Prospective predictors of decline v. stability in mild cognitive impairment with Lewy bodies or Alzheimer's disease

Abstract

Background 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). Methods 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. Results 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. Conclusions 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.

A Longitudinal Study of Plasma pTau181 in Mild Cognitive Impairment with Lewy Bodies and Alzheimer's Disease

“…Alzheimer's disease (AD) and dementia with Lewy bodies (DLB) are the two most common neurodegenerative causes of dementia, between them accounting for 79% of cases in a UK brain bank study 1 . Both these diseases have a mild cognitive impairment (MCI) prodrome, and we have reported that MCI with Lewy bodies (MCI‐LB) has a faster decline and increased conversion to dementia compared with MCI‐AD, 2,3 which is consistent with evidence that at the dementia stage people with DLB have more rapid decline 4 and decreased survival times 5 compared with AD.…”

Progression to Dementia in Mild Cognitive Impairment With Lewy Bodies or Alzheimer Disease

“… 21 In a subset of this cohort, we have also previously found that those with MCI-LB were more likely to feature a progressive decline in cognitive scores than patients with MCI-AD. 3 Our results here indicate that this also manifests in a greater annual risk of developing dementia than MCI-AD.…”

“…We previously identified that visual hallucinations were associated with a poorer cognitive prognosis in a subset of this cohort (n = 70), but this association was not observed with fluctuating cognition 3 ; the daily variation in cognitive function characteristic of this symptom may obscure progressive decline in cognitive measures but still manifest in more clinically relevant functional declines as seen here (i.e., someone may score better on the day of a research cognitive assessment but at home show increased reliance on caregivers as a direct consequence of the intermittent but significant “lows” associated with this clinical symptom).…”

“…Dementia with Lewy bodies (DLB) has a worse prognosis than Alzheimer disease (AD), with increased hospitalization 1 and shorter survival time. 2 We have previously found 3 that the cognitive prodrome of DLB, mild cognitive impairment (MCI) with Lewy bodies (MCI-LB), for which research diagnostic criteria were recently published, 4 was more likely to demonstrate a progressive cognitive decline than MCI due to AD (MCI-AD). The respective cognitive prodromes may therefore progress at different rates, as in dementia.…”

Effects of the consumption of guarana on human health: A narrative review

“…While mild cognitive impairment is part of the normal cognitive changes that occur in dementia (Sanford, 2017), cognitive dysfunction is a symptomatic domain identified in many mental disorders such as major depressive disorder, which contributes significantly to occupational and functional disability (Pan et al., 2019). Furthermore, functional cognitive disorders are a group of overlapping conditions in which cognitive symptoms are present but are inconsistently experienced and unrelated to systemic or brain diseases (McWhirter et al., 2020); they are neurodegenerative in nature rather than subjective or functional (Hamilton et al., 2020). Approximately 25% of patients who visit memory clinics receive diagnoses that may indicate the presence of functional cognitive disorders (McWhirter et al., 2020), with a prevalence of 3%−19% among those older than 65 years old (Gauthier et al., 2006).…”