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.     

BOLD-fMRI和DTI结合神经导航在枕叶视觉功能区附近病变切除中的应用

目的 探讨血氧水平依赖性功能磁共振成像（BOLD - fMRI）与磁共振弥散张量成像技术(DTI)融合结合神经导航在枕叶视觉功能区附近病变切除术中的应用价值。方法 利用BOLD-fMRI、DTI结合神经导航进行图像融合,在20例视觉功能区附近病变患者术前设计手术入路,术中定位视觉功能区,指导手术,合理保护功能区,切除病变。结果 15例镜下全切除,5例大部切除。术后复查MRI及DTI视皮层及视辐射保护完好。结论 BOLD - fMRI和DTI融合技术在神经导航下应用可以准确确定大脑枕叶视觉功能区和视辐射走行,术前精确定位功能区,提高病变切除程度,降低术后致残率,提高患者术后生活质量。     

汉-英双语言脑功能区外科手术定位的探讨

目的探讨中国人汉-英语的脑功能区定位及手术方法。方法对1例广东籍汉语普通话-英语双语言脑功能区低级别胶质瘤病人，术前通过汉、英语语义、语音和图文实验任务，经功能磁共振（fMRI）定位汉语和英语皮质区．由神经功能导航制定手术计划和定位，术中采用超声探测肿瘤，全麻唤醒下双语定位监测功能区，行显微手术切除病变。结果fMRI检出汉语激活区在肿瘤的前下外部，即额中下回后部，英语激活区则位于近肿瘤的额上中回后部。切除肿瘤过程中英语较汉语出现明显障碍征象。肿瘤获次全切除，术后出现短暂辅助运动区（SMA）综合征，英语运动性失语于术后1周内恢复；术后3个月，fMRI显示英语激活区重塑位移。术后8个月随访，病人恢复正常生活和工作，术前癫痫症状消失。结论①采用双语方式进行fMRI扫描定位、神经导航功能区定位和术中清醒状态下双语监测，使双语言脑功能区病变病人的手术治疗成为可能。②在保留母语功能的前提下，对第2语言区病变做到最大限度切除后，其语言功能仍可能得到恢复。     

多模态影像联合电生理监测在脑功能区胶质瘤手术中的应用研究

目的研究多模态影像联合电生理监测技术在脑功能区胶质瘤手术中的保护脑功能的应用价值。方法回顾性分析5例语言区和55例运动区胶质瘤患者的临床资料。术前行功能磁共振定位功能区,弥散张量成像显示重要传导束,融合多模态影像构建功能神经导航,术中采用皮层体感诱发电位定位中央沟,并运用皮层-皮层下电刺激技术监测语言区、运动区和皮层下重要神经传导束,在保护功能前提下尽可能切除病灶。术后评价肿瘤切除程度和神经功能。结果 5例语言区胶质瘤和30例病变毗邻运动皮层胶质瘤患者术前功能磁共振成功定位功能区,通过弥散张量成像3例语言区胶质瘤和42例运动区胶质瘤患者分别重建出弓状束和锥体束。术中电刺激语言区和运动区检出率分比为100%和92.7%;92.7%的运动区肿瘤患者可通过皮层体感诱发电位技术定位中央沟。术中神经导航对手术具有指导作用。肿瘤影像全切率86.7%,术后功能保留率91.7%。结论运用多模态影像技术有助于术前定位脑功能区,功能神经导航有助于术前规划、术中引导病灶切除,但需注意影像漂移。术中电生理监测技术是定位和保护脑功能结构的主要手段。     

汉-英-法多语者脑功能区手术定位的探讨

目的 探讨中国人汉-英-法多语者的脑功能区定位,应用唤醒手术及直接皮层电刺激技术,探讨多语者脑功能区肿瘤的手术方法.方法 对一例浙江籍汉语普通话-英语-法语多语者,同时也是左额叶低级别胶质瘤患者进行手术,术前完成汉、英、法语言试验任务,经功能磁共振定位汉语、英语、法语皮质区;术中采用超声探测肿瘤,全麻唤醒下应用皮层直接电刺激技术确定多语言的功能区,依据功能区边界切除肿瘤.评价术前、术后语言功能.结果 通过fMRI检出汉、英、法3种语言激活区,且3种语言区基本重合,位于左额中、上回的后部及颞上回.切除肿瘤过程中,应用皮层直接电刺激技术发现了汉、英、法3种语言的功能区,其中英、法语言区基本重合,但与汉语语言区并不完全重合,颞上回后部存在特异性的语言区.肿瘤次全切除,术后出现短暂运动性失语,3种语言均受损,但于半年内恢复,其中汉语的恢复较快,英语、法语恢复慢.术后1年随访,患者恢复正常生活和工作,3种语青功能均恢复至术前水平,未发现语言转换障碍,术前癫痫症状消失.结论 采用多语方式进行扫描定位和术中清醒状态下多语监测使得多语脑功能区病变患者的手术治疗成为可能.     

皮层电刺激技术在语言区附近病变手术中的应用

目的探讨唤醒状态下皮层电刺激技术在语言区附近病变手术中的应用价值。方法 79例语言区附近病变的患者,在唤醒状态下利用皮层电刺激技术,通过执行三类语言任务:数数字、图片命名与语言理解来进行语言区定位,避开语言区在显微镜下切除病变。结果本组患者51例术前语言功能正常,28例有不同程度语言功能障碍。75例患者完成了语言区定位。病变全切除30例,次全切除26例,大部切除23例。术后语言功能19例较前好转,53例无变化,4例出现短暂性运动性失语,3例出现短暂性感觉性失语,均于2周内基本恢复正常。结论唤醒状态下多种语言任务的联合应用可以提高皮层电刺激语言区定位的准确性,减少术后语言功能障碍的发生;语言区与切除皮层之间的相对安全距离是10mm。     

脑功能区胶质瘤手术中的新技术

目的探讨切除脑功能区胶质瘤手术新技术与方法。方法48例脑功能区胶质瘤经术前常规MRI、弥散张力成像(DTI)和fMRI定位大脑皮层功能区及功能投射纤维束,以神经导航为前导,在术中全麻唤醒状态下,通过术中B超定位脑内病灶,皮层体感诱发电位(Co-SEP)及皮层直接电刺激术(Co-ST)脑功能区定位,并在清醒状态下切除病变。术后随访时间3-42个月。结果16例Co-SEP确定中央沟,42例Co-ST明确运动区,16例Co-ST确定语言运动区;肿瘤全切35例,次全切除9例,部分切除4例。术后1个月神经症状好转44例,术后出现暂时性局部神经症状36例;长期局部神经症状加重4例,无手术死亡。全部患者无手术痛苦回忆。结论术中全麻唤醒、皮层-皮层下电刺激术和脑超声技术是切除功能区胶质瘤必备的三项基本技术;术前fMRI与DTI为脑功能区手术提供十分重要信息,神经功能导航为术中功能区定位提供重要前导,综合使用这些现代技术能够在术中明确脑功能区与肿瘤切除范围的关系,做到最大限度地切除脑功能区病变和保护脑功能。     

起源于语言功能区及其附近的难治性癫痫的手术治疗

目的探讨起源于语言功能区及其附近的难治性癫痫术前评估和显微手术治疗的方法。方法16例起源于语言区癫痫患者术前使用了长程视频脑电图、功能磁共振成像（fMRI）等检查,明确癫痫灶与功能区的位置关系,并用中国修订韦氏成人智力量表（WAIS—RC）及语言流畅性试验对患者语言功能进行术前评估,术中使用fMRI神经导航配合皮层脑电描记（ECoG）,在保护语言功能区的基础上显微手术切除癫痫灶。术后行视频脑电图及语言功能再评估情况随访。结果16例患者中有2例术后出现了短暂的运动性语言功能障碍,1W内恢复正常。术后1个月、3个月复查脑电图（EEG）：13例正常,3例提示轻度异常EEG。术后3个月随访语言功能及流畅性再评估情况与术前比较无明显差异。结论fMRI神经导航配合ECoG显微手术切除癫痫灶,在治疗癫痫的同时能最大程度地保护语言功能。     

神经导航融合DTI在大脑功能区附近病变手术的临床应用

目的探讨神经导航融合DTI在大脑功能区附近病变手术的应用价值。方法对40例病变位于大脑功能区附近(20例位于额顶叶中央沟附近,13例位于枕叶视觉距状裂附近,7例位于左侧语言中枢附近)的右利手病人,术前行磁共振弥散张量成像(DTI),获得白质纤维束原始资料,经神经导航融合DTI和解剖像并三维重建后,术中在导航辅助下行显微手术。结果病变全切34例,次全切6例。术后神经功能好转或无变化35例,出现一过性加重5例。无遗留永久性功能障碍。结论神经导航融合DTI可以准确定位功能区,操作性强,易推广,术中实时保护周边邻近传导束,减少术后神经功能障碍并发症,安全范围内最大程度切除,具有颇高的临床意义。     

正常国人汉语语言Broca区的fMRI刺激模式筛选

目的 为临床应用筛选出能够在fMRI上稳定激活Broca区的汉语语言任务刺激模式.方法 选用正常右利手国人10名,采用组块设计,应用西门子SONATA 1.5T MRI分别在不同的汉语语言任务下进行脑功能成像,汉语语言任务分四组默读组、朗读组、图片命名组、文字阅读组.图像资料经FADA与AFNI软件后处理获得脑区激活图.结果 默读组仅见少量小脑区激活,未见Broca区激活;朗读组有9例可见Broca区激活,时间-信号强度动态曲线稳定;图片命名组有7例、文字阅读组有8例可见Broca区激活,但同时伴有强烈的视皮层激活.结论 汉语朗读任务可以作为临床fMRI中激活Broca区的语言任务刺激模式.     

Study on the pathogenic mechanism of Broca's and Wernicke's aphasia

OBJECTIVE: To study the mechanisms of aphasia by observing cerebral blood flow and metabolism changes in language functional areas of the brain using imaging, in order to develop a language rehabilitation plan for aphasia patients. METHODS: Fifty-eight patients who suffered from Broca's or Wernicke's aphasia secondly to cerebral infarction were evaluated using the Western aphasia battery and Frenchay dysarthria assessment. CT and MRI were obtained to identify the location of lesions, and the language areas were analysed with magnetic resonance spectroscopy (MRS) and perfusion-weighted imaging (PWI). The results were compared with those of the contralateral hemisphere. RESULTS: Of the 58 patients, there were 23 Broca's aphasia patients, 29 Wernicke's aphasia patients and six other aphasia types. We excluded five patients accompanied by dysarthria, six patients with other aphasia types and 14 patients with much more disease lesions. Finally, we analysed the remaining 12 Broca's aphasia and 21 Wernicke's aphasia patients by MRS and PWI. MRS shows that the N-acetylaspartate, choline and creatine of the Broca's or Wernicke's area were reduced than those of the contralateral hemisphere, while PWI results show that the damaged Broca's or Wernicke's areas were in a hypoperfusion state. CONCLUSIONS: Broca's or Wernicke's area of aphasia patients exhibits hypoperfusion and hypometabolism, indicating that they might be the mechanisms of Broca's or Wernicke's aphasia.     

Is Broca's area involved in the processing of passive sentences? An event-related fMRI study

We used functional magnetic resonance imaging (fMRI) to investigate whether activation in Broca's area is greater during the processing of passive versus active sentences in the brains of healthy subjects. Twenty Japanese native speakers performed a visual sentence comprehension task in which they were asked to read a visually presented sentence and to identify the agent or the patient in the sentence by pressing a button. We found that the processing of passive sentences elicited no greater activation than that of active sentences in Broca's area. However, passive sentences elicited greater activation than active sentences in the left frontal operculum and the inferior parietal lobule. Thus, our neuroimaging results suggest that deficits in the comprehension of passive sentences in Japanese aphasics are induced not by lesions to Broca's area, but to the left frontal operculum and/or the inferior parietal lobule.     

Simultaneous event-related potential and near-infrared spectroscopic studies of semantic processing

Near-infrared optical topography (NIROT) signals and event-related potentials (ERPs) were measured simultaneously during a semantic processing task to evaluate the ability of these techniques to detect hemodynamic and electrophysiologic responses generated by semantic anomalies and to compare these results to earlier independent functional magnetic resonance imaging (fMRI) and ERP measurements. Candidate brain regions were first identified from activations detected by NIROT during a simple block-design task (in this case reading sentences vs. passive viewing), and defined regions (corresponding to Broca's and Wernicke's areas) were used for guiding the localization of optodes and electrodes for recording during tasks involving semantic anomalies. In five of six subjects, ERP measurements showed the characteristic N400 wave, whereas event-related NIROT showed results that agreed with previous fMRI studies. There were transient hemodynamic signals recorded in specific optodes that corresponded to activation in Broca's area, but slightly anterior to the region activated during the simple reading task, and in Wernicke's area, but slightly inferior to that for the simple reading task. A between-subject correlation of the ERP and NIRS data was also employed to identify areas of activation. The highest correlations were obtained in Broca's area, centered more anterior than for the reading task and in Wernicke's area, slightly inferior to that for the reading task. This study confirms that event-related studies are feasible using NIROT and produce results similar to those obtained with fMRI. Even though the spatial resolution is lower in NIROT than in fMRI, small differences in the locations of activation centers could be detected with NIROT. This, together with the feasibility of simultaneous ERP recording, makes NIROT attractive as a new approach to studying language function in healthy subjects as well as in those with functional abnormalities.     

Language-related brain function during word repetition in post-stroke aphasics

We compared fMRI findings (using SPM99) obtained with repetition task in normal subjects with those of two patients with Broca's and Wernicke's aphasia who received speech therapy and showed complete recovery. Both aphasic patients with left hemisphere damage who showed complete recovery exhibited activation of only the compensatory area in the right hemisphere during the repetition task. Recovery from Broca's aphasia involves reorganization and neuromodulation between the external temporopolar area and the anterior superior temporal area of the superior temporal gyrus, putamen and the inferior frontal gyrus, while that from Wernicke's aphasia involves reorganization and neuromodulation between the superior temporal gyrus of the temporal region, the posterior supramarginal gyrus and inferior parietal lobule of the parietal region.     

Categorical speech processing in Broca's area: an fMRI study using multivariate pattern-based analysis

Although much effort has been directed toward understanding the neural basis of speech processing, the neural processes involved in the categorical perception of speech have been relatively less studied, and many questions remain open. In this functional magnetic resonance imaging (fMRI) study, we probed the cortical regions mediating categorical speech perception using an advanced brain-mapping technique, whole-brain multivariate pattern-based analysis (MVPA). Normal healthy human subjects (native English speakers) were scanned while they listened to 10 consonant-vowel syllables along the /ba/-/da/ continuum. Outside of the scanner, individuals' own category boundaries were measured to divide the fMRI data into /ba/ and /da/ conditions per subject. The whole-brain MVPA revealed that Broca's area and the left pre-supplementary motor area evoked distinct neural activity patterns between the two perceptual categories (/ba/ vs /da/). Broca's area was also found when the same analysis was applied to another dataset (Raizada and Poldrack, 2007), which previously yielded the supramarginal gyrus using a univariate adaptation-fMRI paradigm. The consistent MVPA findings from two independent datasets strongly indicate that Broca's area participates in categorical speech perception, with a possible role of translating speech signals into articulatory codes. The difference in results between univariate and multivariate pattern-based analyses of the same data suggest that processes in different cortical areas along the dorsal speech perception stream are distributed on different spatial scales.     

Functional changes in the activity of brain regions underlying emotion processing in the elderly

Aging is associated with a decline in both cognitive and motor abilities that reflects deterioration of underlying brain circuitry. While age-related alterations have also been described in brain regions underlying emotional behavior (e.g., the amygdala), the functional consequence of such changes is less clear. To this end, we used blood oxygenation-level dependent (BOLD) functional magnetic resonance imaging (fMRI) to explore age-related changes in brain regions underlying emotion processing. Twelve young (age <30 years) and 14 elderly subjects (age >60 years) were studied with BOLD fMRI during a paradigm that involved perceptual processing of fearful and threatening stimuli. Consistent with previous reports, direct group comparisons revealed relatively increased BOLD fMRI responses in prefrontal cortical regions, including Broca's area, and relatively decreased responses in the amygdala and posterior fusiform gyri in elderly subjects. Importantly, additional analyses using an elderly-specific brain template for spatial normalization of the elderly BOLD fMRI data confirmed these divergent regional response patterns. While there was no difference between groups in accuracy on the task, elderly subjects were significantly slower (delayed reaction times) in performing the task. Our current data suggest that elderly subjects engage a more distributed neocortical network during the perceptual processing of emotional facial expressions. In light of recent converging data from two other studies, our observed effects may reflect age-related compensatory responses and/or alternative strategies in processing emotions, as the elderly appear to engage cognitive/linguistic systems in the context of reduced sensory and/or limbic responses.     

Language area localization with three-dimensional functional magnetic resonance imaging matches intrasulcal electrostimulation in Broca's area.

In this study, intraoperative electrocortical stimulation mapping (ioESM), the current gold standard for the localization of critical language areas, is compared with functional magnetic resonance imaging (fMRI) in a 14-year-old girl with medically intractable epilepsy caused by a tumor in the region of Broca's area. Prior to the operation, four different fMRI tasks that target inferior frontal language areas were applied. Prior to the resection, ioESM as well as fMRI detected no language areas at the exposed cortical area. After removal of the tumor, a unique opportunity presented itself, where ioESM could be performed in the depth of a now exposed and intact gyrus. One specific locus that was indicated to be a critical language area by multiple-task fMRI was targeted. IoESM selectively confirmed the location of this language area to within an estimated 3 mm. We propose that the combined use of different fMRI tasks increases the sensitivity and specificity for the detection of essential language areas.     

Broca's region subserves imagery of motion: a combined cytoarchitectonic and fMRI study

Broca's region in the dominant cerebral hemisphere is known to mediate the production of language but also contributes to comprehension. Here, we report the differential participation of Broca's region in imagery of motion in humans. Healthy volunteers were studied with functional magnetic resonance imaging (fMRI) while they imagined movement trajectories following different instructions. Imagery of right-hand finger movements induced a cortical activation pattern including dorsal and ventral portions of the premotor cortex, frontal medial wall areas, and cortical areas lining the intraparietal sulcus in both cerebral hemispheres. Imagery of movement observation and of a moving target specifically activated the opercular portion of the inferior frontal cortex. A left-hemispheric dominance was found for egocentric movements and a right-hemispheric dominance for movement characteristics in space. To precisely localize these inferior frontal activations, the fMRI data were coregistered with cytoarchitectonic maps of Broca's areas 44 and 45 in a common reference space. It was found that the activation areas in the opercular portion of the inferior frontal cortex were localized to area 44 of Broca's region. These activations of area 44 can be interpreted to possibly demonstrate the location of the human analogue to the so-called mirror neurones found in inferior frontal cortex of nonhuman primates. We suggest that area 44 mediates higher-order forelimb movement control resembling the neuronal mechanisms subserving speech.