Previous neuropathological studies regarding traumatic brain injury have primarily focused on changes in large structures, for example, the clinical prognosis after cerebral contusion, intrace- rebral hematoma, and ep...Previous neuropathological studies regarding traumatic brain injury have primarily focused on changes in large structures, for example, the clinical prognosis after cerebral contusion, intrace- rebral hematoma, and epidural and subdural hematoma. In fact, many smaller injuries can also lead to severe neurological disorders. For example, cerebral microbleeds result in the dysfunc- tion of adjacent neurons and the disassociation between cortex and subcortical structures. These tiny changes cannot be adequately visualized on CT or conventional MRI. In contrast, gradient echo sequence-based susceptibility-weighted imaging is very sensitive to blood metabolites and microbleeds, and can be used to evaluate traumatic cerebral microbleeds with high sensitivity and accuracy. Cerebral microbleed can be considered as an important imaging marker for dif- fuse axonal injury with potential relevance for prognosis. For this reason, based on experimental and clinical studies, this study reviews the role of imaging data showing traumatic cerebral microbleeds in the evaluation of cerebral neuronal injury and neurofunctional loss.展开更多
Restorative cell-based therapies for experimental brain injury, such as stroke and traumatic brain injury,substantially improve functional outcome. We discuss and review state of the art magnetic resonance imaging met...Restorative cell-based therapies for experimental brain injury, such as stroke and traumatic brain injury,substantially improve functional outcome. We discuss and review state of the art magnetic resonance imaging methodologies and their applications related to cell-based treatment after brain injury. We focus on the potential of magnetic resonance imaging technique and its associated challenges to obtain useful new information related to cell migration, distribution, and quantitation, as well as vascular and neuronal remodeling in response to cell-based therapy after brain injury. The noninvasive nature of imaging might more readily help with translation of cell-based therapy from the laboratory to the clinic.展开更多
Hypothalamic-pituitary-adrenal axis dysfunction may lead to the occurrence of critical illness-related corticosteroid insufficiency.Critical illness-related corticosteroid insufficiency can easily occur after traumati...Hypothalamic-pituitary-adrenal axis dysfunction may lead to the occurrence of critical illness-related corticosteroid insufficiency.Critical illness-related corticosteroid insufficiency can easily occur after traumatic brain injury,but few studies have examined this occurrence.A multicenter,prospective,cohort study was performed to evaluate the function of the hypothalamic-pituitary-adrenal axis and the incidence of critical illness-related corticosteroid insufficiency during the sub-acute phase of traumatic brain injury.One hundred and forty patients with acute traumatic brain injury were enrolled from the neurosurgical departments of three tertiary-level hospitals in China,and the critical illness-related corticosteroid insufficiency incidence,critical-illness-related corticosteroid insufficiency-related risk factors,complications,and 28-day mortality among these patients was recorded.Critical illness-related corticosteroid insufficiency was diagnosed in patients with plasma total cortisol levels less than 10μg/dL(275.9 nM)on post-injury day 4 or when serum cortisol was insufficiently suppressed(less than 50%)during a dexamethasone suppression test on post-injury day 5.The results demonstrated that critical illness-related corticosteroid insufficiency occurred during the sub-acute phase of traumatic brain injury in 5.6%of patients with mild injury,22.5%of patients with moderate injury,and 52.2%of patients with severe injury.Traumatic brain injury-induced critical illness-related corticosteroid insufficiency was strongly correlated to injury severity during the sub-acute stage of traumatic brain injury.Traumatic brain injury patients with critical illness-related corticosteroid insufficiency frequently presented with hemorrhagic cerebral contusions,diffuse axonal injury,brain herniation,and hypotension.Differences in the incidence of hospital-acquired pneumonia,gastrointestinal bleeding,and 28-day mortality were observed between patients with and without critical illness-related corticosteroid insufficiency during the sub-acute phase of traumatic brain injury.Hypotension,brain-injury severity,and the types of traumatic brain injury were independent risk factors for traumatic brain injury-induced critical illness-related corticosteroid insufficiency.These findings indicate that critical illness-related corticosteroid insufficiency is common during the sub-acute phase of traumatic brain injury and is strongly associated with poor prognosis.The dexamethasone suppression test is a practical assay for the evaluation of hypothalamic-pituitary-adrenal axis function and for the diagnosis of critical illness-related corticosteroid insufficiency in patients with traumatic brain injury,especially those with hypotension,hemorrhagic cerebral contusions,diffuse axonal injury,and brain herniation.Sub-acute infection of acute traumatic brain injury may be an important factor associated with the occurrence and development of critical illness-related corticosteroid insufficiency.This study protocol was approved by the Ethics Committee of General Hospital of Tianjin Medical University,China in December 2011(approval No.201189).展开更多
Blast-induced traumatic brain injury(b-TBI)is a kind of significant injury to soldiers in the current military conflicts.However,the mechanism of b-TBI has not been well understood,and even there are some contradictor...Blast-induced traumatic brain injury(b-TBI)is a kind of significant injury to soldiers in the current military conflicts.However,the mechanism of b-TBI has not been well understood,and even there are some contradictory conclusions.It is crucial to reveal the dynamic mechanism of brain volume and shear deformations under blast loading for better understanding of b-TBI.In this paper,the numerical simulation method is adopted to carry out comprehensive and in-depth researches on this issue for the first time.Based on the coupled Eulerian-Lagrangian method,the fluid-structure coupling model of the blast wave and human head is developed to simulate two situations,namely the head subjected to the frontal and lateral impacts.The simulation results are analyzed to obtain the underlying dynamic mechanisms of brain deformation.The brain volume deformation is dominated by the local bending vibration of the skull,and the corresponding frequency for the forehead skull under the frontal impact and the lateral skull faced to the lateral impact is as high as 8 kHz and 5 kHz,respectively.This leads to the high-frequency fluctuation of brain pressure and the large pressure gradient along the skull,totally different from the dynamic response of brain under head collisions.While the brain shear deformation mainly depends on the relative tangential displacement between the skull and brain and the anatomical structure of inner skull,being not related to the brain pressure and its gradient.By further comparing the medical statistics,it is inferred that diffuse axonal injury and brain contusion,the two most common types of b-TBI,are mainly attributed to brain shear deformations.And the von Mises stress can be adopted as the indicator for these two brain injuries.This study can provide theoretical guidance for the diagnosis of b-TBI and the development of protective equipment.展开更多
目的:研究磁共振磁敏感加权成像(SWI)和扩散加权成像(DWI)对脑弥漫性轴索损伤(DAI)的诊断价值及其检出病灶情况与临床病情严重程度、预后评价间的关系。方法:对64例临床疑诊DAI的患者常规行头CT和核磁T1WI、T2WI、DWI和SWI序列扫描,分...目的:研究磁共振磁敏感加权成像(SWI)和扩散加权成像(DWI)对脑弥漫性轴索损伤(DAI)的诊断价值及其检出病灶情况与临床病情严重程度、预后评价间的关系。方法:对64例临床疑诊DAI的患者常规行头CT和核磁T1WI、T2WI、DWI和SWI序列扫描,分析其各自信号特征及分布特点,比较各序列上脑内轴索损伤病灶的检出率和检出体积差异,并与GCS评分、GOS评分进行相关性分析。结果:SWI较其他序列上能更多清楚地显示脑内微小出血灶(P<0.01),而DWI较其他序列能更好更多检出水肿灶(P<0.01)。SWI、DWI检出病灶体积均明显高于T1WI和T2WI,前两者比较经Mann-Whitney U检验差异具有统计学意义(P<0.01)。SWI检出的微出血病灶数、总病灶数和体积,DWI检出小水肿病灶数、微出血病灶数、总病灶数和体积,以及各主要病灶分布部位病灶数均与入院时GCS评分、检查前1 h GCS评分及出院后3个月随访GOS评分之间呈负相关(P<0.05),SWI检出小水肿病灶数量与出院后3个月随访GOS评分也具负相关(P<0.05)。结论:联合SWI和DWI序列能非常敏感地检出外伤后DAI患者的脑内微出血灶和小水肿灶,为DAI的早期临床诊断及预后评价提供更多客观依据。展开更多
基金supported by grants from the State-Funded Construction Projects Key Clinical Specialist(2013-2015)the Hunan Provincial Science and Technology Department,No.2009FJ3092
文摘Previous neuropathological studies regarding traumatic brain injury have primarily focused on changes in large structures, for example, the clinical prognosis after cerebral contusion, intrace- rebral hematoma, and epidural and subdural hematoma. In fact, many smaller injuries can also lead to severe neurological disorders. For example, cerebral microbleeds result in the dysfunc- tion of adjacent neurons and the disassociation between cortex and subcortical structures. These tiny changes cannot be adequately visualized on CT or conventional MRI. In contrast, gradient echo sequence-based susceptibility-weighted imaging is very sensitive to blood metabolites and microbleeds, and can be used to evaluate traumatic cerebral microbleeds with high sensitivity and accuracy. Cerebral microbleed can be considered as an important imaging marker for dif- fuse axonal injury with potential relevance for prognosis. For this reason, based on experimental and clinical studies, this study reviews the role of imaging data showing traumatic cerebral microbleeds in the evaluation of cerebral neuronal injury and neurofunctional loss.
基金supported by NIH grants RO1 NS64134 and RO1 NS 48349
文摘Restorative cell-based therapies for experimental brain injury, such as stroke and traumatic brain injury,substantially improve functional outcome. We discuss and review state of the art magnetic resonance imaging methodologies and their applications related to cell-based treatment after brain injury. We focus on the potential of magnetic resonance imaging technique and its associated challenges to obtain useful new information related to cell migration, distribution, and quantitation, as well as vascular and neuronal remodeling in response to cell-based therapy after brain injury. The noninvasive nature of imaging might more readily help with translation of cell-based therapy from the laboratory to the clinic.
基金supported by the National Natural Science Foundation of China,No.81671902(to XC)81501704(to YC)+3 种基金the Project of Tianjin Applied Basic and Cutting-edge Technological Research of China,No.17JCYBJC25200(to XC)15JCQNJC44900(to YC)Tianjin Health Care Elite Prominent Young Doctor Development Program(to XC)the Young and Middle-aged Backbone Innovative Talent Program(to XC)
文摘Hypothalamic-pituitary-adrenal axis dysfunction may lead to the occurrence of critical illness-related corticosteroid insufficiency.Critical illness-related corticosteroid insufficiency can easily occur after traumatic brain injury,but few studies have examined this occurrence.A multicenter,prospective,cohort study was performed to evaluate the function of the hypothalamic-pituitary-adrenal axis and the incidence of critical illness-related corticosteroid insufficiency during the sub-acute phase of traumatic brain injury.One hundred and forty patients with acute traumatic brain injury were enrolled from the neurosurgical departments of three tertiary-level hospitals in China,and the critical illness-related corticosteroid insufficiency incidence,critical-illness-related corticosteroid insufficiency-related risk factors,complications,and 28-day mortality among these patients was recorded.Critical illness-related corticosteroid insufficiency was diagnosed in patients with plasma total cortisol levels less than 10μg/dL(275.9 nM)on post-injury day 4 or when serum cortisol was insufficiently suppressed(less than 50%)during a dexamethasone suppression test on post-injury day 5.The results demonstrated that critical illness-related corticosteroid insufficiency occurred during the sub-acute phase of traumatic brain injury in 5.6%of patients with mild injury,22.5%of patients with moderate injury,and 52.2%of patients with severe injury.Traumatic brain injury-induced critical illness-related corticosteroid insufficiency was strongly correlated to injury severity during the sub-acute stage of traumatic brain injury.Traumatic brain injury patients with critical illness-related corticosteroid insufficiency frequently presented with hemorrhagic cerebral contusions,diffuse axonal injury,brain herniation,and hypotension.Differences in the incidence of hospital-acquired pneumonia,gastrointestinal bleeding,and 28-day mortality were observed between patients with and without critical illness-related corticosteroid insufficiency during the sub-acute phase of traumatic brain injury.Hypotension,brain-injury severity,and the types of traumatic brain injury were independent risk factors for traumatic brain injury-induced critical illness-related corticosteroid insufficiency.These findings indicate that critical illness-related corticosteroid insufficiency is common during the sub-acute phase of traumatic brain injury and is strongly associated with poor prognosis.The dexamethasone suppression test is a practical assay for the evaluation of hypothalamic-pituitary-adrenal axis function and for the diagnosis of critical illness-related corticosteroid insufficiency in patients with traumatic brain injury,especially those with hypotension,hemorrhagic cerebral contusions,diffuse axonal injury,and brain herniation.Sub-acute infection of acute traumatic brain injury may be an important factor associated with the occurrence and development of critical illness-related corticosteroid insufficiency.This study protocol was approved by the Ethics Committee of General Hospital of Tianjin Medical University,China in December 2011(approval No.201189).
文摘Blast-induced traumatic brain injury(b-TBI)is a kind of significant injury to soldiers in the current military conflicts.However,the mechanism of b-TBI has not been well understood,and even there are some contradictory conclusions.It is crucial to reveal the dynamic mechanism of brain volume and shear deformations under blast loading for better understanding of b-TBI.In this paper,the numerical simulation method is adopted to carry out comprehensive and in-depth researches on this issue for the first time.Based on the coupled Eulerian-Lagrangian method,the fluid-structure coupling model of the blast wave and human head is developed to simulate two situations,namely the head subjected to the frontal and lateral impacts.The simulation results are analyzed to obtain the underlying dynamic mechanisms of brain deformation.The brain volume deformation is dominated by the local bending vibration of the skull,and the corresponding frequency for the forehead skull under the frontal impact and the lateral skull faced to the lateral impact is as high as 8 kHz and 5 kHz,respectively.This leads to the high-frequency fluctuation of brain pressure and the large pressure gradient along the skull,totally different from the dynamic response of brain under head collisions.While the brain shear deformation mainly depends on the relative tangential displacement between the skull and brain and the anatomical structure of inner skull,being not related to the brain pressure and its gradient.By further comparing the medical statistics,it is inferred that diffuse axonal injury and brain contusion,the two most common types of b-TBI,are mainly attributed to brain shear deformations.And the von Mises stress can be adopted as the indicator for these two brain injuries.This study can provide theoretical guidance for the diagnosis of b-TBI and the development of protective equipment.
文摘目的:研究磁共振磁敏感加权成像(SWI)和扩散加权成像(DWI)对脑弥漫性轴索损伤(DAI)的诊断价值及其检出病灶情况与临床病情严重程度、预后评价间的关系。方法:对64例临床疑诊DAI的患者常规行头CT和核磁T1WI、T2WI、DWI和SWI序列扫描,分析其各自信号特征及分布特点,比较各序列上脑内轴索损伤病灶的检出率和检出体积差异,并与GCS评分、GOS评分进行相关性分析。结果:SWI较其他序列上能更多清楚地显示脑内微小出血灶(P<0.01),而DWI较其他序列能更好更多检出水肿灶(P<0.01)。SWI、DWI检出病灶体积均明显高于T1WI和T2WI,前两者比较经Mann-Whitney U检验差异具有统计学意义(P<0.01)。SWI检出的微出血病灶数、总病灶数和体积,DWI检出小水肿病灶数、微出血病灶数、总病灶数和体积,以及各主要病灶分布部位病灶数均与入院时GCS评分、检查前1 h GCS评分及出院后3个月随访GOS评分之间呈负相关(P<0.05),SWI检出小水肿病灶数量与出院后3个月随访GOS评分也具负相关(P<0.05)。结论:联合SWI和DWI序列能非常敏感地检出外伤后DAI患者的脑内微出血灶和小水肿灶,为DAI的早期临床诊断及预后评价提供更多客观依据。
