阿茲海默症2011年診斷標準的新思維

阿茲海默症是最常見的失智症，隨著世界人口老化的趨勢，阿茲海默症將成為全世界在公共健康醫療上很重要的課題。在2011 年之前，在臨床和研究上最常用也是最準確的阿茲海默症診斷標準就是1984 年由美國國家神經疾病與腦中風研究所和阿茲海默症暨相關疾病協會提出的診斷標準。阿茲海默症的相關研究在這20 多年來有非常大的進展。在臨床、基因、生化、分子生物和腦部影像的研究都指出，我們有可能在一個人尚未發展到失智症之前就診斷阿茲海默症。2011 年美國國家老年研究院與阿茲海默症協會聯合發表了阿茲海默症新的診斷標準。這個診斷標準不僅嘗試涵蓋了阿茲海默症整個病程，同時也將這幾年來在生物標記上的發現加入診斷標準中。新的診斷標準將阿茲海默症分做3 個時期：臨床前阿茲海默症、因阿茲海默症造成的輕度認知功能障礙以及阿茲海默失智症。在生物標記上則將能檢測類澱粉蛋白沈積和神經損傷的檢查加入，以確定此病人的病理變化是否和阿茲海默症相關。雖然在這新的診斷標準中有一些部分是建議在研究上使用，但整個新診斷標準所提出的概念已使我們對阿茲海默症的病程有一個全新的視野。

Alzheimer's disease (AD) is the most common cause of dementia and will lead to a worldwide public health crisis. Before 2011, the most widely used and best validated diagnostic criteria for AD were the NINCDS-ADRDA (National Institute of Neurological and Communicative Disorders and Stroke - Alzheimer's Disease and Related Disorders Association) criteria published in 1984. Alzheimer's research has greatly evolved over the past decades. Major scientific advances in clinical, genetics, biochemistry, molecular biology, and neuroimaging have suggested that the brain changes that cause AD can be detected before a person becomes demented. The National Institute on Aging and the Alzheimer's Association updated the diagnostic guidelines covering the full spectrum of AD in 2011. The newly proposed criteria reflect the evidence of the time course of pathology and biomarkers in relation to clinical symptoms of AD. The new criteria emphasize that the AD pathophysiological process starts years and perhaps decades before clinical symptoms, and that biomarkers can detect amyloid β deposition and the effects of neuronal injury in the brain. These guidelines describe the 3 stages of AD: the earliest preclinical stage of AD, mild cognitive impairment due to AD, and dementia due to AD. The new guidelines address the use of neuroimaging and biomarkers in the cerebral spinal fluid that may help to determine whether changes in the brain are due to Alzheimer's disease. The most advance of the new criteria is to propose the concept of preclinical AD. Although part of new criteria is intended purely for research purposes, it changes our view about the disease process of AD.