Physiological Analysis Of Voluntary Movement

该项目的目标是更多地了解正常人和自愿运动障碍患者的运动控制，如帕金森氏病、肌张力障碍、小脑性共济失调和中风偏瘫。我们使用的工具包括临床神经生理学方法，如脑电、肌电和经颅磁刺激(TMS)，以及正电子发射断层扫描和功能磁共振成像(FMRI)的神经成像。目前，该科正在进行的研究项目包括正常生理学、肌张力障碍的病理生理学和治疗、帕金森氏症、S病的运动迟缓以及偏瘫的康复。 我们正在努力确定脑电方法，以实时预测某人何时移动，以及他们将移动右手还是左手。我们优化了预测的特征和分类方法。我们的实时研究表明，我们可以在运动发生之前可靠地预测人类的运动意图。我们现在正试图减少遗漏预测，并探索预测运动意图偏侧性的方法。这项工作应该与脑机接口相关。 对简单动作的研究已经有很多年了，但人类做出的大多数动作都比较复杂。我们一直在用EEG和fMRI研究复杂的实践运动。功能磁共振成像显示出顶叶和运动前活动的模式，无论是哪只手进行运动，更多的是在左半球。脑电的连贯性分析表明，在运动的准备和执行过程中，顶区和运动前区是一致的，从而推断与事件相关的功能连接。使用事件相关功能磁共振成像，我们评估了正常人和意念运动性失用症患者传递性(工具相关)和非传递性(交际性)实践运动的大脑半球偏侧化。这项研究的发现指向正常实践运动的左半球组织。两名IMA患者的初步研究结果表明，实践运动受损与偏侧模式的改变有关，特别是在疾病更严重的情况下。 我们一直在做许多关于肌张力障碍的研究，主要是在局灶性手部肌张力障碍的患者中。我们花了相当多的时间来追寻这样的假设，即在肌张力障碍患者中存在缺乏自主运动的周围抑制。我们已经用TMS证明了这一点。我们现在正在探索环绕抑制的机制，研究不同类型的已知抑制过程。我们也在使用脑电方法，看看这是否有助于揭示周围抑制机制。为了确定局灶性手性肌张力障碍患者皮质内抑制缺陷的脑电证据，我们记录了来自正中神经电刺激的头皮体感诱发电位，以量化高频振荡，这可能反映了皮质中抑制性中间神经元的活动。我们一直在研究局灶性手性肌张力障碍患者躯体感觉辨别缺陷的电生理相关性。我们还在研究眼睑痉挛和斜颈患者的眨眼反射。在这项研究中，我们正在评估眨眼反射的R3成分，并将其与一级未受影响的亲属和对照组进行比较。我们有兴趣了解在未受影响的一级亲属中是否存在可能的神经生理标记物。 我们目前正在探索运动障碍的遗传学，有几个不同的患者群体。我们评估了大约250名局灶性肌张力障碍患者(眼睑痉挛、斜颈、作家痉挛、Meige综合征和痉挛性发音困难)。这一集合包括局灶性肌张力障碍的家庭，以及零星病例。此外，我们还在通过一个有多名成员受到影响的大家庭(40人)来研究特发性震颤的遗传学。这两项研究都旨在确定导致这种特定运动障碍的一个或多个基因。 在帕金森氏症领域，我们正在评估各种类型的非侵入性脑刺激的疗效。在一项安慰剂对照试验中，高频重复TMS导致帕金森？S病患者步态和手部运动速度的改善。我们现在正在研究经颅直流电刺激。 考虑到跌倒在老年人中的重要性，我们还在研究姿势不稳定及其随年龄的变化。我们正在追寻一个假设，即不稳定姿势的神经探测器随着年龄的增长而恶化。我们有EEG和fMRI研究证明这些神经探测器的证据。沿着姿势稳定性的研究路线，我们也在评估视觉在使用虚拟现实(VR)进行姿势控制中的作用。 在偏瘫的研究中，我们正在研究失语的生理学。我们已经证实了磁共振光谱学技术用于分析GABA的可行性，并正在将其应用于皮质下卒中患者。我们还在评估在中风患者中使用高频重复TMS的安全性，希望这将成为物理治疗的有用辅助手段。

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, dystonia, cerebellar ataxia, and hemiplegia from stroke. The tools we use include clinical neurophysiological methods such as electroencephalography, electromyography, and transcranial magnetic stimulation (TMS) and neuroimaging with positron emission tomography and functional magnetic resonance imaging (fMRI). Currently active projects in the Section include studies of normal physiology, the pathophysiology and treatment of dystonia, the bradykinesia in Parkinson?s disease, and recovery from hemiplegia. We are trying to determine EEG methods to predict in real time when someone is going to move and whether they will move their right or left hand. We have optimized features and classification methods for the prediction. Our real-time study demonstrated that we can reliably predict human movement intention before movement occurs. We are now attempting to reduce missed-predictions and explore methods to predict laterality of movement intention. The work should be relevant for use with a brain-computer interface. Simple movements have been studied for many years, but most movements humans make are more complex. We have been studying complex praxis movements with both EEG and fMRI. fMRI shows a pattern of parietal and premotor activity, more in the left hemisphere regardless of the hand used for making the movement. Coherence analysis with EEG has shown that parietal and premotor areas are coherent during preparation and execution of movement, inferring event related functional connectivity. Using event-related fMRI we assessed hemispheric lateralization of transitive (tool-related) and intransitive (communicative) praxis movements in normal people and patients with ideomotor apraxia. The findings of this study point to left hemispheric organization of normal praxis movements. Preliminary findings from two patients with IMA suggest that impaired praxis movements are associated with an altered pattern of lateralization, particularly if the disorder is more severe. We have been doing many studies of dystonia largely in patients with focal hand dystonia. We have devoted considerable time in pursuing the hypothesis that there is a deficient surround inhibition with voluntary movement in dystonic patients. We have demonstrated this with TMS. We are now pursuing the mechanism of surround inhibition studying different types of known inhibitory processes. We are also using EEG methods to see if this will help reveal surround inhibition mechanisms. In another effort to identify EEG evidence of deficient intracortical inhibition in focal hand dystonia, we recorded scalp somatosensory evoked potentials from median nerve electric stimulation to quantify high frequency oscillations, which may reflect the activity of inhibitory interneurons in the cortex. We have been studying the electrophysiological correlate of the deficit in somesthetic discrimination in focal hand dystonia. We are also studying the blink reflex in patients with blepharospasm and torticollis. In this study, we are evaluating the R3 component of the blink reflex and comparing it with first degree unaffected relatives and control subjects. We are interested to see if there is a possible neurophysiological marker in the unaffected first degree relatives. We are currently exploring the genetics of movement disorders with several different populations of patients. We have evaluated approximately 250 patients with focal dystonia (blepharospasm, torticollis, writer's cramp, Meige's Syndrome and spasmodic dysphonia). This collection includes families where focal dystonia is present, as well as, sporadic cases. In addition, we are also looking into the genetics of essential tremor through a large family (40 people) with multiple members affected. Both studies are aimed at identifying the gene or genes responsible for the specific movement disorder. In the area of Parkinson's Disease, we are evaluating the efficacy of various types of non-invasive brain stimulation. High frequency repetitive TMS lead to improvement in the speed of gait and hand movements in patients with Parkinson?s Disease in a placebo controlled trial. We are now studying transcranial direct current stimulation. We are also studying postural instability and its changes with aging, given the importance of falls in the elderly. We are pursuing the hypothesis that neural detectors of unstable postures deteriorate with aging. We have evidence for these neural detectors with both EEG and fMRI studies. Along this line of research of postural stability, we are also evaluating the role of vision in postural control using virtual reality (VR). In studies of hemiplegia, we are studying the physiology of diaschisis. We have confirmed the feasibility of a magnetic resonance spectroscopy technique for analysis of GABA and are applying this now to patients with subcortical stroke. We are also assessing the safety of using high frequency repetitive TMS in patients with stroke, hoping that this will be a useful adjunct to physical therapy.