利用功能磁共振成像对皮质下脑梗死运动功能恢复机制的研究

目的利用功能磁共振成像(fMRI)对皮质下脑梗死运动功能恢复的神经机制进行探讨。方法选择运动功能恢复较好的慢性期单侧皮质下脑梗死患者23例为患者组,年龄匹配的健康志愿者24例为对照组。用FuglMeyer量表评价患者的运动功能。fMRI实验采用组块设计,分别进行双手虚握拳运动,采用统计参数图比较2组执行手运动任务时脑激活的异同。结果对照组及患者组健手运动主要激活运动对侧感觉运动区、同侧小脑半球及双侧辅助运动区。患者组患手运动激活部位与对照组相同。与对照组比较,患者组患手运动时病灶侧初级运动皮质(M1)激活增强。结论在运动通路皮质下脑梗死患者运动功能恢复中,病灶侧M1区激活增强起重要作用。     

早期康复治疗对急性脑梗死患者上肢运动功能的影响

目的探究康复治疗在急性脑梗死患者手运动功能恢复上的作用。方法利用BOLD-f MRI技术与Fugl-Meyer(FMA)运动功能评分评定方法,比较脑梗死急性期患者38例治疗前、后(2周)手运动中枢激活区(SMC)体积及偏侧化指数(LI)的变化,并比较分析其治疗过程中的康复情况(FMA评分)。结果脑梗死患者38例中,其健手被动运动的LI值大于患手;康复治疗组患手(右手)治疗前、后(2周)的运动激活SMC的LI值比较,差异有统计学意义(P0.05);康复治疗组的FMA评分明显高于常规治疗组,且FMA评分呈上升状态,至治疗第12周后趋于平缓。结论康复治疗对急性脑梗死患者的手运动功能恢复具有积极的作用,以发病后的前12周进行康复治疗的效果为佳。     

功能性磁共振成像对卒中后偏瘫病人上肢运动功能的康复机制研究

目的探索卒中后偏瘫病人低频重复经颅磁刺激及强化职业治疗中,功能性磁共振成像对皮损半球改善及其上肢运动功能的恢复机制研究。方法对129例脑卒中偏瘫病人皮损半球进行低频重复经颅磁刺激及职业治疗(15 d内12次,每次40 min),且病人入院及出院时进行功能性磁共振成像检查,对Brodmann分区4区与6区的激活像素数的偏向指数进行计算(偏向指数范围为-1～+1)。根据干预前功能性磁共振成像将病人分为两组:第1组为双侧激活组(72例);第2组为单侧激活组(57例)。然后基于Fugl-Meyer运动功能评分及Wolf运动功能测试进行运动评分。结果干预后两组Fugl-Meyer运动功能评分及Wolf运动功能测试结果均较干预前改善(P0.01)。双侧激活组偏向指数显著提高(P0 05),这表明激活像素向损伤半球迁移;单侧激活组损伤脑半球活动显著增加(P0.05)。结论功能性磁共振成像治疗方案可能通过诱发病人皮质功能重组,特别是皮损半球皮质功能重组,进而促进运动受影响上肢功能的恢复。     

左侧偏瘫患者上肢运动脑激活区与健康人对比的功能磁共振研究

目的研究在运动通路损伤后,肢体运动所反应的激活脑区的特异性改变,并用功能磁共振表达出来,初步探讨脑梗死后脑功能重塑的机制。方法分别对正常组及偏瘫组进行左侧上肢运动,试验采用组块设计模式;运用BOLD-fMRI技术及Brain-Voyager软件分析方法显示激活情况。结果正常组左上肢主动运动脑激活区主要分布在右侧初级感觉运动皮层(SM1)及左侧小脑;而偏瘫组双侧大脑运动皮层均有明显激活,包括双侧初级感觉运动皮层(SM1)、运动前区(PMC)和次级运动区(PPC),双侧丘脑、小脑蚓部、右侧小脑、右侧岛叶、壳核,以及健侧大脑的苍白球、扣带回。结论偏瘫组较正常组出现更多的锥体外系及次级运动区的激活,从而推测脑梗死后脑功能重塑的机制在于通过功能区的转移和次级功能区的功能代偿。     

fMRI在利手、非利手简单运动模式下手运动区脑功能研究中的应用

目的探讨脑功能磁共振成像（fMRI）在利手、非利手简单运动模式下手运动区脑功能研究中的应用价值。方法选择17例健康志愿者,均为右利手,分别行简单手指运动—拇指对掌运动,采用3．0TMRI扫描机,平面回波成像（EPI）技术,应用主机自带分析软件进行数据处理。将MR／信号图重叠在常规MRI T1 FLAIR序列横断面或矢状位图像上,得到fMRI图像,通过与常规MR／图像对比,观察运动皮层活化区出现的形式、位置、数目。结果在利手及非利手运动模式下,17例均获得良好对侧初级运动区（M1）区及部分双侧辅助运动区（SMA）和运动前区（PMA）激活图像,非利手者有部分获得同侧M1区激活图像。结论fMRI可用于利手、非利手简单运动模式下手运动区脑功能的研究。     

经颅磁刺激可改善卒中患者的运动功能

对于健康大脑,两侧半球皮质以一种相似的程度相互抑制,其本质为“相互抵消”。当患者发生卒中时,患侧半球对健侧半球的抑制程度减弱,从而导致健侧大脑半球抑制活性增强。因此,美国哈佛医学院的Mansur等提出一种理论,即如果降低健侧大脑半球活动性,就能消除对患侧半球的抑制作用,进而改善运动功能。最近的研究已表明,无创性皮质脑刺激是一种有效的卒中恢复治疗方法,经颅磁刺激(TMS)能够在意识清醒的受试者中提供无创性和无痛的脑皮质刺激,因此,重复TMS(rTMS)可能有助于调节卒中后大脑的活动性,从而促进卒中后的恢复。为了验证上述理论,M…     

急性脑梗死患者脑磁图运动相关磁场特征研究

目的研究急性脑梗死患者脑磁图运动相关磁场的变化特征。方法2003-06~2004-08对河北省人民医院9例急性脑梗死患者和6名健康志愿者进行MEGMRCFs检测。患者看到一侧闪光信号提示后,相应侧食指做一次抬起放下运动触发光电耦合作为“0”时刻,MRCFs波峰由等价电流偶极子(ECD)评估,并与超薄MRI进行影像融合。结果MRCFs波峰的ECD均位于两侧初级运动皮层“手区”,患者组MRCFs波峰潜伏期延迟(P<0.01),尤以患侧为重,患侧ECD强度较健侧减小(P<0.01)。结论MEG测定MR-CFs可客观、灵敏的检测出急性脑梗死患者运动皮层功能的损伤。     

经颅磁刺激用于卒中患者手功能恢复的研究进展

<正>人手所具有的复杂运动功能既依赖于其解剖结构,更需要精确的神经控制。研究手功能的神经调控对进一步认识中枢神经系统对复杂运动的调控过程有重要意义。研究表明,卒中后患侧大脑半球的运动皮质对健侧大脑半球运动皮质的抑制作用减弱,导致卒中后出现健侧大脑半球过度活跃~([1])。在卒中慢性期,处于失衡状态是患侧大脑半球的皮质运动区功能重组的障碍之一。因此,若达到促进卒中患者手功能恢复的目的,一方面需增加受损脑区     

运动想像疗法对急性脑梗死患者上肢运动功能恢复的影响

目的 探讨运动想像疗法对急性期脑梗死偏瘫患者上肢功能恢复的影响.方法 随机选取50例脑梗死偏瘫患者,采用单盲法分为对照治疗组(药物治疗+早期运动疗法)和运动想像治疗组(药物+早期运动疗法+运动想像疗法),每组各25例.治疗前和治疗40 d时,采用Fugt-Meyer量表(FMA)评价患侧上肢运动功能,使用量角器测定患侧手腕主动活动范围(AROM),应用功能独立性评定量表(FIM)评价进食、梳洗、穿脱上衣等功能.结果 2组患者FMA、AROM和FIM评分均较治疗前显著提高(P<0.05),治疗后运动想像治疗组各项评分均优于对照组(P<0.05)(FMA28.33±8.63对15.93±5.39;AROM 19.55-I-8.30对11.97±6.59;FIM 16.83±5.43对12.51±3.36).结论 急性期常规运动康复训练+运动想像疗法可促进脑梗死偏瘫患者的运动功能恢复.     

具身运动想象联合常规康复对卒中后感觉运动网络影响的研究

目的探讨具身认知视角下的运动想象疗法（以下简称具身运动想象）联合常规康复对首发卒中偏瘫患者感觉运动网络（SMN）的影响及相关神经机制。 方法选取2020年1~6月于南京医科大学附属脑科医院神经内科及康复医学科住院的15例首发卒中偏瘫患者纳入治疗组,进行具身运动想象联合常规康复治疗;同时,选取15名年龄、性别及文化程度和治疗组相匹配的健康受试者作为对照组。治疗组患者治疗前和治疗4周后均进行静息态功能磁共振（rs-fMRI）扫描,记录Fugl-Meyer运动功能评定（FMA）量表评分和改良Barthel指数（MBI）评分。采用rs-fMRI构建SMN,并且通过对治疗组治疗前后以及对照组的SMN脑区进行功能连接（FC）分析来研究网络内的变化,并采用基于种子点的患侧初级感觉运动皮层（S1M1）与全脑间FC的变化情况,研究S1M1与全脑之间的FC重组。 结果治疗后,治疗组FMA评分由（65.67±16.95）分升高到（149.58±17.95）分,MBI评分由（24.17±8.21）分升高到（65.00±8.79）分,差异均有统计学意义（P<0.05）。SMN内FC显示,治疗前,治疗组较对照组双侧S1M1、患侧S1M1和辅助运动区（SMA）、患侧S1M1和小脑、SMA和小脑间FC降低,差异有统计学意义（P<0.05）。治疗组治疗后患侧S1M1和小脑的FC较治疗前增强,差异有统计学意义（P<0.05）。基于种子点的全脑FC分析显示,治疗前,治疗组患侧S1M1和健侧距状回、患侧中央后回FC减弱,差异有统计学意义（P<0.05）;治疗后患侧S1M1和患侧额中回、健侧小脑FC较治疗前增强,差异有统计学意义（P<0.05）。相关性分析发现,患侧S1M1和小脑的FC连接强度增量与FMA增量有中度相关性（r=0.581,P=0.023）,与MBI增量有强相关性（r=0.757,P=0.002）。 结论具身运动想象联合常规康复可改善首发卒中偏瘫患者的运动功能和日常生活能力,相关脑重塑机制可能是其可显著修复SMN网络内和全脑的FC,增加与认知相关的脑区FC。     

Functional magnetic resonance imaging of reorganization in rat brain after stroke

Functional recovery after stroke has been associated with brain plasticity; however, the exact relationship is unknown. We performed behavioral tests, functional MRI, and histology in a rat stroke model to assess the correlation between temporal changes in sensorimotor function, brain activation patterns, cerebral ischemic damage, and cerebrovascular reactivity. Unilateral stroke induced a large ipsilateral infarct and acute dysfunction of the contralateral forelimb, which significantly recovered at later stages. Forelimb impairment was accompanied by loss of stimulus-induced activation in the ipsilesional sensorimotor cortex; however, local tissue and perfusion were only moderately affected and cerebrovascular reactivity was preserved in this area. At 3 days after stroke, extensive activation-induced responses were detected in the contralesional hemisphere. After 14 days, we found reduced involvement of the contralesional hemisphere, and significant responses in the infarction periphery. Our data suggest that limb dysfunction is related to loss of brain activation in the ipsilesional sensorimotor cortex and that restoration of function is associated with biphasic recruitment of peri- and contralesional functional fields in the brain.     

脑缺血的全脑保护概念

就卒中后功能恢复而言,所有脑区、细胞类型和细胞成分均应受到保护,而不仅仅是保护某一脑区或某一细胞类型。神经保护治疗的临床试验至今依然令人失望,未来脑缺血的治疗可能有赖于全脑保护,而不是选择性地保护灰质或神经元核周质。在脑缺血的全脑保护概念中,脑白质和神经胶质细胞的保护以及远离缺血核心的脑保护尤为重要。     

Hemispheric Activation during Planning and Execution Phases in Reaching post Stroke: A consort study

Enhanced activation in the non-lesion hemisphere in stroke patients was widely observed during movement of the affected upper limb, but its functional role related to motor planning and execution is still unknown.This study was to characterize the activation in the non-lesion hemisphere during movement planning and execution by localizing sources of high-density electroencephalography (EEG) signal and estimating the source strength (current density [A/m²]).Ten individuals with chronic stroke and shoulder/elbow coordination deficits and 5 healthy controls participated in the study.EEG (64 channels) was recorded from scalp electrodes while the subjects performed a reach task involving shoulder flexion and elbow extension of the affected (patients) or dominant (controls) upper extremity. Sources of the EEG were obtained and analyzed at 17 time points across movement preparation and execution phases. A 3-layer boundary element model was overlaid and used to identify the brain activation sources. A distributed current density model, low-resolution electromagnetic tomography (LORETA) L1 norm method, was applied to the data pre-processed by independent component analysis.Subjects with stroke had stronger source strength in the sensorimotor cortices during the movement compared with the controls. Their contralesional/lesional activation ratio (CTLR) for the primary motor cortices was significantly higher than that of the controls during the movement-planning phase, but not during the execution phase. The CTLR was higher in planning than in the execution phase in the stroke group.Excessive contralesional motor cortical activation appears to be more related to movement preparation rather than execution in chronic stroke.     

大鼠左右大脑中动脉缺血再灌注模型比较

目的探讨大鼠左右大脑中动脉缺血再灌注模型的差异。方法选择右利雄性Wistar大鼠48只,按照随机数字表分为左侧大脑中动脉缺血再灌注组(左侧优势组)、右侧大脑中动脉缺血再灌注组(右侧非优势组),每组24只,每组使用各自侧别的假手术对照。血管内线栓法阻塞大脑中动脉2h,然后再灌注。测试神经功能,取脑分别进行常规TTC染色和HE染色,测量脑梗死体积,光镜下观察脑组织病理变化。结果左侧优势组再灌注24、48和72h神经功能缺损评分明显低于右侧非优势组(P<0.05)。左侧优势组缺血程度较右侧非优势组重。左侧优势组神经元数量严重缺失,海马细胞排列紊乱,脑梗死体积明显大于右侧非优势组[(102.1±8.8)mm3 vs(97.0±11.2)mm3,P<0.05]。结论大鼠优势半球大脑中动脉阻塞后,神经功能缺损程度较非优势侧严重,脑梗死体积更大。大鼠优势半球局灶性脑缺血模型重复性好,而且可靠。     

Aerobic exercise training increases brain volume in aging humans

BACKGROUND: The present study examined whether aerobic fitness training of older humans can increase brain volume in regions associated with age-related decline in both brain structure and cognition. METHODS: Fifty-nine healthy but sedentary community-dwelling volunteers, aged 60-79 years, participated in the 6-month randomized clinical trial. Half of the older adults served in the aerobic training group, the other half of the older adults participated in the toning and stretching control group. Twenty young adults served as controls for the magnetic resonance imaging (MRI), and did not participate in the exercise intervention. High spatial resolution estimates of gray and white matter volume, derived from 3D spoiled gradient recalled acquisition MRI images, were collected before and after the 6-month fitness intervention. Estimates of maximal oxygen uptake (VO2) were also obtained. RESULTS: Significant increases in brain volume, in both gray and white matter regions, were found as a function of fitness training for the older adults who participated in the aerobic fitness training but not for the older adults who participated in the stretching and toning (nonaerobic) control group. As predicted, no significant changes in either gray or white matter volume were detected for our younger participants. CONCLUSIONS: These results suggest that cardiovascular fitness is associated with the sparing of brain tissue in aging humans. Furthermore, these results suggest a strong biological basis for the role of aerobic fitness in maintaining and enhancing central nervous system health and cognitive functioning in older adults.     

Extensive deep gray matter volume reductions in children and adolescents with fetal alcohol spectrum disorders

Background: The link between the numerous cognitive, motor, and behavioral difficulties of individuals with fetal alcohol spectrum disorders (FASD) and underlying specific structural brain injuries can be investigated using high‐resolution imaging. Differential sensitivity of the brain’s “relay” stations, namely the deep gray matter structures, may play a key factor given their multifaceted role in brain function. The purpose of our study was to analyze differences in deep gray matter volumes of children and adolescents with FASD relative to age/sex‐matched controls and to examine whether any volume differences were consistent across the age range of neurodevelopment. Methods: Children and adolescents (N = 28, 6 to 17 years) diagnosed with FASD and 56 age‐ and sex‐matched healthy controls (i.e., 2 matched controls per FASD subject) underwent 3‐dimensional T1‐weighted MRI scans that were used for the automated volume measurement (FreeSurfer) of the intracranial space, total white matter, cortical gray matter, and 6 deep gray matter structures, namely the hippocampus, amygdala, thalamus, caudate, putamen, and globus pallidus, with left and right measured separately. Volumes were compared between FASD and controls, as well as changes with age. Results: Significant reductions of volume in FASD were observed for the intracranial vault (7.6%), total white matter (8.6%), total cortical gray matter (7.8%), and total deep gray matter (13.1%). All 6 deep gray matter structures showed significant volume reductions bilaterally with the caudate (approximately 16%) and globus pallidus (approximately 18%) being most affected. The hippocampus, thalamus, and globus pallidus showed reductions in all 3 age subgroups (6 to 9, 10 to 13, and 14 to 17 years) but the caudate and putamen had smaller volumes for FASD only within the 2 youngest subgroups; the amygdala was only smaller for FASD in the 2 oldest subgroups. Conclusions: Significant, but variable, volume reductions throughout the deep gray matter are observed over a wide age range of 6 to 17 years in FASD.     

A structural-functional basis for dyslexia in the cortex of Chinese readers

Developmental dyslexia is a neurobiologically based disorder that affects approximately 5-17% of school children and is characterized by a severe impairment in reading skill acquisition. For readers of alphabetic (e.g., English) languages, recent neuroimaging studies have demonstrated that dyslexia is associated with weak reading-related activity in left temporoparietal and occipitotemporal regions, and this activity difference may reflect reductions in gray matter volume in these areas. Here, we find different structural and functional abnormalities in dyslexic readers of Chinese, a nonalphabetic language. Compared with normally developing controls, children with impaired reading in logographic Chinese exhibited reduced gray matter volume in a left middle frontal gyrus region previously shown to be important for Chinese reading and writing. Using functional MRI to study language-related activation of cortical regions in dyslexics, we found reduced activation in this same left middle frontal gyrus region in Chinese dyslexics versus controls, and there was a significant correlation between gray matter volume and activation in the language task in this same area. By contrast, Chinese dyslexics did not show functional or structural (i.e., volumetric gray matter) differences from normal subjects in the more posterior brain systems that have been shown to be abnormal in alphabetic-language dyslexics. The results suggest that the structural and functional basis for dyslexia varies between alphabetic and nonalphabetic languages.     

Gray and white matter changes associated with tool-use learning in macaque monkeys

We used noninvasive MRI and voxel-based morphometry (VBM) to detect changes in brain structure in three adult Japanese macaques trained to use a rake to retrieve food rewards. Monkeys, who were naive to any previous tool use, were scanned repeatedly in a 4-T scanner over 6 weeks, comprising 2 weeks of habituation followed by 2 weeks of intensive daily training and a 2-week posttraining period. VBM analysis revealed significant increases in gray matter with rake performance across the three monkeys. The effects were most significant (P < 0.05 corrected for multiple comparisons across the whole brain) in the right superior temporal sulcus, right second somatosensory area, and right intraparietal sulcus, with less significant effects (P < 0.001 uncorrected) in these same regions of the left hemisphere. Bilateral increases were also observed in the white matter of the cerebellar hemisphere in lobule 5. In two of the monkeys who exhibited rapid learning of the rake task, gray matter volume in peak voxels increased by up to 17% during the intensive training period; the earliest changes were seen after 1 week of intensive training, and they generally peaked when performance on the task plateaued. In the third monkey, who was slower to learn the task, peak voxels showed no systematic changes. Thus, VBM can detect significant brain changes in individual trained monkeys exposed to tool-use training for the first time. This approach could open up a means of investigating the underlying neurobiology of motor learning and other higher brain functions in individual animals.