Journal of neurotrauma
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Journal of neurotrauma · Oct 2003
Comparative StudyEffects of daily versus weekly testing and pre-training on the assessment of neurologic impairment following diffuse traumatic brain injury in rats.
A number of test paradigms have been used to determine acute and chronic motor and cognitive deficits after experimental traumatic brain injury (TBI). Some involve daily testing of either trained or untrained animals whereas others utilize periodic testing over extended time periods. Which test paradigm is the most appropriate for the assessment of motor and cognitive deficits is, however, unclear. ⋯ Daily assessment promoted rapid functional recovery whereas weekly assessments did not significantly affect outcome in injured animals over the 4-week assessment period. Spontaneous exploratory activity was decreased after TBI and was not influenced by task exposure. These studies demonstrate that the functional assessment paradigm needs to be considered when quantifying functional deficits following diffuse TBI in rats.
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Journal of neurotrauma · Sep 2003
Comparative StudyCerebral perfusion pressure directed therapy following traumatic brain injury and hypotension in swine.
There is a paucity of studies, clinical and experimental, attesting to the benefit of cerebral perfusion pressure (CPP) directed pressor therapy following traumatic brain injury (TBI). The current study evaluates this therapy in a swine model of TBI and hypotension. Forty-five anesthetized and ventilated swine received TBI followed by a 45% blood volume bleed. ⋯ There was no difference in betaAPP immunoreactivity between the SAL and PHE groups (p > 0.05). In this swine model of TBI and hypotension, CPP directed pressor therapy improved brain oxygenation and maintained cerebro-vascular CO(2) reactivity. Brain edema was lower, but lung edema was greater, suggesting a higher propensity for pulmonary complications.
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Journal of neurotrauma · Sep 2003
Comparative StudySoluble cell adhesion molecule L1-Fc promotes locomotor recovery in rats after spinal cord injury.
Previous studies suggest that the cell adhesion molecule L1 promotes neurite growth by neutralizing white matter associated inhibitors of axonal growth. We made a soluble chimeric dimer by linking mouse L1 to human Fc. This L1-Fc construct (40 microg/mL) markedly facilitated neurite outgrowth, as well as neuronal adhesion to white matter on frozen sections of spinal cord. ⋯ However, the limited corticospinal tract growth across the injury site cannot account for the observed locomotor recovery. Thus, L1 may be stimulating growth of other motor tracts or protecting axons and neurons. More studies are required to elucidate the mechanisms of L1-Fc-induced locomotor recovery.
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Journal of neurotrauma · Aug 2003
Autonomic dysreflexia in acute spinal cord injury: an under-recognized clinical entity.
While autonomic dysreflexia (AD) is well recognized in the chronic stage of spinal cord injury (SCI) this potentially life-threatening complication has been only rarely documented in the acute phase (1 month) after SCI. Based on our clinical experience we hypothesized that AD is under-recognized in the acute phase of SCI. This study was undertaken to determine the incidence and clinical associations of early AD in our center. ⋯ Although numerous reports emphasize AD as a potential complication of chronic SCI, our study demonstrates that AD occurs in 5.7% of patients with acute SCI above T6. Patients with severe cervical SCI are particularly susceptible to the early onset of AD. Clinicians need to be aware and highly vigilant of the potential development of AD in the acute phase of SCI.
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Journal of neurotrauma · Aug 2003
Comparative StudyMetabolic changes in the vicinity of brain contusions: a proton magnetic resonance spectroscopy and histology study.
Proton MR spectroscopy (1H-MRS) has been previously used to monitor metabolic changes in areas of diffuse brain injury. We studied metabolism in the close vicinity of experimental traumatic brain contusions and remote on the contralateral side from 1h to 28d post-injury. Changes of creatine and phosphocreatine (Cr&PCr), N-acetylaspartate (NAA), choline (Cho), inositol (Ino), taurine (Tau), glutamate (Glu), and lactate (Lac) were assessed and compared to neuronal, glial and inflammatory changes in histology. ⋯ A partial contribution of lipids to this signal cannot be fully excluded. The contralateral side showed mild astroglial activation in histology, but no changes in 1H-MRS. The study demonstrates the feasibility of volume selective 1H-MRS using the LCModel (Linear Combination of Model in vitro spectra of metabolites solutions) to monitor metabolic changes close to focal traumatic lesions and suggests how metabolic alterations can be differentiated in cause.