Day of injury CT scan as an index to pre-injury brain morphology

Evolution of Severe Closed Head Injury: Assessing Ventricular Volume and Behavioral Measures at 30 and 90 Days Post-Injury

Background: Assessing functional outcomes in Severe Closed Head Injury (SCHI) is complex due to brain parenchymal changes. This study examines the Ventricles to Intracranial Volume Ratio (VBR) as a metric for these changes and its correlation with behavioral scales. Methods: Thirty-one SCHI patients were included. VBR was derived from CT scans at 3, 30, and 90 days post-injury and compared with Levels of Cognitive Functioning (LCF), Disability Rating Scale (DRS), and Early Rehabilitation Barthel Index (ERBI) assessments at 30 and 90 days. Results: Ten patients were excluded post-decompressive craniectomy or ventriculoperitoneal shunt. Findings indicated a VBR decrease at 3 days, suggesting acute phase compression, followed by an increase from 30 to 90 days, indicative of post-acute brain atrophy. VBR correlated positively with the Marshall score in the initial 72 h, positioning it as an early indicator of subsequent brain atrophy. Nevertheless, in contrast to the Marshall score, VBR had stronger associations with DRS and ERBI at 90 days. Conclusions: VBR, alongside behavioral assessments, presents a robust framework for evaluating SCHI progression. It supports early functional outcome correlations informing therapeutic approaches. VBR's reliability underscores its utility in neurorehabilitation for ongoing SCHI assessment and aiding clinical decisions.

EphB3 interacts with initiator caspases and FHL-2 to activate dependence receptor cell death in oligodendrocytes after brain injury

Clinical trials examining neuroprotective strategies after brain injury, including those targeting cell death mechanisms, have been underwhelming. This may be in part due to an incomplete understanding of the signalling mechanisms that induce cell death after traumatic brain injury. The recent identification of a new family of death receptors that initiate pro-cell death signals in the absence of their ligand, called dependence receptors, provides new insight into the factors that contribute to brain injury. Here, we show that blocking the dependence receptor signalling of EphB3 improves oligodendrocyte cell survival in a murine controlled cortical impact injury model, which leads to improved myelin sparing, axonal conductance and behavioural recovery. EphB3 also functions as a cysteine-aspartic protease substrate, where the recruitment of injury-dependent adaptor protein Dral/FHL-2 together with capsase-8 or -9 leads to EphB3 cleavage to initiate cell death signals in murine and human traumatic brain-injured patients, supporting a conserved mechanism of cell death. These pro-apoptotic responses can be blocked via exogenous ephrinB3 ligand administration leading to improved oligodendrocyte survival. In short, our findings identify a novel mechanism of oligodendrocyte cell death in the traumatically injured brain that may reflect an important neuroprotective strategy in patients.

A population-based study on the influence of brain atrophy on 20-year survival after age 85

BACKGROUND

Individuals aged 80 years and older is the fastest growing segment of the population worldwide. To understand the biology behind increasing longevity, it is important to examine factors related to survival in this age group. The relationship between brain atrophy and survival after age 85 remains unclear.

METHODS

A population-based sample (n = 239) had head CT scans at age 85 and was then followed until death. Cortical atrophy and ventricular size were assessed. Statistical analyses included Cox proportional hazards models with time to death as the outcome and considering a large number of possible confounders, including baseline cognitive function, incident dementia, and somatic disorders.

RESULTS

Mean survival time (±SD) was 5.0 ± 3.6 years (range 0.10-19.8 years). Decreased survival was associated with temporal, and frontal atrophy, sylvian fissure width and a number of ventricular measures after adjustment for potential confounders. In participants without dementia at baseline (n = 135), decreased survival was associated with temporal lobe atrophy and bifrontal ratio. In those with dementia (n = 104), decreased survival was associated with third ventricle width, cella media ratio, and ventricle-to-brain and ventricle-to-cranial ratio.

CONCLUSIONS

Several indices of brain atrophy were related to decreased survival after age 85, regardless of dementia status. Brain atrophy is rarely mentioned as a significant indicator of survival in the elderly, independent of traditional predictors such as cardiovascular disease or cancer. The biology behind the influence of brain atrophy on survival needs to be further scrutinized.

Head size may modify the impact of white matter lesions on dementia

We aimed to examine whether total intracranial volume (TICV), a marker of premorbid brain size, modified the impact of the apolipoprotein E (apoE) e4 phenotype and ischemic white matter lesions (WMLs) on odds for dementia. The study comprised a population-based sample of 104 demented and 135 nondemented 85-year-olds, and included physical and neuropsychiatric examinations, and head computerized tomography (CT). Dementia disorders were defined according to standard criteria. TICV and WMLs were rated on computerized tomography. Using the highest group as reference, the risk for dementia, Alzheimer's disease (AD), and vascular dementia (VaD) was increased in those with the smallest half, tertile, and quartile of TICV. Smaller TICV increased the odds of dementia, Alzheimer's disease, and vascular dementia in participants with WMLs. WMLs were not associated with increased odds of dementia in those with the largest TICV. The interaction term WMLs*TICV was also significant. TICV did not modify the odds of dementia in those with the apolipoprotein e4 phenotype. Our results suggest that the impact of brain pathology on the risk of dementia is modified by premorbid brain size.

Post-traumatic headache: is it for real? Crossfire debates on headache: pro

Mild traumatic brain injury is very common in Western societies, affecting approximately 1.8 million individuals in the USA. Even though between 30% and 90% of patients develop post-traumatic headache, post-traumatic headache remains a very controversial disorder. Particularly when it comes to chronic post-traumatic headache following mild closed head injury and headache attributed to whiplash injury. Some experts are disputing its existence as a genuine disorder. Indistinct disease classification, unresolved pathophysiological mechanism, and the role of accident-related legal issues further fuel this controversy. The complex combination of pain and neuropsychological symptoms needs further research in understanding the underlying pathophysiological mechanisms associated with the acute headache following trauma but more so the mechanisms associated with the development of chronic pain in some patients. Investigators should refrain from oversimplifying these complex mechanisms as hysteric exaggeration of everyday complains and from implying greed as motivation for this potentially very disabling disease.

Post-traumatic headache

Post-traumatic headache (PTH) is a very controversial disorder, particularly when it comes to chronic PTH following mild closed head injury and headache attributed to whiplash injury. Nevertheless, mild traumatic brain injury is very common in Western societies, affecting approximately 1.8 million individuals in the USA. Between 30 and 90% of patients develop PTH. Generally, this headache resolves within the first 3 weeks after the accident without any specific therapy or long-term complications but in a minority of patients chronic PTH develops and can be associated with serious neurological and neuropsychological deficits. Sufficient psychological or neurobiological markers for PTH do not exist, thus treatment can be very challenging and should always be multidisciplinary, even in the early stages of disease, to make every reasonable effort in preventing the development of chronic pain.

Brain atrophy and cognitive impairment in survivors of acute respiratory distress syndrome

PRIMARY OBJECTIVES

Acute Respiratory Distress Syndrome (ARDS) is characterized by severe acute lung injury, hypoxemia and is associated with neurological and cognitive impairments. This study assessed quantitative brain and ventricular volumes in survivors of ARDS with brain computed tomography (CT) scans compared to normal controls. It also compared the medical and cognitive outcome data of patients with ARDS with and without CT scans.

RESEARCH DESIGN

Observational cohort study.

METHODS

Sixty-six consecutive acute respiratory distress patients, of which 15 patients with ARDS underwent brain CT and 51 patients had no brain imaging. Brain CT scans from 15 survivors of ARDS were compared to age- and sex-matched normal controls. Clinical radiological findings and ventricular volumes, brain volume and generalized brain atrophy.

RESULTS

The patients with ARDS and brain imaging had cognitive impairments, significant brain atrophy, ventricular enlargement and 53% had atrophy or lesions by radiological report.

CONCLUSIONS

Clinicians need to be aware that ARDS can cause significant long-term brain-related morbidity manifest by brain atrophy, lesions and neurocognitive impairments.

MRI-based brain volumetry in chronic whiplash patients: no evidence for traumatic brain injury

INTRODUCTION

Cognitive complaints, such as poor concentration and memory deficits, are frequent after whiplash injury and play an important role in disability. The origin of these complaints is discussed controversially. Some authors postulate brain lesions as a consequence of whiplash injuries. Potential diffuse axonal injury (DAI) with subsequent atrophy of the brain and ventricular expansion is of particular interest as focal brain lesions have not been documented so far in whiplash injury.

OBJECTIVE

To investigate whether traumatic brain injury can be identified using a magnetic resonance (MR)-based quantitative analysis of normalized ventricle-brain ratios (VBR) in chronic whiplash patients with subjective cognitive impairment that cannot be objectively confirmed by neuropsychological testing.

MATERIALS AND METHODS

MR examination was performed in 21 patients with whiplash injury and symptom persistence for 9 months on average and in 18 matched healthy controls. Conventional MR imaging (MRI) was used to assess the volumes of grey and white matter and of ventricles. The normalized VBR was calculated.

RESULTS

The values of normalized VBR did not differ in whiplash patients when compared with that in healthy controls (F = 0.216, P = 0.645).

CONCLUSIONS

This study does not support loss of brain tissue following whiplash injury as measured by VBR. On this basis, traumatic brain injury with subsequent DAI does not seem to be the underlying mechanism for persistent concentration and memory deficits that are subjectively reported but not objectively verifiable as neuropsychological deficits.

Day-of-injury computerized tomography, rehabilitation status, and development of cerebral atrophy in persons with traumatic brain injury

OBJECTIVE

To compare day-of-injury (DOI) computerized tomography (CT) findings with acute injury severity markers, disability at acute hospital admission and discharge from inpatient rehabilitation, injury severity markers, and degree of postacute cerebral atrophy on magnetic resonance imaging (MRI).

DESIGN

Retrospective chart review of 240 consecutive traumatic brain injury (TBI) admissions (mean age 31.7 +/- 15.8 yrs) with moderate-to-severe initial brain injury. All DOI CT abnormalities were qualitatively rated. Disability was assessed using the Disability Rating Scale (DRS) and the FIM measure. In a representative subset, cerebral atrophy was determined by the ventricle-to-brain ratio (VBR) method and quantified from MRI scans 25 or more days postinjury.

RESULTS

CT classification resulted in nonsignificant differences in DRS and FIM ratings at the time of discharge from the rehabilitation unit, except in brainstem injury subjects who had significantly higher DRS and lower FIM scores at rehabilitation discharge. At 25 or more days postinjury, presence of any DOI CT abnormality was associated with larger VBR. Increased VBR, as an index of cerebral atrophy, was associated with worse rehabilitation discharge DRS and FIM ratings.

CONCLUSIONS

Other than brainstem injury, DOI CT findings relate poorly to rehabilitation outcome. Presence of DOI CT abnormalities were associated with the development of cerebral atrophy, which was associated with poorer rehabilitation discharge DRS and FIM scores.

Frontal lobes and attention: processes and networks, fractionation and integration

The frontal lobes (FL), are they a general adaptive global capacity processor, or a series of fractionated processes? Our lesion studies focusing on attention have demonstrated impairments in distinct processes due to pathology in different frontal regions, implying fractionation of the "supervisory system." However, when task demands are manipulated, it becomes evident that the frontal lobes are not just a series of independent processes. Increased complexity of task demands elicits greater involvement of frontal regions along a fixed network related to a general activation process. For some task demands, one or more anatomically distinct frontal processes may be recruited. In other conditions, there is a bottom-up nonfrontal/frontal network, with impairment noted maximally for the lesser task demands in the nonfrontal automatic processing regions, and then as task demands change, increased involvement of different frontal (more "strategic") regions, until it appears all frontal regions are involved. With other measures, the network is top-down, with impairment in the measure first noted in the frontal region and then, with changing task demands, involving a posterior region. Adaptability is not just a property of FL, it is the fluid recruitment of different processes anywhere in the brain as required by the current task.

Correlation of atrophy measures on MRI with neuropsychological sequelae in children and adolescents with traumatic brain injury

To examine the relationship between neuropsychological sequelae and atrophy parameters from magnetic resonance imaging (MRI) following paediatric moderate-to-severe traumatic brain injury (TBI), 19 head injured children and adolescents were studied at least 6 years after injury. Three-dimensional MRI scans were obtained. A semi-automatic computerized method was used to estimate ventricular volumes and the corpus callosum area. Tests of intellectual, memory, visuospatial, frontal lobe, and motor speed functioning were administered to all patients and to 19 matched normal control subjects. Patients' performance significantly differed from controls in general intellectual function, visual memory, visuospatial and frontal lobe tests. The corpus callosum area correlated strongly with several measures involving processing speed and visuospatial function. Ventricular enlargement was less related to neuropsychological outcome. In conclusion, quantitative measurement of the corpus callosum on MRI reflects neuropsychological outcome better than ventricular dilation in paediatric patients.

Brain imaging and behavioral outcome in traumatic brain injury

Brain imaging studies have become an essential diagnostic assessment procedure in evaluating the effects of traumatic brain injury (TBI). Such imaging studies provide a wealth of information about structural and functional deficits following TBI. But how pathologic changes identified by brain imaging methods relate to neurobehavioral outcome is not as well known. Thus, the focus of this article is on brain imaging findings and outcome following TBI. The article starts with an overview of current research dealing with the cellular pathology associated with TBI. Understanding the cellular elements of pathology permits extrapolation to what is observed with brain imaging. Next, this article reviews the relationship of brain imaging findings to underlying pathology and how that pathology relates to neurobehavioral outcome. The brain imaging techniques of magnetic resonance imaging, computerized tomography, and single photon emission computed tomography are reviewed. Various image analysis procedures, and how such findings relate to neuropsychological testing, are discussed. The importance of brain imaging in evaluating neurobehavioral deficits following brain injury is stressed.

Traumatic brain injury, alcohol and quantitative neuroimaging: preliminary findings

Magnetic resonance (MR) quantitative neuroimaging analysis was undertaken with a large group of normal (n = 197) and traumatically brain injured (TBI, n = 99) adults. Of the TBI subjects 18 patients were identified with a history of substance-related abuse (TBI/Abuse group). Both the TBI/ Abuse group and the remaining sample of TBI patients (n = 81, TBI/Non-abuse group) without a history of substance-related abuse differed significantly from the control group on most quantitative MR imaging analyses. The TBI/Abuse group displayed the greatest degree of atrophic change. However, the TBI/Abuse group had a significantly lower Glasgow Coma Scale (GCS) score, ostensibly suggesting that those with substance-related abuse suffered more severe brain injury than non-abuse TBI patients. When a subset (n = 18) of the TBI/Non-abuse group was matched by GCS, gender and age to the TBI/Abuse group, both groups differed significantly from the control group on most morphometric measures, but did not differ from one another. Results are discussed in terms of the potential adverse role that substance-related abuse, particularly alcohol, plays in the individual who sustains traumatic injury to the brain.

Trauma-induced degenerative changes in brain injury: a morphometric analysis of three patients with preinjury and postinjury MR scans

Three patients with pretraumatic and posttraumatic brain injury (TBI) MR imaging of the brain are presented. Two patients had moderate to severe injury, whereas the third patient sustained a mild injury. Using imaging software to conduct morphometric analyses, quantitative neuropathologic change was ascertained in each TBI patient. Each case was compared quantitatively to preinjury scans as well as to an age-matched control group. For the moderately to severely injured patients, extensive degenerative changes were found throughout the various cortical structures and the cerebellum, whereas most midbrain and brainstem measures did not demonstrate significant change. For these two patients, the most significant changes occurred within the ventricular system, where generalized ventricular dilation was observed post-TBI. In the mild case, no significant anatomic changes were evident. These case studies demonstrate the use of quantitative methods for examining the structural basis of TBI sequelae.

Diencephalic changes in traumatic brain injury: relationship to sensory perceptual function

Magnetic resonance (MR) imaging scans of 33 traumatically brain-injured (TBI) patients were compared quantitatively to MR scans of controls matched for age and gender. Quantitative estimates of thalamic, internal capsule, and third ventricle morphology were obtained in each TBI patient. Comparisons were made to normal control subjects and revealed significant reduction in thalamic volume with corresponding increase in third ventricle. Measurements of internal capsule reflected nonsignificant changes. Significant correlations were observed between sensory-perceptual functioning, as measured by the Reitan-Kløve Sensory-Perceptual Exam, and thalamic volume in TBI patients. A decrease in thalamic volume was associated with an increase in sensory-perceptual errors.

Neuropsychological outcome and quantitative image analysis of acute haemorrhage in traumatic brain injury: preliminary findings

The effect on neuropsychological outcome of the number of acute haemorrhages, lesion volume, and lesion location in traumatic brain injury (TBI) was evaluated. Haemorrhagic lesion volume was associated with severity of injury. However, the number of petechial haemorrhages was not reliably associated with any of the clinical outcome measures. Likewise, despite the use of detailed morphometric methods to quantify volume, the acute lesion size did not significantly relate to neuropsychological sequelae. Furthermore, brain quadrant localization methods did not enhance outcome prediction. These results are discussed in the context of acute lesion analysis contrasted with chronic TBI-induced neuropathological changes associated with neuropsychological outcome.