Journal of neurotrauma
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Journal of neurotrauma · Dec 2010
Association of chronic vascular changes with functional outcome after traumatic brain injury in rats.
We tested the hypothesis that vascular remodeling in the cortex, hippocampus, and thalamus is associated with long-term functional recovery after traumatic brain injury (TBI). We induced TBI with lateral fluid-percussion (LFP) injury in adult rats. Animals were followed-up for 9 months, during which we tested motor performance using a neuroscore test, spatial learning and memory with a Morris water maze, and seizure susceptibility with a pentylenetetrazol (PTZ) test. ⋯ Chronic alterations in CBF could not be attributed to changes in vascular density. Association of thalamic hypervascularity to epileptogenesis warrants further studies. Finally, hippocampal hypoperfusion may predict later seizure susceptibility in the LFP injury model of TBI, which could be of value for pre-clinical antiepileptogenesis trials.
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Journal of neurotrauma · Dec 2010
Benefits of sports participation for executive function in disabled athletes.
We investigated the effect of sports activity on physically-disabled individuals using behavioral and electrophysiological techniques. Visual go/no-go discriminative and simple response tasks were used. Participants included 17 disabled athletes, 9 from open-skill (wheelchair basketball) and eight from closed-skill (swimming) sports, and 18 healthy non-athletes. ⋯ The late P3 component had longer latency and smaller amplitude in the disabled athletes only in the discriminative response task. The N2 component, which reflected inhibition/execution processing in the discriminative response task, was delayed and reduced in the swimmer group, but was comparable to healthy subjects in the basketball group. Our results show that (1) the ERP components related to perceptual processing, and late components related to executive processing, were impaired in disabled subjects; and (2) open-skill sports such as basketball may partially compensate for executive control impairment by fostering the stability of motor responses and favoring response flexibility.
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Journal of neurotrauma · Dec 2010
Interferon-γ decreases chondroitin sulfate proteoglycan expression and enhances hindlimb function after spinal cord injury in mice.
Glial cells, including astrocytes and macrophages/microglia, are thought to modulate pathological states following spinal cord injury (SCI). In the present study, we evaluated the therapeutic effects of interferon-γ (IFN-γ), which is one of the cytokines regulating glial function, in a mouse contusive SCI model. We found that intraperitoneal injection of IFN-γ significantly facilitated locomotor improvement following SCI. ⋯ In addition, IFN-γ treatment enhanced the number of serotonin-positive nerve fibers and myelinated nerve fibers around the lesion epicenter. We also found that glial cell line-derived neurotrophic factor (GDNF) and insulin-like growth factor-1 (IGF-1) were upregulated post-SCI following IFN-γ treatment. Our results indicate that IFN-γ exhibits therapeutic effects in mouse contusive SCI, presumably by reducing CSPG expression from reactive astrocytes and increasing the expression of neurotrophic factors.
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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
Increased survival and reinnervation of cervical motoneurons by riluzole after avulsion of the C7 ventral root.
Although adult motoneurons do not die if their axons are injured at some distance from the cell body, they are unable to survive injury caused by ventral root avulsion. Some of the injured motoneurons can be rescued if the ventral root is re-inserted into the spinal cord. Brachial plexus injuries that involve the complete or partial avulsion of one or more cervical ventral roots can be treated successfully only if satisfactory numbers of motoneurons remain alive following such an injury at the time of reconstructive surgery. ⋯ Much greater numbers of axons regenerated when reimplantation was followed by riluzole treatment (573 ± 9 SEM). These results show that injured adult motoneurons can be rescued by riluzole treatment, even if they cannot regenerate their axons. Reinnervation of the peripheral targets can also be further improved with riluzole treatment.