Division of Psychiatry, University College London, London, United Kingdom.
Curr Opin Psychiatry. 2017 Mar;30(2):102-107. doi: 10.1097/YCO.0000000000000307.
Alzheimer's disease is most likely universal in older individuals with Down syndrome, due to having three copies of the amyloid precursor protein gene, resulting in amyloid-beta plaque deposition. Down syndrome is an important population in which to consider clinical trials of treatments to prevent or delay the development of dementia. However, assessment of subtler cognitive changes is challenging due to the presence of intellectual disability.
Recent research confirmed that older adults with Down syndrome often present with cognitive decline: more than 80% may experience dementia by age 65 years. Efforts have been made to improve and validate neuropsychological assessment and to describe the relationship with comorbidities such as epilepsy and haemorrhagic stroke. There have also been advances in biomarkers such as neuroimaging using amyloid PET.
Clinical trials of treatments, particularly in the presymptomatic phase of Alzheimer's disease, are important to consider in individuals with Down syndrome given their high dementia burden, and may also serve as proof of concept for other forms of Alzheimer's disease. However, further work is required to improve outcome measures and better understand the biomarkers of progression of disorder and their relationship with symptom development during the presymptomatic period.
唐氏综合征患者由于携带三倍的淀粉样前体蛋白基因，导致淀粉样-β斑块沉积，因此在老年人群中极有可能普遍患有阿尔茨海默病。唐氏综合征是一个重要的人群，需要考虑开展临床试验以预防或延缓痴呆的发生。然而，由于存在智力障碍，评估更微妙的认知变化具有挑战性。
最近的研究证实，唐氏综合征的老年人经常出现认知能力下降：超过 80%的人可能在 65 岁之前患有痴呆症。人们已经努力改进和验证神经心理学评估，并描述与癫痫和出血性中风等共病的关系。在使用淀粉样蛋白 PET 的神经影像学等生物标志物方面也取得了进展。
鉴于唐氏综合征患者的痴呆负担很重，考虑对其进行治疗的临床试验，特别是在阿尔茨海默病的无症状阶段，这一点非常重要，这也可能为其他形式的阿尔茨海默病提供概念验证。然而，还需要进一步的工作来改善评估结果，并更好地了解疾病进展的生物标志物及其与无症状期症状发展的关系。
