Journal of neurotrauma
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Journal of neurotrauma · Nov 2017
Characterization of chronic axonal degeneration using diffusion tensor imaging in canine spinal cord injury: A quantitative analysis of DTI parameters according to histopathological differences.
Diffusion tensor imaging (DTI) is more sensitive than conventional magnetic resonance imaging (MRI) for the identification of axonal degeneration. However, no study to date has used DTI to evaluate the severity of axonal degeneration in canine spinal cord injury (SCI). Therefore, the aim of this study was to characterize multi-grade axonal degeneration (mild, moderate, and severe) in a canine model of spinal cord compression injury using DTI. ⋯ The severity of AxD demonstrated a negative linear correlation with fractional anisotropy and positive linear correlations with spherical index and radial diffusivity; additionally, positive U-shaped correlations were identified between the severity of AxD and mean diffusivity and axial diffusity (AD). These results demonstrate a potential clinical application for DTI in the noninvasive monitoring of histological changes post-SCI. DTI could be utilized for the early diagnosis and assessment of SCI and, ultimately, used to optimize the treatment and rehabilitation of SCI patients.
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Journal of neurotrauma · Nov 2017
Clinical TrialContinuous monitoring and visualization of optimum spinal cord perfusion pressure in patients with acute cord injury.
The optimum spinal cord perfusion pressure (SCPP) after traumatic spinal cord injury (TSCI) is unknown. Here, we describe techniques to compute and display the optimum SCPP in real time. We recruited adults within 72 h of severe TSCI (American Spinal Injuries Association [ASIA] grades A-C). ⋯ Mean SCPP deviation from cSCPPopt correlated with worse neurological outcome at 9-12 months: ASIA grade improved in 30% of patients with <5 mm Hg deviation, 10% of patients with 5-15 mm Hg deviation, and no one with >15 mm Hg deviation. We conclude that real-time computation and visualization of cSCPPopt after TSCI are feasible. cSCPPopt appears to enhance glucose utilization at the injury site and varies widely between and within patients. Our data suggest that targeting cSCPPopt after TSCI might improve neurological outcome.
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Journal of neurotrauma · Nov 2017
Safety of Autologous Human Schwann Cell Transplantation in Subacute Thoracic Spinal Cord Injury.
The rationale for implantation of autologous human Schwann cells (SCs) in persons with subacute spinal cord injury (SCI) is based on evidence that transplanted SCs are neuroprotective, support local axonal plasticity, and are capable of myelinating axons. A Phase I clinical trial was conducted to evaluate the safety of autologous human SC transplantation into the injury epicenter of six subjects with subacute SCI. The trial was an open-label, unblinded, non-randomized, non-placebo controlled study with a dose escalation design and standard medical rehabilitation. ⋯ There were no adverse events or serious adverse events related to the cell therapy. There was no evidence of additional spinal cord damage, mass lesion, or syrinx formation. We conclude that it is feasible to identify eligible candidates, appropriately obtain informed consent, perform a peripheral nerve harvest to obtain SCs within 5-30 days of injury, and perform an intra-spinal transplantation of highly purified autologous SCs within 4-7 weeks of injury.
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Journal of neurotrauma · Nov 2017
Application of the Rat Grimace Scale as a Marker of Supraspinal Pain Sensation after Cervical Spinal Cord Injury.
Experimental models of neuropathic pain (NP) typically rely on withdrawal responses to assess the presence of pain. Reflexive withdrawal responses to a stimulus are used to evaluate evoked pain and, as such, do not include the assessment of spontaneous NP nor evaluation of the affective and emotional consequences of pain in animal models. Additionally, withdrawal responses can be mediated by spinal cord reflexes and may not accurately indicate supraspinal pain sensation. ⋯ Rodents exhibited significantly higher RGS scores at week 5 post-injury as compared to baseline and laminectomy controls before the application of the stimulus, suggesting the presence of spontaneous NP. Additionally, there was a significant increase in RGS scores after the application of the acetone. These data suggest that the RGS can be used to assess spontaneous NP and determine the presence of evoked supraspinal pain sensation after experimental cervical SCI.
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Journal of neurotrauma · Nov 2017
Anatomical recruitment of spinal V2a interneurons into phrenic motor circuitry after high cervical spinal cord injury.
More than half of all spinal cord injuries (SCIs) occur at the cervical level, often resulting in impaired respiration. Despite this devastating outcome, there is substantial evidence for endogenous neuroplasticity after cervical SCI. Spinal interneurons are widely recognized as being an essential anatomical component of this plasticity by contributing to novel neuronal pathways that can result in functional improvement. ⋯ Transneuronal tracing with pseudorabies virus (PRV) was used to identify interneurons within the phrenic circuitry. There was a robust increase in the number of PRV-labeled V2a interneurons ipsilateral to the C2 hemisection, demonstrating that significant numbers of these excitatory spinal interneurons were anatomically recruited into the phrenic motor pathway two weeks after injury, a time known to correspond with functional phrenic plasticity. Understanding this anatomical spinal plasticity and the neural substrates associated with functional compensation or recovery post-SCI in a controlled, experimental setting may help shed light onto possible cellular therapeutic candidates that can be targeted to enhance spontaneous recovery.