Dai Weiying, Lopez Oscar L, Carmichael Owen T, Becker James T, Kuller Lewis H, Gach H Michael
Department of Computer Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
Stroke. 2008 Feb;39(2):349-54. doi: 10.1161/STROKEAHA.107.495457. Epub 2008 Jan 3.
The purpose of this study was to examine regional cerebral blood flow (rCBF) in normal cognitive-performing subjects with hypertension (HTN) using continuous arterial spin-labeled MRI. The most common explanation for the effect of blood pressure on cognition is that HTN increases the risk of cerebrovascular disease, and it may increase the risk for Alzheimer disease possibly through small vessel disease, ischemia, oxidative stress, and inflammation. However, few studies to date have examined the rCBF of cognitively normal subjects with HTN in population-based cohorts, and none have used continuous arterial spin-labeled MRI. This is a noninvasive technique that does not require either injections or ionizing radiation and can measure absolute rCBF rates over the entire brain.
rCBF was measured at 1.5 T using continuous arterial spin-labeled MRI in 41 cognitively normal subjects who were participating in the Cardiovascular Health Study Cognition Study. A deformable atrophy-corrected registration method was used to warp the rCBF maps to the standard colin27 brain space. Image and cluster-based statistical analyses were performed between subject groups.
Cognitively normal subjects with HTN (n=19) had decreased rCBF in the putamen, globus pallidus, bilaterally, and in the left hippocampus compared with normotensives (n=22). In addition, decreased rCBF was observed in the right and left anterior cingulate gyrus with extension to the subcallosal region, left posterior cingulate gyrus and medial precuneus, left lateral inferior and superior frontal, and inferior parietal, left orbitofrontal, and left superior temporal cortices.
rCBF is affected in normal subjects with HTN, not only in the subcortical regions, but also in limbic and paralimbic structures. We hypothesize that the HTN creates a vulnerability state for the development of neurodegenerative disorders, especially Alzheimer disease.
本研究旨在使用连续动脉自旋标记磁共振成像（MRI）检查患有高血压（HTN）的认知功能正常受试者的局部脑血流量（rCBF）。血压对认知产生影响的最常见解释是，高血压会增加脑血管疾病的风险，并且可能通过小血管疾病、缺血、氧化应激和炎症增加患阿尔茨海默病的风险。然而，迄今为止，很少有研究在基于人群的队列中检查患有高血压的认知正常受试者的rCBF，并且没有研究使用连续动脉自旋标记MRI。这是一种非侵入性技术，既不需要注射也不需要电离辐射，并且可以测量全脑的绝对rCBF速率。
在参与心血管健康研究认知研究的41名认知正常受试者中，使用连续动脉自旋标记MRI在1.5 T下测量rCBF。使用可变形萎缩校正配准方法将rCBF图谱扭曲到标准的colin27脑空间。在受试者组之间进行基于图像和聚类的统计分析。
与血压正常者（n = 22）相比，患有高血压的认知正常受试者（n = 19）双侧壳核、苍白球以及左侧海马体的rCBF降低。此外，在右侧和左侧前扣带回中观察到rCBF降低，并延伸至胼胝体下区域、左侧后扣带回和楔前叶内侧、左侧额下回和额上回以及顶下叶、左侧眶额皮质和左侧颞上皮质。
患有高血压的正常受试者的rCBF受到影响，不仅在皮质下区域，而且在边缘和边缘旁结构中。我们假设高血压为神经退行性疾病，尤其是阿尔茨海默病的发展创造了一种易损状态。
