Can traumatic brain injury cause psychiatric disorders?

Mania Following Traumatic Brain Injury: A Systematic Review

OBJECTIVE

Traumatic brain injury (TBI) is a leading cause of mortality and morbidity worldwide. Mania is an uncommon, but debilitating, psychiatric occurrence following TBI. The literature on mania following TBI is largely limited to case reports and case series. In the present review, the investigators describe the clinical, diagnostic, and treatment characteristics of mania following TBI.

METHODS

A systematic search of MEDLINE, EMBASE, and PsycINFO was conducted for English-language studies published from 1980 to July 15, 2021. The included studies provided the required individual primary data and sufficient information on clinical presentation or treatment of manic symptoms. Studies with patients who reported a history of mania or bipolar disorder prior to TBI and studies with patients who sustained TBI before adulthood were excluded.

RESULTS

Forty-one studies were included, which reported information for 50 patients (the mean±SD age at mania onset was 39.1±14.3 years). Patients were more frequently male, aged <50 years, and without a personal or family history of psychiatric disorders. Although 74% of patients reported mania developing within 1 year following TBI, latencies of up to 31 years were observed. Illness trajectory varied from a single manic episode to recurrent mood episodes. Rapid cycling was reported in six patients. Mood stabilizers and antipsychotics were most frequently used to improve symptoms.

CONCLUSIONS

Heterogeneity of lesion locations and coexisting vulnerabilities make causality difficult to establish. Valproate or a second-generation antipsychotic, such as olanzapine or quetiapine, may be considered first-line therapy in the absence of high-level evidence for a more preferred treatment. Early escalation to combined therapy (mood stabilizer and second-generation antipsychotic) is recommended to control symptoms and prevent recurrence. Larger prospective studies and randomized controlled trials are needed to refine diagnostic criteria and provide definitive treatment recommendations.

DTI-derived parameters differ between moderate and severe traumatic brain injury and its association with psychiatric scores

BACKGROUND AND AIM

Diffusion tensor imaging (DTI) parameters in the corpus callosum have been suggested to be a biomarker for prognostic outcomes in individuals with diffuse axonal injury (DAI). However, differences between the DTI parameters on moderate and severe trauma in DAI over time are still unclear. A secondary goal was to study the association between the changes in the DTI parameters, anxiety, and depressive scores in DAI over time.

METHODS

Twenty subjects were recruited from a neurological outpatient clinic and evaluated at 2, 6, and 12 months after the brain injury and compared to matched age and sex healthy controls regarding the DTI parameters in the corpus callosum. State-Trace Anxiety Inventory and Beck Depression Inventory were used to assess psychiatric outcomes in the TBI group over time.

RESULTS

Differences were observed in the fractional anisotropy and mean diffusivity of the genu, body, and splenium of the corpus callosum between DAI and controls (p < 0.02). Differences in both parameters in the genu of the corpus callosum were also detected between patients with moderate and severe DAI (p < 0.05). There was an increase in the mean diffusivity values and the fractional anisotropy decrease in the DAI group over time (p < 0.02). There was no significant correlation between changes in the fractional anisotropy and mean diffusivity across the study and psychiatric outcomes in DAI.

CONCLUSION

DTI parameters, specifically the mean diffusivity in the corpus callosum, may provide reliable characterization and quantification of differences determined by the brain injury severity. No correlation was observed with DAI parameters and the psychiatric outcome scores.

Alcohol Use Disorder Increases Risk of Traumatic Brain Injury-Related Hospitalization: Insights From 3.8 Million Children and Adolescent Inpatients

Objectives

We conducted a cross-sectional study to identify the demographic predictors of traumatic brain injury (TBI), and the risk of association of psychiatric comorbidities including alcohol use disorder (AUD) and TBI-related hospitalizations in the children and adolescent population.

Methods

We included 3,825,523 children and adolescent inpatients (age 8-18 years) using the nationwide inpatient sample (NIS) database (2010-2014), and 61,948 inpatients had a primary diagnosis of TBI. These inpatients were grouped by comorbid AUD (N = 2,644). Multivariable logistic regression model adjusted for demographics, and psychiatric comorbidities including other substance use disorders (SUDs) was used to evaluate the odds ratio (OR) of AUD as a risk factor for TBI-related hospitalization.

Results

The majority of the TBI inpatients were adolescents (12-18 years, 82.2%), males (71.2%), and whites (59.2%). Males had three times higher odds (95% CI 3.14-3.26) for TBI-related hospitalization compared to females. Among psychiatric comorbidities, mood (4.1%) and anxiety (2.2%) disorders were prevalent in TBI inpatients, and were not associated with increased odds for TBI-related hospitalization. Among SUD, alcohol and tobacco use (4.4% each), and cannabis use (3.5%) were prevalent, and among all substances, AUD was associated with higher odds (OR 3.5, 95% CI 3.35-3.67) of TBI-related hospitalization. These patients with TBI and comorbid AUD also had higher odds for abusing stimulants (OR 5.11, 95% CI 3.85-6.77), cannabis (OR 4.69, 95% CI 4.12-5.34), and tobacco (OR 3.77, 95% CI 3.34-4.27).

Conclusion

AUD is an independent risk factor for TBI-related hospitalization with an increased risk of 50% in the children and adolescent population compared to non-alcohol users. TBI inpatients with AUD are prevalent in white, and male adolescents. These at-risk populations are also at higher risk of comorbid mood disorders and increased substance use including stimulants, cannabis, and tobacco.

Characterizing the Risk of Depression Following Mild Traumatic Brain Injury: A Meta-Analysis of the Literature Comparing Chronic mTBI to Non-mTBI Populations

Objective: Mild traumatic brain injury (mTBI) is associated with depressed mood acutely post-injury, but there is little evidence regarding long-term depression. The aim of this study was to determine the odds ratio (OR) of depression chronically following mTBI.

Methods: We searched Medline (PubMed), ProQuest, and Web of Science from date of database creation to January 23, 2019, for eligible studies examining depression at least 6 months post-injury in adult subjects with mTBI of any etiology, including civilians and military. Three authors independently reviewed titles and abstracts for study eligibility. Data were extracted and collated by two investigators. Risk of bias was assessed with the SIGN methodology. Study data were pooled using random-effects meta-analysis. The primary exposure was mTBI, and the primary outcome was depression. Secondary exploratory variables were time of assessment, age at injury, age at assessment, sex, and etiology.

Results: We included 47 cross-sectional studies (n = 25,103 mTBI and 29,982 control), 26 cohort studies (n = 70,119 mTBI, 262,034 control), four prospective observational studies (n = 1,058 mTBI and 733 control), two prospective longitudinal studies (n = 119 mTBI, 81 control), two case-control studies (n = 56 mTBI, 56 control), and one randomized controlled trial (n = 252 mTBI, 3,214 control). mTBI was associated with a 3.29-fold increased risk of depression (OR 3.29, 95% CI 2.68–4.03, I² = 96%). The OR for depression did not change when subjects were assessed at 6–12 months (OR 2.43, 1.45–4.07), years 1–2 (OR 4.12, 2.10–8.07); 2–10 (OR 3.28, 2.42–4.46), or 10+ (OR 3.42, 1.51–7.77). Similar risk of depression was sustained across different age at injury (<25: OR 2.26, 1.82–2.81; 25–35: OR 4.67, 3.06–7.14; >35: OR 2.69, 1.42–5.10) and different age at assessment (<40 years: OR 3.14, 2.48–3.99; >40 years: OR 4.57, 2.54–8.24). Female sex had a non-significant increase in OR (OR 19.97, 2.39–166.93) compared to male (OR 3.0, 2.33–3.86). mTBI etiology had no impact on depression.

Conclusions: Those experiencing mTBI are more than three times more likely to experience depression compared to those without a history of mTBI, and this risk remains decades beyond the mTBI event. Future longitudinal studies are needed to identify and mitigate this risk.

Increased Sleep Disturbances and Pain in Veterans With Comorbid Traumatic Brain Injury and Posttraumatic Stress Disorder

STUDY OBJECTIVES

Veterans are at an increased risk for traumatic brain injury (TBI) and posttraumatic stress disorder (PTSD), both of which are associated with sleep disturbances and increased pain. Furthermore, sleep disturbances and pain are reciprocally related such that each can exacerbate the other. Although both TBI and PTSD are independently linked to sleep disturbances and pain, it remains unclear whether Veterans with comorbid TBI+PTSD show worse sleep disturbances and pain compared to those with only TBI or PTSD. We hypothesized that sleep and pain would be worse in Veterans with comorbid TBI+PTSD compared to Veterans with only TBI or PTSD.

METHODS

Veterans (n = 639) from the VA Portland Health Care System completed overnight polysomnography and self-report questionnaires. Primary outcome variables were self-reported sleep disturbances and current pain intensity. Participants were categorized into four trauma-exposure groups: (1) neither: without TBI or PTSD (n = 383); (2) TBI: only TBI (n = 67); (3) PTSD: only PTSD (n = 126); and (4) TBI+PTSD: TBI and PTSD (n = 63).

RESULTS

The PTSD and TBI+PTSD groups reported worse sleep compared to the TBI and neither groups. The TBI+PTSD group reported the greatest pain intensity compared to the other groups.

CONCLUSIONS

These data suggest sleep and pain are worst in Veterans with TBI and PTSD, and that sleep is similarly impaired in Veterans with PTSD despite not having as much pain. Thus, although this is a complex relationship, these data suggest PTSD may be driving sleep disturbances, and the added effect of TBI in the comorbid group may be driving pain in this population.

Clinical characteristics of patients with bipolar disorder and premorbid traumatic brain injury: a cross-sectional study

BACKGROUND

About one in ten diagnosed with bipolar disorder (BD) has experienced a premorbid traumatic brain injury (TBI), while not fulfilling the criteria of bipolar and related disorder due to another medical condition (BD due to TBI). We investigated whether these patients have similar clinical characteristics as previously described in BD due to TBI (i.e. more aggression and irritability and an increased hypomania/mania:depression ratio) and other distinct clinical characteristics.

METHODS

Five hundred five patients diagnosed with BD type I, type II, or not otherwise specified, or cyclothymia were interviewed about family, medical, and psychiatric history, and assessed with the Young Mania Rating Scale (YMRS) and the Inventory of Depressive Symptoms Clinician Rated 30 (IDS-C₃₀). Principal component analyses of YMRS and IDS-C₃₀ were conducted. Bivariate analyses and logistic regression analyses were used to compare clinical characteristics between patients with (n = 37) and without (n = 468) premorbid TBI.

RESULTS

Premorbid TBI was associated with a higher YMRS disruptive component score (OR 1.7, 95% CI 1.1-2.4, p = 0.0077) and more comorbid migraine (OR 4.6, 95% CI 1.9-11, p = 0.00090) independently of several possible confounders. Items on disruptive/aggressive behaviour and irritability had the highest loadings on the YMRS disruptive component. Premorbid TBI was not associated with an increased hypomania/mania:depression ratio.

CONCLUSIONS

Disruptive symptoms and comorbid migraine characterize BD with premorbid TBI. Further studies should examine whether the partial phenomenological overlap with BD due to TBI could be explained by a continuum of pathophysiological effects of TBI across the diagnostic dichotomy. Trial registration ClinicalTrials.gov: NCT00201526. Registered September 2005 (retrospectively registered).

Neurobehavioral Abnormalities Associated with Executive Dysfunction after Traumatic Brain Injury

Objective: This article will address how anomalies of executive function after traumatic brain injury (TBI) can translate into altered social behavior that has an impact on a person’s capacity to live safely and independently in the community.

Method: Review of literature on executive and neurobehavioral function linked to cognitive ageing in neurologically healthy populations and late neurocognitive effects of serious TBI. Information was collated from internet searches involving MEDLINE, PubMed, PyscINFO and Google Scholar as well as the authors’ own catalogs.

Conclusions: The conventional distinction between cognitive and emotional-behavioral sequelae of TBI is shown to be superficial in the light of increasing evidence that executive skills are critical for integrating and appraising environmental events in terms of cognitive, emotional and social significance. This is undertaken through multiple fronto-subcortical pathways within which it is possible to identify a predominantly dorsolateral network that subserves executive control of attention and cognition (so-called cold executive processes) and orbito-frontal/ventro-medial pathways that underpin the hot executive skills that drive much of behavior in daily life. TBI frequently involves disruption to both sets of executive functions but research is increasingly demonstrating the role of hot executive deficits underpinning a wide range of neurobehavioral disorders that compromise relationships, functional independence and mental capacity in daily life.

Selective Serotonin Reuptake Inhibitors for Treating Neurocognitive and Neuropsychiatric Disorders Following Traumatic Brain Injury: An Evaluation of Current Evidence

The prevalence of neuropsychiatric disorders following traumatic brain injury (TBI) is 20%-50%, and disorders of mood and cognition may remain even after recovery of neurologic function is achieved. Selective serotonin reuptake inhibitors (SSRI) block the reuptake of serotonin in presynaptic cells to lead to increased serotonergic activity in the synaptic cleft, constituting first-line treatment for a variety of neurocognitive and neuropsychiatric disorders. This review investigates the utility of SSRIs in treating post-TBI disorders. In total, 37 unique reports were consolidated from the Cochrane Central Register and PubMed (eight randomized-controlled trials (RCTs), nine open-label studies, 11 case reports, nine review articles). SSRIs are associated with improvement of depressive but not cognitive symptoms. Pooled analysis using the Hamilton Depression Rating Scale demonstrate a significant mean decrease of depression severity following sertraline compared to placebo-a result supported by several other RCTs with similar endpoints. Evidence from smaller studies demonstrates mood improvement following SSRI administration with absent or negative effects on cognitive and functional recovery. Notably, studies on SSRI treatment effects for post-traumatic stress disorder after TBI remain absent, and this represents an important direction of future research. Furthermore, placebo-controlled studies with extended follow-up periods and concurrent biomarker, neuroimaging and behavioral data are necessary to delineate the attributable pharmacological effects of SSRIs in the TBI population.

Risk Factors for New-Onset Depression After First-Time Traumatic Brain Injury

BACKGROUND

Major depression after traumatic brain injury (TBI) has devastating consequences as it increases the risk of suicide, impairs overall quality of life, and affects interpersonal, occupational, and social functioning. Although the literature has reported factors associated with depression after TBI, very few studies have examined the prevalence and correlates focused on the development of new-onset depression (NOD) after first-time TBI. Our study aimed to identify TBI- and non-TBI-related factors associated with the development of NOD in the first year after TBI.

METHODS

A total of 103 subjects with first-time TBI were seen within 12 months postinjury and evaluated for the development of NOD at 3, 6, and 12 months.

RESULTS

Frontal lobe functioning, frontal lesions, and pre-TBI/early post-TBI social impairment were not found to be predictors of development of NOD within the first year after injury. Decreased post-TBI social functioning as perceived by the subject at 3, 6, and 12 months was found to be associated with NOD at each of these time points, respectively.

CONCLUSION

The study findings highlight the importance of psychotherapeutic interventions to address the individuals' overall perception of their social impairment in the early-TBI period. This may help decrease the progression of major depression within the first year after injury.

Traumatic Brain Injury, Sleep Quality, and Suicidal Ideation in Iraq/Afghanistan Era Veterans

The objective of this study was to test the hypothesis that sleep quality mediates the association between traumatic brain injury (TBI) history and current suicidal ideation. Measures of TBI history, sleep quality, and suicidal ideation were administered to 130 Iraq/Afghanistan veterans. As expected, sleep quality mediated the effect of TBI history on current suicidal ideation (indirect effect, 0.0082; 95% confidence interval, 0.0019-0.0196), such that history of TBI was associated with worse sleep quality, which was, in turn, associated with increased suicidal ideation. These findings highlight the importance of assessing TBI history and sleep quality during suicide risk assessments for veterans.

The Impact of Traumatic Brain Injury on the Aging Brain

Traumatic brain injury (TBI) has come to the forefront of both the scientific and popular culture. Specifically, sports-related concussions or mild TBI (mTBI) has become the center of scientific scrutiny with a large amount of research focusing on the long-term sequela of this type of injury. As the populace continues to age, the impact of TBI on the aging brain will become clearer. Currently, reports have come to light that link TBI to neurodegenerative disorders such as Alzheimer's and Parkinson's diseases, as well as certain psychiatric diseases. Whether these associations are causations, however, is yet to be determined. Other long-term sequelae, such as chronic traumatic encephalopathy (CTE), appear to be associated with repetitive injuries. Going forward, as we gain better understanding of the pathophysiological process involved in TBI and subclinical head traumas, and individual traits that influence susceptibility to neurocognitive diseases, a clearer, more comprehensive understanding of the connection between brain injury and resultant disease processes in the aging brain will become evident.

Association of traumatic brain injury with subsequent neurological and psychiatric disease: a meta-analysis

OBJECTIVE

Mild traumatic brain injury (TBI) has been proposed as a risk factor for the development of Alzheimer's disease, Parkinson's disease, depression, and other illnesses. This study's objective was to determine the association of prior mild TBI with the subsequent diagnosis (that is, at least 1 year postinjury) of neurological or psychiatric disease.

METHODS

All studies from January 1995 to February 2012 reporting TBI as a risk factor for diagnoses of interest were identified by searching PubMed, study references, and review articles. Reviewers abstracted the data and assessed study designs and characteristics.

RESULTS

Fifty-seven studies met the inclusion criteria. A random effects meta-analysis revealed a significant association of prior TBI with subsequent neurological and psychiatric diagnoses. The pooled odds ratio (OR) for the development of any illness subsequent to prior TBI was 1.67 (95% CI 1.44-1.93, p < 0.0001). Prior TBI was independently associated with both neurological (OR 1.55, 95% CI 1.31-1.83, p < 0.0001) and psychiatric (OR 2.00, 95% CI 1.50-2.66, p < 0.0001) outcomes. Analyses of individual diagnoses revealed higher odds of Alzheimer's disease, Parkinson's disease, mild cognitive impairment, depression, mixed affective disorders, and bipolar disorder in individuals with previous TBI as compared to those without TBI. This association was present when examining only studies of mild TBI and when considering the influence of study design and characteristics. Analysis of a subset of studies demonstrated no evidence that multiple TBIs were associated with higher odds of disease than a single TBI.

CONCLUSIONS

History of TBI, including mild TBI, is associated with the development of neurological and psychiatric illness. This finding indicates that either TBI is a risk factor for heterogeneous pathological processes or that TBI may contribute to a common pathological mechanism.

Sleep disruption and the sequelae associated with traumatic brain injury

Sleep disruption, which includes a loss of sleep as well as poor quality fragmented sleep, frequently follows traumatic brain injury (TBI) impacting a large number of patients each year in the United States. Fragmented and/or disrupted sleep can worsen neuropsychiatric, behavioral, and physical symptoms of TBI. Additionally, sleep disruption impairs recovery and can lead to cognitive decline. The most common sleep disruption following TBI is insomnia, which is difficulty staying asleep. The consequences of disrupted sleep following injury range from deranged metabolomics and blood brain barrier compromise to altered neuroplasticity and degeneration. There are several theories for why sleep is necessary (e.g., glymphatic clearance and metabolic regulation) and these may help explain how sleep disruption contributes to degeneration within the brain. Experimental data indicate disrupted sleep allows hyperphosphorylated tau and amyloid β plaques to accumulate. As sleep disruption may act as a cellular stressor, target areas warranting further scientific investigation include the increase in endoplasmic reticulum and oxidative stress following acute periods of sleep deprivation. Potential treatment options for restoring the normal sleep cycle include melatonin derivatives and cognitive behavioral therapy.

Neuropsychology of Neuroendocrine Dysregulation after Traumatic Brain Injury

Endocrine dysfunction is a common effect of traumatic brain injury (TBI). In addition to affecting the regulation of important body functions, the disruption of endocrine physiology can significantly impair mental functions, such as attention, memory, executive function, and mood. This mini-review focuses on alterations in mental functioning that are associated with neuroendocrine disturbances in adults who suffered TBI. It summarizes the contribution of hormones to the regulation of mental functions, the consequences of TBI on mental health and neuroendocrine homeostasis, and the effects of hormone substitution on mental dysfunction caused by TBI. The available empirical evidence suggests that comprehensive assessment of mental functions should be standard in TBI subjects presenting with hormone deficiency and that hormone replacement therapy should be accompanied by pre- and post-assessments.

Functional neuroimaging of traumatic brain injury: advances and clinical utility

Functional deficits due to traumatic brain injury (TBI) can have significant and enduring consequences upon patients' life quality and expectancy. Although functional neuroimaging is essential for understanding TBI pathophysiology, an insufficient amount of effort has been dedicated to the task of translating functional neuroimaging findings into information with clinical utility. The purpose of this review is to summarize the use of functional neuroimaging techniques - especially functional magnetic resonance imaging, diffusion tensor imaging, positron emission tomography, magnetic resonance spectroscopy, and electroencephalography - for advancing current knowledge of TBI-related brain dysfunction and for improving the rehabilitation of TBI patients. We focus on seven core areas of functional deficits, namely consciousness, motor function, attention, memory, higher cognition, personality, and affect, and, for each of these, we summarize recent findings from neuroimaging studies which have provided substantial insight into brain function changes due to TBI. Recommendations are also provided to aid in setting the direction of future neuroimaging research and for understanding brain function changes after TBI.

Microbleeds on susceptibility-weighted MRI in depressive and non-depressive patients after mild traumatic brain injury

The aim of this study was to explore the relationship between abnormality on susceptibility-weighted imaging (SWI) and newly-developed depression after mild traumatic brain injury. The study registered 200 patients with closed TBI and normal finding at CT and conventional MRI. All patients underwent MRI including conventional MR sequences and SWI. The number and volume of microbleed lesions were semi-automatically outlined and manually counted. All patients were followed up with the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-IV) within 1 year after TBI. The difference in microbleed lesions on SWI was compared between the depressive and non-depressive groups. The depressive group had a higher rate of abnormality on SWI than did the non-depressive group (p < 0.001). Among patients that had exhibited microbleed lesions, the number and volume of lesions were greater in the depressive group than the non-depressive group (both p < 0.001). These differences in numbers and volume of lesions were found only at the frontal, parietal and temporal lobes (all p < 0.001). Among patients that had exhibited microbleed lesions, the number and volume of lesions in other areas were not significantly different between the depressive and non-depressive groups (all p > 0.05). In conclusion, SWI was useful to identify the microbleed lesions after mild TBI. The distribution range and location of microbleed lesions were correlated with depression after TBI.

Mood disorders after TBI

In this article, we examine the epidemiology and risk factors for the development of the most common mood disorders observed in the aftermath of TBI: depressive disorders and bipolar spectrum disorders. We describe the classification approach and diagnostic criteria proposed in the fifth edition of the Diagnostic and Statistical Manual for Mental Disorders. We also examine the differential diagnosis of post-TBI mood disorders and describe the mainstay of the evaluation process. Finally, we place a special emphasis on the analysis of the different therapeutic options and provide guidelines for the appropriate management of these conditions.

Reversal of established traumatic brain injury-induced, anxiety-like behavior in rats after delayed, post-injury neuroimmune suppression

Abstract Traumatic brain injury (TBI) increases the risk of neuropsychiatric disorders, particularly anxiety disorders. Yet, there are presently no therapeutic interventions to prevent the development of post-traumatic anxiety or effective treatments once it has developed. This is because, in large part, of a lack of understanding of the underlying pathophysiology. Recent research suggests that chronic neuroinflammatory responses to injury may play a role in the development of post-traumatic anxiety in rodent models. Acute peri-injury administration of immunosuppressive compounds, such as Ibudilast (MN166), have been shown to prevent reactive gliosis associated with immune responses to injury and also prevent lateral fluid percussion injury (LFPI)-induced anxiety-like behavior in rats. There is evidence in both human and rodent studies that post-traumatic anxiety, once developed, is a chronic, persistent, and drug-refractory condition. In the present study, we sought to determine whether neuroinflammation is associated with the long-term maintenance of post-traumatic anxiety. We examined the efficacy of an anti-inflammatory treatment in decreasing anxiety-like behavior and reactive gliosis when introduced at 1 month after injury. Delayed treatment substantially reduced established LFPI-induced freezing behavior and reactive gliosis in brain regions associated with anxiety and continued neuroprotective effects were evidenced 6 months post-treatment. These results support the conclusion that neuroinflammation may be involved in the development and maintenance of anxiety-like behaviors after TBI.

Traumatic brain injury - modeling neuropsychiatric symptoms in rodents

Each year in the US, ∼1.5 million people sustain a traumatic brain injury (TBI). Victims of TBI can suffer from chronic post-TBI symptoms, such as sensory and motor deficits, cognitive impairments including problems with memory, learning, and attention, and neuropsychiatric symptoms such as depression, anxiety, irritability, aggression, and suicidal rumination. Although partially associated with the site and severity of injury, the biological mechanisms associated with many of these symptoms - and why some patients experience differing assortments of persistent maladies - are largely unknown. The use of animal models is a promising strategy for elucidation of the mechanisms of impairment and treatment, and learning, memory, sensory, and motor tests have widespread utility in rodent models of TBI and psychopharmacology. Comparatively, behavioral tests for the evaluation of neuropsychiatric symptomatology are rarely employed in animal models of TBI and, as determined in this review, the results have been inconsistent. Animal behavioral studies contribute to the understanding of the biological mechanisms by which TBI is associated with neurobehavioral symptoms and offer a powerful means for pre-clinical treatment validation. Therefore, further exploration of the utility of animal behavioral tests for the study of injury mechanisms and therapeutic strategies for the alleviation of emotional symptoms are relevant and essential.

Effects of neurosurgical treatment and severity of head injury on cognitive functioning, general health and incidence of mental disorders in patients with traumatic brain injury

Background

Neurosurgical treatment and the severity of head injury (HI) can have remarkable effect on patients’ neuropsychiatric outcomes.

Objectives

This research aimed to study the effect of these factors on cognitive functioning, general health and incidence of mental disorders in patients with a traumatic brain injury (TBI).

Patients and Methods

In this descriptive, longitudinal study, 206 TBI patients entered the study by consecutive sampling; they were then compared according to neurosurgery status and severity of their HI. Both groups underwent neurosurgical and psychological examinations. The mini mental state examination (MMSE) and general health questionnaire–28 items (GHQ-28) were administered to the study participants. At follow-up, four months later, the groups underwent a structured clinical interview by a psychiatrist based on the diagnostic and statistical manual of mental disorders, fourth edition (DSM-IV) diagnostic criteria regarding the presence of mental disorders.

Results

Analysis of covariance (ANCOVA) and multivariate analysis of covariance (MANCOVA) were performed and adjusted for the effect of confounding variables (age, gender, Glasgow outcome scale (GOS) , and level of education). The severity of HI had the most significant effect for the following variables; cognitive functioning and physical symptoms (P < 0.05). The effect of the neurosurgical treatment factor was not significant; however, the interaction effect of the two variables on social dysfunction, and total score of the GHQ-28 questionnaire appeared to be significant (P < 0.05). Fisher's exact test indicated that after a four month follow-up period, no significant differences were seen between the two groups (with or without neurosurgery) in the incidence of mental disorders, while χ² Test showed that having a more severe HI is significantly correlated with the incidence of mental disorders (P < 0.01).

Conclusions

The implications of this study should be discussed with an emphasis on negative, effective factors on the cognitive – behavioral and neuropsychiatric outcomes of a TBI.

Mild Traumatic Brain Injury among the Geriatric Population

Mild traumatic brain injury (TBI) is an unfortunately common occurrence in the elderly. With the growing population of older adults in the United States and globally, strategies that reduce the risk of becoming injured need to be developed, and diagnostic tools and treatments that may benefit this group need to be explored. Particular attention needs to be given to polypharmacy, drug interactions, the use of anticoagulants, safety issues in the living environment, elder abuse, and alcohol consumption. Low-mechanism falls should prompt health care providers to consider the possibility of head injury in elderly patients. Early and tailored management of our seniors following a mild TBI can provide them with the best possible quality of life. This review will discuss the current literature on mild TBI in the older adult, address gaps in research, and discuss the implications for future care of the older TBI patient.

Post-traumatic stress disorder: the neurobiological impact of psychological trauma

The classic fight-or-flight response to perceived threat is a reflexive nervous phenomenon thai has obvious survival advantages in evolutionary terms. However, the systems that organize the constellation of reflexive survival behaviors following exposure to perceived threat can under some circumstances become dysregulated in the process. Chronic dysregulation of these systems can lead to functional impairment in certain individuals who become “psychologically traumatized” and suffer from post-traumatic stress disorder (PTSD), A body of data accumulated over several decades has demonstrated neurobiological abnormalities in PTSD patients. Some of these findings offer insight into the pathophysiology of PTSD as well as the biological vulnerability of certain populations to develop PTSD, Several pathological features found in PTSD patients overlap with features found in patients with traumatic brain injury paralleling the shared signs and symptoms of these clinical syndromes.

Neurobiological consequences of traumatic brain injury

Traumatic brain injury (TBI) is a worldwide public health problem typically caused by contact and inertial forces acting on the brain. Recent attention has also focused on the mechanisms of injury associated with exposure to blast events or explosions. Advances in the understanding of the neuropathophysiology of TBI suggest that these forces initiate an elaborate and complex array of cellular and subcellular events related to alterations in Ca⁺⁺ homeostasis and signaling. Furthermore, there is a fairly predictable profile of brain regions that are impacted by neurotrauma and the related events. This profile of brain damage accurately predicts the acute and chronic sequelae that TBI survivors suffer from, although there is enough variation to suggest that individual differences such as genetic polymorphisms and factors governing resiliency play a role in modulating outcome. This paper reviews our current understanding of the neuropathophysiology of TBI and how this relates to the common clinical presentation of neurobehavioral difficulties seen after an injury.

Genetic predictors of response to treatment with citalopram in depression secondary to traumatic brain injury

OBJECTIVES

To determine which serotonergic system-related single nucleotide polymorphisms (SNPs) predicted variation in treatment response to citalopram in depression following a traumatic brain injury (TBI).

METHODS

Ninety (50 M/40 F, aged 39.9, SD = 18.0 years) post-TBI patients with a major depressive episode (MDE) were recruited into a 6-week open-label study of citalopram (20 mg/day). Six functional SNPs in genes related to the serotonergic system were examined: serotonin transporter (5HTTLPR including rs25531), 5HT1A C-(1019)G and 5HT2A T-(102)C, methylene tetrahydrofolate reductase (MTHFR) C-(677)T, brain-derived neurotrophic factor (BDNF) val66met and tryptophan hydroxylase-2 (TPH2) G-(703)T. Regression analyses were performed using the six SNPs as independent variables: Model 1 with response (percentage Hamilton Depression (HAMD) change from baseline to endpoint) as the dependent variable and Model 2 with adverse event index as the dependent variable (Bonferroni corrected p-value < 0.025).

RESULTS

MTHFR and BDNF SNPs predicted greater treatment response (R(2)= 0.098, F = 4.65, p = 0.013). The 5HTTLPR predicted greater occurrence of adverse events (R(2)= 0.069, F = 5.72, p = 0.020).

CONCLUSION

Results suggest that polymorphisms in genes related to the serotonergic system may help predict short-term response to citalopram and tolerability to the medication in patients with MDE following a TBI.

Rates of major depressive disorder and clinical outcomes following traumatic brain injury

CONTEXT

Uncertainties exist about the rates, predictors, and outcomes of major depressive disorder (MDD) among individuals with traumatic brain injury (TBI).

OBJECTIVE

To describe MDD-related rates, predictors, outcomes, and treatment during the first year after TBI.

DESIGN

Cohort from June 2001 through March 2005 followed up by structured telephone interviews at months 1 through 6, 8, 10, and 12 (data collection ending February 2006).

SETTING

Harborview Medical Center, a level I trauma center in Seattle, Washington.

PARTICIPANTS

Five hundred fifty-nine consecutively hospitalized adults with complicated mild to severe TBI.

MAIN OUTCOME MEASURES

The Patient Health Questionnaire (PHQ) depression and anxiety modules were administered at each assessment and the European Quality of Life measure was given at 12 months.

RESULTS

Two hundred ninety-seven of 559 patients (53.1%) met criteria for MDD at least once in the follow-up period. Point prevalences ranged between 31% at 1 month and 21% at 6 months. In a multivariate model, risk of MDD after TBI was associated with MDD at the time of injury (risk ratio [RR], 1.62; 95% confidence interval [CI], 1.37-1.91), history of MDD prior to injury (but not at the time of injury) (RR, 1.54; 95% CI, 1.31-1.82), age (RR, 0.61; 95% CI, 0.44-0.83 for > or = 60 years vs 18-29 years), and lifetime alcohol dependence (RR, 1.34; 95% CI, 1.14-1.57). Those with MDD were more likely to report comorbid anxiety disorders after TBI than those without MDD (60% vs 7%; RR, 8.77; 95% CI, 5.56-13.83). Only 44% of those with MDD received antidepressants or counseling. After adjusting for predictors of MDD, persons with MDD reported lower quality of life at 1 year compared with the nondepressed group.

CONCLUSIONS

Among a cohort of patients hospitalized for TBI, 53.1% met criteria for MDD during the first year after TBI. Major depressive disorder was associated with history of MDD and was an independent predictor of poorer health-related quality of life.

Psychiatric disorders and traumatic brain injury

Psychiatric disorders after traumatic brain injury (TBI) are frequent. Researches in this area are important for the patients' care and they may provide hints for the comprehension of primary psychiatric disorders. Here we approach epidemiology, diagnosis, associated factors and treatment of the main psychiatric disorders after TBI. Finally, the present situation of the knowledge in this field is discussed.

Neurobehavioral sequelae of traumatic brain injury: evaluation and management

Traumatic brain injury (TBI) is a worldwide public health problem. Over the last several decades, improvements in acute care have resulted in higher survival rates. Unfortunately, the majority of survivors of moderate and severe TBI have chronic neurobehavioral sequelae, including cognitive deficits, changes in personality and increased rates of psychiatric illness. These neurobehavioral problems are understandable in the context of the typical profile of regional brain damage associated with trauma. This paper presents an overview of the neurobehavioral sequelae of TBI and outlines issues to consider in the evaluation and management of these challenges.

Neuroprotective role of Bacopa monnieri extract in epilepsy and effect of glucose supplementation during hypoxia: glutamate receptor gene expression

The experiments were designed to study the glutamate gene expression during epilepsy in adult and hypoxic insult to brain during the neonatal period and the therapeutic role of neuroprotective supplements. We investigated the role of metabotropic glutamate-8 receptor (mGluR8) gene expression in cerebellum during epilepsy and neuroprotective role of Bacopa monnieri extract in epilepsy. We also studied the effect of NMDA receptor 1 (NMDAR1) gene expression during neonatal hypoxia and therapeutic role of glucose, oxygen and epinephrine supplementation. During epilepsy a significant down-regulation (P < 0.01) of mGluR8 gene expression was observed which was up-regulated (P < 0.05) near control level after B. monnieri treatment which is supported by Morris water maze experiment. In hypoxic neonates we observed up-regulation (P < 0.001) of the NMDAR1 gene expression whereas glucose and glucose + oxygen was able to significantly reverse (P < 0.001) the gene expression to near control level when compared to hypoxia and epinephrine treatment which was supported by open field test. Our results showed that B. monnieri treatment to epileptic rats significantly brought the reversal of the down-regulated mgluR8 gene expression toward control level. In neonatal rats, hypoxia induced expressional and functional changes in the NMDAR1 receptors of neuronal cells which is corrected by supplementation of glucose alone or glucose followed by oxygen during the resuscitation to prevent the glutamate related neuronal damage. Thus, the results suggest the clinical significance of corrective measures for epileptic and hypoxic management.

Psychosis related to neurological conditions: pro and cons of the dis- / mis-connectivity models of schizophrenia

Schizophrenia is still a condition with obscure causes and psychopathology. This paper aims to discuss the “disconnectivity” hypothesis in relation to some neurological conditions which are known to alter brain connectivity, as well as mimicking some aspects of the disorder. After a short historical introduction to the concept, we will examine the evidence for connectivity problems in schizophrenia, separating the anatomical level from the functional level. Then, we will discuss three different issues concerning connectivity: i) local reduction in connectivity without neuronal loss (within the gray matter); ii) reduction in or alteration of long-range connectivity (within the white matter); and iii) abnormal targets for connections. For each of these aspects, we will look at the conditions able to reproduce anomalies capable of increasing susceptibility to schizophrenia. We conclude that psychosis is more likely to occur: i) when long-range connectivity is concerned; ii) when lesions result in lengthening and scattering of conduction times; and iii) when there are high dopamine levels, shedding light on or adding weight to the idea of an interaction between dopamine and connectivity.

Substance Use Disorders and Neurologic Illness

Because of the high rates of substance use disorders among the general and clinical populations, and the abuse potential of many medications commonly used in the treatment of neurologic illnesses, the treating neurologist must deal with drug misuse and abuse in practice. The most important tool neurologists must have in their arsenal is the ability to assess for and recognize substance use disorders in their patients. Any treatment plan developed for such patients must include ongoing management of substance abuse issues. After a substance use disorder is diagnosed, the neurologist must make proper referrals to adjunctive support interventions (Alcoholics Anonymous or Narcotics Anonymous) and chemical dependency specialists, and work closely and in collaboration with these components of the patient's overall treatment. The treating neurologist should be aware of the myriad neurologic sequelae of drug use, because most drugs of abuse, including alcohol, can have neurologic manifestations resulting from acute intoxication, acute withdrawal, or chronic use. Drug use (past and present) should be included in the differential diagnosis for any patient with an atypical constellation of symptoms or with isolated neurologic deficits. If the treatment of a neurologic condition requires the use of a potentially addictive substance, particularly when the patient has a history of substance use disorders, then the clinician must minimize the risk of addiction by giving the least addictive substances and developing a plan to manage the use of the drug throughout the treatment period.