Vicenzini Edoardo, Ricciardi Maria Chiara, Altieri Marta, Puccinelli Francesco, Bonaffini Novella, Di Piero Vittorio, Lenzi Gian Luigi
Department of Neurological Sciences, University of Rome, La Sapienza, Rome, Italy.
Eur Neurol. 2007;58(2):84-9. doi: 10.1159/000103642. Epub 2007 Jun 12.
An impairment of cerebral microvessels is reported both in normal ageing and in senescence-associated processes, as well as in Alzheimer's disease (AD) and vascular dementia (VaD). The aim of this study was to explore cerebral hemodynamics by transcranial Doppler in VaD and AD, compared with age-matched control subjects.
Transcranial Doppler was investigated in all patients in the basal condition. Cerebral vasoreactivity to hyper- and hypocapnia was evaluated with CO2 mixture inhalation followed by hyperventilation.
We studied 60 AD and 58 VaD patients and 62 nondemented controls. Both AD and VaD subjects showed lower flow velocities (FV) and higher pulsatility indices (PI) as compared with controls. Lower total vasomotor reactivity and lower response to hypercapnia were observed in the AD and VaD groups as compared with controls. AD and VaD patients did not show significant differences in FV, PI values or cerebral vasoreactivity.
Reduced FV and increased PI with a significant vasoreactivity reduction in VaD and AD patients are indicators of impairment of cerebral microvasculature circulation in both diseases. The identification of vascular function impairment in all kinds of dementia could be of help in identifying patients who would thus benefit more from specific therapeutic approaches.
据报道，在正常衰老、衰老相关过程以及阿尔茨海默病（AD）和血管性痴呆（VaD）中均存在脑微血管损伤。本研究的目的是通过经颅多普勒（TCD）探讨VaD和AD患者的脑血流动力学，并与年龄匹配的对照受试者进行比较。
在所有患者的基础状态下进行经颅多普勒检查。通过吸入二氧化碳混合气随后进行过度通气来评估脑血管对高碳酸血症和低碳酸血症的反应性。
我们研究了60例AD患者、58例VaD患者和62例非痴呆对照者。与对照组相比，AD和VaD受试者均表现出较低的血流速度（FV）和较高的搏动指数（PI）。与对照组相比，AD组和VaD组的总血管运动反应性较低，对高碳酸血症的反应也较低。AD和VaD患者在FV、PI值或脑血管反应性方面未显示出显著差异。
VaD和AD患者FV降低、PI升高且血管反应性显著降低是这两种疾病脑微循环障碍的指标。识别各种痴呆中的血管功能障碍可能有助于确定哪些患者将从特定治疗方法中获益更多。
