PHYSIOLOGICAL ANALYSIS OF VOLUNTARY MOVEMENT

这个项目的目标是了解更多关于 控制正常人和患者的运动 随意运动障碍，如帕金森病， 小脑共济失调中风偏瘫和肌张力障碍一个主要 整个实验室的科学目标是了解和 可能会影响先天性脑梗死患者的皮质重组 或中枢神经系统的后天性损伤。多模态 方法（PET和功能性MRI，EEG的神经成像， 经颅磁刺激）被用来确定 功能性脑地形图的长期重组模式 在个别中风患者中。患者数据分析 皮质下病变表明皮质的再生 活动和兴奋性模式取决于病变部位 在内囊内。光谱功率和相干性分析 的脑电图已被用来研究学习双手运动， 以不同的速度移动。之间的同步 大脑的初级和次级运动区域 利用脑电相干性研究运动速率控制 测量.不同的感觉运动整合策略， 观察到的快速和缓慢的重复动作 移动速率。与事件有关的一致性， 运动开始揭示了运动的皮层相关性 战略改变。结果表明， 运动速度不是一个线性过程。我们曾研究 大脑和主动活动的肌肉之间的连贯性， 评估运动皮层是如何控制肌肉的 通过分析振荡的频率编码， 时间关系。在阿尔法中观察到了独立的关系 和β频段。这样的分析对他的 生理学的见解，但也帮助我们了解 相干分析的相位特征。皮质肌的 沟通和皮层代表的过程中的分级 用脑电频域分析法研究了力的产生。 皮质-肌肉通讯，表示为EEG-EMG 连贯性是不敏感的生产力水平，而皮质 对侧中央区β带功率变化为 与力的大小成线性关系。结果表明， EEG-EMG相干性作为皮质-肌肉运动的恒定测量 偶合器.通过脑电图和正电子发射断层扫描，我们确定了正常的 初级感觉皮层的球状组织退化 在支持感觉性肌张力障碍概念的局灶性肌张力障碍患者中， 异常在肌张力障碍中起致病作用。我们研究了 氯氮平治疗全身性和难治性局灶性肌张力障碍疗效观察 客观和主观指标显示， 症状然而，它的使用受到副作用的限制。我们使用 从事空间任务的正常受试者的PET 视觉和听觉刺激的定位。多式联运地区是 确定的以及具体的模式领域。我们的研究结果表明 就像在视觉系统中， 听觉系统延伸到初级听觉皮层之外， 包括后顶叶和前额叶区域。这些 结果可以解释视觉和听觉的分离 对于病变涉及这些的患者，报告了空间缺陷 地区我们研究了一组弗里德赖希病患者， 通过MRI检测共济失调，以检测铁 齿状核的内容。初步结果显示， 年轻人小脑中铁含量增加的明显趋势 Friedreich共济失调患者，但不是更晚期的老年患者， 患者

The goal of this project is to learn more about the control of movement in normal humans and in patients with voluntary movement disorders such as Parkinson's disease, cerebellar ataxia, hemiplegia from stroke and dystonia. One major scientific target of the whole laboratory is to understand and possibly influence cortical reorganization in patients with congenital or acquired lesions of the central nervous system. A multi-modality approach (neuroimaging with PET and functional MRI, EEG, and transcranial magnetic stimulation) is being used to determine patterns of long-term reorganization of functional brain topography in individual stroke patients. Analysis of data from patients with subcortical lesions indicated that the reoganization of the cortical activity and excitability patterns depends on the site of the lesion within the internal capsule. Spectral power and coherence analyses of EEG have been used to study learning bimanual movement and making movements at different rates. Synchronization among primary and secondary motor areas of the human brain during movement rate control was studied by EEG coherence measurement. Different sensorimotor integration strategies were observed with auditory-cued repetitive movements of fast and slow movement rates. Event-related coherence focusing on the movement onset revealed the cortical correlates of movement strategy change. The results suggest that the increase of the movement rate is not a linear process. We have examined coherence between the brain and voluntarily active muscle to evaluate how the motor cortex controls the muscle. Frequency-coding of the oscillations was revealed by analyzing the temporal relationships. Separate relationships were seen in the alpha and beta frequency bands. Such analysis has been useful for its physiological insights, but has also helped us in our understanding of the phase feature of coherence analysis. Corticomuscular communication and cortical representation of the process of graded force production was studied by EEG frequency domain analysis. Corticomuscular communication expressed as EEG-EMG coherence was insensitive to the produced force level, while cortical power change in beta band over the contralateralcentral area was linearly correlated with the force level. The results suggest the EEG-EMG coherence as a constant measure of cortico-muscular coupling. Using EEG and PET, we determined that the normal homuncular organization of the primary sensory cortex is degraded in patients with focal dystonia supporting the concept that sensory abnormalities play a pathogenetic role in dystonia. We examined the efficacy of clozapine for generalized and refractory focal dystonias. Objective and subjective measures revealed clinical improvement in symptoms. However, its use was limited by side effcts. We used PET in normal subjects engaged in tasks involving spatial localization of visual and auditory stimuli. Multimodal areas were identified as well as modality specific areas. Our findings suggest that, like in the visual system, the hierarchical organization of the auditory system extends beyond the primary auditory cortex to include areas in the posterior parietal and prefrontal regions. These results may explain the dissociation of the visual and auditory spatial deficits reported for patients with lesions involving these regions. We have studied a group of patients with Friedreich's ataxia by means of MRI in order to detect differences in the iron content of the dentate nucleus. The preliminary results showed a clear trend towards increased iron in the cerebellum in young patients with Friedreich's ataxia but not in more advanced older patients.