Prediction of 7‐year's conversion from subjective cognitive decline to mild cognitive impairment

Subjective cognitive decline (SCD) is a high‐risk yet less understood status before developing Alzheimer's disease (AD). This work included 76 SCD individuals with two (baseline and 7 years later) neuropsychological evaluations and a baseline T1‐weighted structural MRI. A machine learning‐based model was trained based on 198 baseline neuroimaging (morphometric) features and a battery of 25 clinical measurements to discriminate 24 progressive SCDs who converted to mild cognitive impairment (MCI) at follow‐up from 52 stable SCDs. The SCD progression was satisfactorily predicted with the combined features. A history of stroke, a low education level, a low baseline MoCA score, a shrunk left amygdala, and enlarged white matter at the banks of the right superior temporal sulcus were found to favor the progression. This is to date the largest retrospective study of SCD‐to‐MCI conversion with the longest follow‐up, suggesting predictable far‐future cognitive decline for the risky populations with baseline measures only. These findings provide valuable knowledge to the future neuropathological studies of AD in its prodromal phase.     

Prospective memory on a novel clinical task in older adults with mild cognitive impairment and subjective cognitive decline

Despite the relevance of prospective memory to everyday functioning and the ability to live independently, prospective memory tasks are rarely incorporated into clinical evaluations of older adults. We investigated the validity and clinical utility of a recently developed measure, the Royal Prince Alfred Prospective Memory Test (RPA-ProMem), in a demographically diverse, non-demented, community-dwelling sample of 257 older adults (mean age = 80.78?years, 67.7% female) with amnestic mild cognitive impairment (aMCI, n = 18), nonamestic mild cognitive impairment (naMCI, n = 38), subjective cognitive decline (SCD, n = 83) despite intact performance on traditional episodic memory tests, and healthy controls (HC, n = 118). Those with aMCI and naMCI performed significantly worse than controls on the RPA-ProMem and its subtasks (time-based, event-based, short-term, long-term). Also, those with SCD scored significantly lower than controls on long-term, more naturalistic subtasks. Additional results supported the validity and inter-rater reliability of the RPA-ProMem and demonstrated a relation between test scores and informant reports of real-world functioning. The RPA-ProMem may help detect subtle cognitive changes manifested by individuals in the earliest stages of dementia, which may be difficult to capture with traditional episodic memory tests. Also, assessment of prospective memory can help guide the development of cognitive interventions for older adults at risk for dementia.     

Objective napping,cognitive decline,and risk of cognitive impairment in older men

IntroductionLittle is known about the longitudinal association between napping and cognitive impairment in older adults.MethodsWe used wrist actigraphy to measure naps in 2751 community-dwelling older men. Cognition was assessed repeatedly over 12 years, and clinically significant cognitive impairment was determined by physician diagnosis, Alzheimer's medication use or a significant cognitive decline.ResultsAfter adjustment for all covariates, men with longer napping duration had greater cognitive decline and higher risk of cognitive impairment. Men who napped for ≥120 min/day (vs. <30 min/day) were 66% more likely to develop cognitive impairment (odds ratio = 1.66, 95% CI: 1.09–2.54) in 12 years. Further adjustment for nighttime sleep quality did not appreciably alter the results. The association between napping and cognitive impairment was more pronounced among those with higher sleep efficiency and average sleep duration.DiscussionNapping might be useful as an early marker of cognitive impairment in the elderly, and its cognitive effects may differ by nighttime sleep.     

The dual role of cognitive reserve in subjective cognitive decline and mild cognitive impairment: a 7-year follow-up study

Journal of Neurology - The aim of this study was to evaluate the effect of cognitive reserve (CR), in progression from subjective cognitive decline (SCD) to mild cognitive impairment (MCI) and...     

The effects of aging in the hippocampus and cognitive decline

Aging is a natural process that is associated with cognitive decline as well as functional and social impairments. One structure of particular interest when considering aging and cognitive decline is the hippocampus, a brain region known to play an important role in learning and memory consolidation as well as in affective behaviours and mood regulation, and where both functional and structural plasticity (e.g., neurogenesis) occur well into adulthood. Neurobiological alterations seen in the aging hippocampus including increased oxidative stress and neuroinflammation, altered intracellular signalling and gene expression, as well as reduced neurogenesis and synaptic plasticity, are thought to be associated with age-related cognitive decline. Non-invasive strategies such as caloric restriction, physical exercise, and environmental enrichment have been shown to counteract many of the age-induced alterations in hippocampal signalling, structure, and function. Thus, such approaches may have therapeutic value in counteracting the deleterious effects of aging and protecting the brain against age-associated neurodegenerative processes.     

Rate of progression from mild cognitive impairment to dementia in an essential tremor cohort: A prospective,longitudinal study

BackgroundEssential tremor (ET), among the most common neurological diseases, is associated with cognitive dysfunction. Yet, nearly all knowledge of ET-related cognitive impairment is static and cross-sectional (e.g., prevalence), with virtually no dynamic information (i.e., course and progression, conversion rates, and clinical outcomes).ObjectivesTo quantify the rate of progression from mild cognitive impairment (MCI) to dementia in a cohort of elderly ET cases.Methods167 ET cases, enrolled in a prospective, longitudinal, clinical-pathological study, underwent an extensive neuropsychological testing battery at baseline (T1), 1.5 years (T2), and 3 years (T3). Results of these assessments informed clinical diagnoses of normal cognition (ET-NC), MCI (ET-MCI), and dementia (ET-D).ResultsAt baseline, 26 cases (82.7 ± 7.7 years) were diagnosed with ET-MCI and were available for follow-up at T2. At T2, three of 26 (11.5%) had converted to ET-D. At the start of T2, 23 cases (83.6 ± 7.7 years) were diagnosed with ET-MCI and were available for follow-up at T3. At T3, six of 23 (26.1%) converted to ET-D. The average annual conversion rate from ET-MCI to ET-D was 12.5%.ConclusionsThe study of cognitive impairment in ET is a nascent field, with limited data. We show that the conversion rate from ET-MCI to ET-dementia was 12.5%. Available studies on historical controls have reported conversion rates of 2.6–6.3%. Data such as these systematically fill gaps in knowledge, creating a scientifically-derived knowledge base to guide physicians and patients in clinical settings.     

Progression from normal cognition to mild cognitive impairment in a diverse clinic-based and community-based elderly cohort

Introduction

Investigation of the conversion rates from normal cognition (NC) to mild cognitive impairment (MCI) is important, as effective early intervention could potentially prevent or substantially delay the onset of dementia. However, reported conversion rates differ across studies and recruitment source. Our study examined predictors of conversion from NC to MCI in a racially and ethnically diverse sample drawn both from community and clinic recruitment sources.

Race and cognitive decline among community-dwelling elders with mild cognitive impairment: findings from the Memory and Medical Care Study

Objective: Previous studies have reported conflicting findings on the relationship between race and cognitive decline in elders with dementia. Few studies have examined the role of race in cognitive decline in mild cognitive impairment (MCI). We investigate the relationship between race and cognitive decline in participants with MCI in a community-based, longitudinal study of cognitively impaired elders.

Method: Based on a validated method utilizing a neuropsychiatric battery, 133 subjects [mean age: 78.7 years (SD?=?6.5); female: 112 (76.7%); black: 59 (44.4%)] out of 512 participants in the Memory and Medical Care Study were diagnosed with MCI. The main outcome measure was the Telephone Interview for Cognitive Status (TICS) score over three years. Other baseline subject characteristics (demographics, health-related variables, behavioral, and psychiatric symptoms) were included in the analysis.

Results: Overall, the three-year decline in mean TICS score was significantly higher among African Americans than non-African Americans [3.31 (SD: 7.5) versus 0.96 (SD: 3.0), t-value?=?1.96, p-value?=?0.05]. General estimating equation analyses revealed that African American race was associated with a faster rate of cognitive decline in all models.

Conclusion: The rate of cognitive decline in MCI appears to be faster in African Americans than non-African Americans in the community. Diagnosis of MCI among African American elders could lead to early interventions to prevent or delay cognitive decline in the future.     

Cognitive impairment in Parkinson's disease: Associations between subjective and objective cognitive decline in a large longitudinal study

BackgroundCognitive decline creates substantial morbidity and cost in Parkinson's disease (PD) and clinicians have limited tools for counseling patients on prognosis. We aimed to use data from a randomized, controlled trial of isradipine in Parkinson's disease (STEADY-PD III) to determine which objective cognitive domain deficits drive patient complaints of cognitive symptoms.MethodsNeuro-Quality of Life (Neuro-QoL) Cognition: General Concerns (GC), and Cognition: Executive Function (EF) (subjective measures), were administered at baseline, 1, 2, and 3 years in 324 people with PD. Baseline Montreal Cognitive Assessment (MoCA) was divided into 4 domains: visuospatial/executive, memory, attention, and language (objective measures). Spearman rank correlations and multiple regression models adjusted for other clinical variables evaluated associations between baseline Neuro-QoL domains and individual MoCA domains. Multiple regression models evaluated the association between baseline MoCA domain performance and Neuro-QoL change over three years. Cox proportional hazards predicted development of PD-MCI based on baseline and time-varying Neuro-QoL reporting.ResultsHigher MoCA memory performance was associated with better Neuro-QoL-GC (β = 0.75, SE = 0.391, p = 0.05) and Neuro-QoL-EF (β = 0.81, SE = 0.36, p = 0.02) at baseline. There was a trend for baseline MoCA memory to predict the degree of subjective cognitive decline on the Neuro-QoL-EF (β = 0.70, SE = 0.42, p = 0.09). Baseline depression and anticholinergic use were associated with worsened Neuro-QoL-EF and Neuro-QoL-GC. Increasing subjective cognitive complaints in Neuro-QoL-EF were associated with development of PD-MCI over 3 years of follow-up (HR = 0.95, CI = 0.90–1.0, p = 0.039).ConclusionsObjective memory impairment may be a stronger predictor than executive or visuospatial dysfunction for the presence of subjective cognitive complaints in early PD.     

Subjective ratings of cognitive and emotional functioning in patients with mild cognitive impairment and patients with subjective memory complaints but normal cognitive functioning

In a retrospective chart review, 39 patients referred for a clinical neuropsychological examination were identified as showing either mild cognitive impairment of the amnestic type (MCI-A; N = 21) or subjective memory complaints but with normal memory function (SMC; N = 18). During the clinical interview, patients and informants were routinely asked to make subjective ratings regarding the patient’s cognitive and affective functioning in everyday life. The purpose of this study was to determine whether these two patient groups (and their informants) significantly differed in their subjective reports about level of cognitive and affective difficulties. It was predicted that SMC patients would report higher levels of cognitive and emotional dysfunction than MCI-A patients. It was further predicted that MCI-A patients would underreport cognitive difficulties (compared to informant reports); SMC patients would demonstrate the opposite pattern. Results supported these predictions and suggest that routine assessment of subjective experiences of patients in conjunction with informant ratings may aid clinical diagnosis, particularly when the primary complaint is a decline in memory.     

Relation between acute and long-term cognitive decline after surgery: Influence of metabolic syndrome

IntroductionThe relationship between persistent postoperative cognitive decline and the more common acute variety remains unknown; using data acquired in preclinical studies of postoperative cognitive decline we attempted to characterize this relationship.MethodsLow capacity runner (LCR) rats, which have all the features of the metabolic syndrome, were compared postoperatively with high capacity runner (HCR) rats for memory, assessed by trace fear conditioning (TFC) on the 7th postoperative day, and learning and memory (probe trial [PT]) assessed by the Morris water-maze (MWM) at 3 months postoperatively. Rate of learning (A_L) data from the MWM test, were estimated by non-linear mixed effects modeling. The individual rat’s TFC result at postoperative day (POD) 7 was correlated with its A_L and PT from the MWM data sets at postoperative day POD 90.ResultsA single exponential decay model best described A_L in the MWM with LCR and surgery (LCR–SURG) being the only significant covariates; first order A_L rate constant was 0.07 s⁻¹ in LCR–SURG and 0.16 s⁻¹ in the remaining groups (p < 0.05). TFC was significantly correlated with both A_L (R = 0.74; p < 0.0001) and PT (R = 0.49; p < 0.01).ConclusionSeverity of memory decline at 1 week after surgery presaged long-lasting deteriorations in learning and memory.     

Short-term practice effects in mild cognitive impairment: Evaluating different methods of change

Practice effects are improvements on cognitive tests as a result of repeated exposure to testing material. However, variability exists in the literature about whether patients with amnestic mild cognitive impairment (MCI) display practice effects, which may be partially due to the methods used to calculate these changes on repeated tests. The purpose of the current study was to examine multiple methods of assessing short-term practice effects in 58 older adults with MCI. The cognitive battery, which included tests of memory (Hopkins Verbal Learning Test–Revised and Brief Visuospatial Memory Test–Revised) and processing speed (Symbol Digit Modalities Test and Trail Making Test Parts A and B), was administered twice across one week. Dependent t tests showed statistically significant improvement on memory scores (ps < .01, ds = 0.8–1.3), but not on processing speed scores. Despite this, the sample showed no clinically meaningful improvement on any cognitive scores using three different reliable change indices. Regression-based change scores did identify relatively large groups of participants who showed smaller than expected practice effects, which may indicate that this method is more sensitive in identifying individuals who may portend a declining trajectory. Practice effects remain a complex construct, worthy of continued investigation in diverse clinical conditions.     

不宁腿综合征与认知障碍的前瞻性研究:基于社区的5年纵向队列研究

目的探讨不宁腿综合征(RLS/WED)与认知功能减退间的关系。方法这是一项基于上海黄浦区五里桥社区≥50岁人群的前瞻性研究。首先于2009年,使用中国版简易精神状态检查量表(MMSE-C)对该社区中222例RLS/WED患者(基于2003版诊断标准制定的量表筛查)和1669例无RLS/WED患者进行认知功能评定,通过问卷调查和病案回顾的方法收集混杂因素信息,建立基线标准,5年后(2014年)随访该人群的认知功能(MMSE-C)。通过Logistic regression方法分析RLS/WED人群与认知功能减退的相关性。结果仅调整年龄和性别后,RLS/WED对认知能力减退有保护作用(OR=0.68, 95%CI:0.46~0.99,P=0.04)。然而,继续调整其他混杂因素(包括性别、年龄、职业、教育状况、糖尿病、高血压、鼾症、失眠、吸烟和饮酒、体重指数、载脂蛋白Eε4、抑郁、头部创伤史、全身麻醉史、冠状动脉疾病史、脑梗死、脑出血史)后,RLS/WED和认知能力减退无显著相关性(OR=0.64, 95%CI:0.40~1.04,P=0.07)。结论基于社区随访5年的前瞻性研究未发现RLS与认知功能减退有相关性。     

部分前循环脑梗死与遗忘型轻度认知功能损害患者认知功能的对比研究

目的 比较部分前循环脑梗死(partial anterior circulation infact,PACI)和遗忘型轻度认知损害(amnesic mild cognitive impairment,aMCI)患者的认知损害的特点.方法 选择29例符合牛津社区卒中项目(Oxford Community Stroke Droject,OCSP)分型的PACI患者,35例符合Petersen 诊断标准的aMCI患者,以及60例健康老年人为对照组,采用认知功能筛选测验-C2.1(Cognitive Ability Screening Instrument-C2.1,CASI)评定认知功能.结果 PACI组(86.28±12.04)和aMCI组(89.86±6.03)的CASI总分均比正常对照组(95.57±3.44)低,差异具有统计学意义[F(2)=8.547,P<0.05],而PACI组与aMCI组间无统计学差异.在CASI分领域方面,与对照组相比,PACI组在心算力(P=0.000)和定向力(P=0.021)两方面均较差;与aMCI组比较,PACI组的心算力(P=0.000)较aMCI组差,而短时记忆(P=0.016)和思维流畅性(P=0.005)方面则较好.aMCI组与对照组相比,在短时记忆(P=0.000)、抽象与判断能力(P=0.013)和思维流畅性(P=0.001)方面均较差.结论 PACI患者存在认知损害,尤其在心算力和定向力方面,与aMCI患者相比,可能更好地保留了执行功能,推测缺血性脑卒中与神经退行性变引起的认知损害可能涉及不同认知领域.