老年糖尿病颅内动脉流速异常与脑血管事件发生关系的研究

目的 评价经颅多普勒超声(TCD)检测老年轻尿病患者颅内动脉血流异常的预后价值。方法 对86例60—85岁老年2型糖尿病患者进行TCD检测并前瞻性随访69个月。结果 本组老年糖尿病患者血流速度异常率较高，占60．5％，且以流速异常增高为主；随访期间，6例发生非脑血管病死亡，17例发生非致死性脑梗死，1例发生非致死性脑出血，2例发生一过性脑缺血发作(TIA)。所有20例发生脑血管事件的患者进入研究时，颅内动脉血流速度异常者脑血管事件发生率显著高于颅内动脉血流速度正常者(P＜0．01)。在流速异常患者中2支或2支以上血管病变者较单支血管病变者更易发生脑血管病变(P＜0．01)。结论 老年糖尿病患者经颅多普勒超声检测颅内动脉血流速度异常对随后脑血管事件的发生有预测价值。     

大脑中动脉狭窄患者脑血管储备能力与缺血性卒中事件的随访研究

目的观察大脑中动脉(MCA)狭窄患者脑血管储备能力(CVR)与缺血性卒中发生的关系及其危险因素的随访研究。方法连续纳入2014年2月~2016年9月在广州医科大学附属第三医院荔湾医院神经内科门诊或住院就诊行经颅多普勒超声(TCD)检查者中发现MCA狭窄患者的临床资料及脑血管储备能力(CVR),并进行为期1 y的随访,观察患者发生缺血性卒中的情况。结果 (1)共纳入212例患者,其中31例(14.6%)在随访期间发生缺血性卒中(卒中组);(2)卒中组患者CVR为(12.6±4.8)%,明显低于非卒中组(19.3±4.5)%,两者差异有统计学意义(P0.05);(3)卒中组中MCA轻度、中度、重度狭窄者分别为6例(19.4%)、11例(35.5%)、14例(45.2%),与非卒中组比较差异有统计学意义(P0.05);(4)经Logistic回归分析显示CVR是缺血性卒中事件的独立危险因素。结论在MCA狭窄的患者中CVR高、狭窄程度低的缺血性卒中事件发生风险低,且CVR是缺血性卒中的独立危险因素。     

经颅多普勒超声屏气试验评价脑血管反应性及其与脑血管病危险因素关系的研究

目的应用经颅多普勒超声(TCD)屏气试验评价正常人及具有脑血管病危险因素患者的脑血管反应性(CVR)及其与脑血管危险因素的关系。方法采用TCD屏气试验对137例具有各种脑血管病危险因素患者及87名不同年龄段的正常人群,分别检测屏气前后大脑中动脉(MCA)流速增长的百分数,即屏气指数(BHI)作为CVR的评价指标,并对CVR与危险因素进行Logistic回归分析。结果>60岁组及41~60岁组的正常人屏气前后平均血流速度(Vm及Vm′)低于20~40岁组(均P<0.05),而>60岁组Vm及Vm′又低于41~60岁组(均P<0.05),而BHI值差异无显著性。高血压、高三酰甘油、高胆固醇、糖尿病、吸烟均与BHI异常有关,其中高血压的关系最为密切。结论TCD屏气试验作为一种简单、方便、经济的检测手段,可有效地用于CVR评价。高血压病能显著影响CVR。     

TCD对55例2型糖尿病患者脑血流变化的临床研究

目的应用经颅多普勒超声（TCD）检查老年糖尿病患者颅内血管状况，以了解糖尿病与血流动力学变化的关系。方法对55例老年糖尿病患者与60例非糖尿病者进行TCD检查，观察大脑中动脉（MCA）、颈内动脉（ICA）终末端、大脑前动脉（ACA）、大脑后动脉（PcA）的血流速度和频谱信号。结果老年糖尿病患者颅内动脉血流速度明显增快，其血管狭窄发生率高于非糖尿病者。结论TCD检查对老年糖尿病患者颅内血管状况的评价具有重要的参考价值。     

脑血管反应性与缺血性卒中

目的观察缺血性卒中患者脑血管反应性（CVR）变化,确定两者之间的相关性。方法采用经颅多普勒超声（TCD）结合屏气试验检测76例缺血性卒中患者及62例对照病例的屏气指数（BHI）。结果缺血性卒中患者组的BHI明显低于对照组（P〈0.001）,Logistic 回归显示,由BHI所表示的CVR是缺血性卒中的独立影响因素（P=0.000）。结论降低的CVR是缺血性脑卒中的独立危险因素,应该重视CVR在脑缺血发生、发展过程中的独立影响作用。     

脑梗死患者脑血管反应性研究

目的应用经颅多普勒超声结合屏气试验评价脑梗死患者的脑血管反应性（CVR）。方法采用经颅多普勒超声结合屏气试验检测30例急性期颈内动脉系统脑梗死患者,30例急性期腔隙性脑梗死患者的屏气指数（BHI）,并与60例健康者进行对比。结果急性期颈内动脉系统脑梗死患者和腔隙性脑梗死患者屏气指数均显著低于对照组,颈内动脉系统脑梗死侧显著低于对侧和腔隙性脑梗死患者。结论脑血管反应性与脑梗死有密切关系,检测脑血管反应性对于预测脑卒中风险至关重要。     

经颅多普勒血管搏动指数与脑血管反应性的关系

目的 研究经颅多普勒(TCD)搏动指数(PI)与脑血管反应性(CVR)的关系.方法 对70例PI增高患者(PI增高组)应用TCD行CO2吸入、过度换气和屏气试验检测CVR,并与PI正常者(正常对照组)进行比较.结果 (1)CO2吸入试验:PI增高组的大脑中动脉(MCA)平均血流速度(Vm)增加率[(21.61±7.39)%]明显低于正常对照组[(44.86±10.18)%] (P<0.01).(2)过度换气试验: PI增高组MCA Vm下降率[(21.89±6.60)%]明显低于正常对照组[(33.63±8.62)%](P<0.01).(3)屏气试验:PI增高组Vm增高率为(22.69±8.37)%、屏气指数为(0.58±0.24),显著低于正常对照组[(46.53±11.83)%、(1.16±0.37)](均P<0.01).结论 TCD PI增高可反映CVR下降.     

糖尿病与非糖尿病脑梗塞病人的经颅多普勒研究

应用经颅多普勒超声（ＴＣＤ）检测糖尿病脑梗塞ＤＣＩ和非糖尿病脑梗塞（ＮＤＣＩ）各１８例，并与１８例正常对照组进行比较，发现两组病人都以收缩期峰值血流速度（Ｖｐ）的改变为主，ＤＣＩ组的Ｖｐ异常又显著高于ＮＤＣＩ组（Ｐ＜０．０１）。Ｖｐ的改变主要是速度增快，且多伴有血管杂音，可见涡流信号。这些改变以ＭＣＡ和ＣＳ最突出，ＡＣＡ、ＢＡ、ＶＡ和ＰＣＡ均有累及。结果表明ＤＣＩ病人血管损害的范围比ＮＤＣＩ病人广泛得多，可以解释糖尿病病人脑卒中患病率高的原因。     

大脑中动脉狭窄患者脑血管反应性变化与脑梗死的关系

目的探讨大脑中动脉狭窄患者脑血管反应性变化与脑梗死的关系。方法 56例大脑中动脉狭窄患者（观察组）,按影像学表现和临床症状分为无脑梗死组（I组）30例,脑梗死（II组）26例,另设60例年龄、性别配对的健康者为对照组。常规经颅多普勒检查后进行屏气试验,记录屏气前后中动脉收缩期流速、舒张期流速、平均流速、搏动指数,计算屏气指数。结果观察组56例中,大脑中动脉单侧狭窄31例,双侧狭窄25例;中度狭窄37条血管,重度狭窄44条血管;屏气后各组搏动指数均减低,但对照组有显著性差异,中动脉狭窄组没有显著性差异;对照组屏气指数显著高于中动脉狭窄组,无症状组显著高于有症状组,中度狭窄组显著高于重度狭窄组。结论大脑中动脉狭窄患者脑血管反应性和脑储备功能减低,屏气指数是检测脑血管储备功能的重要指标,可以用于脑卒中的预测。     

TCD对55例2型糖尿病患者脑血流变化的临床研究

目的应用经颅多普勒超声(TCD)检查老年糖尿病患者颅内血管状况,以了解糖尿病与血流动力学变化的关系。方法对55例老年糖尿病患者与60例非糖尿病者进行TCD检查,观察大脑中动脉(MCA)、颈内动脉(ICA)终末端、大脑前动脉(ACA)、大脑后动脉(PCA)的血流速度和频谱信号。结果老年糖尿病患者颅内动脉血流速度明显增快,其血管狭窄发生率高于非糖尿病者。结论TCD检查对老年糖尿病患者颅内血管状况的评价具有重要的参考价值。     

经颅彩色多功超声诊断脑动脉狭窄与脑血管造影的对比研究

目的 验证经颅彩色多功超声（TCCD）诊断大脑中动脉（MCA）狭窄的可靠性。方法 对168例行脑血管造影的脑血管病患者同时进行了TCCD检查。结果 脑血管造影诊断狭窄的MCA18条,TCCD检出15条有狭窄。造影未证实有狭窄的MCA血管中,TCCD检出2条有狭窄。TCCD诊断MCA狭窄的敏感性和特异性为83％和88％。结论 TCCD诊断MCA狭窄准确性较好,优于经颅多普勒（TCD）。     

经颅多普勒超声诊断脑动脉痉挛与数字减影血管造影的对比研究

目的探讨经颅多普勒超声(TCD)诊断大脑中动脉(MCA)、椎动脉(VA)、基底动脉(BA)痉挛的可靠性。方法对50例蛛网膜下腔出血患者同时行TCD和数字减影血管造影(DSA)检查并进行对比分析。结果DSA发现MCA痉挛26条，其中TCD检出21条，DSA未证实有痉挛的MCA中，TCD检出4条，TCD诊断MCA痉挛的敏感性为80．8％，特异性为84．0％，而且MCA痉挛程度越重，TCD敏感性越高。DSA发现BA痉挛18条，其中经TCD检出13条，DSA未证实有痉挛的BA中，TCD检出4条，TCD诊断BA痉挛的敏感性为72．2％，特异性为76．5％。DSA发现VA痉挛28条，其中经TCD检出20条，DSA未证实有痉挛的VA中，TCD检出6条，TCD诊断VA痉挛的敏感性为71．4％，特异性为76．9％。结论TCD诊断MCA、VA、BA痉挛有较高的可靠性。     

小脑顶核电刺激对脑外伤患者脑血流速度和颅内压的影响

目的　探讨小脑顶核电刺激对脑外伤患者脑血流速度和颅内压的影响。方法　选择 2 0例脑外伤患者 ,其中 7例行手术治疗。用小脑顶核电刺激方法对所有患者实施电刺激 ,应用经颅多普勒超声技术检测刺激前后大脑前、中、后动脉 (ACA ,MCA,PCA)血流速度。通过颅内压监护持续监测刺激前后颅内压的变化。结果　实施刺激后 10分钟 ,脑血流速度升高 ,2 0～ 30分钟达高峰。刺激前 ACA,MCA,PCA血流速度分别为 45 .5± 8.3cm/ s,5 3.6± 10 .2 cm / s和 36 .9± 8.4cm / s;刺激后分别为 6 0 .2± 9.6 cm/ s,6 7.2± 11.7cm/ s和 37.2± 8.6 cm/ s;ACA和MCA的血流速度在刺激后明显升高 (P <0 .0 5 )。 7例脑外伤患者小脑顶核电刺激前后颅内压无明显变化 (P>0 .0 5 )。结论　小脑顶核电刺激后可明显提高脑外伤患者颅内血流速度 ,改善脑循环 ,对颅内压变化无明显影响。     

脑白质疏松症的血流动力学及局部脑血流变化的研究

目的　观察脑白质疏松症 (LA )血流动力学及局部脑血流量的变化 ,以探讨LA的发病机制。方法　对 6 7例LA患者行经颅多普勒 (TCD)检查 ,并对其中 19例患者行单光子发射计算机断层扫描 (SPECT)检查 ,观察局部脑血流 (rCBF)灌注情况。结果　轻、中、重 3组LA患者颈内动脉系统动脉平均峰值流速 (Vm)显著低于对照组 (P <0 0 5 ,P <0 0 1) ,重度LA组椎 基底动脉系统Vm显著低于对照组及轻度LA组 (P <0 0 5 ) ;轻、中、重 3组LA患者脉动指数 (PI)显著高于正常对照组 (P <0 0 1,P <0 0 0 1) ,中、重度组LA患者PI显著高于正常对照组及轻度组 (P <0 0 1,P <0 0 0 1)。SPECT检查发现LA患者灰质rCBF减少者为 5 2 6 % ,白质rCBF减少者为 78 9%。结论　LA患者存在广泛的脑血流低灌注和脑动脉硬化 ,并有随脑血流低灌注程度加重而LA病变加重的趋势 ,低灌注和脑动脉硬化是LA的主要发病机制。     

脑梗塞患者的诱发电位,经颅多普勒与CT等对照研究

对８６例脑梗塞患者的脑诱发电位和经颅多普勒（ＴＣＤ）进行分析，并与ＣＴ／ＭＲＩ检查作对照，体感诱发电位（Ｓｏｍａｔｏｓｅｎｓｏｒｙ Ｅｖｏｋｅｄ Ｐｏｔｅｎｔｉａｌ，ＳＥＰ）异常率８２．６％，脑干听觉诱发电位（Ｂｒａｉｎｓｔｅｍ Ａｕｄｉｔｏｒｙ Ｅｖｏｋｅｄ Ｐｏｔｅｎｔｉａｌ，ＢＡＥＰ）异常率７４．４％经颅多普勒（Ｔｒａｎｓｃｒａｎｉａｌ Ｄｏｐｐｌｅｒ，ＴＣＤ）为９０．７％。脑梗塞位于大脑半     

Changes in cerebral blood flow induced by passive and active elbow and hand movements

Transcranial Doppler ultrasonography (TCD) has been widely used to obtain information about changes in cerebral perfusion during monitor activity after stroke. This type of application is greatly limited when severe motor deficits are presnet that impede the performance of an active motor task. In this study, we explored the effect of performing passive arm movements on cerebral perfusion. Twenty healthy subjects were investigated. A bilateral TCD monitoring of the middle cerebral artery (MCA) flow velocity was performed during the following experimental conditions: 1-min of active and passive flexion extension elbow movement and 1-min of active and passive dorsal extension hand movement. Each task was performed with both left and right arms. The percentage increase in flow velocity from rest to task performance was calculated. Each task produced a significantly greater increase in mean flow velocity in the contralateral MCA with respect to the ipsilateral. When comparing the effect of passive and active tasks, no significant difference in mean flow velocity changes recorded in the ipsilateral and the contralateral MCA was detected regarding either elbow or hand movements. These findings demonstrate the possibility of obtaining information about changes in hemispheric cerebral perfusion during passive movements involving elbow and hand. This type of application deserves further attention in the study of cerebral functional changes following cerebral lesions. Received: 30 May 2000 / Accepted: 24 July 2000     

转颈对眩晕患者基底动脉流速的影响

目的　采用TCD观测转颈对正常人及眩晕患者基底动脉流速的影响。方法　正常对照组 3 6例 ,眩晕患者 3 1例 ,TCD常规检查椎 -基底动脉及转颈时基底动脉流速的变化。结果　正常人随年龄增大 ,椎 -基底动脉流速下降 ,转颈前后基底动脉流速差异无显著性 ;眩晕患者椎 -基底动脉流速下降 ,转颈后基底动脉流速明显下降 ,较转颈前差异有显著性 (P <0 .0 5 )。结论　转颈后基底动脉流速下降≥ 2 0 % ,即为转颈试验阳性 ,提示患者椎—基底动脉系统代偿能力差 ,存在椎动脉狭窄等病变的可能 ,需进一步检查     

Dynamics of cerebral blood flow autoregulation in hypertensive patients

In hypertensive patients, the upper and lower limits of cerebral autoregulation are shifted to higher levels. However, the dynamics of cerebral autoregulation in hypertensive patients are less well known. We compared the dynamics of cerebral autoregulation in 21 treated hypertensive patients (13 men and 8 women; mean age: 48.9+/-13.6 years) and in 21 normotensive subjects (13 men and 8 women; mean age: 51+/-14.5 years) by transcranial Doppler (TCD) of the middle cerebral artery (MCA) during the acute decrease in blood pressure induced by standing up after 2 min in squatting position. MCA maximal outline blood flow velocity (FV), blood pressure (Finapres) and end-tidal PCO2 were continuously monitored and computerised. A cerebral vascular resistance index (CR) was calculated as follows: mean arterial BP/MCA mean FV with normalised changes in CR per second during the blood pressure decrease (CR slope). The CR slope reflecting the rate of cerebral autoregulation did not differ between the two groups and within the hypertensive patients [well controlled (8 patients) and not controlled (13 patients)]. The time to maximum decrease of CR (T1) and the time to full recovery of CR after the initial drop (T2) were also similar in the two groups (controls T1: 11.3+/-3.1 s, T2: 12+/-5.9 s; hypertensive T1: 11.7+/-2.5 s, T2: 10.7+/-4.5 s) and within hypertensive patients. These findings suggest that the dynamics of cerebral autoregulation are well preserved in hypertensive patients, with no difference according to the efficiency of treatment of hypertension.     

Influence of blood pressure and cardiac output on cerebral blood flow and autoregulation in acute stroke measured by TCD

Although the dependence of cerebral perfusion on blood pressure has been well studied, little data is available about the effect cardiac output has on cerebral flow velocity and autoregulation, particularly during acute stroke. To improve cerebral perfusion, we treated 10 patients who suffered from an acute ischemic stroke of the middle cerebral artery with a hypervolemic hemodilution combined with dopamine-dobutamine. The influence of blood pressure and cardiac output on the blood flow velocity in the middle cerebral artery was measured using transcranial doppler sonography (TCD). Under the therapy, a dosage-dependent increase of 12% in blood pressure (BP) and 53% increase in cardiac output was observed. There was a significant (p > 0.01) correlation between TCD-mean flow velocity (V_m) and cardiac output (r = 0.33) as well as between V_m and blood pressure (r = 0.52) on the affected side. The unaffected side showed no correlation between V_m and cardiac output (r = 0.01), or between V_m and blood pressure (r = 0.03). Systolic flow velocity increased significantly in both hemispheres. As an expression of increasing cerebral vascular resistance, the pulsating index (PI) increased significantly (p > 0.01) in the affected hemisphere as well as in the unaffected hemisphere. This suggests that during acute stroke blood flow velocity and autoregulation in the affected vascular region depend not only on cerebral perfusion pressure but also on CO levels.