动态脑电图、诱发电位判断脑血管病昏迷患者的预后

目的：评价动态脑电图（EEG）、体感诱发电位（SEP）、脑干听觉诱发电位（BAEP）三种神经电生理检查在脑血管病昏迷患者预后判断中的作用。方法：对急性脑卒中致昏迷65例患者进行EEG、SEP、BAEP检查。EEG按Young标准分为Ⅰ—Ⅴ级;BAEP分析Ⅰ、Ⅲ、Ⅴ波各波潜伏期、峰间期及双侧波幅差,结果按Cant标准分为Ⅰ-Ⅲ级;SEP分析N20波,结果也分为Ⅰ-Ⅲ级。预后分为清醒、持续植物状态和死亡三种情况。结果：65例患者,EEG、BAEP、SEP均为Ⅰ级的15例患者中,死亡3例,持续植物状态2例,清醒10例;EEG、BAEP、SEP均为Ⅱ级的13例患者中,死亡5例,持续植物状态2例,清醒6例;属EEGⅢ级及其以上、BAEP及SEPⅢ级的37例患者中,死亡24例,持续植物状态9例,清醒仅4例。结论：EEG、BAEP和SEP的分级高低（异常程度）与昏迷患者的预后有密切关系,分级越高病死率越高。EEG、BAEP和SEP相结合,可以提高判断脑血管病昏迷患者预后的准确性。     

动态脑电监测对急危重症脑血管病的预后评估

目的:探讨急性期动态脑电图(AEEG)监测技术在急重症脑血管病预后评估中的临床价值.方法:对147例急性重症脑血管病患者的视频/长程动态脑电图监测结果和其临床预后进行相关性分析.结果:AEEG分级与GCS评分呈负相关(r=-0.757,P＜0.01);AEEG分级评分越高,患者预后越差(P＜0.01).结论:AEEG监测对于急性危重脑血管病的病情及预后判断有重要的临床应用价值.     

昏迷病人的脑电图表现及与预后的关系

目的 :探讨昏迷病人的脑电图表现和预后之间的关系。方法 :对 16 9例昏迷病人的脑电图进行回顾性分析 ,并将其与临床结局作对照。结果 :脑电图慢波型昏迷 12 0例中死亡 2 3例 (19 1% ) ;α昏迷型 11例中死亡 9例 (81 8% ) ;β昏迷型 3例和纺锤昏迷型 2例均存活 ;发作波型昏迷 13例中死亡 2例 (15 3% ) ;平坦波型昏迷 2 0例中死亡 17例 (85 % )。结论 :脑电图可作为判断昏迷病人临床预后的参考指标 ,平坦波昏迷和α波昏迷者大多死亡。β昏迷和纺锤昏迷则预后良好。     

动态脑电图加刺激对昏迷病人预后的临床观察

目的：探讨脑电图(EEG)及其反应性对昏迷病人预后评估的应用价值。方法：利用EEG加刺激(疼痛、呼唤)对58例昏迷病人进行24h连续监测，观察脑波的动态变化。结果：纺锤波昏迷和可变化的慢波(0、8)昏迷对刺激反应相对敏感，预后较好。无反应的慢波型(θ、δ或单一慢波)昏迷和8波昏迷，预后较差；α波、平坦波、暴发-抑制波型昏迷，对刺激无反应，死亡率为100％。周期性放电型昏迷，即使能存活下来，也留有严重的后遗症。24hEEG监测加上对刺激反应的观察对脑死亡的诊断价值明显优于常规EEG检查。结论：利用EEG加刺激的方法，对昏迷的病人进行监测，可提高对预后及脑死亡的正确判断率。     

脑电图对病毒性脑炎的预后评估

目的：探讨病毒性脑炎急性期脑电图（EEG ）检查对预后评估的临床意义。方法：回顾性分析51例病毒性脑炎患者的临床资料,并在出院6个月后对EEG异常的50例患者进行预后评估。结果：51例中50例为异常EEG ,异常率为98％,其中轻度异常17例（33％）,中度异常26例（51％）,重度异常7例（14％）。规范化抗病毒治疗至少3周,出院半年时随访,17例原EEG轻度异常者中预后差者5例（29％）,26例中度异常者中预后差者18例（69％）,7例重度异常者预后均差（100％）。3组预后比较差异有统计学意义（P＜0．05）,经线性趋势检验,3组的预后差率与EEG异常程度呈正相关。结论：EEG对病毒性脑炎的预后评估有重要的临床意义,病毒性脑炎患者急性期 EEG异常程度越重,预后越差。     

昏迷病人的脑电图监测

目的：探讨昏迷病人的脑电图监测应用价值。方法：对78例昏迷病人的脑电图监测记录结果及临床预后进行回顾性分析。结果：慢波型昏迷：61例(78％)死亡7例，B昏迷：1例(1％)预后良好，α-昏迷：2例(3％)均死亡，三相波：5例(6％)死亡3例，周期复合波4例(5％)死亡3例，平坦波：5例(6％)死亡3例，植物状态2例。结论：脑电图监测对昏迷病人的预后评估有一定意义。     

7例心肺复苏后昏迷病人的EEG检测与预后评估

各种原因所致心跳呼吸骤停 ,经心肺复苏 (ＣＰＲ)后 ,脑复苏即成为抢救成败的关键。ＥＥＧ检查是了解脑病理状态的一种重要手段 ,无疑对预后判断有重要意义。现将我院 2 0 0 0年 5～ 11月在ＩＣＵ病房及急诊抢救室的 7例患者 ,进行床边动态脑电图 (ＥＥＧ)检测 ,现报告如下。1　资料与方法临床资料 :本组 7例患者中 ,男 5例 ,女 2例 ,存活的 2名均为女性。年龄 19～ 75岁 ,平均 48岁 ,存活者的年龄均小于平均年龄。病程 4小时～ 31个月。临床分为浅昏迷 1例 ,深昏迷 5例 ,去大脑皮质状态 1例。病因 :剖宫产术后 1例 ,心脏搭桥术后 1例 ,颅脑…     

昏迷病人动态脑电图的临床应用

目的 动态脑电图检测对昏迷病人的应用价值.方法 对107例昏迷患者采用多次动态脑电图检测.分析脑电图改变与临床结局的关系.结果 平坦波昏迷死亡率较高(94.7%),慢波型昏迷死亡率较低(30.3%),且预后较好.结论 对昏迷病人实施动态脑电图监测,可提高对预后评估及脑死亡的正确判断率.     

利用脑电图反应性分级对脑血管病意识障碍患者预后的预测

目的：探讨脑电图（EEG ）反应性分级（EEG classification based on EEG reactivity , ECBER）对脑血管病意识障碍患者预后的评估。方法：使用美国尼高力（Nicolet ）公司的脑电监护仪对80例符合标准的患者行EEG检查,根据Synek、王晓梅、ECBER 3种不同EEG分级标准对EEG结果进行分级,以患者发病1个月内生存和死亡为观察指标,分析ECBER标准对患者的预后的预测价值。结果：Synek、王晓梅、ECBER 3种 EEG分级与患者预后均有明显的相关性,相关系数分别为0．592、0．622、0．611（P均＜0．001）。结论：ECBER对脑血管病意识障碍患者预后的评估有确切肯定的价值。     

脑电图在昏迷病人中的应用及愈后分析

目的：探讨脑电图（EEG）在昏迷病人中的应用及与愈后的关系。方法：对80例昏迷病人的EEG及愈后进行分析研究。结果：80例昏迷病人中：其中α波昏迷1例治愈；β波昏迷2例中，1例治愈（50％），1例死亡；θ波昏迷30例中18例治愈，好转7例（83．3％），未愈5例；δ波昏迷27例中16例治愈，好转5例（77．8％），未愈6例；睡眠-纺锤波4例中3例治愈，1例好转（100％）；电静息16中1例好转（0．06％），15例死亡。结论：EEG可直接反映昏迷病人的脑功能状态，其愈后的严重程度依次为电静息〉δ波昏迷〉θ波昏迷〉睡眠-纺锤波昏迷。对愈后判断有重要价值。     

Forebrain-dominant deficit in cerebrovascular reactivity in Alzheimer's disease

Epidemiologic evidence and postmortem studies of cerebral amyloid angiopathy suggest that vascular dysfunction may play an important role in the pathogenesis of Alzheimer's disease (AD). However, alterations in vascular function under in vivo conditions are poorly understood. In this study, we assessed cerebrovascular-reactivity (CVR) in AD patients and age-matched controls using CO₂-inhalation while simultaneously acquiring Blood-Oxygenation-Level-Dependent (BOLD) MR images. Compared with controls, AD patients had widespread reduction in CVR in the rostral brain including prefrontal, anterior cingulate, and insular cortex (p < 0.01). The deficits could not be explained by cardiovascular risk factors. The spatial distribution of the CVR deficits differed drastically from the regions of cerebral blood flow (CBF) deficits, which were found in temporal and parietal cortices. Individuals with greater CVR deficit tended to have a greater volume of leukoaraiosis as seen on FLAIR MRI (p = 0.004). Our data suggest that early AD subjects have evidence of significant forebrain vascular contractility deficits. The localization, while differing from CBF findings, appears to be spatially similar to PIB amyloid imaging findings.     

Differential cerebrovascular CO2 reactivity in anterior and posterior cerebral circulations

The potential differences in cerebrovascular responses between the anterior and posterior circulations to changes in CO₂ are unclear in humans. Using transcranial Doppler ultrasound, we compared the CO₂ reactivity of the (1) BA and PCA and (2) MCA and PCA during hyperoxic rebreathing in supine position. The reactivity in the BA and PCA was similar in both absolute (1.27 ± 0.5 and 1.27 ± 0.6 cm/s/Torr; P = 0.992) and relative (3.98 ± 1.3 and 3.66 ± 1.5%/Torr CO₂; P = 0.581) measures, suggesting that the PCA is an adequate surrogate measure of reactivity for the BA. The MCA reactivity was greater than the PCA in absolute (2.09 ± 0.7 and 1.22 ± 0.5 cm/s/Torr CO₂; P < 0.001), but not relative measures (3.25 ± 1.0 and 3.56 ± 1.6%/Torr CO₂; P = 0.629). Our findings (a) confirm regional differences in the absolute reactivity in the human brain and (b) suggest that in cerebrovascular studies investigating functions mediated by posterior brain structures (e.g., control of breathing), the posterior vasculature should also be insonated.     

Guidelines for the recording and quantitative analysis of electroencephalographic activity in research contexts

Developments in technologic and analytical procedures applied to the study of brain electrical activity have intensified interest in this modality as a means of examining brain function. The impact of these new developments on traditional methods of acquiring and analyzing electroencephalographic activity requires evaluation. Ultimately, the integration of the old with the new must result in an accepted standardized methodology to be used in these investigations. In this paper, basic procedures and recent developments involved in the recording and analysis of brain electrical activity are discussed and recommendations are made, with emphasis on psychophysiological applications of these procedures.     

脑血管病的脑电地形图研究

采用脑电地形图（ＢＥＡＭ）对６３例脑血管病病人脑电活动进行了研究。一组正常人（ｎ＝３３）脑电地形图与之对比，做出显著概率差异地形图，当Ｚ值≥２．００时判为异常。结果表明：ＢＥＡＭ在发现脑血管病病人脑电活动异常及病灶定侧定位方面，较脑电图（ＥＥＧ）目测分析敏感准确；轻微脑缺血病人（ＴＩＡ、ＲＩＮＤ）ＢＥＡＭ的异常明显率高于ＣＴ；在ＢＥＡＭ各频域指标中，以δ、θ、δ＋θ／α＋β为佳；可作为脑血管病病人的病灶定侧定位的一项独立指标。     

BOLD‐based cerebrovascular reactivity vascular transfer function isolates amplitude and timing responses to better characterize cerebral small vessel disease

Cerebrovascular reactivity (CVR) is a dynamic measure of the cerebral blood vessel response to vasoactive stimulus. Conventional CVR measures amplitude changes in the blood‐oxygenation‐level‐dependent (BOLD) signal per unit change in end‐tidal CO₂ (P_ETCO₂), effectively discarding potential timing information. This study proposes a deconvolution procedure to characterize CVR responses based on a vascular transfer function (VTF) that separates amplitude and timing CVR effects. We implemented the CVR‐VTF to primarily evaluate normal‐appearing white matter (WM) responses in those with a range of small vessel disease. Comparisons between simulations of P_ETCO₂ input models revealed that boxcar and ramp hypercapnia paradigms had the lowest relative deconvolution error. We used a T₂* BOLD‐MRI sequence on a 3 T MRI scanner, with a boxcar delivery model of CO₂, to test the CVR‐VTF approach in 18 healthy adults and three white matter hyperintensity (WMH) groups: 20 adults with moderate WMH, 12 adults with severe WMH, and 10 adults with genetic WMH (CADASIL). A subset of participants performed a second CVR session at a one‐year follow‐up. Conventional CVR, area under the curve of VTF (VTF‐AUC), and VTF time‐to‐peak (VTF‐TTP) were assessed in WM and grey matter (GM) at baseline and one‐year follow‐up. WMH groups had lower WM VTF‐AUC compared with the healthy group (p < 0.0001), whereas GM CVR did not differ between groups (p > 0.1). WM VTF‐TTP of the healthy group was less than that in the moderate WMH group (p = 0.016). Baseline VTF‐AUC was lower than follow‐up VTF‐AUC in WM (p = 0.013) and GM (p = 0.026). The intraclass correlation for VTF‐AUC in WM was 0.39 and coefficient of repeatability was 0.08 [%BOLD/mm Hg]. This study assessed CVR timing and amplitude information without applying model assumptions to the CVR response; this approach may be useful in the development of robust clinical biomarkers of CSVD.     

Continuous time-domain monitoring of cerebral autoregulation in neurocritical care

Integration of various brain signals can be used to determine cerebral autoregulation in neurocritical care patients to guide clinical management and to predict outcome. In this review, we will discuss current methodology of multimodal brain monitoring focusing on secondary ‘reactivity indices’ derived from various brain signals which are based on a ‘moving correlation coefficient’. This algorithm was developed in order to analyze in a time dependent manner the degree of correlation between two factors within a time series where the number of paired observations is large. Of the various primary neuromonitoring sources which can be used to calculate reactivity indices, we will focus in this review on indices based on transcranial Doppler (TCD), intracranial pressure (ICP), brain tissue oxygenation (PbtO₂) and near infrared spectroscopy (NIRS). Furthermore, we will demonstrate how reactivity indices can show transient changes of cerebral autoregulation and can be used to optimize management of arterial blood pressure (ABP) and cerebral perfusion pressure (CPP).     

Vascular determinants of cholinergic deficits in Alzheimer disease and vascular dementia

Alzheimer's disease (AD) and vascular dementia (VaD) are widely accepted as the most common forms of dementia. Cerebrovascular lesions frequently coexist with AD, creating an overlap in the clinical and pathological features of VaD and AD. This review assembles evidence for a role for cholinergic mechanisms in the pathogenesis of VaD, as has been established for AD. We first consider the anatomy and vascularization of the basal forebrain cholinergic neuronal system, emphasizing its susceptibility to the effects of arterial hypertension, sustained hypoperfusion, and ischemic cerebrovascular disease. The impact of aging and consequences of disruption of the cholinergic system in cognition and in control of cerebral blood flow are further discussed. We also summarize preclinical and clinical evidence supporting cholinergic deficits and the use of cholinesterase inhibitors in patients with VaD. We postulate that vascular pathology likely plays a common role in initiating cholinergic neuronal abnormalities in VaD and AD.