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Late CT findings in brain trauma: relationship to cognitive and behavioral sequelae and to vocational outcome.

OBJECTIVE: The purpose of this study was to determine the degree of correlation between cerebral atrophy observed on CT scans after severe blunt brain trauma and later neuropsychological status, as well as to evaluate the relative prognostic values of a number of indexes of cerebral atrophy. MATERIALS AND METHODS: The study group comprised 32 previously healthy men 18-65 years old who had severe blunt trauma of the brain (initial scores on Glasgow coma scale of 7 or less). Their cognitive and behavioral statuses were evaluated when the patients were discharged from the hospital, which occurred when the recovery process showed a plateau. Overall vocational status was evaluated 1 year after discharge. The clinical evaluation was performed by a multidisciplinary team. Multiple linear indexes derived from brain CT scans obtained about 3 months after injury in patients with blunt brain trauma were correlated with cognitive and behavioral sequelae of brain damage and with vocational placement, as evaluated by a rehabilitation team about 1 year after trauma. RESULTS: A high correlation was found between the width of the third ventricle and outcome. The prognostic value of the width of the third ventricle was superior to that of any other index studied, and it correlated best with late cognitive status (Spearman r = .57, p < .01). CONCLUSION: The width of the third ventricle is a useful prognostic index in cases of diffuse brain trauma. It indicates diencephalic atrophy, caused either by diffuse axonal injury or by hypoxia. It may indicate a role of diencephalic structures in higher cortical functions.

Adolescent↗

Global hypoxia per se is an unusual cause of axonal injury.

Irreversible hypoxic brain damage and axonal injury are present in over 90% of fatal blunt head injuries. Given the frequency of each, difficulties arise as to whether or not they are due to different mechanisms and, as such, can be separately recognised and quantified. Recent literature has raised the possible role of hypoxia in the formation of axonal bulbs. The present study of 17 cases of cardio-respiratory arrest, 12 of status epilepticus, 3 of carbon monoxide poisoning and 12 controls was designed to test the relationship between hypoxia and axonal injury and to test the hypothesis whether or not the two entities can be separated into primary and secondary forms of traumatic brain injury. Axonal damage was seen in 9/17 and 7/12 of the cases with cardiac arrest and status epilepticus, respectively, in most of whom there was also evidence of raised intracranial pressure (ICP). All 3 cases of carbon monoxide poisoning had evidence of white matter damage in keeping with the classical pattern of selective vulnerability. It is concluded that the great majority of axonal damage identified in cases dying after cardiac arrest and status epilepticus can be attributed to raised ICP and the vascular complications of internal herniation. However, in some cases, axonal damage was seen in the absence of an elevated ICP, although its amount and distribution were different from diffuse axonal injury. In many cases there was an increase in expression of neuronal beta amyloid precursor protein.

Adolescent↗

Cerebral correlates of disturbed executive function and memory in survivors of severe closed head injury: a SPECT study.

Thirty six patients in the chronic stage after severe closed head injury were examined with tests of executive function, memory, intelligence, and functional capacities in daily living. Correlations were sought between test results and Tc-99m-HMPAO uptake of frontal, temporal, and thalamic regions assessed by SPECT. Neither the number of significant correlation coefficients between memory tests and regional uptake nor that between temporal uptake and tests exceeded chance. For the remaining tests, correlations to thalamic regions were stronger than those to the frontal regions, and those to right brain regions stronger than those to homologous left brain regions. Relationships of thalamic isotope uptake to neuropsychological performance may reflect the impact of diffuse brain damage and particularly of diffuse axonal injury on mental capacities.

Adult↗

Maternal persistent vegetative state with successful fetal outcome.

A woman suffered from massive blunt injuries in a motor vehicle accident at a presumed 4 weeks' gestation, but she successfully carried the fetus for an additional 29 weeks. Premature labor began at 33 weeks' gestation and a live 1,890 g male was delivered. His development was normal for the 12-months postnatal follow-up period. The patient remained in a persistent vegetative state. Only 12 cases of severely brain-injured pregnant patients who delivered babies have been reported in English literature. Such patients need special maternal and fetal monitoring. As shown in our patient, successful fetal outcome could be obtained in a mother who suffered from hypovolemic shock and diffuse axonal injury, was treated with numerous medications from 4 weeks' gestation, and survived premature labor at 33 weeks' gestation in a persistent vegetative state. This report represents the longest interval from maternal vegetative state to obstetric delivery. From our case, it would seem that no clear limit exists that restricts the physician's ability to support a severely injured pregnant patient.

Adult↗

Recovery process of immediate prolonged posttraumatic coma following severe head injury without mass lesions.

The recovery process of immediate posttraumatic coma was investigated in 24 patients with severe head injury. The correlation between poor outcome in the recovery process and magnetic resonance (MR) imaging findings was analyzed. MR imaging was performed within the first 7 days for all patients. The recovery process was classified into phase 1 for recovery to moderately disabled and phase 2 to good recovery (GR) according to the Glasgow Outcome Scale. The median of phase 1 was 21.0 days. Four patients did not recover to GR and had poor outcome. Twenty patients recovered to GR. Thirteen patients had short phase 2 of under 10 days and seven patients had long phase 2 of over 60 days. All patients had abnormal lesions on MR imaging considered to be diffuse axonal injury. The number of lesions ranged from two to 10, with a mean of five. Lesions in the dorsal upper brainstem were significantly associated with poor outcome (p < 0.05). The combination of focal lesions in the callosal splenium and dorsal upper brainstem was most common in patients with poor outcome. Patients with long phase 2 had significantly more lesions than patients with short phase 2.

Adolescent↗

[Long-term follow-up MRI in children with craniocerebral trauma].

PURPOSE: A prospective study was initiated for the correlation of the findings in the initial cranial CT with the long-term follow-up MRI in children with severe head injury. Another aim was the evaluation of frequency and location of lesions, found only in MRI. METHODS: 70 children with severe head injury and initially performed pathological CCT were followed up (mean time 3 years) by MRI. RESULTS: 71% of the children had a pathological MRI. In 43% of the children with subdural bleeding could be found parenchymal lesions in the underlying cortex. All 15 children with epidural bleeding had unsuspicious findings at the former hematoma. All of the contusions were found as parenchymal residual lesions. 44% of the children had evidence of parenchymal lesions in the follow-up MRI initially and retrospectively not revealable. 16 lesions in the corpus callosum were only revealed by MRI. CONCLUSION: This study shows the higher sensitivity of magnetic resonance imaging in non-hemorrhagic parenchymal lesions and in "diffuse axonal injury". A MRI-examination is recommended in children with severe head injury, especially in patients with normal CCT and posttraumatic neurological deficits.

Adolescent↗

Cognitive test performances related to early and late computed tomography findings after closed-head injury.

Computed tomography (CT) findings from early (less than 24 hours) and late scan (6 months) after closed-head injury (CHI) were compared to cognitive test scores obtained on an average of 4 months after injury in a consecutive series of 53 patients. The presence of parenchymal lesion was associated with poor test results, indicating cognitive inflexibility and disinhibition of routine response tendencies in novel tasks. These deficits have previously been found to be related in particular to frontal-lobe dysfunction, but the present study did not support the hypothesis that frontal lesion is the principal cause of this impairment in CHI. Parenchymal lesions in the right and left hemisphere were associated with spatial and verbal deficits, respectively. Ventricular enlargement in the late CT was related to cognitive inefficiency, both being strongly associated with age. The results suggest that parenchymal lesion in the early CT is an indicator of diffuse axonal injury, which results in cognitive inflexibility during recovery.

Adolescent↗

Neuroanatomic correlates of CVLT-C performance following pediatric traumatic brain injury.

Traumatic brain injury (TBI) frequently results in memory problems, and the degree of memory impairment is related to injury severity and is commonly associated with lesions in frontal and temporal brain areas. This study examined the relationship among injury severity, brain lesions, and memory in children with moderate to severe TBI using Donders' (1999) 5-factor model of performance on the California Verbal Learning Test-Children's Version (CVLT-C). Seventy-six children underwent magnetic resonance imaging (MRI) scans 3 months post-TBI and testing 1 year post-TBI. Results showed injury severity (Glasgow Coma Scale) was not predictive of performance on 4 of the 5 factors. Volume of frontal and/or temporal brain lesions was significantly predictive of performance on 3 of the 5 factors. Unexpectedly, lesion volume outside these areas (extra-frontotemporal) was predictive of performance on all 5 factors. In contrast, Verbal IQ at 1 year was most strongly associated with preinjury factors (socioeconomic status and special education involvement), although extra-frontotemporal lesions also contributed to the variability in this measure. Results suggest that in children with moderate to severe TBI, extra-frontal/temporal lesions are predictive of memory outcome 1 year postinjury above and beyond initial severity or frontal/temporal contusions. This finding may relate to widespread diffuse axonal injury, which potentially disconnects brain circuits mediating memory following moderate to severe TBI.

Adolescent↗

Comprehensive predictions of outcome in closed head-injured patients. The development of prognostic equations.

A comprehensive diagnostic evaluation was administered to 162 closed head-injured patients within 1 to 21 days (mean, 7.5 days) after injury. Each evaluation consisted of (1) power spectral analyses of electroencephalogram (EEG) recorded from 19 scalp locations referenced to age-matched norms, (2) brainstem auditory evoked potentials, (3) computed tomography (CT)-scan, and (4) Glasgow Coma Score (GCS) at time of admission (GCS-A) and at time of EEG test (GCS-T). Functional outcome at one year following injury was assessed using the Rappaport Disability Rating Scale (DRS), which measures the level of disability in the six diagnostic categories of (1) eye opening, (2) best verbal response, (3) best motor response, (4) self-care ability for feeding, grooming, and toileting, (5) level of cognitive functioning, and (6) employability. The ability of the different diagnostic measures to predict outcome at one year following injury was assessed using stepwise discriminant analyses to identify patients in the extreme outcome categories of complete recovery versus death and multivariate regression analyses to predict patients with intermediate outcome scores. The best combination of predictor variables was EEG and GCS-T, which accounted for 74.6% of the variance in the multivariate regression analysis of intermediate outcome scores and 95.8% discriminant accuracy between good outcome and death. The best single predictors of outcome in both the discriminant analyses and the regression analyses were EEG coherence and phase. A gradient of prognostic strength of diagnostic measures was EEG phase greater than EEG coherence greater than GCS-T greater than CT-scan greater than EEG relative power. The value of EEG coherence and phase in the assessment of diffuse axonal injury was discussed.

Activities of Daily Living↗

Multiple immunostaining methods to detect traumatic axonal injury in the rat fluid-percussion brain injury model.

Immunohistochemistry using beta-amyloid precursor protein (APP) N-terminus antibodies is routinely used to detect traumatic axonal injury (TAI). The temporal and regional distributions of APP C- and N-terminus immunoreactivity were investigated in rats with experimental brain injury and compared to distribution of neurofilament (NF) immunoreactivity. Male Sprague-Dawley rats underwent right lateral fluid-percussion (FP) brain injury or sham injury. Six FP injury rats and two control rats were transcardially fixed with 10% formalin at 1, 6, 24, and 48 hours, and 1 and 2 weeks after injury and serial 6 microm-thick paraffin sections were prepared. At 6 hours after injury, APP C-terminus immunostaining labeled small neurons and axonal deposits in the injured parasagittal cortex, striatum, thalami, and dorsal medulla, whereas APP N-terminus and NF immunostaining showed few axonal deposits in the parasagittal cortex. At 24-48 hours post-injury, marked axonal damage, including axonal swelling and bulbs, was observed in the injured cerebral hemisphere, cerebellar white matter, and medulla. NF immunostaining was most sensitive for axonal damage in the injured deep cortical layers, cerebellum, and medulla. At 1-2 weeks after injury, APP N-terminus immunostaining mainly showed dot-like axonal profiles in the injured thalamus. APP C-terminus immunoreactivity may serve as an early marker of TAI, and the C-terminal fragments of APP may be involved in the evolution of TAI because C-terminal fragments of APP are neurotoxic and pro-apoptotic. Multiple immunostaining methods may be required to fully recognize the extent of TAI.

Amyloid beta-Protein Precursor↗

Management and outcome of severe head injuries in the Trent region 1985-90.

In a five year period, 39 children (29 boys, 10 girls) aged 2 months to 13 years (mean 7.8 years) were studied who had suffered a major head injury (29 road traffic accidents, six falls, and four non-accidental injury). The injury had been assessed clinically and by cranial computed tomography or cranial ultrasound (in a single baby of 2 months). Initial Glasgow coma scores for all subjects ranged from 3-11 (mean 5.5), intact survivors 5-11 (7.4), minor handicap 4-11 (6.1), major handicap 3-6 (4.3), fatalities 3-6 (4.1). All were treated with sedation, paralysis, hyperventilation (arterial carbon dioxide tension 3.0-3.5 kPa), intracranial pressure monitoring and moderate body surface hypothermia to 32 degrees C. Nine children died and 30 survived (nine intact, 13 minor disability, and eight major disability). The worst cerebral perfusion pressure was over 40 mm Hg in all but one survivor, and less than 40 mm Hg in seven of nine fatalities. Severe hypocapnia both in the first 24 hours and overall was correlated with poor outcomes (dead or major disability), as were bilateral contusions or diffuse axonal injury.

Adolescent↗

Outcome from severe head injury related to the type of intracranial lesion. A computerized tomography study.

The influence of the type of intracranial lesion on the final outcome in a consecutive series of 277 severely head-injured patients was analyzed. Patients were studied with computerized tomography (CT) and underwent continuous measurement of intracranial pressure. They received identical treatment according to a standardized protocol. Outcome of patients with either epidural hematoma (38 cases), subdural hematoma (56 cases), brain contusion (87 cases), or diffuse brain damage (96 cases) was rather heterogeneous, and serial CT scanning allowed the authors to outline eight consistent anatomical patterns in the whole series which have stronger prognostic significance than the four major lesion categories mentioned above. Patients with pure extracerebral hematoma (19 cases), single brain contusion (45 cases), general brain swelling (41 cases), and normal CT scans (28 cases) had a significantly better outcome than patients developing acute hemispheric swelling after operation for a large extracerebral hematoma (27 cases), patients with multiple brain contusion, either unilateral or bilateral (74 cases), and patients with diffuse axonal injury (43 cases). These anatomical patterns are interesting because, in addition to having clinical and physiopathological significance, they provide useful prognostic information and facilitate improved therapeutic decision-making in severely head-injured patients.

Adolescent↗

Does routine serial computed tomography of the head influence management of traumatic brain injury? A prospective evaluation.

BACKGROUND: Computed tomography (CT) of the head is the current standard for diagnosing intracranial pathology following blunt head trauma. It is common practice to repeat the head CT to evaluate any progression of injury. Recent retrospective reviews have challenged the need for serial head CT after traumatic brain injury (TBI). This study intends to prospectively examine the value of routine serial head CT after TBI. METHODS: Consecutive adult blunt trauma patients with an abnormal head CT admitted to an urban, Level I trauma center from January 2003 to September 2003 were prospectively studied. Variables collected included: initial head CT results, indication for repeat head CT (routine versus neurologic change), number and results of repeat head CT scans, and clinical interventions following repeat head CT. RESULTS: Over the 9-month period, there were 128 patients admitted with an abnormal head CT after sustaining blunt trauma. The 16 patients who died within 24 hours and the 12 patients who went directly to craniotomy were excluded. The remaining 100 patients make up the study population. Abnormal head CT findings were subarachnoid hemorrhage (47%), intraparenchymal hemorrhage (37%), subdural hematoma (28%), contusion (14%), epidural hematoma (11%), intraventricular hemorrhage (3%), and diffuse axonal injury (2%). Overall, 32 patients (32%) had only the admission head CT, while 68 patients (68%) underwent 90 repeat CT scans. Of the repeat head CT scans, 81 (90%) were performed on a routine basis without neurologic change. The remaining 9 (10%) were performed for a change in Glasgow Coma Scale (n = 5), change in intracranial pressure (n = 1), change in Glasgow Coma Scale and intracranial pressure (n = 1), change in pupil size (n = 1), or sudden appearance of a headache (n = 1). Three patients had their care altered after repeat head CT: two underwent craniotomy and one was started on barbiturate therapy. All three patients had their repeat head CT after neurologic change (decrease in Glasgow Coma Scale in 2 and increase in intracranial pressure in 1). CONCLUSIONS: Serial head CT is common after TBI. Most repeat head CT scans are performed on a routine basis without neurologic change. Few patients with TBI have their management altered after repeat head CT, and these patients have neurologic deterioration before the repeat head CT. The use of routine serial head CT in patients without neurologic deterioration is not supported by the findings of this study.

Adult↗

Brain damage in pigs produced by impact with a non-penetrating captive bolt pistol.

OBJECTIVE: To assess the effect of impact with a nonpenetrating captive bolt pistol in pigs by studying the resulting traumatic brain injury (TBI) and to compare the pathological changes with those found previously in the brains of sheep using a similar experimental paradigm. PROCEDURE: The unrestrained heads of six, anaesthetised, 7- to 8-week-old, Large White pigs were impacted in the temporal region with a nonpenetrating captive bolt pistol. Four hours postimpact, brains were perfusion-fixed with 4% paraformaldehyde. Coronal sections from six levels along the brain were cut and stained with haematoxylin and eosin and immunohistochemically for amyloid precursor protein, a sensitive marker of axonal injury (AI) in the brain after trauma. RESULTS: TBI in pigs was characterised only by very mild AI, whereas AI in sheep after captive bolt impact to the same head region was much more severe and widely distributed and often associated with vascular damage such as contusions, subarachnoid and intraparenchymal haemorrhage. CONCLUSIONS: TBI in pigs was much less severe than in sheep after non-penetrating mechanical impact of similar magnitude, confirming the importance of interspecies differences in determining an appropriate physical method of euthanasia.

Animal Welfare↗

[Lowered VIQ level following traumatic brain injury].

A patient with traumatic brain injury (TBI) is often associated with incidence of cognitive dysfunction as a sequela. We have conducted WAIS-R to 237 patients who were diagnosed as TBI at the Kanagawa Rehabilitation Hospital in order to assess their intellectual function. Twelve patients, whose VIQ being marked significantly lower than PIQ, were retrospectively analyzed in terms of their Functional Independence Measure (FIM), neuropsychological test results and lesions found in diagnostic images. In consequence, presence of a patient group whose VIQ level is significantly lowered due to the TBI sequela is recognized, in addition to a finding that trauma sites of cerebral contusion or other incidents are not necessarily corresponding to the results of neuropsychological test. Furthermore, based on an observation that those patients with lowered VIQ level are also associated with aggravation of PIQ 'digit symbol', Trail Making Test, or word fluency levels. This result was before similar with the result of "32 cases of DAI (diffuse axonal injury)" which authors reported, and it was guessed anew that the main factor of a cognitive dysfunction was damage on axon.

Activities of Daily Living↗

Cognitive impairment after traumatic brain injury: a functional magnetic resonance imaging study using the Stroop task.

The anterior cingulate cortex (ACC) plays a key role in cognition, motor function, and emotion processing. However, little is known about how traumatic brain injury (TBI) affects the ACC system. Our purpose was to compare, by functional magnetic resonance imaging (fMRI) studies, the patterns of cortical activation in patients with cognitive impairment after TBI and those of normal subjects. Cortical activation maps of 11 right-handed healthy control subjects and five TBI patients with cognitive impairment were recorded in response to a Stroop task during a block-designed fMRI experiment. Statistical parametric mapping (SPM99) was used for individual subjects and group analysis. In TBI patients and controls, cortical activation, found in similar regions of the frontal, occipital, and parietal lobes, resembled patterns of activation documented in previous neuroimaging studies of the Stroop task in healthy controls. However, the TBI patients showed a relative decrease in ACC activity compared with the controls. Cognitive impairment in TBI patients seems to be associated with alterations in functional cerebral activity, especially less activation of the ACC. These changes are probably the result of destruction of neural networks after diffuse axonal injury and may reflect cortical disinhibition attributable to disconnection or compensation for an inefficient cognitive process.

Adult↗

Validation of a closed head injury model for use in long-term studies.

To study pharmacotherapy of traumatic brain injury in rats, a modified closed head injury model was used that expresses clinically relevant features including intracranial hypertension and morphological alterations. Long-term survival under ethically acceptable conditions would greatly improve its clinical relevance. To ensure this goal with great reproducibility, the experimental protocol was adapted, in particular the impact-acceleration kinetics. Variations in impact-acceleration conditions were obtained by modifying the stiffness of the impact site and changing the height of a 400 g weight dropped from 51.5 to 31.5 cm (51.5/400; 31.5/400). Impact and acceleration were measured with a force sensor incorporated in a rigid dummy-rat and an accelerometer mounted on the platform onto which the animals are positioned. Significant correlation was shown between impact and acceleration. Accelerations obtained in rats were significantly lower than those in the dummy. Unlike the 51.5/400 group, in the 31.5/400 group no mortality or cranial fractures were observed. In both groups intracranial pressure rose to pathological values immediately after trauma and remained elevated longer than 24 h. Diffuse axonal injury developed in all groups and remained present for at least 7 days. By reducing the impact-acceleration conditions, post-traumatic complications were diminished, while the clinically important features were maintained.

Acceleration↗

Altered brain activation during cognitive control in patients with moderate to severe traumatic brain injury.

BACKGROUND: Persistent deficits in cognitive control have been documented following traumatic brain injury (TBI) but are inconsistently related to the presence and location of focal lesions. OBJECTIVE: Functional magnetic resonance imaging (fMRI) was used to examine brain activation during a cognitive control task in patients with moderate to severe TBI or orthopedic injury (OI). METHODS: Fourteen TBI patients and 10 OI patients underwent fMRI at 3 months postinjury using a stimulus-response compatibility task in which response accuracy and reaction time were measured. Performance between the groups was equated by individually adjusting the amount of training. Groups did not differ in age, gender, or education. RESULTS: Brain activation during stimulus-response incompatibility was greater in TBI patients than in OI patients within the cingulate, medial frontal, middle frontal, and superior frontal gyri. However, the positive regression of activation with response accuracy during stimulus-response incompatibility indicated a stronger relationship for OI patients than the TBI group within the anterior cingulate gyrus, medial frontal, and parietal regions, as well as deep brain structures (eg, brainstem). The number of focal lesions within either the whole brain or within prefrontal areas was not related to brain activation, but there was a relationship between activation and TBI severity. CONCLUSIONS: These findings suggest that neural networks mediating cognitive control are altered after moderate to severe TBI, possibly as a result of diffuse axonal injury, and that the typical relationship of brain activation to performance is disrupted.

Adolescent↗