輕度認知障礙之診斷與治療：臺北榮總經驗

The Diagnosis and Treatment of Mild Cognitive Dementia: Experiences at Taipei Veterans General Hospital

輕度認知障礙（mild cognitive impairment, MCI）是一個介於正常認知功能與輕度失智症之間的一種過渡階段，雖然有少部分的患者會由MCI回復到正常的認知功能，但就大部分的患者而言，這是一個會退化到失智症的高危險群。台北榮總失智症研究團隊10幾年來就失憶型MCI（amnestic MCI）進行了多項長期追蹤研究。失憶型MCI的患者的記憶力和生活功能表現，介於正常老人和輕度阿茲海默失智症之間，海馬迴的體積和每年萎縮的速率也是介於正常老人和輕度阿茲海默失智症之間，同時脂蛋白（Apolipoprotein）基因E第四型，也會增加失憶型MCI每年轉變成為阿茲海默失智症的機率。所以整合目前國際上和我們團隊的研究成果顯示，失憶型MCI無論就認知功能、相關基因和影像學的表現，都符合極早期阿茲海默症（Alzheimer's disease）的表徵。在2011年公布的MCI診斷標準中，已建議將臨床上有失憶型MCI且合併有阿茲海默症生物標記的患者，診斷為因阿茲海默症導致的MCI（MCI due to Alzheimer's disease)，更強調這可能就是極早期阿茲海默症。雖然目前對MCI尚未有臨床試驗證實有效的藥物治療，但仍可能經由危險因子的控制和認知功能訓練等非藥物治療來減緩其病程，以達早期診斷早期治療的目標。

Mild cognitive impairment (MCI) is a transitional state between normal cognition and mild dementia. Although some MCI patients return back to normal cognition, most MCI progress to dementia. The dementia research group in Taipei Veterans General Hospital has conducted several prospective studies to evaluate the manifestation of amnestic MCI and the outcomes of patients who develop the disease. Patients with amnestic MCI experience levels of performance in memory and daily function that range between normal elderly and mild Alzheimer's disease (AD) dementia patients. The hippocampal volume and annual atrophy rates of hippocampus in patients with amnestic MCI also range between normal elderly and mild AD dementia patients. Apolipoprotien E ϵ 4 may increase the risk and shorten the duration of the progression from amnestic MCI to AD dementia. Integrating the present evidence from literature and our research, the clinical, genetic and neuroimaging features of amnestic MCI appear very similar to very early AD. The 2011 diagnostic criteria for MCI suggest diagnosing MCI patients coexisting with AD biomarkers as MCI due to AD. This new criteria emphasize the evidence suggesting that MCI with AD biomarkers may actually be the very early stages of AD. Until now, there is no proved pharmacological treatment for MCI. However, we may decelerate the progression from MCI to dementia by controlling the risk factors and cognitive training. Early diagnosis and early treatment is the best therapy for dementia.