ALZHEIMER’S DISEASE, the most common cause of the progressive loss intellectual abilities known as dementia. Alzheimer’s disease is a devastating and incurable disease that chiefly afflicts old people. It was first described in 1906 by Alois Alzheimer, a German neuropathologist. Alzheimer’s disease is estimated to affect 5% to 10% of people older than 65 as well as a significant number of younger individuals. Already a major public-health problem, it will become an even greater problem as the number and proportion of old people in the population increase.

阿尔茨海默病，是进行性丧失智力能力最常见的原因，被称为痴呆症。阿尔茨海默病是一种主要折磨老年人的，极具破坏力且无法治愈的疾病。1906年，德国神经病理学家阿洛伊斯·阿尔茨海默首次对其进行了描述。据估计，阿尔茨海默病影响了5%至10%的65岁以上的老年人以及相当数量的年轻人。已经成为主要的公共卫生问题，随着人口中老年人数量和比例的增长，它将成为一个更大的问题。

Development. Since the earliest symptoms of Alzheimer’s disease develop gradually, the exact onset of the disease may be difficult to identify. Often the earliest sign is forgetfulness, which may be accompanied by subtle changes in personality. As the disease progresses, other impairments develop, including difficulties with language, perception, and complex motor skills. The patient gradually declines over a period of five to ten years and may reach a point of losing control of body functions and becoming unresponsive to those around him.

发展。由于阿尔茨海默病的最早期症状是逐渐发展的，因此，确定该病确切的发作可能很难。通常最早的迹象是健忘，它可能伴随性格方面的微妙变化。随着该病的进展，会造成其它的损伤，包括语言、感知和复杂的运动技能困难。患者在5至10年内逐渐衰退，并可能达到失去对身体功能控制的阶段，以及对周围的人变得反应迟钝。

Effects on the Family. Alzheimer’s disease causes tremendous psychological strain on the patient and his family. Legal and financial issues often become complicated when an individual is no longer competent to manage his own affairs. Socially, the family may find it hard to maintain the same life-style when the patient is unable to act responsibly. The family faces many difficult decisions as the disease progresses. Often the most difficult decision is whether or when to place the patient in a nursing home during the later stages of the illness.

对家庭的影响。阿尔茨海默病给患者及其家庭造成了巨大的心理压力。当个体不再胜任管理他自己的事务时，法律和财务问题往往会变得复杂。在社会上，当患者无法对行为负责时，该家庭可能会发现很难维持同样的生活方式。随着该病的进展，家庭会面临许多困难决定。通常最困难的决定是，在该疾病的后期，是否或何时将患者安置在养老院。

Effects on the Brain. Alzheimer’s disease is defined by specific changes in the brain. The disease involves shrinkage of the brain together with loss of nerve cells in several areas of the brain thought to be important for intellectual activity. Under the microscope, two abnormalities are usually found. Clusters of damaged nerve endings, called neuritic plaques, are widespread. Malformations called neurofibrillary tangles are present within diseased neurons and may interfere with normal functioning of these cells.

对大脑的影响。阿尔茨海默病是由大脑中特定变化定义的。该病涉及大脑的萎缩，还涉及在大脑中被认为对智力活动很重要的几个区域中神经细胞的丢失。在显微镜下，通常会发现两种异常情况。受损神经末梢的簇分布广泛，称为神经炎性斑块。称为神经元纤维缠结的畸形物存在于患病的神经元中，并且可能干扰这些细胞的正常功能。

In association with these changes in nerve cells are alterations in neurotransmitters, the chemical messengers with which nerve cells communicate. Understanding the changes in these neurotransmitters is particularly important, since many of the drug treatments for neurological and psychiatric diseases work by way of neurotransmitter systems. A major neurotransmitter affected in Alzheimer’s disease is acetylcholine, which plays an important role in memory. A loss of nerve cells deep in the base of the brain has been shown to cause this loss of acetylcholine. While other neurotransmitters also are affected in Alzheimer’s disease, the alterations in acetylcholine are the most severe and the most consistently found.

与神经细胞中这些变化相关的是神经递质的改变，与那些神经细胞传递信息的化学信使相关。理解这些神经递质中的变化尤为重要，因为许多治疗神经和精神病的药物都是通过神经递质系统的方式起作用。一种影响阿尔茨海默病的主要神经递质是乙酰胆碱，它在记忆中起着重要作用。大脑底部深处的神经细胞的丢失已被证明会造成这种乙酰胆碱的丢失。虽然在阿尔茨海默病中其它的神经递质也会受到影响，但人们发现，乙酰胆碱的改变是最严重和最一致的。

Possible Causes. No one knows what causes Alzheimer’s disease. In some cases, the disease appears to run in families, suggesting a role for genetic factors. Some researchers have suggested that an infectious agent similar to a virus may be involved. Another suggested cause is exposure to toxic agents such as aluminum. The cause of Alzheimer’s disease may be very complicated and could involve a number of interacting influences.

可能的原因。没人知道是什么导致了阿尔茨海默病。在一些病例中，该病似乎在家族中遗传，暗示着遗传因素的作用。一些研究者认为，可能涉及一种类似病毒的传染剂。另一些人认为，原因是接触到了毒物，如铝。阿尔茨海默病的原因可能非常复杂，而且可能涉及许多相互作用的影响。

Diagnosis. Although Alzheimer’s disease is the most common cause of dementia, many other diseases can cause similar changes in behavior and intellect. In about 10% to 15% of patients, dementia has a potentially treatable cause such as stroke, brain tumor, head injury, liver or kidney disease, thyroid or other endocrine problems. In addition, some psychiatric disorders, such as depression, can be mistaken for dementia. Since dementia caused by these diseases may be treatable, a thorough evaluation of the patient is essential before accepting the diagnosis of Alzheimer’s disease.

诊断。尽管阿尔茨海默病是痴呆症最常见的原因，但许多其它的疾病也可能引起类似的行为和智力变化。在大约10%至15%的患者中，痴呆症有一个潜在的可以治疗的原因，诸如中风、脑肿瘤、头部损伤、肝脏或肾脏疾病、甲状腺或其它内分泌问题。此外，一些精神病的疾病，如抑郁症，可能被误诊为痴呆症。因为由这些疾病引起的痴呆症可能是可治疗的，在接受阿尔茨海默病的诊断前，对患者的全面评估非常重要。

The evaluation of the patient with dementia starts with an interview, usually by a neurologist or psychiatrist. The doctor will record the history of the disorder, looking for clues as to what may be the cause of the impairment in addition, a complete physical examination and a series of medical tests will be necessary to arrive at a diagnosis. A computerized axial tomography (CAT) scan—an X ray of the head showing both bones and brain tissue—may be used to look for signs of stroke or brain tumors. An electroencephalogram (EEG) is used to measure the electrical activity of the brain, which is abnormal in many kinds of dementia. Occasionally, a spinal tap is used to obtain a sample of the fluid surrounding the brain, so that it may be tested for the presence of infection. Blood tests are used to examine liver, kidney, and endocrine functions. When all other causes have been ruled out, the diagnosis of Alzheimer’s disease is assumed to apply. However, the only certain way to confirm this diagnosis is to examine the brain of the individual at autopsy.

对痴呆症患者的评估通常由神经专科医师和精神科医生以访谈开始。医生会记录病史，此外，寻找有关什么可能是损伤原因的线索，完整的身体检查和一系列药物测试对得出诊断是必要的。计算机轴向断层扫描（CAT）--一种展示头部骨骼和脑组织的X射线—可用于寻找中风或大脑肿瘤的迹象。使用脑电图（EEC）来测量在许多种痴呆症中异常的大脑电活动。偶尔，使用脊椎穿刺来获得大脑周围液体的样本，以便检测是否存在感染。使用血液检测来检查肝脏、肾脏和内分泌的功能。当排除了所有其它原因时，可认为对阿尔茨海默病的诊断是适用的。然而，确认这一诊断唯一确定的方式是在尸检时检查个体的大脑。

Treatment. No specific treatment has been found that consistently ameliorates the symptoms of Alzheimer’s disease or reverses the disease process. However, a variety of therapies can be helpful for the individual affected by this disease. Psychotherapy can help both patient and family learn to deal with the illness. Specific medications can be used to treat the depression and other psychological problems that may accompany the disease. Substantial help can be obtained from patient support groups such as those organized by the Alzheimer’s Disease and Related Disorders Association (360 N. Michigan Ave., Chicago, IL 60601).

治疗。目前尚未发现能够持续改善阿尔茨海默病的症状或逆转该病过程的特殊治疗手段。然而，各种各样的治疗方法对受此疾病影响的个体可能是有帮助的。心理疗法既能帮助患者，也能帮助家庭学习应对这种疾病。可以使用特定药物来治疗抑郁症，以及可能伴随该病的其它心理问题。可从由阿尔茨海默病与相关疾病协会组织的那些支持小组获得实质性的帮助。

Research. Considerable research is being directed toward the development of effective therapies for Alzheimer’s disease. It seems clear, however, that a better understanding of the basic changes in the brain and its neurotransmitters is a necessary first step in this endeavor. Of course, the ultimate goal is to develop therapies that actually prevent or cure the disease.

研究。相当多的研究正在集中到对阿尔茨海默病有效治疗方法的开发上。然而，这似乎很清楚，更好地认识大脑及其神经递质的基本变化是这项努力中必要的第一步。当然，终极目标是开发实际上可以预防或治愈该病的治疗方法。

A number of medical disciplines contribute to the understanding of this devastating condition. Epidemiologists, who study the demographic characteristics of individuals who develop the disorder, may be able to identify factors that place certain people at high risk for the disease. Neurologists, psychiatrists, and psychologists study individual patients in the hope of better defining the nature of their intellectual impairments. New clinical tests that may permit more accurate and earlier diagnosis of the disease are being developed. Positron emission tomography (PET) is one such technique that can actually measure ongoing brain activity in a living human. Much important research requires the use of autopsy tissue. Neuropathologists are working to understand why certain nerve cells are affected by the disease while others are spared. Neuro-chemists are analyzing the neurotransmitter changes that occur and are attempting to formulate treatment strategies. With the combined efforts of these many disciplines, it is hoped that understanding of Alzheimer’s disease will increase substantially in the near future.

许多医学学科都有助于对这种极具破坏力状况的理解。流行病学家研究出现该疾病个体的人口统计学特征，或许能够确定将特定人群置于该病高风险中的因素。神经学家、精神病学家和心理学家研究个体患者，希望更好地定义他们智力损伤的性质。正在开发的新临床试验可能使更准确、更早地诊断该病成为可能。正电子发射断层扫描（PET）就是这样一种技术，实际上可以测量活人正在进行的大脑活动。许多重要的研究都需要使用尸检组织。神经病理学家正在努力了解为什么某些神经细胞会受到该病的影响，而另一些神经细胞为什么却能幸免。神经化学家正在分析发生的神经递质改变，并正在尝试制定治疗策略。伴随这些众多学科的共同努力，希望在不久的将来，对阿尔茨海默病的认识将大幅度提高。

                             PETER J. WHITEHOUSE, M. D.

                                Johns Hopkins University

                              彼得·J. 怀特豪斯，医学博士

                                   约翰·霍普金斯大学

                                         2024年11月23日译

（译者注：该词条位列《大美百科全书》1985年版，第1卷，第649页至650页）