Volume Changes After Traumatic Spinal Cord Injury in Animal Studies - A Systematic Review

There are limited data on the lesion volume changes following spinal cord injury (SCI). In this study, a meta-analysis was performed to evaluate the volume size changes of the injured spinal cord over time among animal studies in traumatic SCI. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a comprehensive electronic search of English literature of PubMed and EMBASE databases from 1946 to 2015 concerning the time-dependent changes in the volume of the spinal cord following mechanical traumatic SCI. A hand-search was also performed for non-interventional, non-molecular, and non-review studies. Quality appraisal, data extraction, qualitative and quantitative analyses were performed afterward. Of 11,561 articles yielded from electronic search, 49 articles were assessed for eligibility after reviewing of titles, abstracts, and references. Ultimately, 11 articles were eligible for quantitative synthesis. The ratio of lesion volume to spinal cord total volume increased over time. Avascularity appeared in spinal cord 4 hours after injury. During the first week, the spinal subarachnoid space decreased. The hemorrhagic lesion size peaked in 1 week and decreased thereafter. Significant loss of gray and white matter occurred from day 3 with a slower progression of white matter damage. Changes of lesion extent over time is critical in pathophysiologic processes after SCI. Early avascularity, rapid loss of gray matter, slow progression of white matter damage, and late cavitation are the pathophysiologic key points of SCI, which could be helpful in choosing the proper intervention on a timely basis

Severity of Spinal Cord Injury Influences Diffusion Tensor Imaging of the Brain

Background: The purpose of this study was to determine whether DTI changes in the brain induced by a thoracic spinal cord injury are sensitive to varying severity of spinal contusion in rats. Methods: A control, mild, moderate, or severe contusion injury was administered over the eighth thoracic vertebral level in 32 Sprague-Dawley rats. At 11 weeks postinjury, ex vivo DTI of the brain was performed on a 9.4T Bruker scanner using a pulsed gradient spin-echo sequence. Results: Mean water diffusion in the internal capsule regions of the brain and pyramid locations of the brainstem were correlated with motor function (r2 = 0.55). Additionally, there were significant differences between injury severity groups for mean diffusivity and fractional anisotropy at regions associated with the corticospinal tract (P = 0.05). Conclusion: These results indicate that DTI is sensitive to changes in brain tissue as a consequence of thoracic SCI

Diffusion tensor imaging with direct cytopathological validation: Characterisation of decorin treatment in experimental juvenile communicating hydrocephalus

BACKGROUND: In an effort to develop novel treatments for communicating hydrocephalus, we have shown previously that the transforming growth factor-β antagonist, decorin, inhibits subarachnoid fibrosis mediated ventriculomegaly; however decorin’s ability to prevent cerebral cytopathology in communicating hydrocephalus has not been fully examined. Furthermore, the capacity for diffusion tensor imaging to act as a proxy measure of cerebral pathology in multiple sclerosis and spinal cord injury has recently been demonstrated. However, the use of diffusion tensor imaging to investigate cytopathological changes in communicating hydrocephalus is yet to occur. Hence, this study aimed to determine whether decorin treatment influences alterations in diffusion tensor imaging parameters and cytopathology in experimental communicating hydrocephalus. Moreover, the study also explored whether diffusion tensor imaging parameters correlate with cellular pathology in communicating hydrocephalus. METHODS: Accordingly, communicating hydrocephalus was induced by injecting kaolin into the basal cisterns in 3-week old rats followed immediately by 14 days of continuous intraventricular delivery of either human recombinant decorin (n = 5) or vehicle (n = 6). Four rats remained as intact controls and a further four rats served as kaolin only controls. At 14-days post-kaolin, just prior to sacrifice, routine magnetic resonance imaging and magnetic resonance diffusion tensor imaging was conducted and the mean diffusivity, fractional anisotropy, radial and axial diffusivity of seven cerebral regions were assessed by voxel-based analysis in the corpus callosum, periventricular white matter, caudal internal capsule, CA1 hippocampus, and outer and inner parietal cortex. Myelin integrity, gliosis and aquaporin-4 levels were evaluated by post-mortem immunohistochemistry in the CA3 hippocampus and in the caudal brain of the same cerebral structures analysed by diffusion tensor imaging. RESULTS: Decorin significantly decreased myelin damage in the caudal internal capsule and prevented caudal periventricular white matter oedema and astrogliosis. Furthermore, decorin treatment prevented the increase in caudal periventricular white matter mean diffusivity (p = 0.032) as well as caudal corpus callosum axial diffusivity (p = 0.004) and radial diffusivity (p = 0.034). Furthermore, diffusion tensor imaging parameters correlated primarily with periventricular white matter astrocyte and aquaporin-4 levels. CONCLUSIONS: Overall, these findings suggest that decorin has the therapeutic potential to reduce white matter cytopathology in hydrocephalus. Moreover, diffusion tensor imaging is a useful tool to provide surrogate measures of periventricular white matter pathology in communicating hydrocephalus. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12987-016-0033-2) contains supplementary material, which is available to authorized users

Investigating Spinal Cord Injury at Different Locations on the Spinal Cord Using Diffusion Tensor Imaging

The current study is derived from a larger study by Yao et al. (2019) that attempts to understand if Diffusion Tensor Imaging (DTI) is a good diagnostic tool for distinguishing spinal cord injured (SCI) participants from healthy controls from a structural perspective. Additionally, the study aims to determine whether the DTI parameters and the clinical functional scores of the Spinal Cord Independence Measure (SCIM) improve over time for SCI when rehabilitation is implemented. The current study has the same aims but takes Yao’s work further by dividing cervical SCI participants based on the exact location of injury (i.e., upper and lower cervically injured). Significant difference tests found that SCI participants, especially those with upper cervical injuries, differed from their matched healthy controls at baseline when measuring the Axial Diffusivity (AD) and Fractional Anisotropy (FA) parameters, mainly at spinal scanning locations at the site and surrounding the site of injury. Additionally, this remained true when incorporating follow up visits after rehabilitation. Furthermore, within differences showed some gradual increase to normalcy for SCI participants. The AD and FA parameters also correlated strongly with the SCIM functional measures for lower cervically injured participants. The results of this analysis provide inclinations on how DTI is a useful diagnostic tool for SCI and how changes over time structurally and functionally may be dependent on the exact location of injury. In conclusion, the current study promotes the idea that further research needs to be done using the AD and FA parameters on different injury locations on the spinal cord

Metachromatic leukodystrophy: Natural evolution and treatment effects

Knaap, M.S. van der [Promotor]Wolf, N.I. [Copromotor]Pouwels, P.J.W. [Copromotor