Journal of neurotrauma
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Journal of neurotrauma · Jan 2011
Electrocortical pathology in a rat model of penetrating ballistic-like brain injury.
Traumatic brain injury (TBI) causes severe disruption of cerebral electrical activity and electroencephalography (EEG) is emerging as a standard tool to monitor TBI patients in the acute period of risk for secondary injuries. However, animal studies of EEG pathology in the context of TBI are surprisingly sparse, largely because of the lack of real-time continuous EEG (cEEG) monitoring in animal TBI models. Here, we performed long-term EEG monitoring to study nonconvulsive seizures (NCS), periodic epileptiform discharges (PED), and EEG power spectra following three injury severity levels in a rat model of penetrating ballistic-like brain injury (PBBI). ⋯ In contrast, decreases in higher frequency power (i.e., 30-35 Hz) remained depressed throughout 14 days. This is the first long-term cEEG study of the acute injury phase in a rat model of severe TBI, demonstrating common occurrences of clinically observed electrocortical pathology, such as NCS, PED, and cortical slowing. These EEG pathologies may serve as critical care biomarkers of brain injury, and offer clinically relevant metrics for studying acute therapeutic interventions.
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Journal of neurotrauma · Dec 2010
Assessing spatial relationships between axonal integrity, regional brain volumes, and neuropsychological outcomes after traumatic axonal injury.
Diffuse traumatic axonal injury (TAI) is a type of traumatic brain injury (TBI) characterized predominantly by white matter damage. While TAI is associated with cerebral atrophy, the relationship between gray matter volumes and TAI of afferent or efferent axonal pathways remains unknown. Moreover, it is unclear if deficits in cognition are associated with post-traumatic brain volumes in particular regions. ⋯ For example, left and right hippocampal volumes correlated with FA in the fornix body (r = 0.600, p = 0.001; r = 0.714, p < 0.001, respectively). In addition, regional brain volumes were associated with deficits in corresponding neuropsychological domains. Our results suggest that TAI may be a primary mechanism of post-traumatic atrophy, and provide support for regional morphometry as a biomarker for cognitive outcome after injury.
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Journal of neurotrauma · Dec 2010
Focal neuronal damage in patients with neuropsychological impairment after diffuse traumatic brain injury: evaluation using ¹¹C-flumazenil positron emission tomography with statistical image analysis.
This study was conducted to identify the regional neuronal damage occurring in patients with neuropsychological impairment following diffuse traumatic brain injury (TBI) compared with normal control subjects. In addition, measures of the neuropsychological tests were correlated with regional ¹¹C-flumazenil (FMZ) binding potential (BP) reductions to clarify the relationship between cognitive impairment and regional neuronal damage. We performed ¹¹C-flumazenil positron emission tomography (FMZ-PET) studies using three-dimensional stereotactic surface projection (3D-SSP) statistical image analysis in eight diffuse axonal injury (DAI) patients (mean age 29.1 ± 11.1 years, range 19-46 years). ⋯ FIQ, verbal IQ (VIQ), and PIQ also negatively correlated with the BZR index in the left medial frontal gyrus. DAI uniformly induced neuronal damage in the medial frontal cortex and the thalamus, which may be related to underlying cognitive impairments in diffuse TBI patients. Future studies to confirm a common area of focal neuronal damage and a direct correlation with neuropsychological testing may validate the use of FMZ-PET for the functional diagnosis of neuropsychological impairments after TBI.
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Journal of neurotrauma · Dec 2010
The effect of spontaneous alterations in brain temperature on outcome: a prospective observational cohort study in patients with severe traumatic brain injury.
There are few prospective studies reporting the effect of spontaneous temperature changes on outcome after severe traumatic brain injury (TBI). Where studies have been conducted, results are based on systemic rather than brain temperature per se. However, body temperature is not a reliable surrogate for brain temperature. ⋯ After adjusting for other predictors of outcome, low brain temperature was independently associated with a worse outcome. Lower brain temperatures (below 37°C) are independently associated with a higher mortality rate after severe TBI. The results suggest that, contrary to current opinion, temperatures within the normal to moderate fever range during the acute post-TBI period do not impose an additional risk for a poor outcome after severe TBI.
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Journal of neurotrauma · Dec 2010
Combining coma score and serum biomarker levels to predict unfavorable outcome following childhood brain trauma.
This study aims to determine if pairing the Glasgow Coma Scale (GCS) with serum biomarker levels may achieve higher outcome predictive values than using either the GCS or biomarker levels alone in childhood brain trauma. Twenty-eight critically ill children with isolated accidental brain trauma were studied in a prospective observational study. The GCS was recorded at various time points post injury. ⋯ This high degree of outcome predictability was also achieved by pairing the GCS with a single biomarker level. The most pronounced improvement in outcome prediction was observed by pairing the post-resuscitation summated GCS with the day-1 serum IL-8 level, which increased the AUC from 0.78 to 0.98 and the sensitivity and specificity from 75% to 100% and 96% respectively. Paired combinations of the GCS and serum biomarker levels greatly enhanced the accuracy of post-traumatic unfavorable outcome prediction than may be achieved using either the GCS or individual biomarker levels alone.