静息态脑功能磁共振成像在急性轻型脑外伤中的应用

目的 分析静息态脑功能磁共振成像在急性轻型脑外伤临床中的应用效果。 方法 选取北京博爱医院2019年5月至2021年5月收治的急性轻型脑外伤患者47例为观察组,同期行常规体检的健康人50例为对照组,采用静息态脑功能磁共振成像采集低频震荡幅度(ALFF),采用简易精神状态检查(MMSE)、蒙特利尔认知评定(MoCA)、Rivermead行为记忆功能测试(RBMT)进行评定。 结果 与对照组相比,观察组MMSE、MocA、RBMT评分均显著降低(t > 18.138, P < 0.001);观察组ALFF降低的脑区包括小脑后叶、小脑扁桃体、下半月小叶、右侧颞上回、右侧颞中回、右侧顶叶和右侧中央后回等,ALFF升高的脑区包括边缘叶、扣带回、楔前叶、左侧小脑、右侧颞上回、右侧颞中回、右侧额上回、右侧额中回和右侧额下回等。 结论 急性轻型脑外伤患者存在多个脑区异常改变,可能与认知障碍有关。     

Dynamic imaging in mild traumatic brain injury: support for the theory of medial temporal vulnerability

OBJECTIVE: To determine whether patients with mild traumatic brain injury (TBI) and persistent postconcussive symptoms have evidence of temporal lobe injury on dynamic imaging. DESIGN: Case series. SETTING: An academic medical center. PARTICIPANTS: Twenty patients with a clinical diagnosis of mild TBI and persistent postconcussive symptoms were referred for neuropsychologic evaluation and dynamic imaging. Fifteen (75%) had normal magnetic resonance imaging (MRI) and/or computed tomography (CT) scans at the time of injury. INTERVENTIONS: Neuropsychologic testing, positron-emission tomography (PET), and single-photon emission-computed tomography (SPECT). MAIN OUTCOME MEASURES: Temporal lobe findings on static imaging (MRI, CT) and dynamic imaging (PET, SPECT); neuropsychologic test findings on measures of verbal and visual memory. RESULTS: Testing documented neurobehavioral deficits in 19 patients (95%). Dynamic imaging documented abnormal findings in 18 patients (90%). Fifteen patients (75%) had temporal lobe abnormalities on PET and SPECT (primarily in medial temporal regions); abnormal findings were bilateral in 10 patients (50%) and unilateral in 5 (25%). Six patients (30%) had frontal abnormalities, and 8 (40%) had nonfrontotemporal abnormalities. Correlations between neuropsychologic testing and dynamic imaging could be established but not consistently across the whole group. CONCLUSIONS: Patients with mild TBI and persistent postconcussive symptoms have a high incidence of temporal lobe injury (presumably involving the hippocampus and related structures), which may explain the frequent finding of memory disorders in this population. The abnormal temporal lobe findings on PET and SPECT in humans may be analogous to the neuropathologic evidence of medial temporal injury provided by animal studies after mild TBI.     

Traumatic brain injury is under-diagnosed in patients with spinal cord injury.

OBJECTIVE: To investigate the occurrence and severity of traumatic brain injury in patients with traumatic spinal cord injury. DESIGN: Cross-sectional study with prospective neurological, neuropsychological and neuroradiological examinations and retrospective medical record review. PATIENTS: Thirty-one consecutive, traumatic spinal cord injury patients on their first post-acute rehabilitation period in a national rehabilitation centre. METHODS: The American Congress of Rehabilitation Medicine diagnostic criteria for mild traumatic brain injury were applied. Assessments were performed with neurological and neuropsychological examinations and magnetic resonance imaging 1.5T. RESULTS: Twenty-three of the 31 patients with spinal cord injury (74%) met the diagnostic criteria for traumatic brain injury. Nineteen patients had sustained a loss of consciousness or post-traumatic amnesia. Four patients had a focal neurological finding and 21 had neuropsychological findings apparently due to traumatic brain injury. Trauma-related magnetic resonance imaging abnormalities were detected in 10 patients. Traumatic brain injury was classified as moderate or severe in 17 patients and mild in 6 patients. CONCLUSION: The results suggest a high frequency of traumatic brain injury in patients with traumatic spinal cord injury, and stress a special diagnostic issue to be considered in this patient group.     

Diffusion tensor magnetic resonance imaging of microstructural abnormalities in children with brain injury

We present two pediatric cases demonstrating that diffusion tensor imaging is more efficient at revealing microstructural abnormalities of the brain than conventional magnetic resonance imaging because it enables measurements of the directionality and integrity of white matter fiber tracts. One patient suffered from left hemiparesis, and the other had right hemiparesis. However, whereas conventional magnetic resonance imaging showed only the findings of traumatic contusional hemorrhages in the left temporal and parietal lobes of the first patient and focal encephalomalacia in the left anterior thalamus of the second patient, diffusion tensor imaging successfully disclosed microstructural abnormalities in the right cerebral peduncle of the midbrain of the first patient and in the posterior limb of the left internal capsule of the second. Theses two cases demonstrate that diffusion tensor imaging is more capable than magnetic resonance imaging at detecting the microstructural pathologic lesions that are responsible for clinical motor weakness, especially when conventional magnetic resonance imaging has failed to detect subtle structural abnormalities.     

磁共振扩散张量成像对轻型颅脑损伤患者评价的临床应用

目的通过核磁共振扩散张量成像(diffusion tensor imaging,DTI)评估轻型颅脑损伤患者颅内损伤情况,探讨DTI在轻型颅脑损伤患者诊断中的应用价值。材料与方法收集CT检查未见出血及骨折的轻型颅脑损伤患者30人,正常对照组30人。在受伤后7天内,行头部MRI检查,并在行头MRI检查当天用Rivermead脑震荡后综合征评估表进行评分。结果轻型颅脑损伤组Rivermead脑震荡后综合征评分高于对照组。轻型颅脑损伤组FA值升高区域有:右侧小脑半球、右侧枕叶及小脑山坡,舌回,右侧额下回的三角部,楔前叶灰质。轻型颅脑损伤组FA值降低区域有:视辐射,大脑脚,右侧胼胝体膝,左侧胼胝体膝,右侧额中回下白质,中央前回下白质。结论轻型颅脑损伤患者存在器质性颅内改变。扩散张量成像对于轻型颅脑损伤造成的颅内病变非常敏感,可以为临床诊断轻型颅脑损伤提供参考依据,并为判断轻型颅脑损伤预后提供一定帮助。     

超急性期轻度脑外伤患者静息态功能性磁共振成像研究

目的利用静息态功能磁共振成像(resting-state functional magnetic resonance imaging,rs-f MRI)低频振幅(amplitude of low-frequency fluctuation,ALFF)探讨超急性期(24 h)轻度脑外伤(mild traumatic brain injury,m TBI)患者脑功能的异常变化。材料与方法选取符合纳入标准的52例m TBI患者(m TBI组)及与之相匹配的21名健康者(对照组)行rs-f MRI扫描,并应用静息态脑功能数据辅助处理(data processing assistant for resting state f MRI,DPARSF)软件进行预处理,对2组的ALFF进行对比分析。结果与健康对照组相比,ALFF显著减低的区域有小脑后叶、右枕叶中回及中央后回;ALFF显著增高的区域有双侧额叶、内侧前额叶、双侧尾状核及岛叶。结论在常规磁共振成像无异常发现的情况下,ALFF技术可以更好地发现m TBI患者超急性期静息态脑功能的异常。     

缺血性脑白质病变伴轻度认知功能障碍患者记忆障碍的静息态功能磁共振成像

目的探讨缺血性脑白质病变伴轻度认知功能障碍患者的记忆损害特征及其与静息态功能磁共振成像(rsfMRI)改变的关系。方法收集缺血性脑白质病变伴轻度认知障碍患者15例(vMCI组)及健康老年志愿者15名(对照组),采用听觉词语学习测验(AVLT)分析记忆功能,采用rs-fMRI分析脑静息态低频波动振幅(ALFF),比较两组记忆评分差异,并与ALFF进行相关分析。结果 vMCI组蒙特利尔认知评估量表(MoCA)、简明精神状态检查量表(MMSE)、短时记忆(STM)评分均低于对照组(P均<0.05)。两组在额顶枕叶和皮质下区域存在广泛异常的自发脑活动。去除年龄、性别和教育程度的影响后,偏相关分析显示,vMCI组双侧壳核ALFF与STM评分呈负相关,左侧楔叶ALFF与MoCA评分呈负相关,左侧额上回/辅助运动区(SMA)与MoCA评分呈正相关,左侧额内侧回/SMA及右侧壳核与MMSE评分呈正相关(P均<0.05)。结论缺血性白质病变伴轻度认知功能障碍患者记忆损害主要表现为短时记忆减退,机制可能与多个脑区功能异常有关,双侧壳核代偿为主要特点。     

DTI纤维追踪法定量分析90名正常国人脑白质老化

目的 采用DTI纤维追踪法定量比较不同年龄组正常自愿者椎体束从大脑脚到中央前回部分(PRPT)FA值的差别及其意义.方法 将90名正常志愿者按年龄分为6组,进行基于纤维追踪的定量DTI研究,图像标准化后分析各组PRPT的FA值与年龄组老化的关系.结果 各年龄组双侧PRPT的FA值分布相似,最低点在放射冠处,最高峰为内囊后肢;各段FA值随年龄增长呈下降趋势,表明这些部位的纤维随年龄增长发生了老化,其中以额叶老化最为明显;并发现额叶及大脑脚白质老化过程中存在突然变化.结论 DTI可以作为评价脑组织细微结构变化和老化过程的敏感工具;额叶及大脑脚白质老化过程中存在突变是否为脑生理上老化的标志有待进一步研究.     

轻度创伤性脑损伤的扩散张量成像研究

目的探讨MR扩散张量成像（DTI）对轻度创伤性脑损伤（m TBI）的诊断价值。材料与方法对35例轻度m TBI患者（病例组）和15名健康对照者（对照组）分别行常规MR、DTI检查。选择双侧额叶白质、双侧内囊区、胼胝体膝部及压部中线位置各一个点（共6个）为感兴趣区,分别测定FA值、ADC值。将病例组与对照组各部位的FA值、ADC值进行统计学分析。结果病例组与对照组间各部位ADC值均无显著性差异。双侧额叶白质区、双侧内囊区及胼胝体压部FA值病例组与对照组均有统计学差异（P〈0.05）。结论 FA值能定量测定轻度创伤性脑损伤后脑组织水分子代谢的情况,DTI可以作为一项客观指标,定量评估轻度脑外伤患者的病情,并为对病情发展和预后的观察带来可能。     

多模态磁共振成像诊断创伤半暗带的研究进展

创伤半暗带是存在于创伤性脑损伤后损伤核心区外周的一可挽回区域,是影响脑损伤患者预后和后期生活质量的一个重要因素。临床通过早期诊断、及时治疗创伤半暗带,可有效阻止其内的脑组织向有害方向发展,从而达到降低创伤性脑损伤所致的高致残率。多模态磁共振成像技术是一种广泛应用于颅脑疾病诊断的手段,具有分辨率高、精确度高、无侵袭性等优点。利用多模态磁共振技术（弥散加权成像、脑灌注成像、动脉自旋标记成像、磁敏感加权成像及磁共振波谱）能了解创伤半暗带的存在、范围以及其内的物质与能量代谢情况等,为临床选择治疗方案及评估疗效与预后提供客观的影像学依据。随着多模态磁共振技术的发展,界定创伤半暗带的磁共振方法也出现了多样化。本文主要就创伤半暗带与脑损伤病理生理机制、多模态磁共振成像序列、多模态磁共振成像评估创伤半暗带等方面进行综述。      

Intracranial stab wound: a case report.

OBJECTIVE: Intracranial stab wounds are relatively uncommon, as the adult skull usually provides an effective barrier to penetration. We present an interesting case of a penetrating intracranial stab wound with several important teaching points. CLINICAL PRESENTATION: A 44-year-old man presented to the emergency department with a 1.2-cm stab wound to the left temporal area. His initial Glasgow Coma Score was 14/15. Computerized tomography of his brain revealed a left temporal lobe haemorrhage and contusion. Magnetic resonance images of his brain revealed a linear haematoma extending from his left temporal lobe into the left middle cerebellar peduncle, consistent with a penetrating injury. He was managed conservatively with intravenous antibiotics and made an excellent recovery. Three weeks after injury, he had mild residual problems with recall and attention. CONCLUSION: Several leaning points exist in this case. Firstly, as stab wounds to the brain frequently present as apparently innocuous facial or scalp lacerations, a high index of suspicion is needed to prevent these injuries presenting with serious late infective complications. Secondly, reports of similar cases in the literature suggest that stab wounds to the temporal region are associated with a high morbidity and mortality. This case demonstrates that a patient with an injury such as this can occasionally make a good functional recovery. Finally, this case highlights the advantage of magnetic resonance imaging over computerized tomography in patients with these injuries once it has been established that there is no residual intracranial metal fragment prior to magnetic resonance imaging. In this case, the entire wound tract was only evident on magnetic resonance imaging and not on the initial computerized tomography scans.     

磁共振弥散张量成像对弥漫性轴索损伤的诊断价值

目的：探讨磁共振弥散张量成像（diffusion tensor magnetic resonance imaging）在弥漫性轴索损伤（diffuse axonal injury,DAI）中的应用价值.方法;对18例DAI患者（DAI组）及18例健康志愿者（对照组）分别行常规磁共振成像（magnetic resonance imaging,MR）及弥散张量成像（diffusion tensor imaging,DTI）,测量胼胝体压部、丘脑及额叶白质的表面弥散系数（apparent diffusion coefficient,ADC）值和部分各向异性分数（fractional anisotropy,FA）值,并进行比较.结果：DTI显示,与对照组比较,DAI组胼胝体压部、丘脑及额叶白质FA值和ADC值均较低（P＜0.01）,胼胝体FA值与格拉斯哥昏迷量表（GCS）评分正相关（P＜0.01）.结论：磁共振弥散张量成像用于诊断和评估DAI非常敏感,并可动态观察DAI的临床转归过程,有助于提示患者的预后.     

2型糖尿病患者认知障碍的神经影像学研究进展

半数以上2型糖尿病(type 2 diabetes mellitus,T2DM)患者伴随轻、中度认知障碍,并以注意力及记忆力减退和信息处理速度及执行能力下降等为主要特征。近年除了在病理生理方面探究T2DM诱发认知功能障碍的机制外,各种MRI序列对于揭示糖尿病患者脑结构及脑功能改变方面有重要价值,如磁敏感加权成像、扩散张量成像、静息态功能磁共振成像及磁共振波谱成像等。作者结合病理生理改变及相关脑结构、功能变化对T2DM伴认知障碍患者的神经影像学研究进展进行综述。     

Abnormalities of language networks in temporal lobe epilepsy

Functional magnetic resonance imaging (fMRI) in patients with temporal lobe epilepsy (TLE) has demonstrated reorganisation of language functions with greater involvement of the non-dominant hemisphere. The structural brain connections supporting this atypical language dominance have not previously been identified. We performed fMRI of language functions and imaging of white matter connections using MR tractography in 14 patients with unilateral TLE and hippocampal sclerosis and 10 controls. Verb generation and reading comprehension paradigms were used to define functional regions which were used to generate starting regions for tractography. Controls and right TLE patients had a left-lateralised pattern of both language-related activations and the associated structural connections. Left TLE patients showed more symmetrical language activations, along with reduced left hemisphere and increased right hemisphere structural connections. Subjects with more lateralised functional activation had also more highly lateralised connecting pathways. We provide evidence for structural reorganisation of white matter tracts that reflects the altered functional language lateralisation in left TLE patients. The combination of fMRI and tractography offers a promising tool for studying the reorganisation of language functions in many neurological conditions and may prove useful in predicting language deficits following temporal lobe surgery.     

颅脑损伤术后精神障碍200例临床分析

目的 探讨外伤性精神障碍与脑叶损伤部位的关系及外伤性精神障碍的愈后。方法通过对200例因颅脑损伤开颅术后出现精神障碍患者的临床资料分析判定外伤性精神障碍与脑叶损伤具体部位的关系及愈后情况。结果单纯额叶损伤69例，单纯颞叶损伤65例，额、颞叶均损伤56例，合并下丘脑损伤10例，以左侧半球损伤为主占124例，以右侧半球损伤为主占76例。随访至术后6个月：痊愈141例，显著好转29例，好转24例，无效6例。结论外伤性精神障碍的出现与脑叶损伤部位密切相关，均损伤了人脑的精神活动中枢且通过积极的综合治疗，愈后良好。     

脑白质疏松轻度认知功能障碍静息态默认网络研究

目的通过静息态功能磁共振成像(rs-fMRI)技术对脑白质疏松(LA)轻度认知障碍(MCI)患者脑默认网络进行分析。方法LA 患者31 例,临床痴呆评分(CDR) 0.5;年龄、性别和受教育程度匹配的正常对照组27 人,CDR 为0。对入组人群进行rs-fMRI 数据采集。使用SPM5 软件进行分析处理,使用fMRI 工具盒对预处理后的数据进行独立成分分析(ICA),组间差异进行双样本t 检验。结果静息状态下,对照组默认网络包括扣带回后部/楔前叶,双侧额叶内侧,双侧颞中回,双侧顶下回、角回,双侧海马。MCI组默认网络激活区域同对照组一致;同对照组相比,MCI患者扣带回前部/左侧额叶内侧、右侧海马旁回/钩回、右侧颞下回、左侧额叶深部白质/尾状核头部激活减低,左侧尾状核/扣带回前部、左侧额叶、左侧颞上回/顶下回的激活升高。结论LA患者静息状态默认网络活动异常,可能与认知障碍的发生有关。     

Evidence of disrupted functional connectivity in the brain after combat-related blast injury

Non-impact blast-related mild traumatic brain injury (mTBI) appears to be present in soldiers returning from deployments to Afghanistan and Iraq. Although mTBI typically results in cognitive deficits that last less than a month, there is evidence that disrupted coordination of brain activity can persist for at least several months following injury (Thatcher et al., 1989, Thatcher et al., 2001). In the present study we examined whether neural communication may be affected in soldiers months after blast-related mTBI, and whether coordination of neural function is associated with underlying white matter integrity. The investigation included an application of a new time–frequency based method for measuring electroencephalogram (EEG) phase synchronization (Aviyente et al., 2010) as well as fractional anisotropy measures of axonal tracts derived from diffusion tensor imaging (DTI). Nine soldiers who incurred a blast-related mTBI during deployments to Afghanistan or Iraq were compared with eight demographically similar control subjects. Despite an absence of cognitive deficits, the blast-related mTBI group exhibited diminished EEG phase synchrony of lateral frontal sites with contralateral frontal brain regions suggesting diminished interhemispheric coordination of brain activity as a result of blast injury. For blast injured (i.e., blast-related mTBI) soldiers we found that EEG phase synchrony was associated with the structural integrity of white matter tracts of the frontal lobe (left anterior thalamic radiations and the forceps minor including the anterior corpus callosum). Analyses revealed that diminished EEG phase synchrony was not the consequence of combat-stress symptoms (e.g., post-traumatic stress and depression) and commonly prescribed medications. Results provide evidence for poor coordination of frontal neural function after blast injury that may be the consequence of damaged anterior white matter tracts.     

功能磁共振成像观察2型糖尿病患者工作记忆

目的 通过功能磁共振成像技术对2型糖尿病患者的工作记忆进行研究,探讨2型糖尿病患者工作记忆的受损状况.方法 采用1-back组块设计,对16例2型糖尿病患者及13名正常对照受试者,进行词语及客体工作记忆任务的fMRI检查,对反应时间、正确率及脑激活图进行分析.结果 2型糖尿病组患者的正确反应时间、正确率与对照组相比差异无统计学意义(P>0.05).与对照组相比,2型糖尿病组在词语工作记忆时,左侧额叶、左侧顶叶及海马旁回等脑区激活显著减弱(P<0.05),客体工作记忆时,右侧额叶、左侧顶叶及双侧枕叶等脑区激活减弱(P<0.05).结论 2型糖尿病患者存在词语及客体工作记忆损害,经典激活脑区存在损害.     

轻度阿尔茨海默病脑血流灌注和脑灰质体积的改变

目的:探究轻度阿尔茨海默病(Alzheimer’s disease,AD)患者的脑血流(Cerebral blood flow,CBF)灌注和脑灰质体积的变化特点。方法:临床招募轻度AD患者和健康对照老年人进行包含3D-T1WI和3D伪连续动脉自旋标记(Three-dimensional pseudo-continuous arterial spin labeling,3D-pcASL)序列的磁共振扫描,运用统计参数图(Statistical parametric mapping,SPM)8软件对两组受试者全脑CBF图进行基于体素的全脑灌注差异的分析;采用基于体素的形态学测量方法(Voxel-based morphometry,VBM)比较两组受试者全脑灰质体积的差异;对灌注有差异的脑区的CBF与简易智力状态检查量表(Mini-mental state examination,MMSE)评分进行相关性分析。结果:共纳入轻度AD患者26例(年龄(73.0±6.8)岁,男16例),年龄、性别相匹配的健康对照者53例(年龄(73.7±8.2)岁,男23例)。与对照组相比,轻度AD组患者CBF灌注减低区主要位于双侧顶叶(以楔前叶、角回为主)、枕叶以及左侧颞叶和额叶;CBF灌注增高区主要位于右海马和海马旁回、右扣带回、基底节核团以及双侧额叶(以眶面和内侧面为主)(P<0.01,FDR校正,团块阈值>100像素)。轻度AD患者的脑灰质萎缩主要位于双侧颞叶内侧结构(海马、海马旁回、杏仁核),也累及双侧岛叶和基底节核团(P<0.01,FDR校正,团块阈值>100像素)。轻度AD组患者左颞顶叶脑回、双侧额上回的CBF值与MMSE评分呈现正相关;双侧内侧和旁扣带回、右前扣带回的CBF值与MMSE评分呈现负相关(P<0.05)。结论:轻度AD患者存在以顶叶为主的低灌注和以海马、基底节区、额叶为主的高灌注改变,而其灰质萎缩主要集中在双侧颞叶内侧结构。     

Differential recovery of behavioral status and brain function assessed with functional magnetic resonance imaging after mild traumatic brain injury in the rat

OBJECTIVE: The relationship between cerebral integrity, recovery of brain function, and neurologic status after mild traumatic brain injury is incompletely characterized. DESIGN: Prospective and randomized study in rodents. SETTING: University laboratory. SUBJECTS: Male Wistar rats (290-310 g). INTERVENTIONS: In rats, quantitative diffusion weighted imaging (DWI), perfusion weighted imaging (PWI), T2-weighted imaging (T2WI), and functional magnetic resonance imaging (fMRI) were performed up to 21 days after weight-induced, closed-head, mild traumatic brain injury (MTBI, n = 6) or sham operation (n = 6). Pixel-by-pixel analysis and region of interest analysis were used to evaluate structural (apparent diffusion coefficient [ADC] and basal cerebral blood flow [bCBF]) and functional magnetic resonance signal changes within the brain, respectively. Quantitative fMRI signal changes were correlated with behavioral measures. MEASUREMENTS AND MAIN RESULTS: Despite normal appearing DWI and T2WI findings following MTBI, persistent hypoperfusion developed that was not associated with cytotoxic edema. In contrast, the ADC was significantly increased by approximately 5% at 1 and 7 days post-MTBI. Post-MTBI fMRI responses to hypercapnia and forepaw stimulation were significantly impaired and showed a differential recovery rate between and within investigated region of interests. Significant dysfunction in forepaw placement test persisted up to day 1 and correlated significantly with fMRI signal changes in the primary somatosensory and motor cortices. CONCLUSIONS: MTBI produced distinct changes on multimodal MRI and behavioral variables acutely and chronically. Following MTBI, fMRI and ADC-bCBF pixel-by-pixel analysis identified subtle structural and functional alterations in the brain that appeared completely normal on conventional DWI and T2WI after concussion injury. The former techniques may therefore provide great potential for understanding mild traumatic brain injury, identifying mechanisms underlying recovery, and investigating specific interventions to enhance functional outcome.