Hamilton Calum A, Matthews Fiona E, Donaghy Paul C, Taylor John-Paul, O'Brien John T, Barnett Nicola, Olsen Kirsty, McKeith Ian G, Thomas Alan J
Translational and Clinical Research Institute, Biomedical Research Building, Newcastle University, Newcastle upon Tyne, NE4 5PL, UK.
Population Health Sciences Institute, Biomedical Research Building, Newcastle University, Newcastle upon Tyne, NE4 5PL, UK.
Psychol Med. 2021 Nov;51(15):2590-2598. doi: 10.1017/S0033291720001130. Epub 2020 May 5.
Mild cognitive impairment (MCI) may gradually worsen to dementia, but often remains stable for extended periods of time. Little is known about the predictors of decline to help explain this variation. We aimed to explore whether this heterogeneous course of MCI may be predicted by the presence of Lewy body (LB) symptoms in a prospectively-recruited longitudinal cohort of MCI with Lewy bodies (MCI-LB) and Alzheimer's disease (MCI-AD).
A prospective cohort (n = 76) aged ⩾60 years underwent detailed assessment after recent MCI diagnosis, and were followed up annually with repeated neuropsychological testing and clinical review of cognitive status and LB symptoms. Latent class mixture modelling identified data-driven sub-groups with distinct trajectories of global cognitive function.
Three distinct trajectories were identified in the full cohort: slow/stable progression (46%), intermediate progressive decline (41%) and a small group with a much faster decline (13%). The presence of LB symptomology, and visual hallucinations in particular, predicted decline v. a stable cognitive trajectory. With time zeroed on study end (death, dementia or withdrawal) where available (n = 39), the same subgroups were identified. Adjustment for baseline functioning obscured the presence of any latent classes, suggesting that baseline function is an important parameter in prospective decline.
These results highlight some potential signals for impending decline in MCI; poorer baseline function and the presence of probable LB symptoms - particularly visual hallucinations. Identifying people with a rapid decline is important but our findings are preliminary given the modest cohort size.
轻度认知障碍（MCI）可能会逐渐恶化为痴呆症，但通常会在较长时间内保持稳定。关于导致病情恶化的预测因素知之甚少，难以解释这种差异。我们旨在探讨在一个前瞻性招募的患有路易体（LB）的MCI（MCI-LB）和阿尔茨海默病（MCI-AD）纵向队列中，MCI这种异质性病程是否可由LB症状的存在来预测。
一个年龄≥60岁的前瞻性队列（n = 76）在近期被诊断为MCI后接受了详细评估，并每年进行随访，重复进行神经心理学测试以及对认知状态和LB症状进行临床复查。潜在类别混合模型确定了具有不同全球认知功能轨迹的数据驱动亚组。
在整个队列中确定了三种不同的轨迹：缓慢/稳定进展（46%）、中度进行性衰退（41%）和一小群衰退快得多的个体（13%）。LB症状的存在，尤其是视幻觉，预示着认知轨迹会从稳定转为衰退。将时间零点设定为研究结束（死亡、痴呆或退出研究，如有数据，n = 39）时，确定了相同的亚组。对基线功能进行调整后，任何潜在类别的存在都变得模糊，这表明基线功能是预测衰退的一个重要参数。
这些结果突出了MCI即将衰退的一些潜在信号；基线功能较差以及可能存在LB症状——尤其是视幻觉。识别衰退迅速的个体很重要，但鉴于队列规模较小，我们的发现是初步的。
