Doepp Florian, Valdueza José M, Schreiber Stephan J
Department of Neurology, University Hospital Charité, Berlin, Germany.
Neurol Res. 2006 Sep;28(6):645-9. doi: 10.1179/016164106X130380.
Increasing life expectancy of the population leads to a higher incidence of dementia. Exact differentiation between the most common types, vascular dementia (VD) and Alzheimer's dementia (AD), is crucial to the development and application of new treatment strategies. Both conditions are thought to differ greatly by their extent of microvascular affection. Transcranial and extracranial ultrasound permits analysis of cerebral hemodynamics and should help to differentiate between VD and AD. We compare multimodal ultrasound data between VD, AD and controls, and give an overview of the literature on this topic.
Twenty VD and 20 AD patients were studied and compared with 12 age-matched controls. Transcranial color-coded ultrasound was performed to assess blood flow velocity (V(mean)) and pulsatility indices (PI) of the middle cerebral artery (MCA). Extracranial duplex and Doppler ultrasound techniques were used to assess the blood volume flow (BVF) in the anterior circulation (both internal carotid arteries [ICA]) and posterior circulation (both vertebral arteries [VA]), the global cerebral blood flow (CBF = BVF(ICA) + BVF(VA)), the global cerebral circulation time (CCT = time delay of echo-contrast bolus arrival between ICA and internal jugular vein) and global cerebral blood volume (CBV = CCT x CBF).
MCA V(mean) in VD (36 +/- 8 cm/s) and AD (43 +/- 13 cm/s) were significantly lower than in controls (59 +/- 13 cm/s) but did not differ significantly between VD and AD groups. PI (1.1 +/- 0.2; 1 +/- 0.2; 0.9 +/- 0.2) only differed significantly between VD group and controls. CBF and CCT in VD (570 +/- 61 ml/min; 8.8 +/- 2.6 s) and AD (578 +/- 77 ml/min; 8.2 +/- 1.4 s) were similar but differed significantly from controls (733 +/- 54 ml/min; 6.4 +/- 0.8 s). BVF in the anterior and posterior circulation of VD group (412 +/- 62 and 158 +/- 38 ml/min) and AD group (428 +/- 62 and 150 +/- 41 ml/min) were significantly lower than in controls (537 +/- 48 and 199 +/- 26 ml/min) but did not differ significantly between the patient groups.
Transcranial and extracranial ultrasound does not help to distinguish between VD and AD. However, our results add insight into the pathophysiology of dementia, arguing in favor of a common 'vascular' pathway in both conditions.
人口预期寿命的增加导致痴呆症发病率上升。准确区分最常见的类型，即血管性痴呆（VD）和阿尔茨海默病性痴呆（AD），对于新治疗策略的开发和应用至关重要。人们认为这两种病症在微血管受累程度上有很大差异。经颅和颅外超声可用于分析脑血流动力学，应有助于区分VD和AD。我们比较了VD、AD患者与对照组的多模态超声数据，并概述了关于该主题的文献。
研究了20例VD患者和20例AD患者，并与12例年龄匹配的对照组进行比较。采用经颅彩色编码超声评估大脑中动脉（MCA）的血流速度（V（平均））和搏动指数（PI）。采用颅外双功超声和多普勒超声技术评估前循环（双侧颈内动脉[ICA]）和后循环（双侧椎动脉[VA]）的血容量流量（BVF）、全脑血流量（CBF = BVF（ICA）+ BVF（VA））、全脑循环时间（CCT = 回声对比剂团块在ICA和颈内静脉之间到达的时间延迟）和全脑血容量（CBV = CCT×CBF）。
VD组（36±8 cm/s）和AD组（43±13 cm/s）的MCA V（平均）显著低于对照组（59±13 cm/s），但VD组和AD组之间无显著差异。PI（1.1±0.2；1±0.2；0.9±0.2）仅在VD组与对照组之间存在显著差异。VD组（570±61 ml/min；8.8±2.6 s）和AD组（578±77 ml/min；8.2±1.4 s）的CBF和CCT相似，但与对照组（733±54 ml/min；6.4±0.8 s）有显著差异。VD组（412±62和158±38 ml/min）和AD组（428±62和150±41 ml/min）前循环和后循环的BVF均显著低于对照组（537±48和199±26 ml/min），但两组患者之间无显著差异。
经颅和颅外超声无助于区分VD和AD。然而，我们的结果为痴呆症的病理生理学提供了新的见解，支持两种病症存在共同的“血管”途径。
