Journal of neurotrauma
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Journal of neurotrauma · Nov 2010
Diffusion tensor imaging and fiber tractography of patients with cervical spinal cord injury.
To verify the usefulness of diffusion tensor imaging (DTI) and fiber tractography (FT) compared with routine magnetic resonance imaging (MRI) in patients with cervical spinal cord injury, and to clarify the relationship between motor and sensory impairments and DTI and FT parameters, we performed routine MRI and DTI on 10 patients with chronic cervical spinal cord injury and on 10 controls. Quantitative parameters of DTI, such as fractional anisotropy (FA) and apparent diffusion coefficient (ADC), were calculated for each cervical cord level. FT parameters of imaginary crossing fiber numbers were also determined at the C3 level, from C3-C6, and from C3-C7, as well as each connection rate. ⋯ In patients with cervical cord injury, abnormal cervical levels detected on routine MRI were not correlated with clinical findings and DTI parameters, but FA of DTI was correlated with motor function, as were imaginary crossing fiber numbers and connection rates of FT. Quantitative DTI and FT analyses were useful in the evaluation of patients with cervical spinal cord injury. The injured cervical spinal cord can be evaluated in more detail and more precisely using DTI and FT, for which findings are correlated with clinical findings such as neurological impairments.
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Journal of neurotrauma · Nov 2010
Nogo receptor deletion and multimodal exercise improve distinct aspects of recovery in cervical spinal cord injury.
We tested the ability of two plasticity-promoting approaches to enhance recovery in a mouse model of incomplete spinal cord injury (SCI). Genetically, we reduced myelin-mediated inhibition of neural plasticity through Nogo66-receptor (NgR) gene deletion. Behaviorally, we utilized a novel multimodal exercise training paradigm. ⋯ Thus either NgR gene deletion or exercise training benefits mice with mild cervical spinal injury. In this lesion model, the effects of NgR deletion and training were not synergistic for the tasks assessed. Further work is required to optimize the interaction between pharmacological and physical interventions for SCI.
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Journal of neurotrauma · Nov 2010
Post-traumatic hypoxia exacerbates brain tissue damage: analysis of axonal injury and glial responses.
Traumatic brain injury (TBI) resulting in poor neurological outcome is predominantly associated with diffuse brain damage and secondary hypoxic insults. Post-traumatic hypoxia is known to exacerbate primary brain injury; however, the underlying pathological mechanisms require further elucidation. Using a rat model of diffuse traumatic axonal injury (TAI) followed by a post-traumatic hypoxic insult, we characterized axonal pathology, macrophage/microglia accumulation, and astrocyte responses over 14 days. ⋯ Extensive microglia/macrophage accumulation detected with the CD68 antibody was maximal at 14 days post-injury in the corpus callosum (macrophages 157.5 ± 55.48; microglia 72.71 ± 20.75), and coincided with regions of axonal damage. Astrocytosis assessed with glial fibrillary acidic protein (GFAP) antibody was also abundant in the corpus callosum and maximal at 14 days, with a trend toward an increase in TAI + Hx animals (18.99 ± 2.45 versus 13.56 ± 0.81; p = 0.0617). This study demonstrates for the first time that a hypoxic insult following TAI perpetuates axonal pathology and cellular inflammation, which may account for the poor neurological outcomes seen in TBI patients who experience post-traumatic hypoxia.
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Journal of neurotrauma · Nov 2010
Post-traumatic hydrocephalus after decompressive craniectomy: an underestimated risk factor.
The incidence of post-traumatic hydrocephalus (PTH) has been reported to be 0.7-51.4%, and we have frequently observed the development of PTH in patients undergoing decompressive craniectomy (DC). For this reason we performed a retrospective review of a consecutive series of patients undergoing DC after traumatic brain injury (TBI). From January 2006 to December 2009, 41 patients underwent DC after closed head injury. ⋯ Patients with craniotomy whose superior limit was <25 mm from the midline had a markedly increased risk of developing hydrocephalus (OR = 17). Craniectomy with a superior limit too close to the midline can predispose patients undergoing DC to the development of hydrocephalus. We therefore suggest performing wide DCs with the superior limit >25 mm from the midline.
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Journal of neurotrauma · Nov 2010
Evaluation of a combined therapeutic regimen of 8-OH-DPAT and environmental enrichment after experimental traumatic brain injury.
When provided individually, both the serotonin (5-HT(1A))-receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) and environmental enrichment (EE) enhance behavioral outcome and reduce histopathology after experimental traumatic brain injury (TBI). The aim of this study was to determine whether combining these therapies would yield greater benefit than either used alone. Anesthetized adult male rats received a cortical impact or sham injury and then were randomly assigned to enriched or standard (STD) housing, where either 8-OH-DPAT (0.1 mg/kg) or vehicle (1.0 mL/kg) was administered intraperitoneally once daily for 3 weeks. ⋯ No statistical distinctions were revealed between the TBI + EE + 8-OH-DPAT and TBI + EE + vehicle groups in functional outcome or CA1/CA3 cell survival, but there were significantly more ChAT(+) cells in the former (p = 0.003). These data suggest that a combined therapeutic regimen of 8-OH-DPAT and EE reduces TBI-induced ChAT(+) cell loss, but does not enhance hippocampal cell survival or neurobehavioral performance beyond that of either treatment alone. The findings underscore the complexity of combinational therapies and of elucidating potential targets for TBI.