity in pericytes significantly increased from 1 h to 4 days after CCI. The expression of Iba1 and GFAP, as markers of microglia and astrocytes, respectively, increased from 4 to 28 days after CCI. The severity of seizure induced by pilocarpine gradually increased, becoming significant at 28 days after CCI. Then, we treated CCI mice with an inhibitor of PDGFR signaling, imatinib, during the postoperative day 0-4 period. Imatinib lowered seizure susceptibility to pilocarpine and suppressed microglial activation in the injured hippocampus at postoperative day 28. These findings indicate that brain pericytes with rapidly increased PDGFRβ expression may drive TBI-induced dysregulation of NVU function and brain hyperexcitability.

Neural Markers of Vulnerability to Anxiety Outcomes after Traumatic Brain Injury

Anxiety outcomes after traumatic brain injury (TBI) are complex, and the underlying neural mechanisms are poorly understood. Here, we developed a multi-dimensional behavioral profiling approach to investigate anxiety-like outcomes in mice that takes into account individual variability. Departing from the tradition of comparing outcomes in TBI versus sham groups, we identified a subgroup within the TBI group that is vulnerable to anxiety dysfunction, and present increased exploration of the anxiogenic zone compared to sham controls or resilient injured animals, by applying dimensionality reduction, clustering, and post hoc validation to behavioral data obtained from multiple assays for anxiety at several post-injury time points. These vulnerable animals expressed distinct molecular profiles in the corticolimbic network, with downregulation in gamma-aminobutyric acid and glutamate and upregulation in neuropeptide Y markers. Indeed, among vulnerable animals, not resilient or sham controls, severity of anxiety-related outcomes correlated strongly with expression of molecular markers. Our results establish a foundational approach, with predictive power, for reliably identifying maladaptive anxiety outcomes after TBI and uncovering neural signatures of vulnerability to anxiety.

Nature-based rehabilitation for adults with acquired brain injury: a scoping review

The objective of this review was to provide an overview of the existing knowledge of the benefits of nature-based rehabilitation for patients with impairments after acquired brain injury. Systematic searches were conducted across PubMed, CINAHL, PsycINFO and Scopus, and seven studies were found to be included for review. Results suggest that nature-based rehabilitation may benefit individuals with acquired brain injury, as both motor - and sensory-motor functions, as well as cognitive functions were significantly improved. Furthermore, two studies found an improvement in quality of life. The benefits on anxiety and depression were not clear. The studies used different approaches, outcome measures and study designs that made comparisons difficult. Recommendations for future studies are offered.

Loss of Consciousness and Altered Mental State as Predictors of Functional Recovery Within 6 Months Following Mild Traumatic Brain Injury

OBJECTIVE

The authors tested the hypothesis that a combination of loss of consciousness (LOC) and altered mental state (AMS) predicts the highest risk of incomplete functional recovery within 6 months after mild traumatic brain injury (mTBI), compared with either condition alone, and that LOC alone is more strongly associated with incomplete recovery, compared with AMS alone.

METHODS

Data were analyzed from 407 patients with mTBI from Head injury Serum Markers for Assessing Response to Trauma (HeadSMART), a prospective cohort study of TBI patients presenting to two urban emergency departments. Four patient subgroups were constructed based on information documented at the time of injury: neither LOC nor AMS, LOC only, AMS only, and both. Logistic regression models assessed LOC and AMS as predictors of functional recovery at 1, 3, and 6 months.

RESULTS

A gradient of risk of incomplete functional recovery at 1, 3, and 6 months postinjury was noted, moving from neither LOC nor AMS, to LOC or AMS alone, to both. LOC was associated with incomplete functional recovery at 1 and 3 months (odds ratio=2.17, SE=0.46, p<0.001; and odds ratio=1.80, SE=0.40, p=0.008, respectively). AMS was associated with incomplete functional recovery at 1 month only (odds ratio=1.77, SE=0.37 p=0.007). No association was found between AMS and functional recovery in patients with no LOC. Neither LOC nor AMS was predictive of functional recovery at later times.

CONCLUSIONS

These findings highlight the need to include symptom-focused clinical variables that pertain to the injury itself when assessing who might be at highest risk of incomplete functional recovery post-mTBI.

Mild traumatic brain injury exacerbates Parkinson's disease induced hemeoxygenase-2 expression and brain pathology: Neuroprotective effects of co-administration of TiO2 nanowired mesenchymal stem cells and cerebrolysin

Mild traumatic brain injury (mTBI) is one of the leading predisposing factors in the development of Parkinson's disease (PD). Mild or moderate TBI induces rapid production of tau protein and alpha synuclein (ASNC) in the cerebrospinal fluid (CSF) and in several brain areas. Enhanced tau-phosphorylation and ASNC alters the molecular machinery of the brain leading to PD pathology. Recent evidences show upregulation of constitutive isoform of hemeoxygenase (HO-2) in PD patients that correlates well with the brain pathology. mTBI alone induces profound upregulation of HO-2 immunoreactivity. Thus, it would be interesting to explore whether mTBI exacerbates PD pathology in relation to tau, ASNC and HO-2 expression. In addition, whether neurotrophic factors and stem cells known to reduce brain pathology in TBI could induce neuroprotection in PD following mTBI. In this review role of mesenchymal stem cells (MSCs) and cerebrolysin (CBL), a well-balanced composition of several neurotrophic factors and active peptide fragments using nanowired delivery in PD following mTBI is discussed based on our own investigation. Our results show that mTBI induces concussion exacerbates PD pathology and nanowired delivery of MSCs and CBL induces superior neuroprotection. This could be due to reduction in tau, ASNC and HO-2 expression in PD following mTBI, not reported earlier. The functional significance of our findings in relation to clinical strategies is discussed.

A Multi-Site Study of Traumatic Brain Injury in Mexico and Colombia: Longitudinal Mediational and Cross-Lagged Models of Family Dynamics, Coping, and Health-Related Quality of Life

Latin America has high rates of traumatic brain injury (TBI), yet reduced mental and physical health outcomes due to limited rehabilitation services. To understand the psychosocial adjustment process in TBI patients in Latin America, the incorporation of cultural values including family-based variables is imperative. The current study examined relations among healthy family dynamics, coping, and mental and physical health related quality of life (HRQL) among a sample of TBI patients across three sites and two countries over the first 4 months post-injury. A sample of 109 acute TBI patients from Mexico and Colombia were recruited, and a series of longitudinal mediation and cross-lag panel analyses were run. Mental and physical HRQL were positively associated with each other, as well as healthy family dynamics and coping. Coping partially mediated the effects of healthy family dynamics on both mental and physical HRQL. Family dynamics showed the strongest cross-lag relationships with coping going from 2 months to 4 months. Similarly, coping showed the strongest cross-lag relationships with both mental and physical HRQL going from baseline to 2 months. Results provide empirical support for the importance of a rehabilitation workforce that has been trained in and can effectively implement family-based interventions for individuals with TBI in Latin America.

Postinjury weight rather than cognitive or behavioral impairment predicts development of posttraumatic epilepsy after lateral fluid-percussion injury in rats

OBJECTIVE

To identify postinjury physiologic, behavioral, and cognitive biomarkers for posttraumatic epilepsy to enrich study populations for long-term antiepileptogenesis studies.

METHODS

The EPITARGET cohort with behavioral follow-up and 1-month 24/7 video-electroencephalography (vEEG) monitoring included 115 adult male Sprague-Dawley rats with lateral fluid-percussion-induced traumatic brain injury (TBI), 23 sham-operated controls, and 13 naive rats. Animals underwent assessment of somatomotor performance (composite neuroscore), anxiety-like behavior (elevated plus maze, open field), spatial memory (Morris water maze), and depression-like behavior (Porsolt forced swim, sucrose preference). Impact force, postimpact apnea time, postimpact seizure-like behavior, and body weight were monitored.

RESULTS

TBI rats were impaired in the composite neuroscore (P < .001) on days (D) 2-14 and in the spatial memory test (P < .001) on D35-39 post-TBI. Differences in the elevated plus-maze (D28 and D126) and in the open field (D29 and D127) between TBI rats and controls were meager. No differences were observed in the Porsolt forced swim and sucrose preference tests as compared with sham-operated controls. Epilepsy developed in 27% of rats by the end of the sixth month. None of the behavioral or cognitive outcome measures discriminated rats with or without epilepsy. The receiver-operating characteristic analysis indicated that a decrease in body weight between D0 and D4 differentiated TBI rats with epilepsy from TBI rats without epilepsy (48% sensitivity, 83% specificity, area under the curve [AUC] 0.679, confidence interval [CI] 95% 0.56-0.80, P < .01). A 16% body weight decrease during D0-D4 could be used as a biomarker to enrich the study population from 27% (observed) to 50%.

SIGNIFICANCE

Single behavioral and cognitive outcome measures showed no power as prognostic/diagnostic biomarkers for posttraumatic epilepsy. A reduction in body weight during the first postinjury week showed some prognostic value for posttraumatic epileptogenesis and could serve as a subacute measure for selectively enriching the study population for long-term preclinical biomarker and therapy discovery studies of posttraumatic epileptogenesis.

Relationship Satisfaction and Depression After Traumatic Brain Injury: An Actor-Partner Interdependence Model of Patients and Caregivers in Mexico and Colombia

OBJECTIVE

Traumatic brain injury represents a major public health concern, particularly in low- and middle-income countries like in Latin America. Family members are often caregivers for individuals with traumatic brain injury, which can result in significant stress. Research is needed to examine depression and quality of the caregiving relationship in these dyads. This study examined relationship quality and depression longitudinally after traumatic brain injury within the caregiving relationship.

DESIGN

Dyads (N = 109) composed of individuals with traumatic brain injury and their caregivers were recruited from three hospitals in Mexico and Colombia. They self-reported depression and relationship satisfaction during hospitalization and at 2 and 4 mos after hospitalization.

RESULTS

A 2-lag Actor Partner Interdependence Model demonstrated that patients and caregivers reporting high relationship satisfaction at baseline experienced lower depression 2 mos later, which then predicted higher caregiver relationship satisfaction at 4 mos. Moreover, patients with high relationship satisfaction at baseline had caregivers with lower depression at 2 mos, which was then associated with patients' higher satisfaction at 4 mos.

CONCLUSIONS

Within individuals with traumatic brain injury and caregivers, depression and relationship satisfaction seem to be inversely related. Furthermore, patients' and caregivers' depression and relationship satisfaction impact each other over time, demonstrating interdependence within the caregiving relationship.