Effect of experimental, morphological and mechanical factors on the murine spinal cord subjected to transverse contusion: A finite element study.
- 作者列表："Fournely M","Petit Y","Wagnac E","Evin M","Arnoux PJ
:Finite element models combined with animal experimental models of spinal cord injury provides the opportunity for investigating the effects of the injury mechanism on the neural tissue deformation and the resulting tissue damage. Thus, we developed a finite element model of the mouse cervical spinal cord in order to investigate the effect of morphological, experimental and mechanical factors on the spinal cord mechanical behavior subjected to transverse contusion. The overall mechanical behavior of the model was validated with experimental data of unilateral cervical contusion in mice. The effects of the spinal cord material properties, diameter and curvature, and of the impactor position and inclination on the strain distribution were investigated in 8 spinal cord anatomical regions of interest for 98 configurations of the model. Pareto analysis revealed that the material properties had a significant effect (p<0.01) for all regions of interest of the spinal cord and was the most influential factor for 7 out of 8 regions. This highlighted the need for comprehensive mechanical characterization of the gray and white matter in order to develop effective models capable of predicting tissue deformation during spinal cord injuries.
: 有限元模型与脊髓损伤的动物实验模型相结合，为研究损伤机制对神经组织变形和由此产生的组织损伤的影响提供了机会。因此，我们建立了小鼠颈脊髓的有限元模型，以研究形态学、实验和力学因素对横断挫伤后脊髓力学行为的影响。用小鼠单侧颈部挫伤的实验数据验证了模型的整体力学行为。对于模型的98个配置，在8个感兴趣的脊髓解剖区域中研究了脊髓材料特性、直径和曲率以及冲击器位置和倾斜度对应变分布的影响。帕累托分析显示，材料特性对脊髓的所有感兴趣区域具有显著影响 (p<0.01)，并且是8个区域中7个区域的最具影响的因素。这强调了需要对灰质和白质进行全面的机械表征，以便开发能够预测脊髓损伤期间组织变形的有效模型。
METHODS:BACKGROUND:Women with disabilities are increasingly becoming pregnant, and growing evidence suggests maternal disability may be associated with increased risk for perinatal complications. OBJECTIVE:A systematic review and meta-analysis were undertaken to examine the association between maternal disabilities and risk for perinatal complications. STUDY DESIGN:Medline, CINAHL, EMBASE, and PsycINFO were searched from inception to July 2018 for full-text publications in English on pregnancy, delivery, and postpartum complications in women with any disability and those with physical, sensory, and intellectual and developmental disabilities specifically. Searches were limited to quantitative studies with a comparison group of women without disabilities. Reviewers used standardized instruments to extract data from and assess the quality of included studies. Pooled odds ratios and 95% confidence intervals were generated using DerSimonian and Laird random effects models for outcomes with data available from ≥3 studies. RESULTS:The review included 23 studies, representing 8,514,356 women in 19 cohorts. Women with sensory (pooled unadjusted odds ratio, 2.85, 95% confidence interval, 0.79-10.31) and intellectual and developmental disabilities (pooled unadjusted odds ratio, 1.10, 95% confidence interval, 0.76-1.58) had elevated but not statistically significant risk for gestational diabetes. Women with any disability (pooled unadjusted odds ratio, 1.45, 95% confidence interval, 1.16-1.82) and intellectual and developmental disabilities (pooled unadjusted odds ratio, 1.77, 95% confidence interval, 1.21-2.60) had increased risk for hypertensive disorders of pregnancy; risk was elevated but not statistically significant for women with sensory disabilities (pooled unadjusted odds ratio, 2.84, 95% confidence interval, 0.85-9.43). Women with any (pooled unadjusted odds ratio, 1.31, 95% confidence interval, 1.02-1.68), physical (pooled unadjusted odds ratio, 1.60, 95% confidence interval, 1.21-2.13), and intellectual and developmental disabilities (pooled unadjusted odds ratio, 1.29, 95% confidence interval, 1.02-1.63) had increased risk for cesarean delivery; risk among women with sensory disabilities was elevated but not statistically significant (pooled unadjusted odds ratio, 1.28, 95% confidence interval, 0.84-1.93). There was heterogeneity in all analyses, and 13 studies had weak-quality ratings, with lack of control for confounding being the most common limitation. CONCLUSION:Evidence that maternal disability is associated with increased risk for perinatal complications demonstrates that more high-quality research is needed to examine the reasons for this risk and to determine what interventions could be implemented to support women with disabilities during the perinatal period.
METHODS::Aims: To estimate healthcare resource utilization (HRU) and costs among patients with spinal muscular atrophy (SMA) type 1 (SMA1) in real-world practice, overall and among patients treated with nusinersen. As a secondary objective, HRU and costs were estimated among patients with other SMA types (i.e. 2, 3, or 4 combined), overall and among patients treated with nusinersen.Materials and methods: Patients with SMA were identified from the Symphony Health's Integrated Dataverse (IDV) open claims database (September 1, 2016-August 31, 2018) and were classified into four cohorts based on SMA type and nusinersen treatment (i.e. SMA1, SMA1 nusinersen, other SMA, and other SMA nusinersen cohorts). The index date was the date of the first SMA diagnosis after December 23, 2016 or, for nusinersen cohorts, the date of nusinersen initiation. The study period spanned from the index date to the earlier among the end of clinical activity or data availability.Results: Patients in the SMA1 (n = 349) and SMA1 nusinersen (n = 45) cohorts experienced an average of 59.4 and 56.6 days with medical visits per-patient-per-year (PPPY), respectively, including 14.1 and 4.6 inpatient days. Excluding nusinersen-related costs, total mean healthcare costs were $137,627 and $92,618 PPPY in the SMA1 and SMA1 nusinersen cohorts, respectively. Mean nusinersen-related costs were $191,909 per-patient-per-month (PPPM) for the first 3 months post-initiation (i.e. loading phase) and $36,882 PPPM thereafter (i.e. maintenance phase). HRU and costs were also substantial among patients in the other SMA (n = 5,728) and other SMA nusinersen (n = 404) cohorts, with an average of 44.5 and 63.7 days with medical visits PPPY and total mean healthcare costs (excluding nusinersen-related costs) of $49,175 and $76,371 PPPY, respectively.Limitations: The database may contain inaccuracies or omissions in diagnoses, procedures, or costs, and does not capture medical services outside of the IDV network.Conclusions: HRU and healthcare costs were substantial in patients with SMA, including in nusinersen-treated patients.
METHODS:OBJECTIVES:To investigate the effect of cervical spondylosis (CS) in the brain with a combination of advanced neuroimaging techniques. METHODS:Twenty-seven patients with CS and 24 age- and gender-matched healthy controls were studied. Disease severity was quantified using the Modified Japanese Orthopaedic Association Scoring System (mJOHA). Magnetic resonance (MR) imaging of the brain and spinal cord, functional MR imaging (fMRI) with a bilateral rest/finger-tapping paradigm, brain diffusion tensor imaging (DTI), voxel-based morphometry (VBM), and MR spectroscopy of the sensorimotor cortex were performed. RESULTS:A total of 92.3% of patients had more than one herniated disc. In the MRI, 33.33% presented signs of myelopathy. The mJOHA score was 13.03 ± 2.83. Compared with controls, DTI results showed significant lower FA values in Corpus callosum, both corticospinal tracts and middle cerebellar peduncles (p < 0.05 corrected). Only in CS patients fMRI results showed activation in both globus pallidi, caudate nucleus, and left thalamus (p < 0.001). Subject-specific activation of the BOLD signal showed in CS patients lower activation in the sensorimotor cortex and increased activation in both cerebellum hemispheres (p < 0.05 corrected). VBM showed bilateral clusters of gray matter loss in the sensorimotor cortex and pulvinar nucleus (p < 0.05 corrected) of CS patients. NAA/Cr was reduced in the sensorimotor cortex of CS patients (p < 0.05). Linear discriminant and support vector machine analyses were able to classify > 97% of CS patients with parameters obtained from the fMRI, DTI, and MRS results. CONCLUSION:CS may lead to distal brain damage affecting the white and gray matter of the sensorimotor cortex causing brain atrophy and functional adaptive changes. KEY POINTS:• This study suggests that patients with cervical spondylosis may present anatomical and functional adaptive changes in the brain. • Cervical spondylosis may lead to white matter damage, gray matter volume loss, and functional adaptive changes in the sensorimotor cortex. • The results reported in this work may be of value to better understand the effect of prolonged cervical spine compression in the brain.