Based on the Wallerian degeneration in the spinal cord pathways,the changes in synaptic connections,and the spinal cord-related cellular responses that alter the cellular structure of the brain,we presumed that brain ...Based on the Wallerian degeneration in the spinal cord pathways,the changes in synaptic connections,and the spinal cord-related cellular responses that alter the cellular structure of the brain,we presumed that brain diffusion tensor imaging(DTI)parameters may change after spinal cord injury.However,the dynamic changes in DTI parameters remain unclear.We established a Beagle dog model of T10 spinal cord contusion and performed DTI of the injured spinal cord.We found dynamic changes in DTI parameters in the cerebral peduncle,posterior limb of the internal capsule,pre-and postcentral gyri of the brain within 12 weeks after spinal cord injury.We then performed immunohistochemistry to detect the expression of neurofilament heavy polypeptide(axonal marker),glial fibrillary acidic protein(glial cell marker),and NeuN(neuronal marker).We found that these pathological changes were consistent with DTI parameter changes.These findings suggest that DTI can display brain structure changes after spinal cord injury.展开更多
With improvements in care of at-risk neonates, more and more children survive. This makes it increasingly important to assess, soon after birth, the prognosis of children with hypoxic-ischemic encephalopathy. Computed...With improvements in care of at-risk neonates, more and more children survive. This makes it increasingly important to assess, soon after birth, the prognosis of children with hypoxic-ischemic encephalopathy. Computed tomography, ultrasound, and conventional magnetic resonance imaging are helpful to diagnose brain injury, but cannot quantify white matter damage. In this study, ten full-term infants without brain injury and twenty-two full-term neonates with hypoxic-ischemic encephalopathy(14 moderate cases and 8 severe cases) underwent diffusion tensor imaging to assess its feasibility in evaluating white matter damage in this condition. Results demonstrated that fractional anisotropy, voxel volume, and number of fiber bundles were different in some brain areas between infants with brain injury and those without brain injury. The correlation between fractional anisotropy values and neonatal behavioral neurological assessment scores was closest in the posterior limbs of the internal capsule. We conclude that diffusion tensor imaging can quantify white matter injury in neonates with hypoxic-ischemic encephalopathy.展开更多
At present,predicting the severity of brain injury caused by global cerebral ischemia/reperfusion injury(GCI/RI)is a clinical problem.After such an injury,clinical indicators that can directly reflect neurological dys...At present,predicting the severity of brain injury caused by global cerebral ischemia/reperfusion injury(GCI/RI)is a clinical problem.After such an injury,clinical indicators that can directly reflect neurological dysfunction are lacking.The change in hippocampal microstructure is the key to memory formation and consolidation.Diffusion tensor imaging is a highly sensitive tool for visualizing injury to hippocampal microstructure.Although hippocampal microstructure,brain-derived neurotrophic factor(BDNF),and tropomyosin-related kinase B(Trk B)levels are closely related to nerve injury and the repair process after GCI/RI,whether these indicators can reflect the severity of such hippocampal injury remains unknown.To address this issue,we established rat models of GCI/RI using the four-vessel occlusion method.Diffusion tensor imaging parameters,BDNF,and Trk B levels were correlated with modified neurological severity scores.The results revealed that after GCI/RI,while neurological function was not related to BDNF and Trk B levels,it was related to hippocampal fractional anisotropy.These findings suggest that hippocampal fractional anisotropy can reflect the severity of hippocampal injury after global GCI/RI.The study was approved by the Institutional Animal Care and Use Committee of Capital Medical University,China(approval No.AEEI-2015-139)on November 9,2015.展开更多
BACKGROUND: This systematic review aims to investigate the prediction value of diffusion tensor imaging for motor function recovery of ischemic stroke patients.METHODS: Cochrane Central Register of Controlled Trials(C...BACKGROUND: This systematic review aims to investigate the prediction value of diffusion tensor imaging for motor function recovery of ischemic stroke patients.METHODS: Cochrane Central Register of Controlled Trials(CENTRAL)(the Cochrane Library 2016, Issue 9), Pub Med, Embase, Clarivate Analytics, Scopus, CINAHL, Chinese Biomedical Literature Database, China National Knowledge Infrastructure and Google Scholar were searched for either motor recovery or corticospinal tract integrity by diffusion tensor imaging in different stroke phase from January 1, 1970, to October 31, 2016. The study design and participants were subjected to metrological analysis. Correlation coeffi cient(r) was used for evaluating the relationship between fractional anisotropy(FA) and motor function outcome. Correlation coeffi cient values were extracted from each study, and 95% confidence intervals(CIs) were calculated by Fisher's z transformation. Meta-analysis was conducted by STATA software.RESULTS: Fifteen studies with a total of 414 patients were included. Meta-analysis showed that FA in the subacute phase had the signifi cant correlation with motor function outcome(ES=0.75, 95%CI 0.62–0.87), which showed moderate quality based on GRADE system. The weight correlation coeffi cient revealed that an effect size(ES) of FA in acute phase and chronic phase was 0.51(95%CI 0.33–0.68) and 0.62(95%CI 0.47–0.77) respectively.CONCLUSION: This meta-analysis reveals that FA in the subacute phase after ischemic stroke is a good predictor for functional motor recovery, which shows moderate quality based on the GRADE system.展开更多
BACKGROUND: Diffusion tensor imaging (DTI) is one of the noninvasive methods to study the morphological structure of brain white matter fibrous bands in vivo, and it has been applied primarily in clinic. DTI is acknow...BACKGROUND: Diffusion tensor imaging (DTI) is one of the noninvasive methods to study the morphological structure of brain white matter fibrous bands in vivo, and it has been applied primarily in clinic. DTI is acknowledged as the more effective imaging method to diagnose ultra-acute and/or acute cerebral infarction. OBJECTIVE: To observe the anisotropic characters of cerebral white matter fibrous bands in patients with ischemic stroke by using DTI, and investigate the correlation between the damage of corticospinal tract and muscle strength in patients with ischemic stroke at acute period. DESIGN: A case-control observation. SETTING: Department of Medical Imaging, Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA. PARTICIPANTS: Nine inpatients with injury of motor function induced by acute ischemic stroke (patient group) at 6 hours to 2 weeks after the attack were selected from the Department of Neurology, Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA from September 2005 to March 2006, and they all accorded with the present diagnostic standard for cerebrovascular disease in China. There were 5 males and 4 females, aged 16-87 years. At the same time, nine healthy right-handed physical examinees matched by age and sex with the patients were taken as the control group, and they all had no nervous disease, mental diseases, cerebrovascular abnormalities and injury history, etc. All the subjects were informed with the detected items and agreed to participate in the study. METHODS: All the 9 patients with ischemic stroke at acute period and 9 healthy subjects were examined with MRI, T1 weighted imaging, T2 weighted imaging and DTI. And the data were processed offline with dTV.II software, the images of fractional anisotropy and directional encoded color (DEC) were obtained, and the three-dimensional fibrous band images of bilateral corticospinal tracts were reconstructed. In the control group, the values of fractional anisotropy of main white matter fibrous bands were measured in the region of interest (ROI) of the anterior limb, knee and posterior limb of internal capsule. In the patient group, the values of fractional anisotropy of white matter were measured in the infarcted sites and corresponding contralateral sites of the patients. The ROI was set in bilateral cerebral peduncles to reconstruct three-dimensionally the bilateral corticospinal tracts. The muscle strength of the affected hand was assessed with Brunnstorm standard in the stroke patients. MAIN OUTCOME MEASURES: The characters of DTI and images of the value of fractional anisotropy, and the manifestations of three-dimensional corticospinal tracts were observed in the two groups. RESULTS: All the data from the 9 patients and 9 healthy volunteers were involved in the analysis of results. ① In the control group, the white matter and gray matter could be distinguished clearly in the image of fractional anisotropic values, the fibers of different directions were shown by different colors in DEC picture, which clearly demonstrated the normal anatomic structure and direction of white matter fibers. In the patient group, the infarctions occurred in the gray matter or white matter could be distinguished in the images of fractional anisotropic values, DEC picture could clearly show the direct influence of the infarcted site on the white matter fibers. The fractional anisotropic values in different white matter structure of the same side were significantly different in the control group (t=3.12, P < 0.05), and the reconstructed images fractional anisotropic values and DEC picture could show most of the main white matter fibrous bands. The fractional anisotropic values of the infarcted sites were significantly lower than the contralateral ones in the patient group (t=5.570, P < 0.01). ② The reconstructed bilateral corticospinal tracts showed that the anatomic forms of the contralateral corticospinal tract of the patients were almost identical to those of normal people, it started from precentral gyrus, downward to the nternal capsule, and extended to pontine and medulla oblongata, each fibrous band was continuous, and the form had good consistency. Because of the involvement of infarction of different severity, the ipsilateral corticospinal tract manifested as continuous interruption and the loss of consistent anatomic structural form. The involved severity of corticospinal tract had significant correlation with that of muscle strength of the ipsilateral hand (r=1.30, P < 0.01). CONCLUSION: ① DTI can display the direction and distribution of cerebral white matter fibrous bands. ② DTI images of fractional anisotropic values and DEC can show the directions and anisotropic degree of white matter fibers in the infarcted sites of stroke patients. ③ The three-dimensional images of fibrous bands can show the conditions of pyramidal tracts more directly. ④ The damaged severity of corticospinal tracts is correlated with that of muscle strength.展开更多
Cerebral small vessel disease(CSVD)is a leading cause of age-related microvascular cognitive decline,resulting in significant morbidity and decreased quality of life.Despite a progress on its key pathophysiological ba...Cerebral small vessel disease(CSVD)is a leading cause of age-related microvascular cognitive decline,resulting in significant morbidity and decreased quality of life.Despite a progress on its key pathophysiological bases and general acceptance of key terms from neuroimaging findings as observed on the magnetic resonance imaging(MRI),key questions on CSVD remain elusive.Enhanced relationships and reliable lesion studies,such as white matter tractography using diffusion-based MRI(dMRI)are necessary in order to improve the assessment of white matter architecture and connectivity in CSVD.Diffusion tensor imaging(DTI)and tractography is an application of dMRI that provides data that can be used to non-invasively appraise the brain white matter connections via fiber tracking and enable visualization of individual patient-specific white matter fiber tracts to reflect the extent of CSVD-associated white matter damage.However,due to a lack of standardization on various sets of software or image pipeline processing utilized in this technique that driven mostly from research setting,interpreting the findings remain contentious,especially to inform an improved diagnosis and/or prognosis of CSVD for routine clinical use.In this minireview,we highlight the advances in DTI pipeline processing and the prospect of this DTI metrics as potential imaging biomarker for CSVD,even for subclinical CSVD in at-risk individuals.展开更多
The underlying changes in the neuronal connectivity adjacent to brain tumours cannot always be depicted by conventional MR imaging. The hypothesis of this study was that preoperative neuropsychological deficits were a...The underlying changes in the neuronal connectivity adjacent to brain tumours cannot always be depicted by conventional MR imaging. The hypothesis of this study was that preoperative neuropsychological deficits were associated with impairment of diffusivity in association fibre bundles. Hence, we investigated the potential of combined diffusion tensor imaging (DTI) fibre tracking and fractional anisotropy (FA) values of the fibres to determine changes in association fibres and their correlation to neuropsychological scores. Our study consisted of eighteen patients with extra-axial brain tumours in areas adjacent to the frontal and temporal lobes. They were assessed pre- and postoperatively with DTI and neuropsychological assessments. MR examinations were performed on a 3T-scanner. FA values were calculated for the uncinate fasciculus, arcuate fasciculus, superior fronto-occipital fasciculus, inferior fronto-occipital fasciculus and corticospinal tracts ipsilateral and contralateral to the tumor. These values were compared with neuropsychological scores for language, memory and attention. The analysis revealed marked differences in pre- and post-excision of the tumor in both FA values and neuropsychological scores. Quantitative DTI was able to show significant differences in diffusivity of the association fibres before and after the surgery (P < 0.05). The additional use of DTI-fibre integrity and neuropsychological tests may aid in prognostication and decision making prior to surgery.展开更多
Diffusion tensor imaging plays an important role in the accurate diagnosis and prognosis of spinal cord diseases. However, because of technical limitations, the imaging sequences used in this technique cannot reveal t...Diffusion tensor imaging plays an important role in the accurate diagnosis and prognosis of spinal cord diseases. However, because of technical limitations, the imaging sequences used in this technique cannot reveal the fine structure of the spinal cord with precision. We used the readout segmentation of long variable echo-trains(RESOLVE) sequence in this cross-sectional study of 45 healthy volunteers aged 20 to 63 years. We found that the RESOLVE sequence significantly increased the resolution of the diffusion images and improved the median signal-to-noise ratio of the middle(C4–6) and lower(C7–T1) cervical segments to the level of the upper cervical segment. In addition, the values of fractional anisotropy and radial diffusivity were significantly higher in white matter than in gray matter. Our study verified that the RESOLVE sequence could improve resolution of diffusion tensor imaging in clinical applications and provide accurate baseline data for the diagnosis and treatment of cervical spinal cord diseases.展开更多
Many studies using diffusion tensor tractography(DTT) have demonstrated that injury of the spinothalamic tract(STT) is the pathogenetic mechanism of central post-stroke pain(CPSP) in intracerebral hemorrhage; however,...Many studies using diffusion tensor tractography(DTT) have demonstrated that injury of the spinothalamic tract(STT) is the pathogenetic mechanism of central post-stroke pain(CPSP) in intracerebral hemorrhage; however, there is no DTT study reporting the pathogenetic mechanism of CPSP in cerebral infarction. In this study, we investigated injury of the STT in patients with CPSP following cerebral infarction, using DTT. Five patients with CPSP following cerebral infarction and eight age-and sex-matched healthy control subjects were recruited for this study. STT was examined using DTT. Among DTT parameters of the affected STT, fractional anisotropy and tract volume were decreased by more than two standard deviations in two patients(patients 1 and 2) and three patients(patients 3, 4, and 5), respectively, compared with those of the control subjects, while mean diffusivity value was increased by more than two standard deviations in one patient(patient 2). Regarding DTT configuration, all affected STTs passed through adjacent part of the infarct and three STTs showed narrowing. These findings suggest that injury of the STT might be a pathogenetic etiology of CPSP in patients with cerebral infarction.展开更多
This study aimed to define the most consistent white matter microarchitecture pattern in Parkinson’s disease(PD)reflected by fractional anisotropy(FA),addressing clinical profiles and methodology-related heterogeneit...This study aimed to define the most consistent white matter microarchitecture pattern in Parkinson’s disease(PD)reflected by fractional anisotropy(FA),addressing clinical profiles and methodology-related heterogeneity.Web-based publication databases were searched to conduct a meta-analysis of whole-brain diffusion tensor imaging studies comparing PD with healthy controls(HC)using the anisotropic effect size–signed differential mapping.A total of 808 patients with PD and 760 HC coming from 27 databases were finally included.Subgroup analyses were conducted considering heterogeneity with respect to medication status,disease stage,analysis methods,and the number of diffusion directions in acquisition.Compared with HC,patients with PD had decreased FA in the left middle cerebellar peduncle,corpus callosum(CC),left inferior fronto-occipital fasciculus,and right inferior longitudinal fasciculus.Most of the main results remained unchanged in subgroup metaanalyses of medicated patients,early stage patients,voxel-based analysis,and acquisition with˂30 diffusion directions.The subgroup meta-analysis of medication-free patients showed FA decrease in the right olfactory cortex.The cerebellum and CC,associated with typical motor impairment,showed the most consistent FA decreases in PD.Medication status,analysis approaches,and the number of diffusion directions have an important impact on the findings,needing careful evaluation in future meta-analyses.展开更多
Objective To study the microscopic changes of white matter and the relationship between white matter changes and cognitive impairment in Alzheimer’s disease(AD)using voxel-based analysis of DTI.Methods Thirty-seven p...Objective To study the microscopic changes of white matter and the relationship between white matter changes and cognitive impairment in Alzheimer’s disease(AD)using voxel-based analysis of DTI.Methods Thirty-seven patients with probable AD,and 32 normal controls(NC)were all examined by MMSE scores,and un-展开更多
The main advantage of diffusion tensor tractography is that it allows the entire neural tract to be evaluated.In addition,configurational analysis of reconstructed neural tracts can indicate abnormalities such as tear...The main advantage of diffusion tensor tractography is that it allows the entire neural tract to be evaluated.In addition,configurational analysis of reconstructed neural tracts can indicate abnormalities such as tearing,narrowing,or discontinuations,which have been used to identify axonal injury of neural tracts in concussion patients.This review focuses on the characteristic features of axonal injury in concussion or mild traumatic brain injury(m TBI)patients through the use of diffusion tensor tractography.Axonal injury in concussion(m TBI)patients is characterized by their occurrence in long neural tracts and multiple injuries,and these characteristics are common in patients with diffuse axonal injury and in concussion(m TBI)patients with axonal injury.However,the discontinuation of the corticospinal tract is mostly observed in diffuse axonal injury,and partial tearing and narrowing in the subcortical white matter are frequently observed in concussion(m TBI)patients with axonal injury.This difference appears to be attributed to the observation that axonal injury in concussion(m TBI)patients is the result of weaker forces than those producing diffuse axonal injuries.In addition,regarding the fornix,in diffuse axonal injury,discontinuation of the fornical crus has been frequently reported,but in concussion(m TBI)patients,many collateral branches form in the fornix in addition to these findings in many case studies.It is presumed that the impact on the brain in TBI is relatively weaker than that in diffuse axonal injury,and that the formation of collateral branches occurs during the fornix recovery process.Although the occurrence of axonal injury in multiple areas of the brain is an important feature of diffuse axonal injury,case studies in concussion(m TBI)have shown that axonal injury occurs in multiple neural tracts.Because axonal injury lesions in m TBI patients may persist for approximately 10 years after injury onset,the characteristics of axonal injury in concussion(m TBI)patients,which are reviewed and categorized in this review,are expected to serve as useful supplementary information in the diagnosis of axonal injury in concussion(m TBI)patients.展开更多
BACKGROUND It is difficult to restore the cognitive functions of patients with impaired cognition caused by brain injury.Diffusion tensor imaging can visualize the integrity of neural tracts in the white matter(WM)thr...BACKGROUND It is difficult to restore the cognitive functions of patients with impaired cognition caused by brain injury.Diffusion tensor imaging can visualize the integrity of neural tracts in the white matter(WM)three-dimensionally.It is unclear whether encephalitis following scrub typhus damages the WM.For the first time,we aimed to report diffusion tensor tractography(DTT)findings in a chronic patient with cognitive impairment following scrub typhus encephalitis,which revealed injury to the Papez circuit of the WM.CASE SUMMARY A 70-year-old male patient was affected by encephalitis caused by scrub typhus that occurred 23 years ago.He had poor cognition and his clinical examination findings were as follows:Mini-Mental Status Examination score,14;and handgrip strength(right/left,kg),32.3/31.3.DTT revealed serious injuries of the left thalamocingulate tract and right mammillothalamic tract in the Papez circuit,and a partial injury of the anterior part of the fornix.CONCLUSION Using DTT,we found a relationship between cognitive impairment and the integrity of the Papez circuit following scrub typhus.展开更多
Objective: Cell structural changes are one of the main features observed during the development of amyotrophic lateral sclerosis(ALS). In this work, we propose the use of diffusion tensor imaging(DTI) metrics to asses...Objective: Cell structural changes are one of the main features observed during the development of amyotrophic lateral sclerosis(ALS). In this work, we propose the use of diffusion tensor imaging(DTI) metrics to assess specific ultrastructural changes in the central nervous system during the early neurodegenerative stages of ALS.Methods: Ultra-high field MRI and DTI data at 17.6 T were obtained from fixed, excised mouse brains, and spinal cords from ALS(G93 A-SOD1) mice.Results: Changes in fractional anisotropy(FA) and linear, planar, and spherical anisotropy ratios(C_L, C_P, and C_S, respectively) of the diffusion eigenvalues were measured in white matter(WM) and gray matter(GM) areas associated with early axonal degenerative processes(in both the brain and the spinal cord). Specifically, in WM structures(corpus callosum, corticospinal tract, and spinal cord funiculi) as the disease progressed, FA, C_L, and C_P values decreased, whereas C_S values increased. In GM structures(prefrontal cortex, hippocampus, and central spinal cord) FA and C_P decreased, whereas the C_L and C_S values were unchanged or slightly smaller. Histological studies of a fluorescent mice model(YFP, G93 A-SOD1 mouse) corroborated the early alterations in neuronal morphology and axonal connectivity measured by DTI.Conclusions: Changes in diffusion tensor shape were observed in this animal model at the early, nonsymptomatic stages of ALS. Further studies of C_L, C_P, and C_S as imaging biomarkers should be undertaken to refine this neuroimaging tool for future clinical use in the detection of the early stages of ALS.展开更多
According to clinical statistics,the mortality of patients with early brainstem hemorrhage is high.In this study,we established rat models of brainstem hemorrhage by injecting type Ⅶ collagenase into the right basote...According to clinical statistics,the mortality of patients with early brainstem hemorrhage is high.In this study,we established rat models of brainstem hemorrhage by injecting type Ⅶ collagenase into the right basotegmental pontine and investigated the pathological changes of early brainstem hemorrhage using multi-sequence magnetic resonance imaging and histopathological methods.We found that brainstem hematoma gradually formed in the injured rats over the first 3 days and then reduced after 7 days.The edema that occurred was mainly of the vasogenic type.No complete myelin sheath structure was found around the focus of the brainstem hemorrhage.The integrity and continuity of nerve fibers gradually deteriorated over the first 7 days.Neuronal degeneration was mild in the first 3 days and then obviously aggravated on the 7^(th)day.Inflammatory cytokines,interleukin-1β,and tumor necrosis factorαappeared on the 1st day after intracerebral hemorrhage,reached peak levels on the 3^(rd)day,and decreased from the 7^(th)day.Our findings show the characteristics of the progression of early brainstem hemorrhage.展开更多
Multiple sclerosis is associated with structural and functional brain alterations leading to cognitive impairments across multiple domains including attention,memory,and the speed of information processing.The hippoca...Multiple sclerosis is associated with structural and functional brain alterations leading to cognitive impairments across multiple domains including attention,memory,and the speed of information processing.The hippocampus,which is a brain important structure involved in memory,undergoes microstructural changes in the early stage of multiple sclerosis.In this study,we analyzed hippocampal function and structure in patients with relapsing-remitting multiple sclerosis and explored correlations between the functional connectivity of the hippocampus to the whole brain,changes in local brain function and microstructure,and cognitive function at rest.We retrospectively analyzed data from 20 relapsing-remitting multiple sclerosis patients admitted to the Department of Neurology at the China-Japan Union Hospital of Jilin University,China,from April 2015 to November 2019.Sixteen healthy volunteers were recruited as the healthy control group.All participants were evaluated using a scale of extended disability status and the Montreal cognitive assessment within 1 week before and after head diffusion tensor imaging and functional magnetic resonance imaging.Compared with the healthy control group,the patients with relapsing-remitting multiple sclerosis had lower Montreal cognitive assessment scores and regions of simultaneously enhanced and attenuated whole-brain functional connectivity and local functional connectivity in the bilateral hippocampus.Hippocampal diffusion tensor imaging data showed that,compared with the healthy control group,patients with relapsing-remitting multiple sclerosis had lower hippocampal fractional anisotropy values and higher mean diffusivity values,suggesting abnormal hippocampal structure.The left hippocampus whole-brain functional connectivity was negatively correlated with the Montreal cognitive assessment score(r=-0.698,P=0.025),and whole-brain functional connectivity of the right hippocampus was negatively correlated with extended disability status scale score(r=-0.649,P=0.042).The mean diffusivity value of the left hippocampus was negatively correlated with the Montreal cognitive assessment score(r=-0.729,P=0.017)and positively correlated with the extended disability status scale score(r=0.653,P=0.041).The right hippocampal mean diffusivity value was positively correlated with the extended disability status scale score(r=0.684,P=0.029).These data suggest that the functional connectivity and presence of structural abnormalities in the hippocampus in patients with relapse-remission multiple sclerosis are correlated with the degree of cognitive function and extent of disability.This study was approved by the Ethics Committee of China-Japan Union Hospital of Jilin University,China(approval No.201702202)on February 22,2017.展开更多
During the last decades,advances in the understanding of genetic,cellular,and microstructural alterations associated to Huntington's disease(HD)have improved the understanding of this progressive and fatal illness...During the last decades,advances in the understanding of genetic,cellular,and microstructural alterations associated to Huntington's disease(HD)have improved the understanding of this progressive and fatal illness.However,events related to early neuropathological events,neuroinflammation,deterioration of neuronal connectivity and compensatory mechanisms still remain vastly unknown.Ultra-high field diffusion MRI(UHFD-MRI)techniques can contribute to a more comprehensive analysis of the early microstructural changes observed in HD.In addition,it is possible to evaluate if early imaging microstructural parameters might be linked to histological biomarkers.Moreover,qualitative studies analyzing histological complexity in brain areas susceptible to neurodegeneration could provide information on inflammatory events,compensatory increase of neuroconnectivity and mechanisms of brain repair and regeneration.The application of ultra-high field diffusion-MRI technology in animal models,particularly the R6/1 mice(a common preclinical mammalian model of HD),provide the opportunity to analyze alterations in a physiologically intact model of the disease.Although some disparities in volumetric changes across different brain structures between preclinical and clinical models has been documented,further application of different diffusion MRI techniques used in combination like diffusion tensor imaging,and neurite orientation dispersion and density imaging have proved effective in characterizing early parameters associated to alteration in water diffusion exchange within intracellular and extracellular compartments in brain white and grey matter.Thus,the combination of diffusion MRI imaging techniques and more complex neuropathological analysis could accelerate the discovery of new imaging biomarkers and the early diagnosis and neuromonitoring of patients affected with HD.展开更多
Objective:To achieve precision medicine,the use of imaging methods to help the clinical detection of cerebral infarction is conducive to the clinical development of a treatment plan and increase of the cure rate and i...Objective:To achieve precision medicine,the use of imaging methods to help the clinical detection of cerebral infarction is conducive to the clinical development of a treatment plan and increase of the cure rate and improvement of the prognosis of patients.Methods:In this work,T2-weighted imaging(T2WI),diffusion-weighted imaging(DWI),susceptibility-weighted imaging(SWI),and diffusion tensor imaging(DTI)examinations were performed on 34 patients with clinically diagnosed cerebral infarction to measure the difference in signal intensity between the lesion and its mirror area and make a comparative analysis by means of the Student-Newman-Keuls method.Results:The detection rate of T2WI was 79%(27/34),the detection rate of DWI was 97%(33/34),the detection rate of SWI was 88%(30/34),and the detection rate of DTI was 94%(32/34).Conclusion:The imaging performance was in the order DWI>DTI>SWI>T2WI for the diagnosis of cerebral infarction,and combined imaging is better than single imaging.展开更多
Cognitive impairment is the most common complication in patients with temporal lobe epilepsy with hippocampal scle rosis.There is no effective treatment for cognitive impairment.Medial septum cholinergic neurons have ...Cognitive impairment is the most common complication in patients with temporal lobe epilepsy with hippocampal scle rosis.There is no effective treatment for cognitive impairment.Medial septum cholinergic neurons have been reported to be a potential target for controlling epileptic seizures in tempo ral lobe epile psy.However,their role in the cognitive impairment of temporal lobe epilepsy remains unclear.In this study,we found that patients with temporal lobe epile psy with hippocampal sclerosis had a low memory quotient and severe impairment in verbal memory,but had no impairment in nonverbal memory.The cognitive impairment was slightly correlated with reduced medial septum volume and medial septum-hippocampus tra cts measured by diffusion tensor imaging.In a mouse model of chronic temporal lobe epilepsy induced by kainic acid,the number of medial septum choline rgic neurons was reduced and acetylcholine release was reduced in the hippocampus.Furthermore,selective apoptosis of medial septum cholinergic neurons mimicked the cognitive deficits in epileptic mice,and activation of medial septum cholinergic neurons enhanced hippocampal acetylcholine release and restored cognitive function in both kainic acid-and kindling-induced epile psy models.These res ults suggest that activation of medial septum cholinergic neurons reduces cognitive deficits in temporal lobe epilepsy by increasing acetylcholine release via projections to the hippocampus.展开更多
基金supported by the National Natural Science Foundation of China, No. 82102676 (to CBL)a grant from Beijing Municipal Science & Technology Commission, No. Z171100001017076 (to JJL)+1 种基金National Key Research and Development Program, No. 2018YFF0301104 (to JJL)Research on Medical Protection Technology and Application of Induced Neural Stem Cells in the Treatment of Military Spinal Cord Injury, No. Z181100004118004 (to JL)
文摘Based on the Wallerian degeneration in the spinal cord pathways,the changes in synaptic connections,and the spinal cord-related cellular responses that alter the cellular structure of the brain,we presumed that brain diffusion tensor imaging(DTI)parameters may change after spinal cord injury.However,the dynamic changes in DTI parameters remain unclear.We established a Beagle dog model of T10 spinal cord contusion and performed DTI of the injured spinal cord.We found dynamic changes in DTI parameters in the cerebral peduncle,posterior limb of the internal capsule,pre-and postcentral gyri of the brain within 12 weeks after spinal cord injury.We then performed immunohistochemistry to detect the expression of neurofilament heavy polypeptide(axonal marker),glial fibrillary acidic protein(glial cell marker),and NeuN(neuronal marker).We found that these pathological changes were consistent with DTI parameter changes.These findings suggest that DTI can display brain structure changes after spinal cord injury.
基金supported by a grant from the Clinical Medicine Science and Technology Projects in Jiangsu Province of China,No.BL2014037a grant from the Changzhou City Science and Technology Support Plan in China,No.CE20165027+1 种基金a grant from the Changzhou Health Development Planning Commission Major Projects in China,No.ZD201515the Changzhou High-Level Health Personnel Training Project Funding
文摘With improvements in care of at-risk neonates, more and more children survive. This makes it increasingly important to assess, soon after birth, the prognosis of children with hypoxic-ischemic encephalopathy. Computed tomography, ultrasound, and conventional magnetic resonance imaging are helpful to diagnose brain injury, but cannot quantify white matter damage. In this study, ten full-term infants without brain injury and twenty-two full-term neonates with hypoxic-ischemic encephalopathy(14 moderate cases and 8 severe cases) underwent diffusion tensor imaging to assess its feasibility in evaluating white matter damage in this condition. Results demonstrated that fractional anisotropy, voxel volume, and number of fiber bundles were different in some brain areas between infants with brain injury and those without brain injury. The correlation between fractional anisotropy values and neonatal behavioral neurological assessment scores was closest in the posterior limbs of the internal capsule. We conclude that diffusion tensor imaging can quantify white matter injury in neonates with hypoxic-ischemic encephalopathy.
基金supported by the Fundamental Research Funds for Central Public Welfare Research Institute of China,Nos.2015CZ-36(to HTL)and 2019CZ-7(to WZW)。
文摘At present,predicting the severity of brain injury caused by global cerebral ischemia/reperfusion injury(GCI/RI)is a clinical problem.After such an injury,clinical indicators that can directly reflect neurological dysfunction are lacking.The change in hippocampal microstructure is the key to memory formation and consolidation.Diffusion tensor imaging is a highly sensitive tool for visualizing injury to hippocampal microstructure.Although hippocampal microstructure,brain-derived neurotrophic factor(BDNF),and tropomyosin-related kinase B(Trk B)levels are closely related to nerve injury and the repair process after GCI/RI,whether these indicators can reflect the severity of such hippocampal injury remains unknown.To address this issue,we established rat models of GCI/RI using the four-vessel occlusion method.Diffusion tensor imaging parameters,BDNF,and Trk B levels were correlated with modified neurological severity scores.The results revealed that after GCI/RI,while neurological function was not related to BDNF and Trk B levels,it was related to hippocampal fractional anisotropy.These findings suggest that hippocampal fractional anisotropy can reflect the severity of hippocampal injury after global GCI/RI.The study was approved by the Institutional Animal Care and Use Committee of Capital Medical University,China(approval No.AEEI-2015-139)on November 9,2015.
文摘BACKGROUND: This systematic review aims to investigate the prediction value of diffusion tensor imaging for motor function recovery of ischemic stroke patients.METHODS: Cochrane Central Register of Controlled Trials(CENTRAL)(the Cochrane Library 2016, Issue 9), Pub Med, Embase, Clarivate Analytics, Scopus, CINAHL, Chinese Biomedical Literature Database, China National Knowledge Infrastructure and Google Scholar were searched for either motor recovery or corticospinal tract integrity by diffusion tensor imaging in different stroke phase from January 1, 1970, to October 31, 2016. The study design and participants were subjected to metrological analysis. Correlation coeffi cient(r) was used for evaluating the relationship between fractional anisotropy(FA) and motor function outcome. Correlation coeffi cient values were extracted from each study, and 95% confidence intervals(CIs) were calculated by Fisher's z transformation. Meta-analysis was conducted by STATA software.RESULTS: Fifteen studies with a total of 414 patients were included. Meta-analysis showed that FA in the subacute phase had the signifi cant correlation with motor function outcome(ES=0.75, 95%CI 0.62–0.87), which showed moderate quality based on GRADE system. The weight correlation coeffi cient revealed that an effect size(ES) of FA in acute phase and chronic phase was 0.51(95%CI 0.33–0.68) and 0.62(95%CI 0.47–0.77) respectively.CONCLUSION: This meta-analysis reveals that FA in the subacute phase after ischemic stroke is a good predictor for functional motor recovery, which shows moderate quality based on the GRADE system.
文摘BACKGROUND: Diffusion tensor imaging (DTI) is one of the noninvasive methods to study the morphological structure of brain white matter fibrous bands in vivo, and it has been applied primarily in clinic. DTI is acknowledged as the more effective imaging method to diagnose ultra-acute and/or acute cerebral infarction. OBJECTIVE: To observe the anisotropic characters of cerebral white matter fibrous bands in patients with ischemic stroke by using DTI, and investigate the correlation between the damage of corticospinal tract and muscle strength in patients with ischemic stroke at acute period. DESIGN: A case-control observation. SETTING: Department of Medical Imaging, Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA. PARTICIPANTS: Nine inpatients with injury of motor function induced by acute ischemic stroke (patient group) at 6 hours to 2 weeks after the attack were selected from the Department of Neurology, Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA from September 2005 to March 2006, and they all accorded with the present diagnostic standard for cerebrovascular disease in China. There were 5 males and 4 females, aged 16-87 years. At the same time, nine healthy right-handed physical examinees matched by age and sex with the patients were taken as the control group, and they all had no nervous disease, mental diseases, cerebrovascular abnormalities and injury history, etc. All the subjects were informed with the detected items and agreed to participate in the study. METHODS: All the 9 patients with ischemic stroke at acute period and 9 healthy subjects were examined with MRI, T1 weighted imaging, T2 weighted imaging and DTI. And the data were processed offline with dTV.II software, the images of fractional anisotropy and directional encoded color (DEC) were obtained, and the three-dimensional fibrous band images of bilateral corticospinal tracts were reconstructed. In the control group, the values of fractional anisotropy of main white matter fibrous bands were measured in the region of interest (ROI) of the anterior limb, knee and posterior limb of internal capsule. In the patient group, the values of fractional anisotropy of white matter were measured in the infarcted sites and corresponding contralateral sites of the patients. The ROI was set in bilateral cerebral peduncles to reconstruct three-dimensionally the bilateral corticospinal tracts. The muscle strength of the affected hand was assessed with Brunnstorm standard in the stroke patients. MAIN OUTCOME MEASURES: The characters of DTI and images of the value of fractional anisotropy, and the manifestations of three-dimensional corticospinal tracts were observed in the two groups. RESULTS: All the data from the 9 patients and 9 healthy volunteers were involved in the analysis of results. ① In the control group, the white matter and gray matter could be distinguished clearly in the image of fractional anisotropic values, the fibers of different directions were shown by different colors in DEC picture, which clearly demonstrated the normal anatomic structure and direction of white matter fibers. In the patient group, the infarctions occurred in the gray matter or white matter could be distinguished in the images of fractional anisotropic values, DEC picture could clearly show the direct influence of the infarcted site on the white matter fibers. The fractional anisotropic values in different white matter structure of the same side were significantly different in the control group (t=3.12, P < 0.05), and the reconstructed images fractional anisotropic values and DEC picture could show most of the main white matter fibrous bands. The fractional anisotropic values of the infarcted sites were significantly lower than the contralateral ones in the patient group (t=5.570, P < 0.01). ② The reconstructed bilateral corticospinal tracts showed that the anatomic forms of the contralateral corticospinal tract of the patients were almost identical to those of normal people, it started from precentral gyrus, downward to the nternal capsule, and extended to pontine and medulla oblongata, each fibrous band was continuous, and the form had good consistency. Because of the involvement of infarction of different severity, the ipsilateral corticospinal tract manifested as continuous interruption and the loss of consistent anatomic structural form. The involved severity of corticospinal tract had significant correlation with that of muscle strength of the ipsilateral hand (r=1.30, P < 0.01). CONCLUSION: ① DTI can display the direction and distribution of cerebral white matter fibrous bands. ② DTI images of fractional anisotropic values and DEC can show the directions and anisotropic degree of white matter fibers in the infarcted sites of stroke patients. ③ The three-dimensional images of fibrous bands can show the conditions of pyramidal tracts more directly. ④ The damaged severity of corticospinal tracts is correlated with that of muscle strength.
文摘Cerebral small vessel disease(CSVD)is a leading cause of age-related microvascular cognitive decline,resulting in significant morbidity and decreased quality of life.Despite a progress on its key pathophysiological bases and general acceptance of key terms from neuroimaging findings as observed on the magnetic resonance imaging(MRI),key questions on CSVD remain elusive.Enhanced relationships and reliable lesion studies,such as white matter tractography using diffusion-based MRI(dMRI)are necessary in order to improve the assessment of white matter architecture and connectivity in CSVD.Diffusion tensor imaging(DTI)and tractography is an application of dMRI that provides data that can be used to non-invasively appraise the brain white matter connections via fiber tracking and enable visualization of individual patient-specific white matter fiber tracts to reflect the extent of CSVD-associated white matter damage.However,due to a lack of standardization on various sets of software or image pipeline processing utilized in this technique that driven mostly from research setting,interpreting the findings remain contentious,especially to inform an improved diagnosis and/or prognosis of CSVD for routine clinical use.In this minireview,we highlight the advances in DTI pipeline processing and the prospect of this DTI metrics as potential imaging biomarker for CSVD,even for subclinical CSVD in at-risk individuals.
文摘The underlying changes in the neuronal connectivity adjacent to brain tumours cannot always be depicted by conventional MR imaging. The hypothesis of this study was that preoperative neuropsychological deficits were associated with impairment of diffusivity in association fibre bundles. Hence, we investigated the potential of combined diffusion tensor imaging (DTI) fibre tracking and fractional anisotropy (FA) values of the fibres to determine changes in association fibres and their correlation to neuropsychological scores. Our study consisted of eighteen patients with extra-axial brain tumours in areas adjacent to the frontal and temporal lobes. They were assessed pre- and postoperatively with DTI and neuropsychological assessments. MR examinations were performed on a 3T-scanner. FA values were calculated for the uncinate fasciculus, arcuate fasciculus, superior fronto-occipital fasciculus, inferior fronto-occipital fasciculus and corticospinal tracts ipsilateral and contralateral to the tumor. These values were compared with neuropsychological scores for language, memory and attention. The analysis revealed marked differences in pre- and post-excision of the tumor in both FA values and neuropsychological scores. Quantitative DTI was able to show significant differences in diffusivity of the association fibres before and after the surgery (P < 0.05). The additional use of DTI-fibre integrity and neuropsychological tests may aid in prognostication and decision making prior to surgery.
文摘Diffusion tensor imaging plays an important role in the accurate diagnosis and prognosis of spinal cord diseases. However, because of technical limitations, the imaging sequences used in this technique cannot reveal the fine structure of the spinal cord with precision. We used the readout segmentation of long variable echo-trains(RESOLVE) sequence in this cross-sectional study of 45 healthy volunteers aged 20 to 63 years. We found that the RESOLVE sequence significantly increased the resolution of the diffusion images and improved the median signal-to-noise ratio of the middle(C4–6) and lower(C7–T1) cervical segments to the level of the upper cervical segment. In addition, the values of fractional anisotropy and radial diffusivity were significantly higher in white matter than in gray matter. Our study verified that the RESOLVE sequence could improve resolution of diffusion tensor imaging in clinical applications and provide accurate baseline data for the diagnosis and treatment of cervical spinal cord diseases.
基金supported by the National Research Foundation(NRF)of Korea Grant funded by the Korean Government(MSIP),No.NRF-2015R1D1A1A01060314
文摘Many studies using diffusion tensor tractography(DTT) have demonstrated that injury of the spinothalamic tract(STT) is the pathogenetic mechanism of central post-stroke pain(CPSP) in intracerebral hemorrhage; however, there is no DTT study reporting the pathogenetic mechanism of CPSP in cerebral infarction. In this study, we investigated injury of the STT in patients with CPSP following cerebral infarction, using DTT. Five patients with CPSP following cerebral infarction and eight age-and sex-matched healthy control subjects were recruited for this study. STT was examined using DTT. Among DTT parameters of the affected STT, fractional anisotropy and tract volume were decreased by more than two standard deviations in two patients(patients 1 and 2) and three patients(patients 3, 4, and 5), respectively, compared with those of the control subjects, while mean diffusivity value was increased by more than two standard deviations in one patient(patient 2). Regarding DTT configuration, all affected STTs passed through adjacent part of the infarct and three STTs showed narrowing. These findings suggest that injury of the STT might be a pathogenetic etiology of CPSP in patients with cerebral infarction.
基金supported by the National Natural Science Foundation(Nos.81621003,81761128023,81220108013,81227002,and 81030027)the Program for Innovative Research Team in University(No.IRT16R52)of China+1 种基金the Professorship Award(No.T2014190)of Chinathe CMB Distinguished Professorship Award(No.F510000/G16916411)administered by the Institute of International Education.
文摘This study aimed to define the most consistent white matter microarchitecture pattern in Parkinson’s disease(PD)reflected by fractional anisotropy(FA),addressing clinical profiles and methodology-related heterogeneity.Web-based publication databases were searched to conduct a meta-analysis of whole-brain diffusion tensor imaging studies comparing PD with healthy controls(HC)using the anisotropic effect size–signed differential mapping.A total of 808 patients with PD and 760 HC coming from 27 databases were finally included.Subgroup analyses were conducted considering heterogeneity with respect to medication status,disease stage,analysis methods,and the number of diffusion directions in acquisition.Compared with HC,patients with PD had decreased FA in the left middle cerebellar peduncle,corpus callosum(CC),left inferior fronto-occipital fasciculus,and right inferior longitudinal fasciculus.Most of the main results remained unchanged in subgroup metaanalyses of medicated patients,early stage patients,voxel-based analysis,and acquisition with˂30 diffusion directions.The subgroup meta-analysis of medication-free patients showed FA decrease in the right olfactory cortex.The cerebellum and CC,associated with typical motor impairment,showed the most consistent FA decreases in PD.Medication status,analysis approaches,and the number of diffusion directions have an important impact on the findings,needing careful evaluation in future meta-analyses.
文摘Objective To study the microscopic changes of white matter and the relationship between white matter changes and cognitive impairment in Alzheimer’s disease(AD)using voxel-based analysis of DTI.Methods Thirty-seven patients with probable AD,and 32 normal controls(NC)were all examined by MMSE scores,and un-
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean Goverment,No.2018R1A6A3A11050913(to YSS)。
文摘The main advantage of diffusion tensor tractography is that it allows the entire neural tract to be evaluated.In addition,configurational analysis of reconstructed neural tracts can indicate abnormalities such as tearing,narrowing,or discontinuations,which have been used to identify axonal injury of neural tracts in concussion patients.This review focuses on the characteristic features of axonal injury in concussion or mild traumatic brain injury(m TBI)patients through the use of diffusion tensor tractography.Axonal injury in concussion(m TBI)patients is characterized by their occurrence in long neural tracts and multiple injuries,and these characteristics are common in patients with diffuse axonal injury and in concussion(m TBI)patients with axonal injury.However,the discontinuation of the corticospinal tract is mostly observed in diffuse axonal injury,and partial tearing and narrowing in the subcortical white matter are frequently observed in concussion(m TBI)patients with axonal injury.This difference appears to be attributed to the observation that axonal injury in concussion(m TBI)patients is the result of weaker forces than those producing diffuse axonal injuries.In addition,regarding the fornix,in diffuse axonal injury,discontinuation of the fornical crus has been frequently reported,but in concussion(m TBI)patients,many collateral branches form in the fornix in addition to these findings in many case studies.It is presumed that the impact on the brain in TBI is relatively weaker than that in diffuse axonal injury,and that the formation of collateral branches occurs during the fornix recovery process.Although the occurrence of axonal injury in multiple areas of the brain is an important feature of diffuse axonal injury,case studies in concussion(m TBI)have shown that axonal injury occurs in multiple neural tracts.Because axonal injury lesions in m TBI patients may persist for approximately 10 years after injury onset,the characteristics of axonal injury in concussion(m TBI)patients,which are reviewed and categorized in this review,are expected to serve as useful supplementary information in the diagnosis of axonal injury in concussion(m TBI)patients.
基金National Research Foundation of Korea funded by the Ministry of Education,No.2013R1A1A4A01013178.
文摘BACKGROUND It is difficult to restore the cognitive functions of patients with impaired cognition caused by brain injury.Diffusion tensor imaging can visualize the integrity of neural tracts in the white matter(WM)three-dimensionally.It is unclear whether encephalitis following scrub typhus damages the WM.For the first time,we aimed to report diffusion tensor tractography(DTT)findings in a chronic patient with cognitive impairment following scrub typhus encephalitis,which revealed injury to the Papez circuit of the WM.CASE SUMMARY A 70-year-old male patient was affected by encephalitis caused by scrub typhus that occurred 23 years ago.He had poor cognition and his clinical examination findings were as follows:Mini-Mental Status Examination score,14;and handgrip strength(right/left,kg),32.3/31.3.DTT revealed serious injuries of the left thalamocingulate tract and right mammillothalamic tract in the Papez circuit,and a partial injury of the anterior part of the fornix.CONCLUSION Using DTT,we found a relationship between cognitive impairment and the integrity of the Papez circuit following scrub typhus.
基金Magnetic Laboratory Visiting Scientist Program,Grant/Award Number 327Chicago Biomedical Consortium,Grant/Award Number 085740National Science Foundation,Grant/Award Number DMR-1157490。
文摘Objective: Cell structural changes are one of the main features observed during the development of amyotrophic lateral sclerosis(ALS). In this work, we propose the use of diffusion tensor imaging(DTI) metrics to assess specific ultrastructural changes in the central nervous system during the early neurodegenerative stages of ALS.Methods: Ultra-high field MRI and DTI data at 17.6 T were obtained from fixed, excised mouse brains, and spinal cords from ALS(G93 A-SOD1) mice.Results: Changes in fractional anisotropy(FA) and linear, planar, and spherical anisotropy ratios(C_L, C_P, and C_S, respectively) of the diffusion eigenvalues were measured in white matter(WM) and gray matter(GM) areas associated with early axonal degenerative processes(in both the brain and the spinal cord). Specifically, in WM structures(corpus callosum, corticospinal tract, and spinal cord funiculi) as the disease progressed, FA, C_L, and C_P values decreased, whereas C_S values increased. In GM structures(prefrontal cortex, hippocampus, and central spinal cord) FA and C_P decreased, whereas the C_L and C_S values were unchanged or slightly smaller. Histological studies of a fluorescent mice model(YFP, G93 A-SOD1 mouse) corroborated the early alterations in neuronal morphology and axonal connectivity measured by DTI.Conclusions: Changes in diffusion tensor shape were observed in this animal model at the early, nonsymptomatic stages of ALS. Further studies of C_L, C_P, and C_S as imaging biomarkers should be undertaken to refine this neuroimaging tool for future clinical use in the detection of the early stages of ALS.
基金supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region, No. 2020D01A13 (to CWW)Chengdu Science and Technology Bureau, No. 2019-YF05-00511-SN (to MT)1.3.5 Project for Disciplines of Excellence, West China Hospital, Sichuan University, Nos. ZY2016102 (to MT), and ZY2016203 (to CY)
文摘According to clinical statistics,the mortality of patients with early brainstem hemorrhage is high.In this study,we established rat models of brainstem hemorrhage by injecting type Ⅶ collagenase into the right basotegmental pontine and investigated the pathological changes of early brainstem hemorrhage using multi-sequence magnetic resonance imaging and histopathological methods.We found that brainstem hematoma gradually formed in the injured rats over the first 3 days and then reduced after 7 days.The edema that occurred was mainly of the vasogenic type.No complete myelin sheath structure was found around the focus of the brainstem hemorrhage.The integrity and continuity of nerve fibers gradually deteriorated over the first 7 days.Neuronal degeneration was mild in the first 3 days and then obviously aggravated on the 7^(th)day.Inflammatory cytokines,interleukin-1β,and tumor necrosis factorαappeared on the 1st day after intracerebral hemorrhage,reached peak levels on the 3^(rd)day,and decreased from the 7^(th)day.Our findings show the characteristics of the progression of early brainstem hemorrhage.
基金supported by the Project of International Cooperation of Jilin Province in China,No.20180414062GH(to XMH)Health research talents Project of Jilin Province in China,No.2019sc2018(to XMH)。
文摘Multiple sclerosis is associated with structural and functional brain alterations leading to cognitive impairments across multiple domains including attention,memory,and the speed of information processing.The hippocampus,which is a brain important structure involved in memory,undergoes microstructural changes in the early stage of multiple sclerosis.In this study,we analyzed hippocampal function and structure in patients with relapsing-remitting multiple sclerosis and explored correlations between the functional connectivity of the hippocampus to the whole brain,changes in local brain function and microstructure,and cognitive function at rest.We retrospectively analyzed data from 20 relapsing-remitting multiple sclerosis patients admitted to the Department of Neurology at the China-Japan Union Hospital of Jilin University,China,from April 2015 to November 2019.Sixteen healthy volunteers were recruited as the healthy control group.All participants were evaluated using a scale of extended disability status and the Montreal cognitive assessment within 1 week before and after head diffusion tensor imaging and functional magnetic resonance imaging.Compared with the healthy control group,the patients with relapsing-remitting multiple sclerosis had lower Montreal cognitive assessment scores and regions of simultaneously enhanced and attenuated whole-brain functional connectivity and local functional connectivity in the bilateral hippocampus.Hippocampal diffusion tensor imaging data showed that,compared with the healthy control group,patients with relapsing-remitting multiple sclerosis had lower hippocampal fractional anisotropy values and higher mean diffusivity values,suggesting abnormal hippocampal structure.The left hippocampus whole-brain functional connectivity was negatively correlated with the Montreal cognitive assessment score(r=-0.698,P=0.025),and whole-brain functional connectivity of the right hippocampus was negatively correlated with extended disability status scale score(r=-0.649,P=0.042).The mean diffusivity value of the left hippocampus was negatively correlated with the Montreal cognitive assessment score(r=-0.729,P=0.017)and positively correlated with the extended disability status scale score(r=0.653,P=0.041).The right hippocampal mean diffusivity value was positively correlated with the extended disability status scale score(r=0.684,P=0.029).These data suggest that the functional connectivity and presence of structural abnormalities in the hippocampus in patients with relapse-remission multiple sclerosis are correlated with the degree of cognitive function and extent of disability.This study was approved by the Ethics Committee of China-Japan Union Hospital of Jilin University,China(approval No.201702202)on February 22,2017.
基金supported in part by the High Magnetic Field Laboratory(NHMFL)and Advanced Magnetic Resonance Imaging and Spectroscopy(AMRIS)under Magnetic Laboratory Visiting Scientist Program Award,No.VSP#327(to RG)。
文摘During the last decades,advances in the understanding of genetic,cellular,and microstructural alterations associated to Huntington's disease(HD)have improved the understanding of this progressive and fatal illness.However,events related to early neuropathological events,neuroinflammation,deterioration of neuronal connectivity and compensatory mechanisms still remain vastly unknown.Ultra-high field diffusion MRI(UHFD-MRI)techniques can contribute to a more comprehensive analysis of the early microstructural changes observed in HD.In addition,it is possible to evaluate if early imaging microstructural parameters might be linked to histological biomarkers.Moreover,qualitative studies analyzing histological complexity in brain areas susceptible to neurodegeneration could provide information on inflammatory events,compensatory increase of neuroconnectivity and mechanisms of brain repair and regeneration.The application of ultra-high field diffusion-MRI technology in animal models,particularly the R6/1 mice(a common preclinical mammalian model of HD),provide the opportunity to analyze alterations in a physiologically intact model of the disease.Although some disparities in volumetric changes across different brain structures between preclinical and clinical models has been documented,further application of different diffusion MRI techniques used in combination like diffusion tensor imaging,and neurite orientation dispersion and density imaging have proved effective in characterizing early parameters associated to alteration in water diffusion exchange within intracellular and extracellular compartments in brain white and grey matter.Thus,the combination of diffusion MRI imaging techniques and more complex neuropathological analysis could accelerate the discovery of new imaging biomarkers and the early diagnosis and neuromonitoring of patients affected with HD.
文摘Objective:To achieve precision medicine,the use of imaging methods to help the clinical detection of cerebral infarction is conducive to the clinical development of a treatment plan and increase of the cure rate and improvement of the prognosis of patients.Methods:In this work,T2-weighted imaging(T2WI),diffusion-weighted imaging(DWI),susceptibility-weighted imaging(SWI),and diffusion tensor imaging(DTI)examinations were performed on 34 patients with clinically diagnosed cerebral infarction to measure the difference in signal intensity between the lesion and its mirror area and make a comparative analysis by means of the Student-Newman-Keuls method.Results:The detection rate of T2WI was 79%(27/34),the detection rate of DWI was 97%(33/34),the detection rate of SWI was 88%(30/34),and the detection rate of DTI was 94%(32/34).Conclusion:The imaging performance was in the order DWI>DTI>SWI>T2WI for the diagnosis of cerebral infarction,and combined imaging is better than single imaging.
基金National Natural Science Foundation of China,Nos.82003 729 (to Ying W),82022071 (to YiW)Natural Science Foundation of Shandong Province of China,No.ZR2020QH357 (to Ying W)Public Welfare Technology Research Program of Zhejiang Province,No.LGF20H09001 1 (to JF)。
文摘Cognitive impairment is the most common complication in patients with temporal lobe epilepsy with hippocampal scle rosis.There is no effective treatment for cognitive impairment.Medial septum cholinergic neurons have been reported to be a potential target for controlling epileptic seizures in tempo ral lobe epile psy.However,their role in the cognitive impairment of temporal lobe epilepsy remains unclear.In this study,we found that patients with temporal lobe epile psy with hippocampal sclerosis had a low memory quotient and severe impairment in verbal memory,but had no impairment in nonverbal memory.The cognitive impairment was slightly correlated with reduced medial septum volume and medial septum-hippocampus tra cts measured by diffusion tensor imaging.In a mouse model of chronic temporal lobe epilepsy induced by kainic acid,the number of medial septum choline rgic neurons was reduced and acetylcholine release was reduced in the hippocampus.Furthermore,selective apoptosis of medial septum cholinergic neurons mimicked the cognitive deficits in epileptic mice,and activation of medial septum cholinergic neurons enhanced hippocampal acetylcholine release and restored cognitive function in both kainic acid-and kindling-induced epile psy models.These res ults suggest that activation of medial septum cholinergic neurons reduces cognitive deficits in temporal lobe epilepsy by increasing acetylcholine release via projections to the hippocampus.
