From the Department of Clinical Neurosciences (A.E.B., C.R.M., B.S., A.S., A.M.Z., E.C., A.C., R.F., Z.I., G.B.P., E.E.S.), Hotchkiss Brain Institute (A.E.B., C.R.M., E.L.M., B.S., A.S., A.M.Z., E.C., A.C., R.F., Z.I., G.B.P., E.E.S.), Department of Radiology (C.R.M., E.L.M., R.F., G.B.P., E.E.S.), Department of Psychiatry (Z.I.), and Mathison Centre for Mental Health Research & Education (Z.I.), University of Calgary; Seaman Family MR Research Centre, Foothills Medical Centre (C.R.M., R.F., G.B.P., E.E.S.), Alberta Health Services, Calgary; Department of Psychology (E.L.M.), St. Francis Xavier University, Antigonish; and Division of Neurology and Department of Medicine (M.G., K.N., G.C.J., R.C.), Department of Biomedical Engineering (C.B.), and Neuroscience and Mental Health Institute (R.C.), University of Alberta, Edmonton, Canada.
Neurology. 2022 Apr 26;98(17):e1716-e1728. doi: 10.1212/WNL.0000000000200136. Epub 2022 Feb 24.
Reduced cerebrovascular reactivity is proposed to be a feature of cerebral amyloid angiopathy (CAA) but has not been measured directly. Employing a global vasodilatory stimulus (hypercapnia), this study assessed the relationships between cerebrovascular reactivity and MRI markers of CAA and cognitive function.
In a cross-sectional study, individuals with probable CAA, mild cognitive impairment, or dementia due to Alzheimer disease and healthy controls underwent neuropsychological testing and an MRI that included a 5% carbon dioxide challenge. Cerebrovascular reactivity was compared across groups controlling for age, sex, and the presence of hypertension, and its associations with MRI markers of CAA in participants with CAA and with cognition across all participants were determined using multivariable linear regression adjusting for group, age, sex, education, and the presence of hypertension.
Cerebrovascular reactivity data (mean ± SD) were available for 26 participants with CAA (9 female; 74.4 ± 7.7 years), 19 participants with mild cognitive impairment (5 female; 72.1 ± 8.5 years), 12 participants with dementia due to Alzheimer disease (4 female; 69.4 ± 6.6 years), and 39 healthy controls (30 female; 68.8 ± 5.4 years). Gray and whiter matter reactivity averaged across the entire brain was lower in participants with CAA and Alzheimer disease dementia compared to healthy controls, with a predominantly posterior distribution of lower reactivity in both groups. Higher white matter hyperintensity volume was associated with lower white matter reactivity (standardized coefficient [β], 95% CI -0.48, -0.90 to -0.01). Higher gray matter reactivity was associated with better global cognitive function (β 0.19, 0.03-0.36), memory (β 0.21, 0.07-0.36), executive function (β 0.20, 0.02-0.39), and processing speed (β 0.27, 0.10-0.45) and higher white matter reactivity was associated with higher memory (β 0.22, 0.08-0.36) and processing speed (β 0.23, 0.06-0.40).
Reduced cerebrovascular reactivity is a core feature of CAA and its assessment may provide an additional biomarker for disease severity and cognitive impairment.
脑血管反应性降低被认为是脑淀粉样血管病（CAA）的特征之一，但尚未直接测量。本研究采用全脑血管扩张刺激（高碳酸血症），评估了脑血管反应性与 CAA 的 MRI 标志物和认知功能之间的关系。
在一项横断面研究中，患有可能的 CAA、轻度认知障碍或阿尔茨海默病引起的痴呆以及健康对照者接受了神经心理学测试和 MRI 检查，包括 5%的二氧化碳挑战。在控制年龄、性别和高血压存在的情况下，比较了各组之间的脑血管反应性，并使用多变量线性回归确定了 CAA 参与者的 MRI 标志物与认知功能之间的关系，以及所有参与者的认知功能之间的关系。
26 名 CAA 参与者（9 名女性；74.4±7.7 岁）、19 名轻度认知障碍参与者（5 名女性；72.1±8.5 岁）、12 名阿尔茨海默病痴呆参与者（4 名女性；69.4±6.6 岁）和 39 名健康对照者（30 名女性；68.8±5.4 岁）的脑血管反应性数据（平均值±标准差）可用。与健康对照组相比，CAA 和阿尔茨海默病痴呆组的整个大脑的灰质和白质反应性平均值较低，两组的反应性均以后部分布为主。更高的白质高信号体积与更低的白质反应性相关（标准化系数[β]，95%置信区间 -0.48，-0.90 至 -0.01）。更高的灰质反应性与更好的整体认知功能（β0.19，0.03-0.36）、记忆（β0.21，0.07-0.36）、执行功能（β0.20，0.02-0.39）和处理速度（β0.27，0.10-0.45）相关，更高的白质反应性与更好的记忆（β0.22，0.08-0.36）和处理速度（β0.23，0.06-0.40）相关。
脑血管反应性降低是 CAA 的核心特征，其评估可能为疾病严重程度和认知障碍提供额外的生物标志物。
