静态功能磁共振分析方法在脑胶质瘤术前语言皮质定位中的初步应用

目的 探讨静态功能磁共振(rsfMRI)分析方法在脑胶质瘤术前语言皮质定位中的应用价值.方法 12例主侧半球脑胶质瘤患者行术前rsfMRI,结合语言任务态血氧饱和依赖功能磁共振成像(BOLD fMRI)定位脑语言皮质,采用唤醒开颅结合术中皮质电刺激验证rsfMRI定位语言皮质的敏感性.结果 12例成功行rsfMRI扫描,10例配合完成语言BOLD fMRI扫描.12例唤醒开颅成功,每例各定位1～7个皮质语言阳性位点,共46个.其中22个语言阳性位点在rsfMRI上显示,其显示语言区的敏感度为47.8％(22/46,12例),13个语言阳性位点在语言BOLD fMRI上表现为激活,敏感度为35.1％(13/37,10例).结论 rsfMRI有助于脑胶质瘤术前语言区定位,但其敏感性有待提高.     

静息态脑功能成像与皮层电刺激定位皮质运动区的对照研究

目的 以术中皮层电刺激为对照,评价运动区附近脑肿瘤患者术前运用基于血氧水平依赖(BOLD)的静息态功能磁共振成像(rs-fMRI)方法定位皮质运动区的准确性.方法 选取18例运动区脑肿瘤患者,手术前采用rs-fMRI定位皮质运动区,以术中皮层电刺激作为皮质运动区定位的标准技术,比较两种技术的符合度,以评价rs-fMRI定位皮质运动区的准确性.结果 rs-fMRI与术中皮层电刺激的吻合率为92.9％,肿瘤全切率为77.8％,11例术后肌力不变,4例术后肌力好转,3例术后肌力下降.结论 rs-fMRI具有较高的敏感性和精确度,可作为术前皮质运动区定位的新方法,为手术方案的制定及预后评估提供有价值的信息.     

3D重建脑表面中央前回辨识及初级皮层运动功能分布研究

目的研究利用三维重建脑表面成像辨识中央前回的方法及其可靠性。方法难治性癫痫经术前评估需要进行颅内电极植入的病例12例,术前行3T磁共振结构像扫描及运动功能磁共振测试,颅内电极植入后行头颅CT扫描。利用磁共振数据,用Brainvoige软件进行脑表面三维重建,并与硬膜下电极CT融合。根据中央前回的形状走行特点,在重建的脑表面上标记中央前回,进而辨识标记术区中央前回。用皮层电刺激和功能磁共振验证所标记中央前回的可靠性。结果 12例均进行了脑表面三维重建,并标记出了中央前回,硬膜下电极CT电极点与三维脑表面融合。统计中央前回上电极点101个,电刺激运动响应73个,响应率72%;对照组中央前回前1cm（统计中央前沟前2个电极范围）,130个电极,17个电极有运动响应,响应率13%,p值小于0.05;功能磁共振手的运动100%中央前回有激活,中央前回前无明显激活。电刺激及功能核磁均验证了本研究方法确定中央前回准确可靠。结论脑表面成像辨识中央前回准确可行,可以利用各初级运动皮层分布的距离进行详细的初级运动皮层的绘制定位。     

fMRI与DTI联合应用在神经导航下切除运动区附近病变

目的 探讨fMRI与DTI联合应用在大脑皮层运动区附近病变手术中的价值.方法 对18例大脑皮层运动区附近病变的患者,采用组块设计,利用血氧水平依赖性功能磁共振成像(BOLD-fMRI)获得运动区皮层激活,利用磁共振弥散张量成像技术(DTI)获得白质纤维束走行,应用神经导航系统进行影像融合后,术中定位皮层运动区与锥体束,经神经电生理检查验证后,避开功能区在显微镜下切除病变.结果 fMRI确定的功能区与术中电生理检查结果基本一致.12例病变全切,6例大部切除.术后肢体肌力好转或无变化14例,3例出现一过性加重,1例遗留永久性功能损害.结论 在神经导航辅助下fMRI与DTI联合应用可以准确定位大脑皮层运动区和锥体束,提高病变切除程度,减少术后运动功能障碍.     

fMRI辅助神经导航技术结合术中脑电监测在癫痫外科中的应用

目的探讨功能磁共振成像(fMRI)辅助神经导航技术结合术中脑电监测对脑功能区癫痫患者术中功能区定位的意义及手术效果的评估。方法对18例头皮脑电异常放电部位位于功能区的难治性癫痫患者(12例位于感觉运动区,6例位于语言区)术前进行fMRI扫描后,将导航序列的fMRI影像传输至神经导航仪,术中应用导航系统定位感觉运动区及语言区,应用术中脑电监测,对癫痫起源部位进一步精确定位,术中最大限度的切除致痫灶,对波及功能区的病灶实行皮层电灼术或多处软膜下横切(MST),术后常规应用抗癫痫药。结果全部患者在预定的癫痫灶局部均可记录到癫痫波,术后出现感觉运动区功能障碍者2例,言语障碍者1例,除1例出现永久感觉障碍外,其余患者均在术后1周内症状缓解。按照Engel分级评价为:I级7例,Ⅱ级5例,Ⅲ级4例,Ⅳ级2例;总有效者16例,有效率达88.9%。结论fMRI结合术中皮层脑电监测可实现个体化、实时、精确地定位病灶及毗邻的脑皮质功能区,达到在保护重要脑功能的前提下最大限度的切除致痫灶的目的。     

超高场磁共振功能成像辅助切除躯体感觉区胶质瘤(附5例报告)

目的应用超高场磁共振功能成像技术进行手术前后研究脑躯体感觉功能区肿瘤与功能区的定位,辅助切除躯体感觉功能区胶质瘤。方法5例邻近或累及躯体感觉功能区的胶质瘤患者,术前行双手持物对接刺激策略,在3.0T磁共振采用血氧水平依赖(BOLD)原理进行图像采集,经工作站(Leonardo syngo 2003A,Siemens)提供的BOLD功能图像分析软件包进行分析获得脑运动功能区的激活图像,参与神经外科手术方案的制定。所有患者均在唤醒麻醉下进行显微外科手术,在术前脑功能磁共振图像指导下利用皮质直接电刺激定位感觉区与运动区。在保护脑功能区功能不受损的前提下,最大程度地切除胶质瘤。术前、术后均行KPS评分,判断患者的状态。结果(1)5例躯体感觉功能区胶质瘤,通过此项技术获得了较好的BOLD功能磁共振成像感觉功能区激活图像,定位躯体感觉功能区。(2)患者在唤醒麻醉下,在术前脑功能磁共振图像指导下利用直接皮质电刺激快捷、准确进行中央后回定位,两者具有良好的一致性。结论应用3.0T MRI可以于术前更好地利用BOLD技术显示躯体感觉功能区与脑胶质瘤的解剖关系,以指导唤醒麻醉下直接皮质电刺激定位躯体感觉功能区的手术,实现最大程度保护患者重要的功能并最大程度地切除肿瘤。     

fMRI功能导航下切除汉语运动性语言区附近病变

目的探讨功能磁共振(functional magnetic resonance imaging,fMRI)导航在汉语运动性语言区附近病变手术中的应用价值。方法对43例大脑皮层运动性语言区附近病变患者,通过组块设计的汉语朗读任务,利用血氧水平依赖性功能磁共振成像(BOLD-fMRI)获得运动性语言区激活,利用磁共振弥散张量成像技术(diffusion tensori maging,DTI)获得白质纤维束走行,将结构影像、fMRI功能影像与DTI的各项异性系数(FA)图像同时传入导航系统,术中定位fMRI确定的语言区,在唤醒状态利用皮层电刺激技术进行语言区验证,避开运动性语言区在显微镜下切除病变。结果本组患者29例术前语言功能正常,14例有不同程度语言功能障碍。38例获得了有效的fM-RI语言区激活,进行了36例核心激活脑区与皮层电刺激比较:25例为重叠关系,11例为邻近关系。手术全切除17例,次全切除14例,大部份切除12例。术后语言功能8例较术前好转,31例无变化,4例出现短暂性运动性失语。结论汉语朗读任务所获得的fMRI运动性语言区激活具有良好的敏感性与准确性;fMRI导航手术可以提高汉语运动性语言区附近病变切除程度,减少术后运动性失语的发生。     

同步脑电图-功能磁共振成像技术在癫痫灶定位中的应用研究

目的 探讨同步脑电图-功能磁共振成像技术(EEG-fMRI)在癫痫灶定位中的作用.方法 13例难治性癫痫患者接受同步EEG-fMRI检查,根据EEG出现癫痫波的时间点作为事件相关时间曲线对fMRI数据进行分析,了解发作间期癫痫样放电时血氧水平依赖信号变化所引起的脑部激活情况,并分析这些区域与神经电生理记录所确定的癫痫灶之间的吻合程度.结果 9例患者癫痫样放电在fMRI上的激活区与皮质电极确定的癫痫灶一致;4例患者癫痫样放电在fMRI上的激活区范围大于皮质电极确定的癫痫灶范围,但最强激活区的位置仍与皮质电极确定的癫痫灶一致.结论 同步EEG-fMRI技术将癫痫灶的功能定位与解剖定位相结合,是一种无创、精确度较高的癫痫灶定位方法 .     

fMRI神经导航下切除汉语感觉性语言中枢邻近区域胶质瘤

目的 评价fMRI定位感觉性语言中枢的敏感性与准确性,探讨fMRI神经导航系统在感觉性语言中枢邻近区域胶质瘤手术中的应用价值.方法 采用组块设计的语言理解任务和血氧水平依赖性功能磁共振成像(BOLD-fMRI)激活31例感觉性语言中枢邻近区域胶质瘤患者的感觉性语言中枢,于神经导航系统下进行结构像与功能像融合以定位感觉性语言中枢;手术中采用皮质电刺激定位感觉性语言中枢.根据fMRI与皮质电刺激吻合度进行分类,以避开感觉性语言中枢,于显微镜下切除胶质瘤.结果 31例患者中感觉性语言中枢功能像达"非常好"标准19例,图像"清楚"10例,图像"采集不成功"2例.感觉性语言中枢与皮质电刺激相关性评价显示,28例中24例为重叠关系,4例为邻近关系.肿瘤完全切除11例,次全切除10例,大部切除10例.手术后语言功能较手术前明显改善9例,无变化19例,短暂性感觉性失语3例.感觉性语言中枢与切除大脑皮质间距离>10 mm者,手术后均未出现语言功能恶化.结论 fMRI定位感觉性语言中枢具有良好的敏感性与准确性.fMRI神经导航系统下切除胶质瘤可以减少感觉性语言中枢邻近区域胶质瘤患者手术后语言理解障碍的发生,提高肿瘤完全切除率.感觉性语言中枢与切除大脑皮质之间的相对安全距离为10 mm.     

正常成人皮质吞咽中枢功能磁共振的初步研究

目的探讨正常成人皮质吞咽中枢的分布与特点。方法采用血氧水平依赖(BOLD)的功能磁共振方法对6例右利手健康志愿者进行吞咽中枢的定位。在GE公司3.0T磁共振仪上,除常规T1、T2扫描外,患者行吞咽动作,获取BOLD信号变化。扫描时间共60秒,在第1、15、30、45秒时受试者分别完成一次空吞咽动作,吞咽时尽量减少唇、舌、头部的运动。采用SPM软件在Functool4.0工作站上对图像数据进行后处理。结果正常受试者吞咽动作的激活部位位于感觉运动皮质外侧、岛叶、扣带回前部、运动前区,眶额皮质、小脑。仅有岛叶的激活信号以左侧半球为著。结论正常成人的吞咽中枢位于多个脑区。自主吞咽动作的启动及调节需要多个脑区的激活。     

Functional MRI and intraoperative brain mapping to evaluate brain plasticity in patients with brain tumours and hemiparesis

OBJECTIVE: To support the hypothesis about the potential compensatory role of ipsilateral corticofugal pathways when the contralateral pathways are impaired by brain tumours. METHODS: Retrospective analysis was carried out on the results of functional MRI (fMRI) of a selected group of five paretic patients with Rolandic brain tumours who exhibited an abnormally high ipsilateral/contralateral ratio of activation-that is, movements of the paretic hand activated predominately the ipsilateral cortex. Brain activation was achieved with a flexion extension of the fingers. Statistical parametric activation was obtained using a t test and a threshold of p<0.001. These patients, candidates for tumour resection, also underwent cortical intraoperative stimulation that was correlated to the fMRI spatial data using three dimensional reconstructions of the brain. Three patients also had postoperative control fMRI. RESULTS: The absence of fMRI activation of the primary sensorimotor cortex normally innervating the paretic hand for the threshold chosen, was correlated with completely negative cortical responses of the cortical hand area during the operation. The preoperative fMRI activation of these patients predominantly found in the ipsilateral frontal and primary sensorimotor cortices could be related to the residual ipsilateral hand function. Postoperatively, the fMRI activation returned to more classic patterns of activation, reflecting the consequences of therapy. CONCLUSION: In paretic patients with brain tumours, ipsilateral control could be implicated in the residual hand function, when the normal primary pathways are impaired. The possibility that functional tissue still remains in the peritumorous sensorimotor cortex even when the preoperative fMRI and the cortical intraoperative stimulations are negative, should be taken into account when planning the tumour resection and during the operation.     

Highly focal BOLD activation on functional MRI in a patient with progressive myoclonic epilepsy and diffuse giant somatosensory evoked potentials

We analyzed the effect of afferent input on patterns of brain electrical activation in a 31-year-old man with progressive myoclonic epilepsy (PME) by measuring the somatosensory evoked potential (SSEP) amplitude at the scalp after median nerve stimulation and examining the changes in the functional magnetic resonance imaging blood oxygen level-dependent (fMRI BOLD) signal. High-amplitude SSEPs were elicited at the wrist in association with highly focal BOLD activation of the contralateral sensorimotor areas. By contrast, no diffuse activation of either the frontal or the posterior parietal cortical areas was observed, as seen in previously recorded data on SSEPs from a healthy control group. The highly focal BOLD activation in this patient suggests that cortex hyperexcitability might be limited to the sensorimotor cortex in PME. The combined EEG-fMRI findings highlight a dissociation between BOLD activation and neurophysiological findings.     

维吾尔语语义加工脑功能定位的磁共振成像研究

目的 利用功能磁共振(fMRI)技术研究维吾尔族对其母语(维吾尔文字)进行词义联想脑功能的激活区及语言的偏侧化.方法 29例健康志愿者作为受试对象,通过视觉刺激对每个单音节实词进行词义联想同时行fMRI,所有数据经神经功能分析软件对相关脑皮质激活区进行个体分析及组分析.结果 多个皮质出现激活区,主要出现在双侧额中回、额下回、枕中回、中央前回及梭状回,左侧颞中回、顶上下小叶、楔前叶,右侧颞上回、舌回.左侧大脑半球激活体积明显大于右侧.结论 多个脑功能区参与维吾尔语义加工,fMRI能够很好地发现这些功能区,维吾尔族语言优势半球为左侧大脑半球.     

fMRI of the sensorimotor cortex in patients with traumatic brain injury after intensive rehabilitation

For evaluating the patterns of brain activation in sensorimotor areas following motor rehabilitation, seven male patients diagnosed with TBI underwent an fMRI study before and after being subjected to motor rehabilitation. Six patients showed a reduction in the BOLD signal of their motor cortical areas during the second fMRI evaluation. A decrease in cerebellum activation was also observed in two patients. Newly activated areas, were observed in four patients after treatment. In addition, an increase in the activation of the supplementary motor area (SMA) following rehabilitation was observed in only one test subject. The findings show that motor rehabilitation in TBI patients produces a decrease in the BOLD signal for the sensorimotor areas that were activated prior to treatment. In addition, we observed the recruitment of different brain areas to compensate for functional loss due to TBI in line with the cortical reorganisation mechanism.     

Anatomical and functional distribution of functional MRI language mapping

ObjectiveThe aim of the present study was to compare localization of the language cortex using electrical cortical stimulation (ECS) and functional magnetic resonance imaging (fMRI) to establish the relevance of fMRI language mapping.MethodsLanguage mapping with fMRI and functional ECS mapping were retrospectively compared in ten patients with refractory epilepsy who underwent fMRI language mapping and functional ECS mapping between June 2012 and April 2019. A shiritori task, a popular Japanese word chain game, was used for fMRI language mapping.ResultsBOLD signal activation was observed in the left inferior frontal gyrus (including the pars opecularis and the pars triangularis), and superior temporal gyrus, which is a language-related area, as well as in the left superior and middle frontal gyri, the intraparietal sulcus, and fusiform gyrus. These results were compared with ECS to elucidate the functional role of the activated areas during fMRI language tasks. These activated areas included language areas, negative motor areas, supplementary motor areas (SMAs), and non-functional areas.ConclusionThe activated areas of fMRI language mapping include language-related areas, the negative motor area, and SMAs. These findings suggest the involvement of language and higher order motor networks in verbal expression.     

Subcortical motor plasticity in patients with sporadic ALS: An fMRI study

OBJECTIVE: To address the potential contribution of subcortical brain regions in the functional reorganization of the motor system in patients with sporadic ALS (sALS) and to investigate whether functional changes in brain activity are different in sALS patients with predominant upper motor neuron (UMN) or lower motor neuron (LMN) dysfunction. METHODS: We studied 16 patients with sALS and 13 healthy controls, using BOLD-fMRI, while they performed a simple visually paced motor task. Seven patients had definite clinical UMN signs while nine patients had prevalent clinical and electrophysiological LMN involvement. fMRI data were analyzed with Brain Voyager QX. RESULTS: Task-related functional changes were identified in motor cortical regions in both patients and healthy controls. Direct group comparisons revealed relatively decreased BOLD fMRI responses in left sensorimotor cortex, lateral premotor area, supplementary motor area and right posterior parietal cortex (p < 0.05 corrected) and relatively increased responses in the left anterior putamen (p < 0.001 uncorrected) in sALS patients. Additional analyses between the two patients subgroups demonstrated significant BOLD fMRI response differences in the anterior cingulate cortex and right caudate nucleus (p < 0.001 uncorrected) with more robust activation of these areas in patients with greater UMN burden. Importantly, there were no significant differences in performance of the motor task between sALS patients and controls as well as between sALS patient subgroups. CONCLUSIONS: Our data demonstrate a different BOLD fMRI pattern between our sALS patients and healthy controls even during simple motor behavior. Furthermore, patients with sALS and greater UMN involvement show a different reorganization of the motor system compared to sALS patients with greater LMN dysfunction.     

Brain Activation Evoked by Sensory Stimulation in Patients with Spinal Cord Injury : Functional Magnetic Resonance Imaging Correlations with Clinical Features

Objective

The purpose of this study is to determine whether the changes of contralateral sensorimotor cortical activation on functional magnetic resonance imaging (fMRI) can predict the neurological outcome among spinal cord injury (SCI) patients when the great toes are stimulated without notice.

Methods

This study enrolled a total of 49 patients with SCI and investigated each patient''s preoperative fMRI, postoperative fMRI, American Spinal Injury Association (ASIA) score, and neuropathic pain occurrence. Patients were classified into 3 groups according to the change of blood oxygenation level dependent (BOLD) response on perioperative fMRI during proprioceptive stimulation with repetitive passive toe movements : 1) patients with a response of contralateral sensorimotor cortical activation in fMRI were categorized; 2) patients with a response in other regions; and 3) patients with no response. Correlation between the result of fMRI and each parameter was analyzed.

Results

In fMRI data, ASIA score was likely to show greater improvement in patients in group A compared to those belonging to group B or C (p<0.001). No statistical significance was observed between the result of fMRI and neuropathic pain (p=0.709). However, increase in neuropathic pain in response to the signal change of the ipsilateral frontal lobe on fMRI was statistically significant (p=0.030).

Conclusion

When there was change of BOLD response at the contralateral sensorimotor cortex on perioperative fMRI after surgery, relief of neurological symptoms was highly likely for traumatic SCI patients. In addition, development of neuropathic pain was likely to occur when there was change of BOLD response at ipsilateral frontal lobe.     

fMRI in patients implanted with a vagal nerve stimulator.

OBJECTIVE: To demonstrate the feasibility and safety of using functional magnetic resonance imaging (fMRI) to determine the blood oxygen level dependent changes (BOLD) in patients undergoing vagal nerve stimulation (VNS) for the treatment of epilepsy.METHODS: Four patients with an implanted vagus nerve stimulator had fMRI images acquired during several cycles of intermittent VNS. Blood oxygen level dependent changes were detected. These regions were then superimposed upon the patients' structural MR images.RESULTS: Patients undergoing VNS tolerated fMRI without difficulty. No complications with the implanted stimulators were encountered. Areas of activation were noted in several cortical regions, including frontal, temporal, parietal, and occipital cortices.CONCLUSION: Our study in four patients shows fMRI can be performed safely in patients with an implanted vagal nerve stimulator. The successful use of fMRI during VNS offers potential advantages over PET imaging by allowing rapid image acquisition and the ability to repeatedly study patients over time. Our preliminary results differ from previous PET or SPECT studies in failing to detect changes in subcortical areas. This finding could be due to the smaller n in this study compared with the other studies.     

Structures involved at the time of temporal lobe spikes revealed by interindividual group analysis of EEG/fMRI data

Purpose: We measured metabolic changes associated with temporal lobe (TL) spikes using combined electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). We selected 18 patients with temporal lobe epilepsy (TLE) who underwent a 2‐h simultaneous EEG–fMRI and had unilateral or bilateral independent TL spikes for interindividual group analysis, in order to identify consistent blood oxygenation level dependent (BOLD) responses to TL spikes. Methods: EEG was postprocessed and spikes were visually identified. fMRI data were preprocessed with motion correction, spatial smoothing, and removal of low frequency drifts. Spike timings were used as events for fMRI statistical analysis. Four hemodynamic response functions were used to account for variability in the BOLD response. Results: Group analysis revealed common areas of BOLD activations and deactivations. The hemodynamic response function (HRF) peaking 3 s after the spike showed activation involving ipsilaterally the mesial temporal structures (presumably the hippocampus), putamen/globus pallidus, inferior insula, and superior temporal gyrus. The HRF peaking at 5 s showed activations involving ipsi‐ and contralaterally the superior temporal gyrus and inferior insula. Both HRFs showed bilateral posterior cingulate deactivations. Discussion: We disclosed involvement of a network of activated areas during unilateral TL spikes, including ipsilateral mesial temporal structures, basal ganglia, and bilateral neocortical temporal regions. Despite the low temporal resolution of fMRI we demonstrated that contralateral temporal involvement occurred later than ipsilateral activation. This contralateral change took place in the absence of visible EEG changes. The posterior cingulate deactivation may reflect the interconnections between this region and other limbic structures. It may also partially correspond to a suspension of the default mode network, as previously described for TL spikes.