The potential for transcranial direct current stimulation to restore motor function in the vegetative state

最近在提供重症监护方面的改进增加了在最严重的脑损伤中存活的机会。其中许多患者进展到一种状态，在这种状态下，意识和外部反应要么缺失(即植物人状态)，要么大大降低(即最低限度意识状态)。现在已经知道，这些患者中的一些人保持着比他们的临床诊断预期更高的意识水平，但他们只是无法用他们的行为表现出来--被困在他们反应迟钝的身体里。最近，我自己的研究为大脑中发生的导致这种反应迟钝的行为提供了一种解释。具体地说，我发现两个大脑区域之间的信息流出现了部分中断，这两个区域需要协同工作，以便自愿控制运动，这首次提出了一个潜在的干预目标，以恢复那些尽管确诊但仍保持一定意识水平的患者的运动控制。该项目旨在评估一种名为经颅直流电刺激(Tdcs)的非侵入性脑刺激形式的潜力，以调节控制运动的大脑区域的活动，并因此提高运动反应性。在拟议的研究中，健康志愿者将在不同的目标区域和不同的参数(例如，会话次数、有/没有伴随任务等)下接受tDCs，同时使用功能磁共振成像(FMRI)记录他们的神经活动。通过将tdcs与功能磁共振相结合，并使用先进的分析方法，我将能够表征由于刺激而导致的运动网络中不同区域之间关系的变化。这项研究有三个主要目标。首先，我将绘制出tdcs对感兴趣的大脑运动网络的影响。其次，我将探索通过使用多个疗程以及同时进行刺激和运动练习来增强刺激效果的潜在效果。最后，我将研究大脑解剖或功能的特定特征是否可以预测个体对刺激的反应程度。这项研究的结果将为更长期的研究计划提供参考，随后将应用于植物人和意识最弱的患者群体，最终目标是开发有效和可用的干预措施来治疗这些疾病。如果成功，这一方案将对患者及其家人和护理人员的生活产生深远影响，为患者提供自受伤以来第一次与世界互动的物质手段。

Recent improvements in the provision of intensive care have increased the chances of surviving the most severe brain injuries. Many of these patients progress to a state in which awareness and external responsiveness are either absent (i.e., the vegetative state) or greatly reduced (i.e., the minimally conscious state). It is now known that some of these patients retain a much higher level of awareness than could be expected by their clinical diagnoses, but they are simply unable to show it with their behaviours - trapped in their unresponsive bodies. Recently, my own research has provided an explanation for what happens in the brain to cause this unresponsive behaviour. Specifically, I identified a partial disruption in the flow of information between two brain regions that need to work together to allow for the voluntary control of movement, suggesting for the first time a potential target for interventions to restore motor control to those patients who, despite their diagnoses, retain a level of awareness. This project is aimed at assessing the potential for a non-invasive form of electrical brain stimulation, known as transcranial direct current stimulation (tDCS), to modulate the activity of the brain regions that control movement, and increase motor responsiveness as a result. In the proposed studies, healthy volunteers will receive tDCS, over different target regions and with different parameters (e.g., number of sessions, with / without an accompanying task, etc.), while their neural activity is recorded with functional magnetic resonance imaging (fMRI). By combining tDCS with fMRI, and using advanced analysis methods, I will be able to characterize the changes that occur in the relationships between the different regions in the motor network as a result of stimulation. This research has three primary objectives. First, I will map out the effects of tDCS over the brain motor network of interest. Second, I will explore potential enhancements in the effects of the stimulation with the use of multiple sessions and simultaneous stimulation and motor practice. Finally, I will investigate whether specific characteristics of the brain anatomy or function can predict the degree to which an individual will respond to the stimulation. The outcomes of this research will inform a longer-term research programme, with subsequent applications in groups of vegetative and minimally conscious patients themselves, with the final goal of developing effective and available interventions to treat these conditions. If successful, this programme will have a profound impact on the lives of the patients, and their families and care-givers, by providing the patients with a physical means of interacting with the world for the first time since their injuries.