Neurobehavioral aspects of postconcussive symptoms after mild head injury

Lifetime Traumatic Brain Injury and Risk of Post-Concussive Symptoms in the Millennium Cohort Study

Traumatic brain injury (TBI) is prevalent among active duty military service members, with studies reporting up to 23% experiencing at least one TBI, with 10-60% of service members reporting at least one subsequent repeat TBI. A TBI has been associated with an increased risk of cumulative effects and long-term neurobehavioral symptoms, impacting operational readiness in the short-term and overall health in the long term. The association between multiple TBI and post-concussive symptoms (PCS), however, defined as symptoms that follow a concussion or TBI, in the military has not been adequately examined. Previous studies in military populations are limited by methodological issues including small sample sizes, the use of non-probability sampling, or failure to include the total number of TBI. To overcome these limitations, we examined the association between the total lifetime number of TBI and total number of PCS among U.S. active duty military service members who participated in the Millennium Cohort Study. A secondary data analysis was conducted using the Millennium Cohort Study's 2014 survey (n = 28,263) responses on self-reported TBI and PCS (e.g., fatigue, restlessness, sleep disturbances, poor concentration, or memory loss). Zero-inflated negative binomial models calculated prevalence ratios (PRs) and 95% confidence intervals (CIs) for the unadjusted and adjusted associations between lifetime TBIs and PCS. A third of military participants reported experiencing one or more TBIs during their lifetime with 72% reporting at least one PCS. As the mean number of PCS increased, mean lifetime TBIs increased. The mean number of PCS by those with four or more TBI (4.63) was more than twice that of those with no lifetime TBI (2.28). One, two, three, and four or more TBI had 1.10 (95% CI: 1.06-1.15), 1.19 (95% CI: 1.14-1.25), 1.23 (95% CI: 1.17-1.30), and 1.30 times (95% CI: 1.24-1.37) higher prevalence of PCS, respectively. The prevalence of PCS was 2.4 (95% CI: 2.32-2.48) times higher in those with post-traumatic stress disorder than their counterparts. Active duty military service members with a history of TBI are more likely to have PCS than those with no history of TBI. These results suggest an elevated prevalence of PCS as the number of TBI increased. This highlights the need for robust, longitudinal studies that can establish a temporal relationship between repetitive TBI and incidence of PCS. These findings have practical relevance for designing both workplace safety prevention measures and treatment options regarding the effect on and from TBI among military personnel.

Volumetric MRI Findings in Mild Traumatic Brain Injury (mTBI) and Neuropsychological Outcome

Region of interest (ROI) volumetric assessment has become a standard technique in quantitative neuroimaging. ROI volume is thought to represent a coarse proxy for making inferences about the structural integrity of a brain region when compared to normative values representative of a healthy sample, adjusted for age and various demographic factors. This review focuses on structural volumetric analyses that have been performed in the study of neuropathological effects from mild traumatic brain injury (mTBI) in relation to neuropsychological outcome. From a ROI perspective, the probable candidate structures that are most likely affected in mTBI represent the target regions covered in this review. These include the corpus callosum, cingulate, thalamus, pituitary-hypothalamic area, basal ganglia, amygdala, and hippocampus and associated structures including the fornix and mammillary bodies, as well as whole brain and cerebral cortex along with the cerebellum. Ventricular volumetrics are also reviewed as an indirect assessment of parenchymal change in response to injury. This review demonstrates the potential role and limitations of examining structural changes in the ROIs mentioned above in relation to neuropsychological outcome. There is also discussion and review of the role that post-traumatic stress disorder (PTSD) may play in structural outcome in mTBI. As emphasized in the conclusions, structural volumetric findings in mTBI are likely just a single facet of what should be a multimodality approach to image analysis in mTBI, with an emphasis on how the injury damages or disrupts neural network integrity. The review provides an historical context to quantitative neuroimaging in neuropsychology along with commentary about future directions for volumetric neuroimaging research in mTBI.

The role of the stress system in recovery after traumatic brain injury: A tribute to Bruce S. McEwen

Traumatic brain injury (TBI) represents a major public health concern. Although the majority of individuals that suffer mild-moderate TBI recover relatively quickly, a substantial subset of individuals experiences prolonged and debilitating symptoms. An exacerbated response to physiological and psychological stressors after TBI may mediate poor functional recovery. Individuals with TBI can suffer from poor stress tolerance, impairments in the ability to evaluate stressors, and poor initiation (and cessation) of neuroendocrine stress responses, all of which can exacerbate TBI-mediated dysfunction. Here, we pay tribute to the pioneering neuroendocrinologist Dr. Bruce McEwen by discussing the ways in which his work on stress physiology and allostatic loading impacts the TBI patient population both before and after their injuries. Specifically, we will discuss the modulatory role of hypothalamic-pituitary-adrenal axis responses immediately after TBI and later in recovery. We will also consider the impact of stressors and stress responses in promoting post-concussive syndrome and post-traumatic stress disorders, two common sequelae of TBI. Finally, we will explore the role of early life stressors, prior to brain injuries, as modulators of injury outcomes.

Reaction time and cognitive-linguistic performance in adults with mild traumatic brain injury

Objective: The purpose of this study was to characterize cognitive-linguistic performance in adults with mild traumatic brain injury (mTBI) to advance assessment and treatment practices. We hypothesized that individuals with mTBI would demonstrate longer reaction times (RTs) and greater error rates when compared to an orthopedic injury (OI) group on a category-naming task. Method: Participants were age and education-matched adults with mTBI (n = 20; 12 females) and adults with OI (n = 21; 5 females) who were discharged to home after an Emergency Department visit. Our primary task was a category-naming task shown to be sensitive to language deficits after mTBI. The task was adapted and administered under speeded and unspeeded conditions. Results: There was a significant main effect of condition on RT (speeded faster than unspeeded) and accuracy (more errors in the speeded condition). There was a marginally significant effect of group on errors, with more errors in the mTBI group than the OI group. Naming RT and accuracy in both conditions were moderately correlated with injury variables and symptom burden. Conclusions: Our data showed a marginal effect of group on accuracy of performance. Correlations found between naming and neurobehavioural symptoms, including sleep quality, suggest that the latter should be considered in future research.

Blast-related traumatic brain injury

A bomb blast may cause the full severity range of traumatic brain injury (TBI), from mild concussion to severe, penetrating injury. The pathophysiology of blast-related TBI is distinctive, with injury magnitude dependent on several factors, including blast energy and distance from the blast epicentre. The prevalence of blast-related mild TBI in modern war zones has varied widely, but detection is optimised by battlefield assessment of concussion and follow-up screening of all personnel with potential concussive events. There is substantial overlap between post-concussive syndrome and post-traumatic stress disorder, and blast-related mild TBI seems to increase the risk of post-traumatic stress disorder. Post-concussive syndrome, post-traumatic stress disorder, and chronic pain are a clinical triad in this patient group. Persistent impairment after blast-related mild TBI might be largely attributable to psychological factors, although a causative link between repeated mild TBIs caused by blasts and chronic traumatic encephalopathy has not been established. The application of advanced neuroimaging and the identification of specific molecular biomarkers in serum for diagnosis and prognosis are rapidly advancing, and might help to further categorise these injuries.

Mild traumatic brain injury: longitudinal regional brain volume changes

PURPOSE

To investigate longitudinal changes in global and regional brain volume in patients 1 year after mild traumatic brain injury (MTBI) and to correlate such changes with clinical and neurocognitive metrics.

MATERIALS AND METHODS

This institutional review board-approved study was HIPAA compliant. Twenty-eight patients with MTBI (with 19 followed up at 1 year) with posttraumatic symptoms after injury and 22 matched control subjects (with 12 followed up at 1 year) were enrolled. Automated segmentation of brain regions to compute regional gray matter (GM) and white matter (WM) volumes was performed by using three-dimensional T1-weighted 3.0-T magnetic resonance imaging, and results were correlated with clinical metrics. Pearson and Spearman rank correlation coefficients were computed between longitudinal brain volume and neurocognitive scores, as well as clinical metrics, over the course of the follow-up period.

RESULTS

One year after MTBI, there was measurable global brain atrophy, larger than that in control subjects. The anterior cingulate WM bilaterally and the left cingulate gyrus isthmus WM, as well as the right precuneal GM, showed significant decreases in regional volume in patients with MTBI over the 1st year after injury (corrected P < .05); this was confirmed by means of cross-sectional comparison with data in control subjects (corrected P < .05). Left and right rostral anterior cingulum WM volume loss correlated with changes in neurocognitive measures of memory (r = 0.65, P = .005) and attention (r = 0.60, P = .01). At 1-year follow-up, WM volume in the left cingulate gyrus isthmus correlated with clinical scores of anxiety (Spearman rank correlation r = -0.68, P = .007) and postconcussive symptoms (Spearman rank correlation r = -0.65, P = .01).

CONCLUSION

These observations demonstrate structural changes to the brain 1 year after injury after a single concussive episode. Regional brain atrophy is not exclusive to moderate and severe traumatic brain injury but may be seen after mild injury. In particular, the anterior part of the cingulum and the cingulate gyrus isthmus, as well as the precuneal GM, may be distinctively vulnerable 1 year after MTBI.

Decreased fractional anisotropy evaluated using tract-based spatial statistics and correlated with cognitive dysfunction in patients with mild traumatic brain injury in the chronic stage

BACKGROUND AND PURPOSE

The relationship between white matter disruption and cognitive dysfunction of patients with mTBI in the chronic stage remains unclear. The aim of this study was to identify white matter integrity by using DTI in patients with mTBI without morphologic traumatic abnormalities seen with conventional imaging and to evaluate the association of such regions with cognitive function.

MATERIALS AND METHODS

Diffusion tensor images from 51 consecutive patients with mTBI without morphologic traumatic abnormalities on conventional MRI were processed, and FA maps were generated as a measure of white matter integrity. All subjects underwent cognitive examinations (MMSE and WAIS-R FIQ). Correlations between the skeletonized FA values in the white matter and the cognitive function were analyzed by using regression analysis.

RESULTS

In patients with mTBI, significantly decreased FA value clusters in the white matter compared with the healthy controls were found in the superior longitudinal fasciculus, superior frontal gyrus, insula, and fornix. Cognitive examination scores positively correlated with FA values in a number of regions in deep brain structures, which were anatomically close or physiologically intimate to the regions with significant FA value reduction, in patients with mTBI.

CONCLUSIONS

The present study shows that patients with mTBI in the chronic stage have certain regions with abnormally reduced white matter integrity in the brain. Although the clinical and pathologic-anatomic correlation of these findings remains to be elucidated, these brain regions are strongly suggested to be related to chronic persistent cognitive impairments in these patients.

Validity of the Virtual Reality Stroop Task (VRST) in active duty military

Virtual environments provide the ability to systematically deliver test stimuli in simulated contexts relevant to real world behavior. The current study evaluated the validity of the Virtual Reality Stroop Task (VRST), which presents test stimuli during a virtual reality military convoy with simulated combat threats. Active duty Army personnel (N = 49) took the VRST, a customized version of the Automated Neuropsychological Assessment Metrics (ANAM)-Fourth Edition TBI Battery (2007) that included the addition of the ANAM Stroop and Tower tests, and traditional neuropsychological measures, including the Delis-Kaplan Executive Function System version of the Color-Word Interference Test. Preliminary convergent and discriminant validity was established, and performance on the VRST was significantly associated with computerized and traditional tests of attention and executive functioning. Valid virtual reality cognitive assessments open new lines of inquiry into the impact of environmental stimuli on performance and offer promise for the future of neuropsychological assessments used with military personnel.

Post-traumatic stress disorder vs traumatic brain injury

Post-traumatic stress disorder (PTSD) and traumatic brain injury (TBI) often coexist because brain injuries are often sustained in traumatic experiences. This review outlines the significant overlap between PTSD and TBI by commencing with a critical outline of the overlapping symptoms and problems of differential diagnosis. The impact of TBI on PTSD is then described, with increasing evidence suggesting that mild TBI can increase risk for PTSD. Several explanations are offered for this enhanced risk. Recent evidence suggests that impairment secondary to mild TBI is largely attributable to stress reactions after TBI, which challenges the long-held belief that postconcussive symptoms are a function of neurological insult This recent evidence is pointing to new directions for treatment of postconcussive symptoms that acknowledge that treating stress factors following TBI may be the optimal means to manage the effects of many TBIs,

Microstructural brain injury in post-concussion syndrome after minor head injury

INTRODUCTION

After minor head injury (MHI), post-concussive symptoms commonly occur. The purpose of this study was to correlate the severity of post-concussive symptoms in MHI patients with MRI measures of microstructural brain injury, namely mean diffusivity (MD) and fractional anisotropy (FA), as well as the presence of microhaemorrhages.

METHODS

Twenty MHI patients and 12 healthy controls were scanned at 3 T using diffusion tensor imaging (DTI) and high-resolution gradient recalled echo (HRGRE) T2*-weighted sequences. One patient was excluded from the analysis because of bilateral subdural haematomas. DTI data were preprocessed using Tract Based Spatial Statistics. The resulting MD and FA images were correlated with the severity of post-concussive symptoms evaluated with the Rivermead Postconcussion Symptoms Questionnaire. The number and location of microhaemorrhages were assessed on the HRGRE T2*-weighted images.

RESULTS

Comparing patients with controls, there were no differences in MD. FA was decreased in the right temporal subcortical white matter. MD was increased in association with the severity of post-concussive symptoms in the inferior fronto-occipital fasciculus (IFO), the inferior longitudinal fasciculus and the superior longitudinal fasciculus. FA was reduced in association with the severity of post-concussive symptoms in the uncinate fasciculus, the IFO, the internal capsule and the corpus callosum, as well as in the parietal and frontal subcortical white matter. Microhaemorrhages were observed in one patient only.

CONCLUSIONS

The severity of post-concussive symptoms after MHI was significantly correlated with a reduction of white matter integrity, providing evidence of microstructural brain injury as a neuropathological substrate of the post-concussion syndrome.

Diffusion tensor imaging and white matter lesions at the subacute stage in mild traumatic brain injury with persistent neurobehavioral impairment

Mild traumatic brain injury (mTBI) can induce long-term behavioral and cognitive disorders. Although the exact origin of these mTBI-related disorders is not known, they may be the consequence of diffuse axonal injury (DAI). Here, we investigated whether MRI at the subacute stage can detect lesions that are associated with poor functional outcome in mTBI by using anatomical images (T(1) ) and diffusion tensor imaging (DTI). Twenty-three patients with mTBI were investigated and compared with 23 healthy volunteers. All patients underwent an MRI investigation and clinical tests between 7 and 28 days (D15) and between 3 and 4 months (M3) after injury. Patients were divided in two groups of poor outcome (PO) and good outcome (GO), based on their complaints at M3. Groupwise differences in gray matter partial volume between PO patients, GO patients and controls were analyzed using Voxel-Based Morphometry (VBM) from T(1) data at D15. Differences in microstructural architecture were investigated using Tract-Based Spatial Statistics (TBSS) and the diffusion images obtained from DTI data at D15. Permutation-based non-parametric testing was used to assess cluster significance at p < 0.05, corrected for multiple comparisons. Twelve GO patients and 11 PO patients were identified on the basis of their complaints. In PO patients, gray matter partial volume was significantly lower in several cortical and subcortical regions compared with controls, but did not differ from that of GO patients. No difference in diffusion variables was found between GO and controls. PO patients showed significantly higher mean diffusivity values than both controls and GO patients in the corpus callosum, the right anterior thalamic radiations and the superior longitudinal fasciculus, the inferior longitudinal fasciculus and the fronto-occipital fasciculus bilaterally. In conclusion, PO patients differed from GO patients by the presence of diffusion changes in long association white matter fiber tracts but not by gray matter partial volume. These results suggest that DTI at the subacute stage may be a predictive marker of poor outcome in mTBI.

Incidence of delayed intracranial hemorrhage in children after uncomplicated minor head injuries

OBJECTIVES

This study sought to determine the incidence of delayed diagnosis of intracranial hemorrhage in the general population and the proportion of children who presented to emergency departments (EDs) with uncomplicated minor head injuries who received delayed diagnoses of intracranial hemorrhage.

METHODS

This was an 8-year, retrospective, cohort study of children <14 years of age who presented to EDs in the Calgary Health Region between April 1992 and March 2000. Cases of uncomplicated minor head injuries and delayed diagnosis of intracranial hemorrhage (intracranial hemorrhage not apparent until > or =6 hours after injury) were identified.

RESULTS

An estimated 17,962 children (95% confidence interval [CI]: 17,412-18,511 children) with uncomplicated minor head injuries were evaluated at Calgary Health Region EDs. Two and 8 children were identified as having delayed diagnoses of intracranial hemorrhage with and without delayed deterioration in level of consciousness (Glasgow Coma Scale scores of <15), respectively. The proportions of children with uncomplicated minor head injuries with delayed diagnoses of intracranial hemorrhage with and without deterioration in level of consciousness were approximately 0.00% (0 of 17,962 children [upper limit of 95% CI: 0.02%]) and 0.03% (5 of 17,962 children [95% CI: 0.01%-0.07%]), respectively. On the basis of population data for the Calgary Health Region, the incidences of delayed diagnosis of intracranial hemorrhage with and without deterioration in level of consciousness were 0.14 and 0.57 cases per 100,000 children per year, respectively.

CONCLUSIONS

The occurrence of delayed diagnosis of intracranial hemorrhage among children who present with uncomplicated minor head injuries is rare.

Re-examination of the Controversial Coexistence of Traumatic Brain Injury and Posttraumatic Stress Disorder: Misdiagnosis and Self-Report Measures

The coexistence of traumatic brain injury (TBI) and posttraumatic stress disorder (PTSD) remains a controversial issue in the literature. To address this controversy, we focused primarily on the civilian-related literature of TBI and PTSD. Some investigators have argued that individuals who had been rendered unconscious or suffered amnesia due to a TBI are unable to develop PTSD because they would be unable to consciously experience the symptoms of fear, helplessness, and horror associated with the development of PTSD. Other investigators have reported that individuals who sustain TBI, regardless of its severity, can develop PTSD even in the context of prolonged unconsciousness. A careful review of the methodologies employed in these studies reveals that investigators who relied on clinical interviews of TBI patients to diagnose PTSD found little or no evidence of PTSD. In contrast, investigators who relied on PTSD questionnaires to diagnose PTSD found considerable evidence of PTSD. Further analysis revealed that many of the TBI patients who were initially diagnosed with PTSD according to self-report questionnaires did not meet the diagnostic criteria for PTSD upon completion of a clinical interview. In particular, patients with severe TBI were often misdiagnosed with PTSD. A number of investigators found that many of the severe TBI patients failed to follow the questionnaire instructions and erroneously endorsed PTSD symptoms because of their cognitive difficulties. Because PTSD questionnaires are not designed to discriminate between PTSD and TBI symptoms or determine whether a patient's responses are accurate or exaggerated, studies that rely on self-report questionnaires to evaluate PTSD in TBI patients are at risk of misdiagnosing PTSD. Further research should evaluate the degree to which misdiagnosis of PTSD occurs in individuals who have sustained mild TBI.

Postconcussion syndrome after minor head injury: brain activation of working memory and attention

After minor head injury (MHI) postconcussive symptoms (PCS) such as memory and attention deficits frequently occur. It has been hypothesised that PCS are caused by microstructural damage to the brain due to shearing injury, which is not detectable with conventional imaging, and may be responsible for a functional deficit. The purpose of this study was to correlate functional magnetic resonance imaging brain activation of working memory and selective attention with PCS. 21 MHI patients and 12 healthy controls were scanned at 3T. Stimulation paradigms were the n-back and Counting Stroop tasks to engage working memory and selective attention, respectively. Functional data analysis consisted of random effects group analyses, correlating brain activation patterns with the severity of PCS as evaluated with the Rivermead postconcussion symptoms questionnaire. At minimal working memory load, activation was seen in patients with greater severity of PCS in the working memory network. With an increase of working memory load, increase of activation was more pronounced in patients with greater severity of PCS. At high and increased working memory load, activation associated with the severity of PCS was seen in the posterior parietal area, parahippocampal gyrus, and posterior cingulate gyrus. Activation related to selective attention processing was increased with greater severity of PCS. The increased activity in relation to working memory and attention, and the recruitment of brain areas outside the working memory network at high working memory load, may be considered a reflection of the brain's compensatory response to microstructural injury in patients with PCS.

Neurocognitive fitness in the sub-acute stage after mild TBI: The effect of age

OBJECTIVE

Age is assumed to be a negative prognostic factor in recovery from moderate-to-severe traumatic brain injury (TBI). Little is known on cognitive performance after mild TBI in relation to age in the sub-acute stage after injury.

METHOD

Ninety-nine mild TBI subjects (age 15-75) were compared with 91 healthy control subjects (age 14-74) in a case-control design. Patients were matched on age, sex and level of education, with control subjects. Mean interval between injury and cognitive assessment was 13 days. Neurocognitive test battery contained tests of verbal memory, selective attention, general speed of information processing and verbal fluency.

RESULTS

An overall effect was found of a single mild TBI on neurocognitive performance in the sub-acute stage after injury. Age did not add significantly to the effect of mild TBI on cognitive functioning.

CONCLUSION

Patients suffering from mild TBI are characterized by subtle neurocognitive deficits in the weeks directly following the trauma. The notion that elderly subjects have a worse outcome in the sub-acute period after mild TBI is at least not in line with the results of this study.

The comparative incidence of reported concussions presenting for follow-up management in South African Rugby Union

OBJECTIVE

The objective of this study was to compare the seasonal concussion incidence for school, university, club and provincial level Rugby Union players in South Africa.

DESIGN

The study presents a retrospective statistical analysis of the number of reported concussions documented annually for groups of Rugby Union players as a proportion of those who received preseason neurocognitive assessment.

SETTING

Between 2002 and 2006, concussion management programs using computerized neuropsychological assessment were implemented for clinical and research purposes by psychologists in selected South African institutions involved in Rugby Union from school through to the professional level.

PARTICIPANTS

The incidence figures were based on 175 concussive episodes reported for 165 athletes who were referred for neurocognitive assessment from a population of 1366 athletes who received preseason baseline testing.

INTERVENTIONS

Concussion management routines varied according to the protocols adopted by the different psychologists and rugby organizations.

MAIN OUTCOME MEASUREMENTS

It was expected that the incidence of concussion would vary significantly due to level of play and different management protocols.

RESULT

There was wide disparity in the manner in which concussion follow-up was managed by the various organizations. Within broadly comparable cohorts, tighter control was associated with a relatively higher concussion incidence for athletes per rugby playing season, with average institutional figures ranging from 4% to 14% at school level and 3% to 23% at adult level.

CONCLUSIONS

This analysis suggests that concussion goes unrecognized and therefore incorrectly managed in a number of instances. Recommendations for optimal identification of concussed athletes for follow-up management are presented.

Outcome after complicated minor head injury

BACKGROUND AND PURPOSE

Functional outcome in patients with minor head injury with neurocranial traumatic findings on CT is largely unknown. We hypothesized that certain CT findings may be predictive of poor functional outcome.

MATERIALS AND METHODS

All patients from the CT in Head Injury Patients (CHIP) study with neurocranial traumatic CT findings were included. The CHIP study is a prospective, multicenter study of consecutive patients, > or =16 years of age, presenting within 24 hours of blunt head injury, with a Glasgow Coma Scale (GCS) score of 13-14 or a GCS score of 15 and a risk factor. Primary outcome was functional outcome according to the Glasgow Outcome Scale (GOS). Other outcome measures were the modified Rankin Scale (mRS), the Barthel Index (BI), and number and severity of postconcussive symptoms. The association between CT findings and outcome was assessed by using univariable and multivariable regression analysis.

RESULTS

GOS was assessed in 237/312 patients (76%) at an average of 15 months after injury. There was full recovery in 150 patients (63%), moderate disability in 70 (30%), severe disability in 7 (3.0%), and death in 10 (4.2%). Outcome according to the mRS and BI was also favorable in most patients, but 82% of patients had postconcussive symptoms. Evidence of parenchymal damage was the only independent predictor of poor functional outcome (odds ratio = 1.89, P = .022).

CONCLUSION

Patients with neurocranial complications after minor head injury generally make a good functional recovery, but postconcussive symptoms may persist. Evidence of parenchymal damage on CT was predictive of poor functional outcome.

Correlates of persistent postconcussional disorder: DSM-IV criteria versus ICD-10

Controversy surrounding the causation of symptom complaints after mild traumatic brain injury (MTBI) is reflected by the existence of alternative diagnostic criteria for postconcussional syndrome (PCS) in the International Classification of Diseases (ICD) and postconcussional disorder (PCD) in the Diagnostic and Statistical Manual of Mental Disorders-4th edition (DSM-IV). Previous studies of persisting symptoms have employed various symptom checklists rather than uniform criteria-based diagnoses. This is the first prospective study of persisting symptom complaints using the formal diagnostic criteria for PCD and PCS and comparing these criteria sets in terms of prevalence, relationship to potential compensation, and emotional/functional status. In this prospective study, an unselected series of adults with uncomplicated MTBI (N = 139) was assessed at 6 months postinjury with a brief neuropsychological battery and measures of psychiatric symptoms/disorders, social support/community integration, health-related quality of life, and global outcome. In parallel analyses, participants with PCD/PCS were compared to those without the disorder. Potential compensation was an equally significant factor in both criteria sets. Persistent PCS criteria were met 3.1 times more frequently than persistent PCD criteria. Significant racial differences in fulfilling PCD/PCS criteria were found. No differences in emotional/functional status patterns or global outcome were found between the criteria sets except for minor dissimilarities in the social/community integration domain. The results demonstrate that despite large differences in the frequency of patients meeting the two diagnostic criteria sets, a clear basis for preferring either the PCD or PCS criteria remains to be determined.

Motor deficits and recovery during the first year following mild closed head injury

OBJECTIVE

This study examined motor impairments over 1 year following mild closed head injury (CHI). It is the first study to serially assess long-term oculomotor and upper-limb visuomotor function following mild head trauma.

METHODS

Thirty-seven patients with mild CHI and 37 matched controls were compared at 1 week, 3 months and 6 months and 31 available pairs at 12 months post-injury on measures of saccades, oculomotor smooth pursuit, upper-limb visuomotor function and neuropsychological performance. Symptomatic recovery was sampled using the Rivermead Postconcussion Symptoms Questionnaire.

RESULTS

At 1 week, the group with CHI reported high levels of post-concussional symptoms and exhibited prolonged saccade latencies, increased directional errors, decreased saccade accuracy and impaired fast sinusoidal smooth pursuit concomitant with increased arm movement reaction time, decreased arm movement speed and decreased motor accuracy on upper-limb visuomotor tracking tasks. Neuropsychological testing identified deficits only in verbal learning and speed of processing while attention, short-term/working memory and general cognitive performance were preserved. At 3 and 6 months, the group with CHI continued to show deficits on several oculomotor and upper-limb visuomotor measures in combination with some deficits on verbal learning and improved, yet abnormal, levels of post-concussional symptoms. At 12 months, the group with CHI had no cognitive impairment but residual deficits in eye and arm motor function and continued to show elevated levels of post-concussional symptoms.

CONCLUSIONS

The findings indicate that multiple motor systems are measurably impaired up to 12 months following mild CHI and that instrumented motor assessment may provide sensitive and objective markers of cerebral dysfunction during recovery from mild head trauma independent of neuropsychological assessment and patient self-report.

Mild head injury—a close relationship between motor function at 1 week post-injury and overall recovery at 3 and 6 months

Based on previous findings of impaired eye and arm motor control after mild closed head injury (CHI), this study examined whether early eye and arm motor function, and the level of post-injury cerebral dysfunction manifested in motor control, relates systematically to recovery at 3 and 6 months after mild CHI. At 1 week post-injury, we assessed oculomotor function, upper-limb visuomotor performance, and cognitive status in 37 mild CHI patients. Re-examination at 3 and 6 months determined outcome in terms of postconcussional symptoms and performance of everyday tasks, as assessed by the Rivermead Postconcussion Symptoms Questionnaire, the Rivermead Head Injury Follow-up Questionnaire and the SF-36 Health Survey. We then examined the association of early motor function, cognitive status and self-reported health condition with outcome using linear regression. Motor-based regression models explained a high proportion of the variance in outcome (70-89%), with motor function at 1 week being more closely related to outcome at 3 and 6 months than early psychometric assessment (13-32%) or self-reported health status (54-79%). These motor-based models incorporated subcortical/subconscious motor functions alongside motor functions that are subject to volitional control and are primarily mediated by frontal, parietal and temporal cortical brain regions. Early assessment of eye and arm motor function may help in improving accuracy of outcome prediction after mild CHI. Such assessment may assist in the better targeting of early health care intervention and help decrease head-trauma-related morbidity and rehabilitation costs.

Relations among sociodemographic, neurologic, clinical, and neuropsychologic variables, and vocational status following mild traumatic brain injury: a follow-up study

OBJECTIVES

To explore the long-term relations among sociodemographic, neurologic, clinical, and neuropsychologic variables, and vocational status in persons with mild traumatic brain injury (MTBI), and to identify the symptoms that determine whether or not these individuals return to work.

DESIGN

Longitudinal quasi-experimental between-groups design.

PARTICIPANTS

Eighty-five MTBI subjects aged between 16 and 65 years.

SETTING

The emergency ward of the Trois-Rivieres Regional Hospital Centre in Quebec, Canada.

MAIN OUTCOME MEASURES

Age, gender, Glasgow Coma Scale score, duration of posttraumatic amnesia, duration of retrograde amnesia, total of symptoms at emergency, time elapsed since the trauma, Paced Auditory Serial Addition Task, Stroop Color Word Test, California Verbal Learning Test, and the number of symptoms at follow-up (12 to 36 months posttrauma).

RESULTS

Only the total number of symptoms reported at follow-up was related to vocational status. The majority of individuals had returned to work 1 year or more post-MTBI. Individuals who had not returned to work reported the greatest number of symptoms, which could be linked to their affective status. Six affective symptoms, 5 cognitive symptoms, 6 physical symptoms, and 8 symptoms relating to social and daily life activities differentiated the participants who had returned to work from those who had not.

CONCLUSIONS

Patient characteristics, injury severity indicators, and cognitive functions were not associated with vocational status. To better understand post-MTBI vocational status, it is important to focus on subjective complaints that arise following the injury.

Neuropsychological diagnosis and outcome in mild traumatic brain injury

Despite its frequency, many, aspects of mild traumatic brain injury (MTBI) remain controversial. This likely reflects the inherent complexities of MTBI and its sequelae as well as various methodological issues in the literature. To further complicate matters, our understanding of what constitutes "necessary" and "sufficient" force to sustain a brain injury, remains limited, particularly in cases of nonimpact brain injury. Little debate exists regarding acute MTBI effects and postconcussional symptoms, although the issue of residual neuropsychological impairment remains hotly contested in many cases. Base rates of neuropsychological "impairment" must be considered in the context of individuals who present for evaluation following possible TBI or MTBI. In this article we highlight some of the critical issues in the assessment and diagnosis of MTBI, including the pitfalls of false-positive and false-negative diagnostic and interpretive errors.

Mild traumatic brain injury induces persistent cognitive deficits and behavioral disturbances in mice

Victims of mild traumatic brain injury (mTBI) do not show clear morphological brain defects, but frequently suffer from long-lasting cognitive deficits, emotional difficulties and behavioral disturbances. In the present study, we investigated the effects of experimental mTBI in mice on cognition, spatial and non-spatial tasks, and depressive-like behavior in mice. Experimental brain injury was induced using a concussive head trauma, which creates the TBI by a weight-drop device. Different groups of mice were tested at 7, 30, 60, and 90 days post-injury for cognitive function (the swim T-maze and the passive avoidance test) and for depression-like behavior (the forced swimming test). These tests have been used infrequently in the past in mTBI research. Significant differences were observed between the injured mice compared to the controls in both the swim T-maze (day 30: p < 0.001) and passive avoidance (day 30: p < 0.05) tests. In addition, a significant difference was detected in the forced swimming test between the injured mice and the controls (day 7: p < 0.05; day 90: p < 0.01), which showed a depressive- like state in the injured animals beginning 7 days post-injury. These results demonstrate that persistent deficits in these tests of cognitive learning abilities and emergence of depressive-like behavior in injured mice are similar to those reported in human post-concussion syndrome.

Rehabilitation interventions after mild head injury

PURPOSE OF REVIEW

This review examines current management and rehabilitation strategies for mild traumatic brain injury, with emphasis on the need to address multiple potential causative factors in order to enhance outcomes and to conduct more controlled efficacy studies.

RECENT FINDINGS

Whilst most individuals who sustain mild traumatic brain injury make a good recovery, a proportion experience significant ongoing disability. In some cases this is due to diffuse axonal injury and cognitive impairment, but in others symptoms are exacerbated by factors such as pain, stress, personality issues or litigation, or in children, previous head injury, behavioural or learning difficulties. Provision of information early after injury results in reduced symptom reporting in adults and children. There is also a need, however, to address these other factors in treatment. Psychological therapy using a cognitive behavioural approach may be helpful, but controlled evaluations of such interventions have been lacking. Recent uncontrolled studies have examined the impact of computer-mediated interventions to remediate visual and verbal processing and oculomotor problems and the impact of quantitative electroencephalography. More rigorous efficacy studies of these approaches are needed. Guidelines for management of sports-related concussion and timing of return to play also require a more solid scientific basis.

SUMMARY

The evidence base for management of mild traumatic brain injury is still very limited. There is a need to conduct more carefully controlled prospective studies and examine the influence of factors not directly related to the brain injury as a basis for formulating more uniform management guidelines.

A Trial of Neuropsychologic Rehabilitation in Mild-Spectrum Traumatic Brain Injury

OBJECTIVE

To test the effectiveness of a neuropsychologic rehabilitation program consisting of psychotherapy and cognitive remediation in the treatment of the affective and neuropsychologic sequelae of mild-spectrum traumatic brain injury (TBI).

DESIGN

Single-blind randomized, wait-listed controlled trial, with repeated measures and multiple baselines.

SETTING

Outpatient clinic in northern New Jersey.

PARTICIPANTS

Twenty persons with persisting complaints after mild and moderate TBI (11 in treatment group, 9 controls).

INTERVENTIONS

The experimental group received both 50 minutes of individual cognitive-behavioral psychotherapy and 50 minutes of individual cognitive remediation, 3 times a week for 11 weeks. The control group was wait-listed and received treatment after conclusion of follow-up.

MAIN OUTCOME MEASURES

Symptom Check List-90R General Symptom Index, plus scales of depression, anxiety, coping, attention, and neuropsychologic functioning.

RESULTS

Compared with the control group, the treatment group showed significantly improved emotional functioning, including lessened anxiety and depression. Most significant improvements in emotional distress were noted at 1 month and 3 months posttreatment. Performance on a measure of divided auditory attention also improved, but no changes were noted in community integration scores.

CONCLUSIONS

Cognitive behavioral psychotherapy and cognitive remediation appear to diminish psychologic distress and improve cognitive functioning among community-living persons with mild and moderate TBI.

Traumatic brain injury, dissociation, and posttraumatic stress disorder in road traffic accident survivors

This study investigated the symptom profiles of acute stress disorder (ASD) and posttraumatic stress disorder (PTSD) in participants who did and did not sustain traumatic brain injury (TBI), following a road traffic accident. The participants were assessed at three time points: as soon as possible posttrauma as well as at 6 weeks and 3 months posttrauma. At the first assessment, fewer participants from the TBI group recalled feeling fear and helplessness at the time of the trauma, fewer TBI participants reported recurrent intrusive thoughts and images, and more TBI participants reported dissociation since the trauma, relative to the non-TBI group. At the second assessment, fewer participants from the TBI group recalled feeling intense helplessness at the time of the trauma. Fewer TBI participants also reported reliving and physiological reactions on trauma reminders relative to the non-TBI group. At 3 months posttrauma, there was no difference in PTSD symptom profile between non-TBI and TBI groups. Our findings indicate that the presence of TBI is likely to influence the distribution of certain symptoms, but need not be a significant barrier to diagnosing ASD and PTSD.

Putting Humpty Dumpty Together Again

Acquired brain injury commonly results in both cognitive and emotional sequela, and it is increasingly recognized that these domains of functioning interact. Consequently, interventions directed at only or primarily one domain may be confounded by this interaction. To maximize treatment potential, we believe cognitive rehabilitation must integrate both cognitive and emotional interventions, and attend to belief systems about, and affective responses to, cognitive challenges. We review the scant literature addressing the impact of combined interventions for clients with acquired brain injury. Integrated with these reviews are 2 case studies that appear to break treatment "myths." Specifically, we address the notion that emotion-focused treatments are appropriate only for clients with awareness or insight and the notion that cognitive interventions are ineffective, and potentially even contraindicated, for clients whose profile suggests emotional distress and functional, as opposed to neurological, impairments. In each of these cases, we demonstrate that combining cognitive and emotional interventions was not only effective but also even more valuable than previous treatment approaches aimed exclusively at one domain. We conclude by emphasizing the importance of understanding emotional response to, and beliefs about, cognitive difficulties in developing effective interventions.

A community survey demonstrated cohort differences in the lifetime prevalence of self-reported head injury

OBJECTIVE

The objective of the study was to assess the lifetime prevalence and validity of self-reported head injury.

STUDY DESIGN AND SETTING

Analysis of a cross-sectional community survey, stratified by birth cohort. Seven thousand four hundred eighty-eight residents of Canberra and Queanbeyan, 3,678 males and 3,810 females, representing three cohorts aged in their 20s, 40s and 60s at the time of the survey, were randomly selected from the Australian Electoral Roll.

RESULTS

The lifetime prevalence of head injury with at least 15 min loss of consciousness ranged from 5.6 to 6.0% across the three cohorts. Self-reported head injury was associated with symptoms of traumatic brain injury or postconcussion syndrome. Reported head injury did not differ across the birth cohorts, contrary to expectations that prevalence rates would increase with age. Analysis of age at first head injury showed significant differences between cohorts in the reported prevalence at age 20, with estimates considerably higher for the youngest cohort.

CONCLUSION

Although the data may reflect real increases in the risk of head injury, it may be that self-reported measures of lifetime prevalence of head injury underestimate prevalence in older cohorts.

Post concussion syndrome

Individuals sustaining mild traumatic brain injuries often report a constellation of physical, cognitive, and emotional/behavioral symptoms referred to as post concussion symptoms (PCS). The most commonly reported post concussion symptoms are headache, dizziness, decreased concentration, memory problems, irritability, fatigue, visual disturbances, sensitivity to noise, judgment problems, depression, and anxiety. Although these PCS often resolve within one month, in some individuals PCS can persist from months to years following injury and may even be permanent and cause disability. When this cluster of PCS is persistent in nature, it is often called the post concussion syndrome or persistent PCS. Both physiological and psychological etiologies have been suggested as causes for persistent post concussion symptoms and this has led to much controversy and debate in the literature. Most investigators now believe that a variety of pre-morbid, injury-related, and post-morbid neuropathological and psychological factors contribute to the development and continuation of these symptoms in those sustaining mild traumatic brain injury (MTBI).

Brain injury in battered women

The goals of the present study were to examine (a) whether battered women in a sample of both shelter and nonshelter women are sustaining brain injuries from their partners and (b) if so, whether such brain injuries are associated with partner abuse severity, cognitive functioning, or psychopathology. Ninety-nine battered women were assessed using neuropsychological, psychopathology, and abuse history measures. Almost three quarters of the sample sustained at least 1 partner-related brain injury and half sustained multiple partner-related brain injuries. Further, in a subset of women (n = 57), brain injury severity was negatively associated with measures of memory, learning, and cognitive flexibility and was positively associated with partner abuse severity, general distress, anhedonic depression, worry, anxious arousal, and posttraumatic stress disorder symptomatology.

Posttraumatic disorders following injury: an empirical and methodological review

Although there has been a marked increase in research on psychological disorders following physical injury in recent years, there are many discrepancies between the reported findings. This paper reviews the prevalence outcomes of recent studies of the mental health sequelae of physical injury with a focus on posttraumatic stress disorder (PTSD), acute stress disorder (ASD), and depression. The review critically outlines some of the methodological factors that may have contributed to these discrepancies. The phenomenological overlap between organic and psychogenic symptoms, the use of narcotic analgesia, the role of brain injury, the timing and content of assessments, and litigation are discussed in terms of their potential to confound findings with this population. Recommendations are proposed to clarify methodological approaches in this area. It is suggested that a clearer understanding of the psychological effects of physical injury will require the widespread adoption of more rigorous, standardized and transparent methodological procedures.

Early identification of mild traumatic brain injury in female victims of domestic violence

BACKGROUND

Domestic violence and traumatic brain injuries (TBIs) are major societal problems with public health implications. The inter-relationship between this specific form of violence and TBI has not been explored. However, a clinically relevant relationship is suggested by recent outcome data showing that TBI survivors who are victims of assault are more prone to a suboptimal outcome.

METHODS

This observational study screened women who presented to 3 metropolitan emergency departments for health issues associated with domestic violence for a possible secondary mild TBI.

RESULTS

Over a 7- to 9-month survey period, a total of 169 women with health issues directly attributable to domestic violence and who were referred to sexual assault-domestic violence health staff were identified. Thirty percent (n = 51) agreed to participate in this survey. A positive loss of consciousness on at least one occasion was reported in 30% of the respondents, and 67% of women reported residual problems that were potentially head-injury related.

CONCLUSION

These data argue for greater vigilance in screening domestic violence victims for mild TBI because earlier identification and treatment of any postconcussive syndrome symptoms seems to diminish their adverse impact on outcome.

Saccade sequences as markers for cerebral dysfunction following mild closed head injury

Diffuse axonal injury caused by mild closed head injury (CHI) is likely to affect the neural networks concerned with the planning and execution of sequences of memory-guided saccades. Thirty subjects with mild CHI and thirty controls were tested on 2- and 3-step sequences of memory-guided saccades. CHI subjects showed more directional errors, larger position errors, and hypermetria of primary saccades and final eye position. No deficits were seen in temporal accuracy (timing and rhythm). These results suggest that computerized tests of saccade sequences can provide sensitive markers of cerebral dysfunction after mild CHI.

Trajectories of cognitive recovery following a minor brain injury

Minor brain injury (MBI) is the most frequently diagnosed head trauma in the United States, with treatment costing more than $1.5 billion annually and many patients incapacitated for months following injury. The purpose of this study was to characterize the brain function disruptions associated with MBI and to determine the time trajectory of recovery, using a theoretical model of attention. Distractibility, impulsivity, irritability, and impaired executive functioning were demonstrated in all participants during the 24 hr after injury. Twenty percent of participants continued to complain of distractibility, impulsivity, and/or irritability throughout the 30-day study. Loss of consciousness was shown to confound participants' healing trajectories. These results suggest that standard emergency room treatment following MBI is inadequate and should include discharge directives to reduce cognitive demands for at least 48 hr at a minimum, for 30 days or longer for those with loss of consciousness.

Effects of underwater sound exposure on neurological function and brain histology

To evaluate the safety of sonar exposure from a neurological perspective, the vulnerability of the central nervous system to underwater exposure with high-intensity, low-frequency sound (HI-LFS) was experimentally examined. Physiological, behavioral and histological parameters were measured in anesthetized, ventilated rats exposed to brief (5 min), underwater HI-LFS. Exposure to 180 dB sound pressure level (SPL) re 1 microPa at 150 Hz (n = 9) did not alter acute cardiovascular physiology (arterial blood pH, pO(2), pCO(2), heart rate, or mean arterial blood pressure) from that found in controls (n = 11). Rats exposed to either 180 dB SPL re 1 microPa at 150 Hz (n = 12) or 194 dB SPL re 1 microPa at 250 Hz (n = 12) exhibited normal cognitive function at 8 and 9 days after sound exposure. Evaluation of neurological motor function revealed a minor deficit 7 days after 180 dB SPL/150 Hz exposure that resolved by 14 days, and no deficits after 194 dB SPL/250 Hz exposure. No overt histological damage was detected in any group. These data suggest that underwater HI-LFS exposure may cause transient, mild motor dysfunction.

Assessing head-injury survivors of motor vehicle crashes at discharge from trauma care

OBJECTIVES

This study examines the needs at discharge from acute care to home of trauma patients with head injuries resulting from motor vehicle crashes.

DESIGN

A retrospective case series was conducted by using the 1997 trauma registry to identify eligible adults. Selected variables were abstracted from medical records and hospital databases.

RESULTS

Thirty-four cases were reviewed. At discharge, rehabilitative needs associated with musculoskeletal injury, brain injury, skin integrity, and pain management were identified, with 55% of patients having needs in two or more domains. Although all patients were referred for follow-up appointments, only 62% of patients returned for trauma-related follow-up within this institution. After initial hospitalization, twenty-four percent of patients were seen in the emergency department, and 6% had trauma-related readmissions.

CONCLUSIONS

This study documents the multidimensional needs of this group of survivors of motor vehicle trauma with head injury who were discharged to home. Findings suggest that mobility skills were formally assessed more often than either self-care skills or cognition, possibly resulting in an underestimate of the amount of disability experienced by this group. There seems to be a gap in continuity of care from hospital to the outpatient setting as evidenced by missed follow-up appointments. Models for continuity-focused trauma care with rehabilitative components are needed.

Balance findings in a child before and after a mild head injury

OBJECTIVE

This case study reviews the preinjury and postinjury balance performance of an 11-year-old child who sustained a mild head injury.

DESIGN

A prospective design was used to document balance 5 days before injury and 1, 4, and 12 weeks after injury.

OUTCOME MEASURES

The assessments used were the balance subtest of the Bruininks-Oseretsky Test of Motor Proficiency, the Pediatric Clinical Test of Sensory Interaction for Balance, and the Postural Stress Test.

RESULTS

One week after the trauma, balance deficits were observed in the three tests. The deficits improved 4 weeks after the injury, and performance remained stable over the following 2 months for two of the evaluations except for the Postural Stress Test performance, which failed to improve in the 3-month period after trauma.

CONCLUSIONS

The good recovery of balance skills observed over the first month after injury seems to validate the current activity restrictions imposed on children after a mild head injury. However, the persistence of poor performance in the area of reactions to external perturbations indicates that some deficits may persist beyond what is expected with this population.

Mild head injury increasing the brain's vulnerability to a second concussive impact

OBJECT

Mild, traumatic repetitive head injury (RHI) leads to neurobehavioral impairment and is associated with the early onset of neurodegenerative disease. The authors developed an animal model to investigate the behavioral and pathological changes associated with RHI.

METHODS

Adult male C57BL/6 mice were subjected to a single injury (43 mice), repetitive injury (two injuries 24 hours apart; 49 mice), or no impact (36 mice). Cognitive function was assessed using the Morris water maze test, and neurological motor function was evaluated using a battery of neuroscore, rotarod, and rotating pole tests. The animals were also evaluated for cardiovascular changes, blood-brain barrier (BBB) breakdown, traumatic axonal injury, and neurodegenerative and histopathological changes between 1 day and 56 days after brain trauma. No cognitive dysfunction was detected in any group. The single-impact group showed mild impairment according to the neuroscore test at only 3 days postinjury, whereas RHI caused pronounced deficits at 3 days and 7 days following the second injury. Moreover, RHI led to functional impairment during the rotarod and rotating pole tests that was not observed in any animal after a single impact. Small areas of cortical BBB breakdown and axonal injury. observed after a single brain injury, were profoundly exacerbated after RHI. Immunohistochemical staining for microtubule-associated protein-2 revealed marked regional loss of immunoreactivity only in animals subjected to RHI. No deposits of beta-amyloid or tau were observed in any brain-injured animal.

CONCLUSIONS

On the basis of their results, the authors suggest that the brain has an increased vulnerability to a second traumatic insult for at least 24 hours following an initial episode of mild brain trauma.

Posttraumatic stress disorder and traumatic brain injury: can they co-exist?

The possibility that posttraumatic stress disorder (PTSD) can develop following traumatic brain injury (TBI) has been the subject of considerable debate. The traditional view has held that impaired consciousness that occurs with TBI precludes encoding of the traumatic experience, and this prevents subsequent reexperiencing symptoms. This paper critically reviews available, empirical studies on PTSD in TBI populations and suggests that these two conditions can co-exist. The various mechanisms that may mediate PTSD following TBI are discussed, and special attention is given to issues that recognize the distinctive features of PTSD following TBI. These processes include implicit processing, biologically mediated fear conditioning, and reconstruction of trauma memories. Finally implications for assessment, treatment, and forensic investigation of PTSD in TBI populations are, addressed. This review concludes that TBI populations provide a useful means by which the role of traumatic memories (and impaired memories) in posttraumatic adjustment can be studied.

P300 event-related potential decrements in well-functioning university students with mild head injury

We compared the performance of 10 well-functioning university students who had experienced a mild head injury (MHI) an average of 6.4 years previously and 12 controls on a series of standard psychometric tests of attention, memory, and thinking and on a series of auditory oddball vigilance tasks to which we also took event-related potentials (ERPs). The MHI and Control groups performed equivalently on all the psychometric tasks and on self-report questionnaires of everyday memory and attention difficulties. The MHI group performed more slowly and with lower accuracy on only the most difficult of the oddball tasks, yet they showed substantially and significantly reduced P300 amplitudes and subsequent attentuation on all the oddball tasks, both easy and difficult. There were no alterations of N1, P2, and N2 components. These data suggest that despite excellent behavioral recovery, subtle information processing deficits involving attention nevertheless may persist long after the original injury and may not be apparent on a variety of standard psychometric measures.

National estimates of non-fatal firearm related injuries other than gunshot wounds

OBJECTIVE

To characterize non-fatal firearm related injuries other than gunshot wounds (non-GSWs) treated in hospital emergency departments in the United States that occur during routine gun handling and recreational use as well as violence related use of a firearm.

METHODS

Cases were identified through the National Electronic Injury Surveillance System (NEISS). During the study period, 1 January 1993 through 31 December 1996, NEISS consisted of a nationally representative sample of 91 hospitals in the United States having at least six beds and providing 24 hour emergency services.

RESULTS

An estimated 65 374, or an average of 16,300 per year, non-fatal, non-GSWs were treated in American hospital emergency departments during the four year study period. Fifty seven per cent of all the non-fatal, non-GSWs were violence related, most of which involved being struck by a firearm. The majority of unintentional non-fatal, non-GSWs were self inflicted and occurred during routine gun handling or recreational use of a firearm; 43% of these injuries resulted from gun recoils.

CONCLUSIONS

Non-fatal, non-GSWs make a notable contribution to the public health burden of firearm related injuries. Firearm related injury prevention programs should focus on not only the reduction of gunshot wounds but also the reduction of unintentional and violence related non-GSWs.

Ambulatory care for traumatic brain injuries in the US, 1995-1997

The burden of mild traumatic brain injury (TBI) is not well understood at the national level, but hospitalization rates show a decline over time. This paper describes ambulatory care for TBI patients at physician offices, hospital outpatient departments, and emergency departments (EDs) in comparison with non-TBI visits for the US during 1995-1997. An estimated 1.4 million visits for TBI were made each year for an average annual rate of 5.4/1,000 population. A decline in annual visit rate was noted during 1995-1997. Visit rates were higher for those aged 0 -14 and 75 and older. Falls (44%) and motor vehicles (28%) were the primary injury causes. Rural-urban differences were found, also in comparison with non-TBI. In 23% of visits to EDs, a CT scan was ordered or performed and in 33%, a mental status exam was conducted. Further investigations are warranted to describe ambulatory care for TBI in more detail, particularly in light of a decline in hospitalization rates.

A unifying hypothesis of Alzheimer's disease. III. Risk factors

Normal ageing and Alzheimer's disease (AD) have many features in common and, in many respects, both conditions only differ by quantitative criteria. A variety of genetic, medical and environmental factors modulate the ageing-related processes leading the brain into the devastation of AD. In accordance with the concept that AD is a metabolic disease, these risk factors deteriorate the homeostasis of the Ca(2+)-energy-redox triangle and disrupt the cerebral reserve capacity under metabolic stress. The major genetic risk factors (APP and presenilin mutations, Down's syndrome, apolipoprotein E4) are associated with a compromise of the homeostatic triangle. The pathophysiological processes leading to this vulnerability remain elusive at present, while mitochondrial mutations can be plausibly integrated into the metabolic scenario. The metabolic leitmotif is particularly evident with medical risk factors which are associated with an impaired cerebral perfusion, such as cerebrovascular diseases including stroke, cardiovascular diseases, hypo- and hypertension. Traumatic brain injury represents another example due to the persistent metabolic stress following the acute event. Thyroid diseases have detrimental sequela for cerebral metabolism as well. Furthermore, major depression and presumably chronic stress endanger susceptible brain areas mediated by a host of hormonal imbalances, particularly the HPA-axis dysregulation. Sociocultural and lifestyle factors like education, physical activity, diet and smoking may also modulate the individual risk affecting both reserve capacity and vulnerability. The pathophysiological relevance of trace metals, including aluminum and iron, is highly controversial; at any rate, they may adversely affect cellular defences, antioxidant competence in particular. The relative contribution of these factors, however, is as individual as the pattern of the factors. In familial AD, the genetic factors clearly drive the sequence of events. A strong interaction of fat metabolism and apoE polymorphism is suggested by intercultural epidemiological findings. In cultures, less plagued by the 'blessings' of the 'cafeteria diet-sedentary' Western lifestyle, apoE4 appears to be not a risk factor for AD. This intriguing evidence suggests that, analogous to cardiovascular diseases, apoE4 requires a hyperlipidaemic lifestyle to manifest as AD risk factor. Overall, the etiology of AD is a key paradigm for a gene-environment interaction. Copyright 2000 John Wiley & Sons, Ltd.

Cognitive performance in multiple trauma patients 3 years after injury

OBJECTIVES

Patients with sequelae from multiple trauma commonly display cognitive disturbances, specifically in the areas of attention and memory. This study was designed to assess cognitive functioning 3 years after severe multiple trauma and to investigate how cognitive performance is related to head injury severity and psychological distress respectively.

METHODS

Sixty-eight multiple trauma patients were tested with a screening battery consisting of six neuropsychological tasks 3 years after injury. A measure of psychological distress (20-item General Health Questionnaire, or GHQ-20) was also administered.

RESULTS

Patients who neither showed signs of reduced consciousness on admission to the hospital nor reported significant psychological distress at follow-up tended to have normal test performance. In five of the six tasks, cognitive impairment was related to the severity of the traumatic brain injury as measured by the Glasgow Coma Scale (GCS). In both attention span tasks, patients designated as cases by the GHQ had significantly lower scores than noncase patients. These bivariate relationships were upheld in multiple regression analyses, in which age, sex, and GCS and GHQ scores were entered as independent variables. When patients with severe head injuries were excluded from the analyses, GCS scores still contributed to the variance in tests of verbal attention span and delayed recall, but performance on attentional tasks was more strongly related to psychological distress than to GCS scores.

CONCLUSIONS

Cognitive deficits in multiple trauma patients were related both to the severity of the traumatic brain injury and to the degree of psychological distress. The strength of the association between brain injury as indicated by GCS scores and cognitive performance differed between different tasks. Neuropsychological testing may assist in differentiating primary organic from secondary psychogenic impairments.

Postconcussive symptoms and posttraumatic stress disorder after mild traumatic brain injury

Postconcussive symptoms after mild traumatic brain injury (MTBI) may be exacerbated by anxiety associated with posttraumatic stress. The aim of this study was to investigate the relationship between postconcussive symptoms and posttraumatic stress disorder (PTSD) in an MTBI population. Survivors of motor vehicle accidents who either sustained an MTBI (N = 46) or no TBI (N = 59) were assessed 6 months posttrauma for PTSD and postconcussive symptoms. Postconcussive symptoms were more evident in MTBI patients with PTSD than those without PTSD, and in MTBI patients than non-TBI patients. Further, postconcussive symptoms were significantly correlated with PTSD symptoms. These findings indicate that postconcussive symptoms may be mediated by an interaction of neurological and psychological factors after MTBI.