Journal of neurotrauma
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Journal of neurotrauma · Sep 2010
Randomized Controlled Trial Comparative StudyHow mild traumatic brain injury may affect declarative memory performance in the post-acute stage.
Memory deficits are among the most frequently reported sequelae of mild traumatic brain injury (MTBI), especially early after injury. To date, these cognitive deficits remain poorly understood, as in most patients the brain is macroscopically intact. To identify the mechanism by which MTBI causes declarative memory impairments, we probed the functionality of the medial temporal lobe (MTL) and the prefrontal cortex (PFC), within 6 weeks after injury in 43 patients from a consecutive cohort, and matched healthy controls. ⋯ In contrast, no difference in prefrontal activation was found between patients and controls, nor was there a relation with injury severity. On a behavioral level, injury severity was inversely related to declarative memory performance. In all, these findings suggest that reduced medial temporal functionality may contribute to poorer declarative memory performance in the post-acute stage of MTBI, especially in patients with longer post-traumatic amnesia.
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Journal of neurotrauma · Sep 2010
Comparative StudyCare of rats with complete high-thoracic spinal cord injury.
The complications of spinal cord injury (SCI) increase in number and severity with the level of injury. A recent survey of SCI researchers reveals that animal models of high SCI are essential. Despite this consensus, most laboratories continue to work with mid- or low-thoracic SCI. ⋯ Here we provide details of our animal care procedures, including acclimatization, housing, diet, antibiotic prophylaxis, surgical procedures, post-operative monitoring, and prevention of complications. In our laboratory, this comprehensive approach consistently produces good outcomes following T3 complete transection SCI: using body weight as an objective indicator of animal health, we have found that our rats typically return to pre-operative weights within 10 days of T3 complete SCI. It is our hope that the information provided here will improve care of experimental animals, and facilitate adoption of models that directly address the complications associated with higher level injuries.
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Journal of neurotrauma · Sep 2010
Comparative StudyBelow level central pain induced by discrete dorsal spinal cord injury.
Central neuropathic pain occurs with multiple sclerosis, stroke, and spinal cord injury (SCI). Models of SCI are commonly used to study central neuropathic pain and are excellent at modeling gross physiological changes. Our goal was to develop a rat model of central neuropathic pain by traumatizing a discrete region of the dorsal spinal cord, thereby avoiding issues including paralysis, urinary tract infection, and autotomy. ⋯ Avulsion induced below-level allodynia that was more robust and enduring than that seen after rhizotomy. This, plus the lack of direct spinal cord damage associated with rhizotomy, suggests that avulsion is not synonymous with rhizotomy, and that avulsion (but not rhizotomy) is a model of central neuropathic pain. The new model described here is the first to use discrete dorsal horn damage by dorsal root avulsion to create below-level bilateral central neuropathic pain.
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Journal of neurotrauma · Sep 2010
Comparative StudyHippocampal θ dysfunction after lateral fluid percussion injury.
Chronic memory deficits are a major cause of morbidity following traumatic brain injury (TBI). In the rat, the hippocampal theta rhythm is a well-studied correlate of memory function. This study sought to investigate disturbances in hippocampal theta rhythm following lateral fluid percussion injury in the rat. ⋯ Further, injured rats were less likely to develop a spatial strategy for Barnes maze navigation compared to control rats. In conclusion, rats sustaining lateral fluid percussion injury demonstrated deficits in hippocampal theta activity. These deficits may contribute to the underlying memory problems seen in chronic TBI.
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Journal of neurotrauma · Sep 2010
Comparative StudyNeuroprotective effects of hyperbaric oxygen treatment on traumatic brain injury in the rat.
This study was designed to evaluate the potential benefits of hyperbaric oxygen (HBO) in the treatment of traumatic brain injury (TBI). The right cerebral cortex of rats was injured by the impact of a 20-g object dropped from a predetermined height. The rats received HBO treatment at 3 ATA for 60 min after TBI. ⋯ Although multiple treatments started at 48 h significantly improved neurological behaviors and reduced brain injury, the overall beneficial effects were substantially weaker than those seen after a single treatment at 6 h. These results suggest that: (1) HBO treatment could alleviate brain damage after TBI; (2) a single treatment with HBO has a time limitation of 12 h post-TBI; and (3) multiple HBO treatments have the possibility to extend the post-TBI delivery time window. Therefore, our results clearly suggest the validity of HBO therapy for the treatment of TBI.