Beike Chen1, Qiang Tan2, Weikang Zhao1, Qiming Yang1, Hongyan Zhang2, Fabao Gao3, Xin Liu2, Hua Feng2, Dianming Jiang4,5. 1. Department of Orthopedics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, People's Republic of China. 2. Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Army Medical University, Chongqing, 400038, People's Republic of China. 3. Department of Radiology, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, People's Republic of China. 4. Department of Orthopedics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, People's Republic of China. 201296@hospital.cqmu.edu.cn. 5. Department of Orthopedics, The Third Affiliated Hospital of Chongqing Medical University (Gener Hospital), Chongqing, 401120, People's Republic of China. 201296@hospital.cqmu.edu.cn.
Abstract
BACKGROUND: Diffusion tensor imaging (DTI) is an effective method to identify subtle changes to normal-appearing white matter (WM). Here we analyzed the DTI data with other examinations, including motor evoked potentials (MEPs), histopathological images, and behavioral results, to reflect the lesion development in different degrees of spinal cord injury (SCI) in acute and subacute stages. METHOD: Except for 2 Sprague -Dawley rats which died from the anesthesia accident, the rest 42 female rats were randomized into 3 groups: control group (n = 6), moderate group (n = 18), and severe group (n = 18). Moderate (a 50-g aneurysm clip with 0.4-mm thickness spacer) or severe (a 50-g aneurysm clip with no spacer) contusion SCI at T8 vertebrae was induced. Then the electrophysiological assessments via MEPs, behavioral deterioration via the Basso, Beattie, and Bresnaha (BBB) scores, DTI data, and histopathology examination were analyzed. RESULTS: In this study, we found that the damage of WM myelin, MEPs amplitude, BBB scores and the decreases in the values of fractional anisotropy (FA) and axial diffusivity (AD) were more obvious in the severe injury group than those of the moderate group. Additionally, the FA and AD values could identify the extent of SCI in subacute and early acute SCI respectively, which was reflected in a robust correlations with MEPs and BBB scores. While the values of radial diffusivity (RD) showed no significant changes. CONCLUSIONS: Our data confirmed that DTI was a valuable in ex vivo imaging tool to identify damaged white matter tracts after graded SCI in rat, which may provide useful information for the early identification of the severity of SCI.
BACKGROUND: Diffusion tensor imaging (DTI) is an effective method to identify subtle changes to normal-appearing white matter (WM). Here we analyzed the DTI data with other examinations, including motor evoked potentials (MEPs), histopathological images, and behavioral results, to reflect the lesion development in different degrees of spinal cord injury (SCI) in acute and subacute stages. METHOD: Except for 2 Sprague -Dawley rats which died from the anesthesia accident, the rest 42 female rats were randomized into 3 groups: control group (n = 6), moderate group (n = 18), and severe group (n = 18). Moderate (a 50-g aneurysm clip with 0.4-mm thickness spacer) or severe (a 50-g aneurysm clip with no spacer) contusion SCI at T8 vertebrae was induced. Then the electrophysiological assessments via MEPs, behavioral deterioration via the Basso, Beattie, and Bresnaha (BBB) scores, DTI data, and histopathology examination were analyzed. RESULTS: In this study, we found that the damage of WM myelin, MEPs amplitude, BBB scores and the decreases in the values of fractional anisotropy (FA) and axial diffusivity (AD) were more obvious in the severe injury group than those of the moderate group. Additionally, the FA and AD values could identify the extent of SCI in subacute and early acute SCI respectively, which was reflected in a robust correlations with MEPs and BBB scores. While the values of radial diffusivity (RD) showed no significant changes. CONCLUSIONS: Our data confirmed that DTI was a valuable in ex vivo imaging tool to identify damaged white matter tracts after graded SCI in rat, which may provide useful information for the early identification of the severity of SCI.
Entities:
Keywords:
Anisotropy; BBB; DTI; MEPs; Neuroimaging; SCI; White matter
Authors: Nathan D Neckel; Haining Dai; John Hanckel; Yichien Lee; Christopher Albanese; Olga Rodriguez Journal: Behav Brain Res Date: 2021-08-03 Impact factor: 3.352