Diaschisis after stroke: a novel approach with arterial spin labeling (ASL) MRI

中风后神经联系联系不全：动脉自旋标记 (ASL) MRI 的新方法

• 批准号: 7193605
• 负责人: JOHN WALTER KRAKAUER
• 金额: $ 17.61万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-02-05 至 2008-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7193605
• 关键词: Diaschisis; after; stroke; novel; approach

DESCRIPTION (provided by applicant): The overall goal of this study is to use continuous arterial spin labeling, CASL, perfusion MRI to characterize diaschisis and determine its contribution to hemiparesis after subacute stroke. Stroke remains the leading cause of death worldwide despite improvements in acute stroke treatment and prevention. Patients show considerable variability in the degree to which they recover and the mechanisms underlying this variability are still largely unknown. One mechanism, termed diaschisis, was proposed almost a century ago to explain part of the initial deficit and the ability to partially recover from it. Diaschisis refers to a reduction of cerebral blood flow in uninjured brain regions that are connected to the area of injury. Animal models suggest that the reduction in cerebral blood flow is the result of decreased neuronal activity in the connected areas. Within this framework, the initial deficit is due to combination of diaschisis and the loss of function at the lesion location, whereas recovery occurs as diaschisis reverses. Previous attempts to study this phenomenon in humans have relied on PET and SPECT, which are expensive, not widely available, and require injection of radioactive tracers, limiting the frequency and practicality of use. As a result, there have been relatively few studies of diaschisis and thus its relevance to stroke deficit and stroke recovery remains to be determined. Here we propose to use arterial spin labeling, ASL, to investigate diaschisis in patients in the subacute and then chronic phases after hemiparetic stroke. ASL is non-invasive MR method that quantifies blood flow. To date it has been used to measure cerebral blood flow, CBF, that has been compromised by vascular occlusive disease. Here we propose a novel application of ASL for detection of decreases in CBF due to reduction in neuronal activity. The main aim of this grant is to demonstrate reductions in CBF in the contralateral cerebellum (crossed cerebellar diaschisis) and in the contralesional hemisphere. We will then correlate these changes with initial motor deficit in 3 to 4 weeks after stroke and with degree of recovery at 6 months.

描述（由申请方提供）：本研究的总体目标是使用连续动脉自旋标记、CASL、灌注MRI来表征神经联系不能，并确定其对亚急性卒中后轻偏瘫的贡献。尽管急性卒中的治疗和预防有所改善，但卒中仍然是世界范围内的主要死亡原因。患者在恢复的程度上表现出相当大的差异，这种差异的机制在很大程度上仍然是未知的。一种机制被称为神经机能不能，大约在世纪前就被提出来解释最初的部分缺陷和部分恢复的能力，神经机能不能是指与受伤区域相连的未受伤大脑区域的脑血流量减少。动物模型表明，脑血流量的减少是连接区域神经元活动减少的结果。在这个框架内，最初的赤字是由于组合的神经联系不能和功能丧失在病变部位，而恢复发生神经联系不能逆转。之前研究人类这种现象的尝试依赖于PET和SPECT，它们价格昂贵，使用不广泛，并且需要注射放射性示踪剂，限制了使用的频率和实用性。因此，对神经机能不能的研究相对较少，因此其与卒中缺陷和卒中恢复的相关性仍有待确定。在这里，我们建议使用动脉自旋标记，ASL，调查在亚急性期，然后慢性期偏瘫中风后的患者的神经联系不能。ASL是一种非侵入性MR方法，可量化血流。迄今为止，它已被用于测量脑血流量，CBF，已被血管闭塞性疾病损害。在这里，我们提出了一种新的应用ASL检测减少CBF由于减少神经元活动。这项研究的主要目的是证明对侧小脑（交叉小脑神经联系不能）和对侧半球的CBF减少。然后，我们将这些变化与卒中后3 - 4周的初始运动缺陷以及6个月时的恢复程度相关联。