Outcome from mild traumatic brain injury

An examination of the factor structure of the Revised Illness Perception Questionnaire modified for adults with mild traumatic brain injury

OBJECTIVE

Factors influencing outcome after mild traumatic brain injury (MTBI) remain poorly understood. In other health conditions patient illness perceptions have been associated with outcome and have provided targets for effective interventions. These have not been systematically explored in MTBI and identifying reliable and valid measures of illness perceptions in MTBI is a first step before such concepts can be explored in clinical and research settings.

METHOD

This study investigated the factor structure and internal consistency reliability of the Illness Perceptions Questionnaire-Revised (IPQ-R) modified for MTBI in a sample of 147 adults recruited within 3 months of injury.

RESULTS

The results demonstrated a close replication of the original factor structure although there were notable exceptions likely to be specific to MTBI and potentially other acutely injured populations. Final scales showed good internal consistency although factors relating to causal attribution were less so.

CONCLUSION

The IPQ-R (MTBI) provides an acceptable measure of key components of injury perceptions after MTBI. Minor refinements appear required if this measure is to make a contribution to research and clinical practice in injury-based populations such as MTBI.

Diffusion tensor imaging of mild traumatic brain injury

Mild traumatic brain injury (mTBI) remains a challenge to accurately assess with conventional neuroimaging. Recent research holds out the promise that diffusion tensor imaging (DTI) can be used to predict recovery in mTBI patients. Unlike computed tomography or conventional magnetic resonance imaging, DTI is sensitive to microstructural axonal injury, the neuropathology that is thought to be most responsible for the persistent cognitive and behavioral impairments that often occur after mTBI. Through the use of newer DTI analysis techniques such as automated region of interest analysis, tract-based voxel-wise analysis, and quantitative tractography, researchers have shown that frontal and temporal association white matter pathways are most frequently damaged in mTBI and that the microstructural integrity of these tracts correlates with behavioral and cognitive measures. Future longitudinal DTI studies are needed to elucidate how symptoms and the microstructural pathology evolve over time. Moving forward, large-scale investigations will ascertain whether DTI can serve as a predictive imaging biomarker for long-term neurocognitive deficits after mTBI that would be of value for triaging patients to clinical trials of experimental cognitive enhancement therapies and rehabilitation methods, as well as for monitoring their response to these interventions.

Acute effects and recovery after sport-related concussion: a neurocognitive and quantitative brain electrical activity study

OBJECTIVE

To investigate the clinical utility and sensitivity of a portable, automatic, frontal quantitative electroencephalographic (QEEG) acquisition device currently in development in detecting abnormal brain electrical activity after sport-related concussion.

DESIGN

This was a prospective, non-randomized study of 396 high school and college football players, including cohorts of 28 athletes with concussion and 28 matched controls. All subjects underwent preseason baseline testing on measures of postconcussive symptoms, postural stability, and cognitive functioning, as well as QEEG. Clinical testing and QEEG were repeated on day of injury and days 8 and 45 postinjury for the concussion and control groups.

MAIN OUTCOMES AND RESULTS

The injured group reported more significant postconcussive symptoms during the first 3 days postinjury, which resolved by days 5 and 8. Injured subjects also performed poorer than controls on neurocognitive testing on the day of injury, but no differences were evident on day 8 or day 45. QEEG studies revealed significant abnormalities in electrical brain activity in the injured group on day of injury and day 8 postinjury, but not on day 45.

CONCLUSIONS

Results from the current study on clinical recovery after sport-related concussion are consistent with early reports indicating a typical course of full recovery in symptoms and cognitive dysfunction within the first week of injury. QEEG results, however, suggest that the duration of physiological recovery after concussion may extend longer than observed clinical recovery. Further study is required to replicate and extend these findings in a larger clinical sample, and further demonstrate the utility of QEEG as a marker of recovery after sport-related concussion.

Concussion or mild traumatic brain injury: parents appreciate the nuances of nosology

We explored whether parents of our pediatric patients valued the diagnostic terms "concussion," "minor traumatic brain injury," and "mild traumatic brain injury" as equivalent or nonequivalent. 1734 of 2304 parents attending a regional pediatric emergency department completed a brief questionnaire assessing the equivalence or nonequivalence of the diagnostic terms "concussion," "minor traumatic brain injury," and "mild traumatic brain injury" in a pairwise fashion. Many parents viewed these diagnostic terms as equivalent, when assessed side by side. For those who considered these diagnostic terms nonequivalent, concussion was regarded as considerably "better" (or less "worse") than minor traumatic brain injury (P < 0.001, χ(2) test) or mild traumatic brain injury (P < 0.001, χ(2) test). A moderate degree of variability was evident in parent/guardian responses. As a group, parents reported that concussion or mild/minor traumatic brain injuries are valued equivalently. However, many parents considered them different, with concussion reflecting a "better" (or less "worse") outcome.

Epidemiology of postconcussion syndrome in pediatric mild traumatic brain injury

BACKGROUND

Much disagreement exists as to whether postconcussion syndrome (PCS) is attributable to brain injury or to other factors such as trauma alone, preexisting psychosocial problems, or medicolegal issues. We investigated the epidemiology and natural history of PCS symptoms in a large cohort of children with a mild traumatic brain injury (mTBI) and compared them with children with an extracranial injury (ECI).

METHODS

This investigation was a prospective, consecutive controlled-cohort study of 670 children who presented to a tertiary referral emergency department with mTBI and 197 children who presented with ECI. For all participants, data were collected by use of a telephone interview of a parent 7 to 10 days after injury. If a change from preinjury symptoms was reported by a parent, follow-up continued monthly until symptom resolution. Outcomes were measured by using the Post Concussion Symptom Inventory, Rivermead Postconcussion Symptom Questionnaire, Brief Symptom Inventory, and Family Assessment Device.

RESULTS

There was a significant difference between the mTBI and ECI groups in their survival curves for time to symptom resolution (log rank [Mantel-Cox] 11.15, P < .001). Three months after injury, 11% of the children in the mTBI group were symptomatic (13.7% of children older than 6 years) compared with 0.5% of the children in the ECI group. The prevalence of persistent symptoms at 1 year was 2.3% in the mTBI group and 0.01% in the ECI group. Family functioning and maternal adjustment did not differ between groups.

CONCLUSIONS

Among school-aged children with mTBI, 13.7% were symptomatic 3 months after injury. This finding could not be explained by trauma, family dysfunction, or maternal psychological adjustment. The results of this study provide clear support for the validity of the diagnosis of PCS in children.

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.

Sex differences in the long-term neuropsychological outcome of mild traumatic brain injury

PRIMARY OBJECTIVE

To investigate possible sex differences in neuropsychological functioning among patients following mild traumatic brain injury (TBI).

METHODS AND PROCEDURES

Retrospective records analysis of the neuropsychological test results of 102 participants with head injury, including 62 males and 40 females.

MAIN OUTCOME AND RESULTS

A multivariate analysis of variance indicated that females and males performed similarly on neuropsychological tests, on average, approximately 2 years after minor head trauma. A sex-by-age interaction effect was found on the Category and Trail Making A Tests, with a pattern similar to those obtained in a previous research.

CONCLUSIONS

Although past research has found that females develop more TBI-related neuropsychological deficits than males in the immediate post-injury period, the present study found that, overall, sex differences in the performance of patients with mild TBI on a variety of neuropsychological tests were insignificant. More investigation into the sex-by-age interaction effect appears warranted.

Chronic impairment of prospective memory after mild traumatic brain injury

Prospective memory (PM), the ability to recall future intentions, is crucial for independent living. Impairment of PM is a common complaint following head injury and is a significant impediment to good recovery, yet no studies have explored PM in mild traumatic brain injury (mTBI). In this study, prospective memory was examined in 31 mTBI patients and matched controls within a month of injury and 3 months after. mTBI patients performed more poorly than controls on the MIST task (Raskin, 2004) within the first month following injury, indicating that PM impairment is part of the acute cognitive sequelae of mTBI. These problems persisted beyond 3 months post-injury, suggesting that PM may be a sensitive indicator of cerebral compromise in mild brain injuries.

Bomb blast, mild traumatic brain injury and psychiatric morbidity: a review

Traumatic brain injury (TBI) arising from blast exposure during war is common, and frequently complicated by psychiatric morbidity. There is controversy as to whether mild TBI from blast is different from other causes of mild TBI. Anxiety and affective disorders such as Post-traumatic Stress Disorder (PTSD) and depression are common accompaniments of blast injury with a significant overlap in the diagnostic features of PTSD with post-concussive syndrome (PCS). This review focuses on this overlap and the effects of mild TBI due to bomb blast. Mild TBI may have been over diagnosed by late retrospective review of returned servicemen and women using imprecise criteria. There is therefore a requirement for clear and careful documentation by health professionals of a TBI due to bomb blast shortly after the event so that the diagnosis of TBI can be made with confidence. There is a need for the early recognition of symptoms of PCS, PTSD and depression and early multi-disciplinary interventions focussed on expected return to duties. There also needs to be a continued emphasis on the de-stigmatization of psychological conditions in military personnel returning from deployment.

Post concussion syndrome: the attraction of the psychological by the organic

Post concussion symptoms following mild traumatic brain injury are a difficult clinical state to conceptualise. The constellation of symptoms include those with an organic signature (and presumed organic aetiology), and those with overt psychological features. A seemingly trivial head injury may result in enduring symptoms. The validity of post concussion syndrome (PCS) has been the focus of much medico-legal debate, as has its cause. Whether PCS is 'neurogenic' or 'psychogenic' in aetiology remains contestable. Babinski, in 1918, hypothesised that an organic factor initiated the symptoms of the disorder now known as PCS, and that this acted as a 'bait', or attractor, for pre-existing and post-injury psychological influences. This hypothesis, which has been neither proven nor disproven over the subsequent nearly one hundred years, deserves reconsideration for it is an appealing model of PCS.

Auditory orienting and inhibition of return in mild traumatic brain injury: a FMRI study

The semiacute phase of mild traumatic brain injury (mTBI) is associated with deficits in the cognitive domains of attention, memory, and executive function, which previous work suggests may be related to a specific deficit in disengaging attentional focus. However, to date, there have only been a few studies that have employed dynamic imaging techniques to investigate the potential neurological basis of these cognitive deficits during the semiacute stage of injury. Therefore, event-related functional magnetic resonance imaging was used to investigate the neurological correlates of attentional dysfunction in a clinically homogeneous sample of 16 patients with mTBI during the semiacute phase of injury (<3 weeks). Behaviorally, patients with mTBI exhibited deficits in disengaging and reorienting auditory attention following invalid cues as well as a failure to inhibit attentional allocation to a cued spatial location compared to a group of matched controls. Accordingly, patients with mTBI also exhibited hypoactivation within thalamus, striatum, midbrain nuclei, and cerebellum across all trials as well as hypoactivation in the right posterior parietal cortex, presupplementary motor area, bilateral frontal eye fields, and right ventrolateral prefrontal cortex during attentional disengagement. Finally, the hemodynamic response within several regions of the attentional network predicted response times better for controls than for patients with mTBI. These objective neurological findings represent a potential biomarker for the behavioral deficits in spatial attention that characterize the initial recovery phase of mTBI.

Giving context to post-deployment post-concussive-like symptoms: blast-related potential mild traumatic brain injury and comorbidities

In the military and Veterans Administration systems, individuals with potential MTBI are presenting with symptoms in excess of what would be expected based on initial injury characteristics and/or at unexpected time periods based on current research findings. This article investigates factors that might account for the discrepancy between current research expectations and some occurrences in clinical practice. The physics of blast waves, as well as animal and human research, relevant to explosions are reviewed. Additional factors that occur within the military blast exposure milieu are also explored because the context in which an injury occurs can potentially impact symptom severity and course of recovery. Differential diagnoses, iatrogenic illness, diagnosis threat, and symptom embellishment are also considered.

The Wechsler Adult Intelligence Scale—III and Malingering in Traumatic Brain Injury

A known-groups design was used to determine the classification accuracy of Wechsler Adult Intelligence Scale—III (WAIS-III) variables in detecting malingered neurocognitive dysfunction (MND) in traumatic brain injury (TBI). TBI patients were classified into the following groups: (a) mild TBI not-MND ( n = 26), (b) mild TBI MND ( n = 31), and (c) moderate/severe (M/S) TBI not-MND ( n = 26). A sample of 80 general clinical patients was used for comparison. Verbal IQ, Verbal Comprehension Index, and Working Memory Index detected approximately 25% of malingerers with a false positive (FP) error rate of approximately 5% in the mild TBI group. Comparable FP rates were obtained in M/S TBI. FP rates for Performance IQ, Perceptual Organization Index, and Processing Speed Index were acceptable in mild TBI but too high in M/S TBI. Previously studied specialized indicators (Vocabulary minus Digit Span and the Mittenberg formula) failed to differentiate malingerers from nonmalingerers. The clinical application of these findings is discussed.

Brain injury forces of moderate magnitude elicit the fencing response

INTRODUCTION

Traumatic brain injury is heterogeneous, both in its induction and ensuing neurological sequelae. In this way, medical care depends on accurately identifying the severity of injury-related forces. Clinically, injury severity is determined by a combination of the Glasgow Coma Scale, length of unconsciousness, posttraumatic amnesia, and persistence of neurological sequelae. In the laboratory, injury severity is gauged by the biomechanical forces and the acute suppression of neurological reflexes. The present communication describes and validates the "fencing response" as an overt indicator of injury force magnitude and midbrain localization to aid in injury identification and classification.

METHODS

Using YouTube, the Internet video database, videos were screened for head injury resulting in unconsciousness and documented for the fencing response. Adult male rats were subjected to midline fluid percussion brain injury at two severities, observed for acute neurological reflexes and the midbrain evaluated histopathologically.

RESULTS

Tonic posturing (fencing response) has been observed to precede convulsions in sports injuries at the moment of impact, where extension and flexion of opposite arms occurs despite body position or gravity. Of the 35 videos identified by an impact to the head and period of unconsciousness, 66% showed a fencing response at the moment of impact, regardless of the side of impact, without ensuing convulsion. Similarly, diffuse brain-injured rats demonstrate a fencing response upon injury at moderate (1.9 atm, 39/44 animals) but not mild severity (1.1 atm, 0/19 animals). The proximity of the lateral vestibular nucleus to the cerebellar peduncles makes it vulnerable to mechanical forces that initiate a neurochemical storm to elicit the neuromotor response, disrupt the blood-brain barrier, and alter the nuclear volume.

CONCLUSIONS

Therefore, the fencing response likely indicates neurological disturbance unique from convulsion associated with mechanical forces of moderate magnitude imparted on the midbrain and can assist in guiding medical care after injury.

Mild traumatic brain injury and posttraumatic stress disorder in returning veterans: perspectives from cognitive neuroscience

A significant proportion of military personnel deployed in support of Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) has been exposed to war-zone events potentially associated with traumatic brain injury (TBI) and posttraumatic stress disorder (PTSD). There has been significant controversy regarding healthcare policy for those service members and military veterans who returned from OEF/OIF deployments with both mild TBI and PTSD. There is currently little empirical evidence available to address these controversies. This review uses a cognitive neuroscience framework to address the potential impact of mild TBI on the development, course, and clinical management of PTSD. The field would benefit from research efforts that take into consideration the potential differential impact of mild TBI with versus without persistent cognitive deficits, longitudinal work examining the trajectory of PTSD symptoms when index trauma events involve TBI, randomized clinical trials designed to examine the impact of mild TBI on response to existing PTSD treatment interventions, and development and examination of potential treatment augmentation strategies.

Word Memory Test failure 23 times higher in mild brain injury than in parents seeking custody: The power of external incentives

PRIMARY OBJECTIVE

Motivation has an important influence on neuropsychological test performances. This study examined effort on the Word Memory Test (WMT) in groups with differing external incentives.

RESEARCH DESIGN

774 adults with Traumatic Brain Injury (TBI), tested as part of a Workers' Compensation, disability or personal injury claim stood to gain financially by appearing impaired on testing. In contrast, parents ordered by the Court to undergo a parenting assessment were highly motivated to do their best on cognitive tests because their goal was to regain custody of their children.

OUTCOMES AND RESULTS

Consistent with these assumptions, 98.3% of 118 parents seeking child custody passed the WMT effort subtests but in cases of mild TBI the pass rate on the WMT was only 60%. The WMT failure rate in the mild TBI sample was 23 times higher than in the group of parents seeking custody. WMT failure was twice as frequent in the mild TBI group than in those with more severe TBI. WMT failure was also much higher in adults with mild TBI than in children with significant impairment from various clinical conditions.

CONCLUSIONS

Such differences in failure rates on the WMT effort subtests cannot be explained by differences in cognitive skills but they are explainable by differences in external incentives. The findings support the recommendation that objective tests of effort should be used when evaluating cognitive impairment.

Determining long-term symptoms following mild traumatic brain injury: Method of interview affects self-report

PRIMARY OBJECTIVE

To examine the role played by two interviewing methods used (spontaneous response and suggested response) in the evaluation of long-term subjective post-mild traumatic brain injury (mTBI) symptoms.

RESEARCH DESIGN

Cohort study.

METHOD AND PROCEDURES

One hundred and eight adult participants were contacted for a follow-up telephone interview 12-36 months after their mTBI. The participants had to firstly spontaneously indicate symptoms that were still present following their mTBI (spontaneous response). Secondly, a list of symptoms was read to the participants and they had to say whether or not they were afflicted by each symptom (suggested response). Paired t-tests were performed to compare the means obtained using the two methods. The percentage of symptoms reported with the two interviewing methods were used to analyse symptom types.

EXPERIMENTAL INTERVENTION

None.

MAIN OUTCOMES AND RESULTS

Results show that participants reported significantly more symptoms and a given symptom when a list was read to the participants. Furthermore, neither the number of symptoms nor the type of symptoms reported is identical for the two interviewing methods.

CONCLUSION

The interviewing method used influences the number and type of long-term post-mTBI symptoms reported by participants.

The effects of mild traumatic brain injury on confrontation naming in adults

PRIMARY OBJECTIVE

To compare confrontation-naming in adults with MTBI to a group of normal adults under increased processing load conditions.

RESEARCH DESIGN

A randomized block, repeated measures design was used to examine confrontation-naming response latency and accuracy using a computerized experimental program.

METHODS AND PROCEDURES

Twenty-four adults having sustained a MTBI (aged 18-53) and 24 age-matched controls named pictures from three levels of vocabulary as quickly and accurately as possible. All MTBI participants were assessed with the Scales of Cognitive Ability for Traumatic Brain Injury (SCATBI) for later comparison.

MAIN OUTCOMES AND RESULTS

The results revealed a main effect of group ( p < or = 0.001) for the latency data and a group by vocabulary level interaction ( p = 0.043) for the accuracy data. No significant correlations were found between response latency and accuracy with performance on the SCATBI. Reaction time measures may reveal inefficiencies not tapped by traditional measures.

Correlates of invalid neuropsychological test performance after traumatic brain injury

PRIMARY OBJECTIVE

To investigate external correlates of invalid test performance after traumatic brain injury, as assessed by the California Verbal Learning Test - Second Edition (CVLT-II) and Word Memory Test (WMT).

RESEARCH DESIGN

Consecutive 2-year series of rehabilitation referrals with a diagnosis of traumatic brain injury (n = 87).

METHODS AND PROCEDURES

Logistic regression analysis was used to determine which demographic and neurological variables best differentiated those with vs. without actuarial CVLT-II or WMT evidence for invalid responding.

MAIN OUTCOMES AND RESULTS

Twenty-one participants (about 24%) performed in the invalid range. The combination of a premorbid psychiatric history with minimal or no coma was associated with an approximately four-fold increase in the likelihood of invalid performance.

CONCLUSIONS

Premorbid psychosocial complicating factors constitute a significant threat to validity of neuropsychological test results after (especially mild) traumatic brain injury. At the same time, care should be taken to not routinely assume that all persons with mild traumatic brain injury and premorbid psychiatric histories are simply malingering. The WMT appears to be a promising instrument for the purpose of identifying those cases where neuropsychological test results are confounded by factors not directly related to acquired cerebral impairment.

Executive dysfunction in traumatic brain injury: the effects of injury severity and effort on the Wisconsin Card Sorting Test

This study examined the persistent effects of traumatic brain injury (TBI) on Wisconsin Card Sorting Test (WCST) performance. Since poor effort can contaminate results in populations with incentive to perform poorly, performance validity was explicitly assessed and controlled for using multiple well-validated cognitive malingering indicators. Participants were 109 patients with mild TBI and 67 patients with moderate-to-severe TBI seen for neuropsychological evaluation at least one year post injury. Patients with diffuse neurological impairment and healthy controls were included for comparison. Results suggested a dose-response effect of TBI severity on WCST performance in patients providing good effort; the mild TBI group did not differ from controls while increased levels of impairment were observed in the moderate-to-severe TBI group. Effort during testing had a larger impact on WCST performance than mild or moderate-to-severe TBI. Clinical implications of these findings are discussed.

A new approach to predicting postconcussion syndrome after mild traumatic brain injury based upon eye movement function

Following on from our earlier findings of a close relationship between motor function and outcome after mild traumatic brain injury (mTBI), this study examined whether it might be possible to predict poor recovery in the form of postconcussion syndrome (PCS) based upon early eye and arm motor function. Within 1 week post-injury, we assessed 37 mTBI patients on measures of saccades, oculomotor smooth pursuit, upper-limb visuomotor function, neuropsychological status, and self-reported health condition. At 3 months, 8 patients met the criteria for PCS. Using discriminant function analyses, we examined whether this future PCS-group could be identified prospectively based on motor function, neuropsychological status, and self-reported health condition at 1 week post-injury. Early eye movement function was the most effective in distinguishing between PCS and non-PCS patients, achieving a sensitivity and specificity of 100% in the present sample. This was followed by self-reported early health condition (sensitivity: 87%, specificity: 97%), early upper-limb motor performance (87%, 97%), neuropsychological function (62%, 100%), and age, gender, education and clinical measures of trauma severity (37%, 87%). Leave-one-out validation analyses confirmed eye movements as the most robust discriminator (sensitivity: 62%, specificity: 97%). Assessment of eye movement function after mTBI may contribute to a prospective identification of patients who develop PCS, supporting the targeting of early health-care intervention.