血管性痴呆的神经影像学进展

痴呆是导致老年人残疾的主要疾病之一。其中有半数的痴呆患者可能是由于脑血管疾病引起或者与之有关。痴呆的诊断仍然以临床表现为主要依据,但是现代神经影像学的发展促进了痴呆临床诊断和治疗研究的深入。血管性痴呆(vasculardementia,VD)为一异源性痴呆综合征,其受以下因素的影响:血管条件、血管相关结构的改变(如脑梗死、脑萎缩、白质病变)和患者个体条件(如年龄、教育、遗传因素)。血管性痴呆有3种主要亚型,即皮质性痴呆(多发梗死性痴呆)、皮质下痴呆(小血管性痴呆)和关键部位梗死性痴呆。皮质性痴呆和关键部位梗死性痴呆常由于大血管…     

老年期痴呆的诊治进展

老年期痴呆顾名思义是指发生在老年期的痴呆,最常见的是阿尔茨海默病(AD)和血管性痴呆(VD),此外还有额颞痴呆(包括Pick病)和路易体痴呆等。近些年,随着相关学科的发展,老年期痴呆在诊断和治疗上取得了很大进展。现主要对对老年期痴呆(主要是AD和VD)的生化指标、电生理检查、神经影像学表现及新药物的治疗效果综述如下。     

上海城区老年性痴呆患病率调查

目的调查上海城区老年人群中痴呆的患病率。方法采用横断面调查,对≥60岁的社区居民3 141名进行了全套神经系统体检、神经心理测试和问卷调查,根据国际统一的诊断标准,DSM-Ⅳ标准诊断痴呆,NINCDS-ADRDA和NINDS-AIREN标准诊断阿尔茨海默病(AD)和血管性痴呆(VaD)并计算人群痴呆的患病率,以及各亚型构成比和患病率。结果诊断痴呆156例,痴呆患病率为5.0%;女性痴呆的患病率为5.8%,显著高于男性(4.0%,P=0.012)。痴呆患病率随年龄的增长有显著升高趋势,随文化程度的提高有显著下降趋势(P<0.001)。AD、VaD、其他类型痴呆和未分型痴呆的比例分别为72.4%、16.0%、5.1%和6.5%;女性AD患病率为4.7%,显著高于男性(2.3%,P<0.001)。AD和VaD的患病率均随年龄的增长而升高(P<0.001)。结论上海城区老年人群中痴呆患病率为5.0%,其中以AD(72.4%)为痴呆的主要类型。     

脑血管性痴呆

痴呆是指精神及智能明显低下,常伴有情感障碍。痴呆的病因甚多。痴呆可分为初老期痴呆和老年痴呆两大类。前者有Alzheimer病、Pick病、Jakob-Creutzfeldt病等,但是Jakob-Creutzfeldt病最近认为系慢病毒感染,列入感染性疾病。老年痴呆分为原发性(原因不明)变性疾病或称为Alzheimer型和脑血管性痴呆(脑动脉硬化性痴呆)两类。关于痴呆的诊断标准如下:(1)显著的定向(时间和地点)障碍;(2)记忆力障碍;(3)计算力低     

广州市城乡55岁及以上人群痴呆患病率调查

目的调查广州市城乡≥55岁人口痴呆的患病率。方法采用分层整群抽样方法,将广州市12个区市分为老城区、新城区、郊区,根据各层≥55岁的人口数占广州市相应年龄段人口总数的比例确定各层应查人数,实查5276人。调查采用筛查和确诊两阶段法,按美国精神障碍诊断和统计手册第4版的标准诊断痴呆。结果①查出痴呆患者183人,粗患病率为3.47%,其中阿尔茨海默病(AD)、血管性痴呆(VD)和其他痴呆的粗患病率分别为2.43%、0.85%和0.19%。年龄标化后的痴呆、AD和VD患病率分别为1.94%、1.28%和0.55%。②女性痴呆粗患病率高于男性(4.35%vs2.21%,P<0.001),二者的年龄标化患病率分别为1.12%、2.72%。痴呆患病率随年龄增长而上升。③农村人口的痴呆患病率(4.32%)高于城镇人口(3.27%),差异有统计学意义(P<0.01)。④文盲者的痴呆患病率(6.17%)较小学(2.68%)和初中及其以上(1.41%)文化程度者高(P<0.001)。结论AD是广州地区老人中主要的痴呆类型,VD次之。老年期痴呆患病率随年龄的增长而升高。文化程度低者痴呆患病率较高。     

血管性痴呆与血管性认知损害的再认识

血管性痴呆(VaD)系指由脑血管病(包括出血性和缺血性脑血管病)导致的、影响日常生活活动能力(ADL)的认知功能障碍.血管性痴呆的两项核心要素是:临床痴呆综合征及作为痴呆病因的脑血管病的客观证据.     

路易体痴呆和帕金森病痴呆是同一疾病吗?

伴随大脑皮质路易小体(LB)形成的痴呆即被定义为路易体痴呆(DLB),其临床特征为波动性认知功能障碍、幻视和帕金森症候群.路易体痴呆在所有痴呆类型中约占20%,而在帕金森病(PD)患者中,近30%也最终发生痴呆即帕金森病痴呆(PDD).     

城乡社区≥55岁人群、可疑痴呆和痴呆患者死亡率及生存率的研究

目的　了解社区≥ 5 5周岁人群、可疑痴呆和痴呆患者的死亡率及生存率。方法　在1997年调查成都地区城乡社区≥ 5 5周岁人群 5 35 3人中痴呆患病率的基础上 ,于 2 0 0 0年用随机整群抽样方法抽取 384 1人调查其死亡及生存情况。在 384 1人中随访到 30 5 8人 ,死亡 391人 ,外出或迁出 392人。基线调查用美国精神障碍诊断与统计手册第 3版修订本的标准诊断痴呆 ,用临床痴呆程度评定量表评定痴呆程度。结果　 (1)基线调查时被评为筛查阴性、复查正常、可疑痴呆和痴呆的患者 ,3 3年后随访时的死亡率分别为 2 9% (2 35人 )、6 2 % (85人 )、15 0 % (19例 )和 2 8 5 % (5 2例 )。其中阿尔茨海默病 (AD)、血管性痴呆 (VD)和其他类型痴呆 (OD)患者死亡率分别为 2 8 8% (40例 )、33 9% (8例 )和 19 9% (4例 )。 (2 )筛查阴性、复查正常、可疑痴呆和痴呆患者的生存率分别为90 5 %、81 8%、6 0 0 %和 37 6 % (χ2 =36 1 31,P <0 0 0 1)。从发病时起 ,AD、VD、OD的 5 0 %生存率时间分别为 7 0年、4 2年、10 3年。结论　痴呆患者死亡率高 ,可疑痴呆者次之 ,正常人最低 ;而生存率则相反。VD患者的死亡率高于AD和OD患者且存活期短。     

路易体痴呆和帕金森病痴呆研究进展

<正>路易体痴呆(dementia with Lewy bodies,DLB)是以痴呆和帕金森综合征为主要临床表现、仅次于阿尔茨海默病(Alzheimer disease,AD)的第二常见的神经变性性痴呆。在帕金森病(Parkinson disease,PD)患者中,痴呆的患病率约为30%~40%[1]。典型帕金森病痴呆(Parkinson disease dementia,PDD)与DLB的诊断依据痴呆     

老年期痴呆的诊断

一、老年期痴呆按世界卫生组织规定 ,发达国家 65岁和发展中国家 60岁以上为老年。痴呆是一种临床综合征 ,有 (近和远 )记忆、认知、语言障碍 ,行为和人格改变 ,必须有记忆和认知障碍 ,语言障碍、行为和人格改变中有一项突出 ;不是发生在谵妄状态等有意识障碍时 ;已严重到影响患者日常生活、职业和社交活动 ;历时4个月以上。临床痴呆严重程度可按临床痴呆评定量表 (ＣＤＲ)判定(表 1 )。老年期发生的痴呆为老年期痴呆。若为脑内原发性、退行性病变所致则为“老年性痴呆”(ＡＤ) ,额颞性痴呆、Ｌｅｗｙ体痴呆、帕金森病性痴呆等 ,由脑血管病…     

Statins and stroke prevention

Four randomized trials with a statin and one trial with a fibrate showed a modest but significant absolute reduction in the incidence of stroke in patients with a previous myocardial infarction. The reasons for the positive effect of statins on stroke end-point are unclear since, paradoxically, the link between serum cholesterol level and stroke has never been fully established. Furthermore, the positive results of statins trials were mainly obtained in patients with an average or a low serum cholesterol level. This suggests nonhypolipidemic effects of these drugs, so-called pleiotropic effects, acting on the biologic promoters of plaque instability. Statins have a good overall safety profile with no increase of hemorrhagic stroke and no increase in cancer. They have positive effects in primary prevention of cardiovascular disease in high-risk young as well as elderly populations. Statins reduced stroke incidence in high-risk (mainly CHD, diabetics and hypertensives) population even with a normal baseline blood cholesterol level, which argues for a global cardiovascular risk-based treatment strategy. In patients with prior strokes, statins likely reduce the incidence of cononary events, but it is not yet proven that statins actually reduce the incidence of recurrent strokes in secondary prevention. If current hypotheses are verified by ongoing trials, we may expect between 20 to 30 more stroke events avoided per 1,000 patients treated during 2 years with a lipid-lowering agent, which adds to the 28 stroke events prevented with an antiplatelet agent over the same time period. This would be one of the most significant advances in stroke and vascular dementia prevention since the era of aspirin therapy.     

Nutrition and stroke prevention

Nutrition is much more important in prevention of stroke than is appreciated by most physicians. The powerful effects of statin drugs in lowering the levels of fasting cholesterol, combined with an unbalanced focus on fasting lipids (as opposed to postprandial fat and oxidative stress), have led many physicians and patients to believe that diet is relatively unimportant. Because the statins can lower fasting lipids by &50% to 60%, and a low-fat diet only lowers fasting cholesterol by &5% to 10%, this error is perhaps understandable. However, a Cretan Mediterranean diet, which is high in beneficial oils, whole grains, fruits, and vegetables and low in cholesterol and animal fat, has been shown to reduce stroke and myocardial infarction by 60% in 4 years compared with the American Heart Association diet. This effect is twice that of simvastatin in the Scandinavian Simvastatin Survival Study: a reduction of myocardial infarction by 40% in 6 years. Vitamins for lowering of homocysteine may yet be shown to be beneficial for reduction of stroke; a key issue is the high prevalence of unrecognized deficiency of vitamin B(12), requiring higher doses of vitamin B(12) than have been used in clinical trials to date. Efforts to duplicate with supplementation the evidence of benefit for vitamins E, C, and beta carotene have been largely fruitless. This may be related to the broad combination of antioxidants included in a healthy diet. A Cretan Mediterranean diet is probably more effective because it provides a wide range of antioxidants from fruits and vegetables of all colors.     

Aspirin and stroke prevention

According to meta-analyses aspirin provides a relative reduction in the rate of major vascular events of 19% in patients with arterial disease in general, whereas for patients with ischaemic cerebrovascular disease this reduction is only 13%. The discrepancy may well result from pathophysiological differences and not from a play of chance. There is no proven difference in efficacy according to dose. The evidence for this equivalence is most compelling in the range between 75 and 1300 mg daily, but still fairly convincing for doses between 30 and 50 mg. In contrast, side effects are clearly more frequent as the dose is higher. Other antiplatelet agents (sulfinpyrazone, ticlopidine, clopidogrel, dipyridamole, orally administered IIb/IIIa inhibitors) have no clear advantages over aspirin and in some cases definite disadvantages; the combination of aspirin and dipyridamole may be more efficacious than aspirin alone, but the evidence hinges on a single trial. If recurrent TIAs occur under treatment with aspirin, the rational response is not to change to a different antiplatelet agent, but to review the diagnosis and consider causes other than artery-to-artery embolism. Platelet aggregation can probably still occur despite complete acetylation of platelets, via pathways other than COX-1 inhibition, but in vitro aggregation tests are an unreliable measure.     

Statins and stroke prevention

Over the past decade, statins have been proven to significantly decrease coronary events in primary and secondary prevention of coronary artery disease. Recent clinical trials have indicated that statins significantly reduce stroke risk in patients with vascular disease. The Cholesterol Treatment Trialists' Collaborators in a meta-analysis including 90,056 patients found that the use of statins determined a significant 17% proportional reduction in the incidence of first-ever stroke of any type per 1 mmol/l low-density lipoprotein (LDL) cholesterol reduction. During an average of 5 years of treatment, the reduction in the overall incidence of stroke was about one sixth per 1 mmol/l LDL cholesterol decrease meaning that 8 fewer participants have any stroke per 1,000 among those with preexisting coronary artery disease at baseline, compared with 5 fewer per 1,000 among the participants with no such history. It is not known whether these findings might be due to the cholesterol reduction effect of statins or to pleiotropic effects of statins, such as improved endothelial function, decreased platelet aggregability, and reduced vascular inflammation. In secondary prevention of stroke, the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) study found that treatment with atorvastatin reduced the risk of recurrent cerebrovascular events in patients with recent stroke or transient ischemic attack but no history of heart disease. Combining the results of patients with no history of heart disease from the SPARCL study and Heart Protection Study in a mini meta-analysis, compared with placebo, statins were associated with a barely nonsignificant difference in recurrent stroke (OR = 0.87, 95% CI = 0.75-1.01, p = 0.07) and a significant difference in the occurrence of major vascular events (OR = 0.78, 95% CI = 0.68-0.88, p = 0.0001) at final follow-up.