Journal of neurotrauma
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Journal of neurotrauma · Aug 2021
Comparative StudyCore Temperature Lability Predicts Sympathetic Interruption and Cognitive Performance during Heat Exposure in Persons with Spinal Cord Injuries.
Among persons with high spinal cord injury (Hi-SCI: > T5), changes in core body temperature (Tcore) and cognitive performance during heat exposure appear related to degree of sympathetic interruption. Twenty men with Hi-SCI (C4-T4, American Spinal Injury Association Impairment Scale [AIS] A-B) and 19 matched, able-bodied controls were acclimated to 27°C baseline (BL) before exposure to 35°C heat challenge (HC). Two groups, differentiated by increase in Tcore during HC, were identified: high responders (HR-SCI: ΔTcore ≥0.5°C; n = 13, C4-T2) and low responders (LR-SCI: ΔTcore <0.5°C; n = 7, C4-T4). ⋯ SRavg increased more in the control group (77.0 ± 52.5 nL/cm2/min) than in the HR-SCI group (15.5 ± 22.0 nL/cm2/min; p = 0.001). Only the HR-SCI group had significant increases in T-Scores of Stroop Word (7.5 ± 4.4; p < 0.001), WAIS-IV Digit Span Sequence (1.9 ± 1.8; p = 0.002), and WAIS-IV Digit Span Total (1.4 ± 1.6; p = 0.008). Persons with SCI who responded to HC with a greater change in Tcore demonstrated evidence of greater sympathetic interruption and had an associated improvement in cognitive performance.
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Journal of neurotrauma · Aug 2021
Diaphragm motor evoked potential induced by cervical magnetic stimulation following cervical spinal cord contusion in the rat.
Cervical spinal injury is typically associated with respiratory impairments due to damage to bulbospinal respiratory pathways and phrenic motoneurons. Magnetic stimulation is a non-invasive approach for the evaluation and modulation of the nervous system. The present study was designed to examine whether cervical magnetic stimulation can be applied to evaluate diaphragmatic motor outputs in a pre-clinical rat model of cervical spinal injury. ⋯ However, the threshold of the diaphragmatic motor-evoked potential was reduced, and the amplitude of the diaphragmatic motor-evoked potential was enhanced in response to cervical magnetic stimulation at the acute injury stage. Moreover, the motor-evoked potentials of the bilateral diaphragm in animals with contusions were generally larger when the coil was placed at the left spinal cord at the subchronic and chronic injury stages. These results suggested that cervical magnetic stimulation can be used to examine the excitability of phrenic motor outputs post-injury, and magnetic stimulation applied more laterally may be more effective for triggering diaphragmatic motor-evoked potentials.
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Journal of neurotrauma · Aug 2021
Intra spinal administration of Netrin-1 promotes locomotor recovery after complete spinal cord transection.
Complete spinal cord lesions interrupt the connection of all axonal projections with their neuronal targets below and above the lesion site. In particular, the interruption of connections with the neurons at lumbar segments after thoracic injuries impairs voluntary body control below the injury. The failure of spontaneous regrowth of transected axons across the lesion prevents the reconnection and reinnervation of the neuronal targets. ⋯ These anatomical findings correlate with a significant recovery of locomotor function. Our work identifies netrin-1 as a biological agent with the capacity to promote the functional repair and recovery of locomotor function after SCI. These findings support the use of netrin-1 as a therapeutic intervention to be tested in humans.
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Journal of neurotrauma · Aug 2021
Temporal Progression of Acute Spinal Cord Injury Mechanisms in a Rat Model: Contusion, Dislocation, and Distraction.
Traumatic spinal cord injuries (SCIs) occur due to different spinal column injury patterns, including burst fracture, dislocation, and flexion-distraction. Pre-clinical studies modeling different SCI mechanisms have shown distinct histological differences between these injuries both acutely (3 h and less) and chronically (8 weeks), but there remains a temporal gap. Different rates of injury progression at specific regions of the spinal cord may provide insight into the pathologies that are initiated by specific SCI mechanisms. ⋯ This indicates early myelin damage often within 3 h. Myelinated axon counts after distraction dropped early and did not demonstrate any significant progression over the next 7 days. Important differences in white matter degeneration were identified between injury types, with distraction injuries showing the least variability across time-points These findings and the observation that white matter injury occurs early, and in many cases, without much dynamic change, highlight the importance of injury type in SCI research-both clinically and pre-clinically.
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Journal of neurotrauma · Aug 2021
Multicenter Study Observational StudyCharacterization of CSF ubiquitin C-terminal hydrolase L1 (UCH-L1) as a biomarker of human acute traumatic spinal cord injury.
A major obstacle for translational research in acute spinal cord injury (SCI) is the lack of biomarkers that can objectively stratify injury severity and predict outcome. Ubiquitin C-terminal hydrolase L1 (UCH-L1) is a neuron-specific enzyme that shows promise as a diagnostic biomarker in traumatic brain injury (TBI), but has not been studied in SCI. In this study, cerebrospinal fluid (CSF) and serum samples were collected over the first 72-96 h post-injury from 32 acute SCI patients who were followed prospectively to determine neurological outcomes at 6 months post-injury. ⋯ Similarly, the failure to gain >8 points on the total motor score at 6 months post-injury was associated with higher 24-h CSF UCH-L1. Unfortunately, serum UCH-L1 levels were not informative about injury severity or outcome. In conclusion, CSF UCH-L1 in acute SCI shows promise as a biomarker to reflect injury severity and predict outcome.