运动双手食指后应用磁源性影像对运动皮质及体感皮质定位

目的确定运动双手食指后应用磁源性影像对运动皮质及体感皮质功能区定位的价值并探讨其成像方法。方法6例受试者接受左、右侧视觉光刺激后运动相应侧食指,双手食指下方各放置一块垫板,垫板上有一个光电偶合器,食指抬起后数据采集计算机即可将光电偶合的一刻为“零”对脑反应信号进行叠加。应用脑磁图记录运动及体感反应叠加后的脑电磁波并将其与相应受试者头MRI叠加形成磁源性影像。结果食指运动后,每个受试者双侧半球均出现一个最高的波峰,左右半球潜伏期分别为(41.5±7.8)ms和(35.5±3.6)ms。受试者之间左、右半球皮质兴奋的潜伏期(W1)差异无显著意义(t=2.046,P=0.096)。将其ECD叠加到MRI上可见ECD均位于中央后回。每个受试者在最高波峰之前出现一个小的波峰,潜伏期为负值,左、右半球分别为-(52.9±25.9)ms和-(63.8±19.5)ms。受试者之间左、右半球皮质兴奋的潜伏期(W2)差异无显著意义(t=1.342,P=0.237)。由磁源性影像显示兴奋的皮质位于中央前回。结论磁源性影像可很好地显示健康受试者运动皮质及体感皮质,可对运动皮质及体感皮质进行精确定位。     

运动双手食指后应用磁源性影像对运动皮质及体感皮质定位

目的 确定运动双手食指后应用磁源性影像对运动皮质及体感皮质功能区定位的价值并探讨其成像方法。方法 6例受试者接受左、右侧视觉光刺激后运动相应侧食指，双手食指下方各放置一块垫板，垫扳上有一个光电偶合器，食指抬起后数据采集计算机即可将光电偶合的一刻为“零”对脑反应信号进行叠加。应用脑磁图记录运动及体感反应叠加后的脑电磁波并将其与相应受试者头MRI叠加形成磁源性影像。结果 食指运动后，每个受试者双侧半球均出现一个最高的波峰，左右半球潜伏期分别为(41．5&;#177;7．8)ms和(35．5&;#177;3．6)ms。受试者之间左、右半球皮质兴奋的潜伏期(WI)差异无显著意义(t＝2．046，P＝0．096)。将其CCD叠加到MRI上可见ECD均位于中央后回。每个受试者在最高波峰之前出现一个小的波峰，潜伏期为负值，左、右半球分别为-(52．9&;#177;25．9)ms和—(63．8&;#177;19．5)ms。受试者之间左、右半球皮质兴奋的潜伏期(W2)差异无显著意义(t＝1．342，P=0．237)。由磁源性影像显示兴奋的皮质位于中央前回。结论 磁源性影像可很好地显示健康受试者运动皮质及体感皮质，可对运动皮质及体感皮质进行精确定位。     

磁源性影像对颅内肿瘤患者初级体感皮质定位的研究

目的:确定磁源性影像(MSI)对颅内肿瘤性病变患者脑初级体感皮质定位的价值。材料与方法:6例颅内肿瘤接近体感皮质的患者,其中男4例,女2例,年龄15~68岁,平均46岁。对患者双侧腕部正中神经进行电刺激。用306通道全头型生物磁仪(MEG)进行脑磁场测量。MRI设备使用GE公司生产的1.5T Signa Horizon成像系统。结果:所有受试者均出现M20波峰(电刺激腕部正中神经后20ms左右出现的体感诱发磁场)及M35波峰(电刺激腕部正中神经后35ms左右出现的体感诱发磁场),M20波峰潜伏期为21.2±0.9ms。MRI显示病变侧脑沟明显变窄。MSI明确地显示出脑体感皮质与肿瘤的立体关系,借此外科医师很容易地识别出中央沟的位置。结论:MSI对帮助术前制定的手术计划、术中的程序以及提供肿瘤与脑功能区的立体关系有重要意义。     

哑区梗死致左侧偏瘫者运动功能恢复过程的磁源性影像分析

目的：应用磁源性影像(MSI)技术探讨康复治疗机制。方法：应用磁源性影像技术观察分析1例哑区梗死致左侧偏瘫者运动功能恢复前后运动皮层诱发磁场变化。结果：康复训练运动功能恢复后，脑磁场诱发反应波出现，潜伏期较对侧明显延长，MSI定位前移。结论：规范康复训练伴随着运动功能的改善，脑结构和功能也发生了相应的变化,MSI研究支持康复训练促进功能恢复的邻近皮层功能代偿学说。重新获得的功能在质量上低于未受损肢体功能，与运动的反应速度、协调性有关。     

磁源性影像在中央区癫痫患者癫痫灶及手区体感皮质定位中的应用

目的 探讨磁源性影像（MSI）对中央区癫痫患者癫痫灶定位及手区体感皮质定位的应用价值。方法 对11例中央区癫痫患者进行脑磁图（MEG）及MR检查,将所获脑解剖结构图及发作间期异常放电、双侧大脑半球手区体感皮质位置叠加,形成MSI;并与术中皮质脑电图（ECoG）结果比较。结果 11例中,MRI显示软化灶4例,局灶性脑皮质发育不良4例,左颞极内侧蛛网膜囊肿1例,2例未见异常;MEG定位癫痫灶与ECoG完全一致9例,不一致2例;术后病理显示局灶性脑皮质发育不良（FCD）6例,微发育不良1例,胶质增生4例。6例癫痫灶与MSI确定的大脑半球手区体感皮质重叠：1例癫痫灶位于手区体感皮质前内侧,2例位于手区体感皮质稍后下方,1例位于手区体感皮质前方2 cm,1例位于手区体感皮质后方2 cm。术后随访Ⅰa级10例;Ⅲ级1例。所有患者未发生明显功能障碍。结论 MSI可明确癫痫灶与手区体感皮质的关系,指导临床进一步治疗。     

磁源成像对中、英文语言功能区的研究

目的：探索通过中、英文单词刺激健康志愿者后用磁源成像（MSI）无创性测定语言功能区的位置。方法：作者使用脑磁图对8例右利健康志愿者进行语言接受功能区的功能成像，在此过程中，受试者进行分别听150对中、英文单词的文字识别任务。结果：MSI显示8例受试者中有7例左侧半球内的兴奋明显强于右侧半球，有1例双侧大脑半球内的兴奋大致相等；中、英文单词刺激的磁反应波峰的后期兴奋（刺激后300-600ms）的磁源均位于颞上回和颞中回的后部。结论：MSI是一项有发展前途的、无创伤性的检查方法，它不但可以判断语言优势半球，而且可以判定语言功能区的位置。     

经颅磁刺激对偏头痛患者皮质功能的评估作用

目的采用经颅磁刺激探讨偏头痛患者的运动诱发电位及枕皮质的兴奋性,以进一步明确偏头痛发病的可能机制。方法对新诊断的偏头痛患者作脑运动诱发电位(brainmotorevokedpotentials,MEP)和磁刺激枕皮质诱发视幻觉的阈值检测。结果共有59例患者参加了试验,男26例、女33例,典型偏头痛17例、普通型偏头痛42例。正常对照22例。发现典型偏头痛患者枕皮质刺激诱发视幻觉的阈值(51±6)%显著低于正常对照组(74±8)%,运动透发电位潜伏期典型偏头痛(17.3±3.0)ms比正常组(12.1±2.7)ms显著延长。结论提示典型偏头痛患者枕皮质神经元兴奋增强,潜伏期延长可能与偏头痛患者脑损伤机制有关。     

经颅磁刺激对偏头痛患者皮质功能的评估作用

目的 采用经颅磁刺激探讨偏头痛患者的运动诱发电位及枕皮质的兴奋性，以进一步明确偏头痛发病的可能机制。方法 对新诊断的偏头痛患者作脑运动诱发电位(brain motor evoked potentials，MEP)和磁刺激枕皮质诱发视幻觉的嗣值检测。结果 共有59例患者参加了试验，男26例、女33例，典型偏头痛17例、普通型偏头痛42例。正常对照22例。发现典型偏头痛患者枕皮质刺激诱发视幻觉的嗣值(51&;#177;6)％显著低于正常对照组(74&;#177;8)％，运动透发电位潜伏期典型值头痛[17．3&;#177;3．0)ms比正常组(12．1&;#177;2．7)ms显著延长。结论 提示典型偏头痛患者枕皮质神经元兴奋增强，潜伏期延长可能与偏头痛患者脑损伤机制有关。     

颞叶躯体感觉中枢——脑磁源成像研究

目的利用脑磁源成像观察正常人在躯体感觉刺激时中枢的兴奋情况。方法研究包括10名正常志愿者。通过专用电刺激仪刺激手部皮肤,固定电流脉冲0.3ms,刺激间期0.5s,叠加1000次。用等电流偶极描述局灶性皮质活动,受试者的头部空间形态用球形模型化。结果体感刺激明显激活位于对侧中央前、后回的第一躯体感觉皮层和颞上回。颞叶ECD的潜伏期比第一躯体感觉中枢的长,ECD的强度较低。结论体感刺激激活对侧第一躯体感觉皮层,颞叶参与处理体感刺激。     

改良强制性运动疗法联合低频重复经颅磁刺激对脑卒中患者偏瘫上肢运动功能的影响

目的:探讨改良强制性运动疗法联合健侧1 Hz重复经颅磁刺激对脑卒中患者偏瘫上肢运动功能恢复的影响。方法:选择2020年5月至10月复旦大学附属金山医院收治的脑卒中患者90例,随机分为对照组(n=30)、改良组(n=30)和联合组(n=30)。对照组给予常规康复训练,改良组在常规康复训练基础上增加改良强制性运动疗法,联合组在常规康复训练基础上给予改良强制性运动疗法联合1 Hz重复经颅磁刺激治疗。于治疗前、治疗4周后采用Fugl-Meyer上肢运动功能评定量表(Fugl-Meyer assessment scale of upper extremity, FMA-UE)评估患者偏瘫上肢运动功能,并同时检测患侧中枢运动传导时间(central motor conduction time, CMCT)。结果:治疗后,对照组、改良组和联合组的FMA-UE评分由(25.97±5.83)分、(25.47±6.96)分和(26.10±5.29)分提高至(32.77±7.68)分、(38.07±8.16)分和(42.17±7.89)分(P0.001);CMCT由(11.78±0.44)ms、(11.62±0.45)ms和(11.78±0.40)ms缩短至(10.91±0.44)ms、(10.58±0.60)ms和(10.19±0.67)ms(P0.001)。联合组各项指标改善最显著(P0.001)。结论:改良强制性运动疗法联合低频重复经颅磁刺激可协同提高脑卒中患者患侧大脑皮质兴奋性,促进半球间平衡重建,有助于患侧皮质脊髓束功能修复,进而改善偏瘫上肢运动功能。     

Asymmetry in the human primary somatosensory cortex and handedness

Brain asymmetry is a phenomenon well known for handedness and language specialization and has also been studied in motor cortex. Less is known about hemispheric asymmetries in the somatosensory cortex. In the present study, we systematically investigated the representation of somatosensory function analyzing early subcortical and cortical somatosensory-evoked potentials (SEP) after electrical stimulation of the right and left median nerve. In 16 subjects, we compared thresholds, the peripheral neurogram at Erb point, and, using MRI-based EEG source analysis, the P14 brainstem component as well as N20 and P22, the earliest cortical responses from the primary sensorimotor cortex. Handedness was documented using the Edinburgh Inventory and a dichotic listening test was performed as a measure for language dominance. Whereas thresholds, Erb potential, and P14 were symmetrical, amplitudes of the cortical N20 showed significant hemispheric asymmetry. In the left hemisphere, the N20 amplitude was higher, its generator was located further medial, and it had a stronger dipole moment. There was no difference in dipole orientation. As a possible morphological correlate, the size of the left postcentral gyrus exceeded that of the right. The cortical P22 component showed a lower amplitude and a trend toward weaker dipole strength in the left hemisphere. Across subjects, there were no significant correlations between laterality indices of N20, the size of the postcentral gyrus, handedness, or ear advantage. These data show that asymmetry of median nerve SEP occurs at the cortical level, only. However, both functional and morphological cortical asymmetry of somatosensory representation appears to vary independently of motor and language functions.     

应用脑磁图对人脑初级体感皮质功能定位的研究

目的　通过脑磁图确定脑初级体感皮质的位置。方法　对 16名右利手健康受试者腕部正中神经进行电刺激 ,引起支配手的脑初级感觉皮质兴奋 ,脑初级感觉皮质的兴奋产生微弱的颅外磁场 ,用脑磁图机对这个微弱的颅外磁场进行测量。脑磁图检查后 ,受试者进行MRI检查 ,扫描序列为SE序列 ,矢状T1WI。结果　所有受试者均出现M 2 0波峰及M 3 5波峰 ,只有 2例出现明显的M 60波峰。将同一受试者M 2 0波峰及M 3 5波峰的等电流偶极与MRI叠加 ,即可明确显示手区初级体感皮质在左、右侧半球的位置。同一受试者M 2 0偶极位置与相应半球的M 3 5偶极位置相近。结论　将脑磁图获得的脑电生理学资料与MRI获得的解剖学资料叠加到一起所得到的磁源性影像可准确地确定脑的手区初级体感皮质的位置。     

Differential brain activation patterns during perception of voice and tone onset time series: a MEG study

Evoked magnetic fields were recorded from 18 adult volunteers using magnetoencephalography (MEG) during perception of speech stimuli (the endpoints of a voice onset time (VOT) series ranging from /ga/ to /ka/), analogous nonspeech stimuli (the endpoints of a two-tone series varying in relative tone onset time (TOT), and a set of harmonically complex tones varying in pitch. During the early time window (approximately 60 to approximately 130 ms post-stimulus onset), activation of the primary auditory cortex was bilaterally equal in strength for all three tasks. During the middle (approximately 130 to 800 ms) and late (800 to 1400 ms) time windows of the VOT task, activation of the posterior portion of the superior temporal gyrus (STGp) was greater in the left hemisphere than in the right hemisphere, in both group and individual data. These asymmetries were not evident in response to the nonspeech stimuli. Hemispheric asymmetries in a measure of neurophysiological activity in STGp, which includes the supratemporal plane and cortex inside the superior temporal sulcus, may reflect a specialization of association auditory cortex in the left hemisphere for processing speech sounds. Differences in late activation patterns potentially reflect the operation of a postperceptual process (e.g., rehearsal in working memory) that is restricted to speech stimuli.     

骨盆辅助式康复机器人联合重复经颅磁刺激对脑卒中后偏瘫患者下肢功能的影响

目的 观察骨盆辅助式康复机器人联合重复经颅磁刺激对脑卒中后偏瘫患者下肢功能的影响。 方法 采用随机数字表法将40例脑卒中后偏瘫患者分为对照组（20例）和实验组（20例）,2组均给予常规康复训练和康复机器人训练,实验组在此基础上辅以重复经颅磁刺激仪,刺激部位为健侧第一躯体皮质运动区（M1）,频率1.0 Hz,强度80%静息运动阈值,连续刺激20 min,刺激时间5 s,间隔时间5 s,每次予以600个脉冲刺激,每周5次,连续治疗8周。于治疗前和治疗8周后（治疗后）采用简式Fugl-Meyer运动量表下肢部分（下肢FMA评分）、Berg平衡量表（Berg评分）和Holden步行功能分级量表（Holden分级）评定2组患者的下肢运动功能、平衡功能和步行能力。 结果 治疗后,2组患者的下肢FMA评分、Berg评分和Holden分级均较组内治疗前均显著改善,差异均有统计学意义（P＜0.05）,且实验组的下肢FMA评分、Berg评分和Holden分级分别（22.05±2.93）分、（39.15±2.68）分和（3.45±0.83）级,明显优于对照组治疗后,差异均有统计学意义（P＜0.05）。 结论 骨盆辅助式康复机器人联合重复经颅磁刺激可有效地改善脑卒中偏瘫患者的下肢运动功能,提高其平衡功能和步行能力。     

A parietal-frontal network studied by somatosensory oddball MEG responses, and its cross-modal consistency

Previous studies using functional magnetic resonance imaging (fMRI) and event-related potentials (ERPs) of the brain have found that a distributed parietal-frontal neuronal network is activated in normals during both auditory and visual oddball tasks. The common cortical regions in this network are inferior parietal lobule (IPL)/supramarginal gyrus (SMG), anterior cingulate cortex (ACC), and dorsolateral prefrontal cortex (DLPFC). It is not clear whether the same network is activated by oddball tasks during somatosensory stimulation. The present study addressed this question by testing healthy adults as they performed a novel median-nerve oddball paradigm while undergoing magnetoencephalography (MEG). An automated multiple dipole analysis technique, the Multi-Start Spatio-Temporal (MSST) algorithm, localized multiple neuronal generators, and identified their time-courses. IPL/SMG, ACC, and DLPFC were reliably localized in the MEG median-nerve oddball responses, with IPL/SMG activation significantly preceding ACC and DLPFC activation. Thus, the same parietal-frontal neuronal network that shows activation during auditory and visual oddball tests is activated in a median-nerve oddball paradigm. Regions uniquely related to somatosensory oddball responses (e.g., primary and secondary somatosensory, dorsal premotor, primary motor, and supplementary motor areas) were also localized. Since the parietal-frontal network supports attentional allocation during performance of the task, this study may provide a novel method, as well as normative baseline data, for examining attention-related deficits in the somatosensory system of patients with neurological or psychiatric disorders.     

fMRI investigation of unexpected somatosensory feedback perturbation during speech

Somatosensory feedback plays a critical role in the coordination of articulator movements for speech production. In response to unexpected resistance to lip or jaw movements during speech, fluent speakers can use the difference between the somatosensory expectations of a speech sound and the actual somatosensory feedback to adjust the trajectories of functionally relevant but unimpeded articulators. In an effort to investigate the neural substrates underlying the somatosensory feedback control of speech, we used an event-related sparse sampling functional magnetic resonance imaging paradigm and a novel pneumatic device that unpredictably blocked subjects' jaw movements. In comparison to speech, perturbed speech, in which jaw perturbation prompted the generation of compensatory speech motor commands, demonstrated increased effects in bilateral ventral motor cortex, right-lateralized anterior supramarginal gyrus, inferior frontal gyrus pars triangularis and ventral premotor cortex, and bilateral inferior posterior cerebellum (lobule VIII). Structural equation modeling revealed a significant increased influence from left anterior supramarginal gyrus to right anterior supramarginal gyrus and from left anterior supramarginal gyrus to right ventral premotor cortex as well as a significant increased reciprocal influence between right ventral premotor cortex and right ventral motor cortex and right anterior supramarginal gyrus and right inferior frontal gyrus pars triangularis for perturbed speech relative to speech. These results suggest that bilateral anterior supramarginal gyrus, right inferior frontal gyrus pars triangularis, right ventral premotor and motor cortices are functionally coupled and influence speech motor output when somatosensory feedback is unexpectedly perturbed during speech production.     

Evoked magnetic fields following noxious laser stimulation of the thigh in humans

Primary somatosensory cortex (SI) and posterior parietal cortex (PPC) are activated by noxious stimulation. In neurophysiological studies using magnetoencephalography (MEG), however, it has been difficult to separate the activity in SI from that in PPC following stimulation of the upper limb, since the hand area of SI is very close to PPC. Therefore, we investigated human pain processing using MEG following the application of a thulium-YAG laser to the left thigh to separate the activation of SI and PPC, and to clarify the time course of the activities involved. The results indicated that cortical activities were recorded around SI, contralateral secondary somatosensory cortex (cSII), ipsilateral secondary somatosensory cortex (iSII), and PPC between 150-185 ms. The precise location of PPC was indicated to be the inferior parietal lobule (IPL), corresponding to Brodmann's area 40. The mean peak latencies of SI, cSII, iSII and IPL were 152, 170, 181, and 183 ms, respectively. This is the first study to clarify the time course of the activities of SI, SII, and PPC in human pain processing using MEG.     

Can magnetoencephalography track the afferent information flow along white matter thalamo-cortical fibers?

White matter thalamo-cortical fibers allow the communication of distant brain regions by carrying neuronal signals. Mapping non-invasively the information flow within white matter fibers is regarded so far as impossible. We investigated here whether information flow propagating along thalamo-cortical fibers can be detected using magnetoencephalography (MEG). Somatosensory evoked fields (SEFs) were recorded from healthy subjects and a patient with a unilateral, prenatally acquired, white matter lesion, which had induced the development of an abnormal trajectory of thalamo-cortical fibers. Equivalent current dipole (ECD) was used to model sources of SEFs. ECD at ~15 ms after stimulus onset was located within or close to the contralateral thalamus at the proximity of a hemodynamic response detected during a similar fMRI experiment. At the M20 peak latency, ECD was localized within the hand area of the contralateral primary somatosensory cortex (Brodmann area 3b (BA3b)). In healthy subjects, ECD changed dynamically position from thalamus to BA3b following a curved path, which was partially overlapping the thalamo-cortical fibers reconstructed by tractography. In the patient, ECD followed a similar path only in the intact hemisphere. In the affected hemisphere, the dipole trajectory circumnavigated the extended lesion on its way to the preserved primary somatosensory cortex--similar to the trajectory findings. Evidence from different methodological approaches converges on the conclusion that MEG can track the afferent information flow along thalamo-cortical fibers and in contrast to the traditional view can localize under presuppositions deep thalamic sources.     

年龄相关的运动功能减退神经机制研究：磁源性影像证据

目的：应用磁源性影像技术探讨在简单视-运动任务活动时的脑增龄性变化神经机制。方法：本文应用磁源性影像技术对13例20—85岁右利手健康男性进行简单视-运动任务活动时脑磁信号时间和空间的表现进行研究。结果：青年组和老年组受试者双手运动潜伏期基本一致，左手平均55ms，右手59ms，差异无显著性意义；脑运动皮层定位显示为双侧手指运动区。高龄老年组运动潜伏期延长，非利手侧较利手侧延长更加明显，平均90—127ms；利手侧半球空间定位可见，而非利手侧半球未显示空间定位。结论：成年人随增龄所发生的运动功能减退主要发生在75岁以后高龄老年人：老年性脑改变导致脑功能普遍减退可能是成年人随增龄所发生的运动功能减退的神经机制之一；成年人随增龄所发生的运动功能减退以神经传导速度减慢和运动协调性差为特征；长期反复运动活动有利于延缓脑运动控制机能的减退速度。