Department of Geriatric Medicine, Alzheimer Centre Nijmegen and Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands.
Neurobiol Aging. 2012 Feb;33(2):428.e21-31. doi: 10.1016/j.neurobiolaging.2010.11.016. Epub 2011 Jan 5.
In Alzheimer's disease (AD) cerebrovascular function is at risk. Transcranial Doppler, near-infrared spectroscopy, and photoplethysmography are noninvasive methods to continuously measure changes in cerebral blood flow velocity (CBFV), cerebral cortical oxygenated hemoglobin (O(2)Hb), and blood pressure (BP). In 21 patients with mild to moderate AD and 20 age-matched controls, we investigated how oscillations in cerebral blood flow velocity (CBFV) and O(2)Hb are associated with spontaneous and induced oscillations in blood pressure (BP) at the very low (VLF = 0.05 Hz) and low frequencies (LF = 0.1 Hz). We applied spectral and transfer function analysis to quantify dynamic cerebral autoregulation and brain tissue oxygenation. In AD, cerebrovascular resistance was substantially higher (34%, AD vs. control: Δ = 0.69 (0.25) mm Hg/cm/second, p = 0.012) and the transmission of very low frequency (VLF) cerebral blood flow (CBF) oscillations into O(2)Hb differed, with increased phase lag and gain (Δ phase 0.32 [0.15] rad; Δ gain 0.049 [0.014] μmol/cm/second, p both < 0.05). The altered transfer of CBF to cortical oxygenation in AD indicates that properties of the cerebral microvasculature are changed in this disease.
在阿尔茨海默病（AD）中，脑血管功能处于危险之中。经颅多普勒、近红外光谱和光电容积描记法是非侵入性方法，可以连续测量脑血流速度（CBFV）、脑皮质氧合血红蛋白（O2Hb）和血压（BP）的变化。在 21 名轻度至中度 AD 患者和 20 名年龄匹配的对照组中，我们研究了脑血流速度（CBFV）和 O2Hb 的波动如何与血压（BP）的自发和诱导波动相关，非常低频率（VLF = 0.05 Hz）和低频率（LF = 0.1 Hz）。我们应用谱和传递函数分析来量化动态脑自动调节和脑组织氧合。在 AD 中，脑血管阻力显著升高（34%，AD 与对照组相比：Δ=0.69（0.25）mmHg/cm/second，p=0.012），并且非常低频率（VLF）脑血流（CBF）波动的传递也不同，相位滞后和增益增加（Δ相位 0.32（0.15）rad；Δ增益 0.049（0.014）μmol/cm/second，p 均<0.05）。AD 中 CBF 向皮质氧合的传递改变表明，这种疾病中大脑微血管的特性发生了变化。
