阿兹海默症（痴呆症），比死亡更可怕的是遗忘

• 阿兹海默症是最常见的神经退行性疾病，它的特点是神经元变性和死亡。它被归类为一种痴呆症，这一术语指的是一种涉及记忆丧失和认知障碍的大脑疾病。

  Alzheimer's disease is the most common form of neurodegenerative disease, meaning it is characterized by the degeneration and death of neurons. It is classified as a type of dementia, a term that refers to a category of brain disorders that involve memory loss and cognitive impairment.

  阿兹海默症最常发生在65岁以上的人群中。这种疾病的病因尚不清楚，通常认为他们与遗传和环境因素相关。阿兹海默症与整个大脑的神经元死亡有关，与健康的大脑相比，这种神经元的死亡较分布较为广泛，以至于大脑的某区域出现萎缩或萎缩。阿兹海默症的一个标志性迹象是神经元内外都形成了错误折叠的蛋白质簇。

  Alzheimer's most often affects adults over the age of 65. The causes of the disease are not well understood, and genetics and environmental factors are thought to be involved. Alzheimer's disease is associated with neuronal death throughout the brain, which can be extensive enough that regions of the brain appear atrophied or shrunken compared to a healthy brain, a hallmark sign of alzheimer's disease is the formation of clusters of misfolded proteins both inside and outside of neurons. 

  其中一种蛋白质，β淀粉样蛋白，存在于健康大脑中神经元周围的细胞外空间。然而，在阿兹海默症期间，错误折叠的β淀粉样蛋白在称为淀粉样斑块的沉积物中聚集在一起。另一种叫做tau蛋白的蛋白质通常存在于神经元内部，参与维持神经结构，在阿兹海默症中也被发现处于错误折叠状态。它在神经元内聚集成束，这种现象被称为神经纤维缠结。

  One of these proteins, amyloid beta protein, is found in the extracellular space around neurons in a healthy brain. During alzheimer's, however, misfolded forms of amyloid beta clumped together in deposits called amyloid plaques. Another protein called tau protein, which is normally found inside neurons and involved in maintaining neural structure, is also found in a misfolded state in alzheimer's. It accumulates inside neurons in bundles called neurofibrillary tangles. 

  尽管淀粉样斑块和神经纤维缠结是阿兹海默症的标志，但尚不清楚它们是否为导致神经退行性变的原因，还是大脑对此的反应的一部分。

  Although amyloid plaques and neurofibrillary tangles are hallmark signs of alzheimer's disease, it is unclear if they contribute to the neurodegeneration or are part of the brain's response to it.

  阿兹海默症最常见的治 疗方法包括抑 制乙酰胆碱酯酶活性的药物，乙酰胆碱酯酶是一种分解神经递质乙酰胆碱的酶。这种被称为乙酰胆碱酯酶抑 制剂的药物可以提高乙酰胆碱的水平，而乙酰胆碱这种物质被认为可以促进健康的认知和记忆。然而，这些治 疗的效果是有限的，并不能阻止阿兹海默症的神经退行性变。因此，它们并不能治愈这种疾病。

  The most common treatments for alzheimer's disease involve drugs that inhibit the activity of acetylcholine esterase, an enzyme that breaks down the neurotransmitter acetylcholine. The drugs, called acetylcholine esterase inhibitors, increase levels of acetylcholine, which is thought to promote healthy cognition and memory. The effects of these treatments are modest, however, and they do not stop neurodegeneration in alzheimer's. Thus they are not a cure for the disease.