Visual associations cued recall A Paradigm for Measuring Episodic Memory Decline in Alzheimer’s Disease

Repeated measurements of episodic memory are needed for monitoring amnestic mild cognitive impairment (aMCI) and mild Alzheimer’s disease (AD). Most episodic memory tests may pose a challenge to patients, even when they are in the milder stages of the disease. This cross-sectional study compared floor effects of the Visual Association Test (VAT) and the Rey Auditory Verbal Learning Test (RAVLT) in healthy elderly controls and in patients with aMCI or AD (N = 125). A hierarchical multiple regression analysis was used to examine whether linear or quadratic trends best fitted the data of cognitive test performance across global cognitive impairment. Results showed that VAT total scores decreased linearly across the range of global cognitive impairment, whereas RAVLT total scores showed a quadratic trend, with total scores levelling off for 90% of aMCI patients and 94% of AD patients. We conclude that the VAT shows few if any floor effects in patients with aMCI and mild AD and is therefore a potentially promising cognitive test for monitoring episodic memory impairment.     

The impact of cognitive interventions on cognitive symptoms in idiopathic Parkinson’s disease: a systematic review

This systematic review addressed efficacy of cognitive stimulation (CS), cognitive training (CT), and cognitive rehabilitation (CR) to improve cognitive functions in Parkinson’s disease (PD) with (PD-MCI) and without mild cognitive impairment (PD-H). Five databases were searched. Twelve CT, four CS, and a combination of CT with CR were found. PD-H benefited from CT or CS compared to active or passive controls in 42.1% of cognitive tests, and in 33.3% of psychological and functional measures. PD-MCI alone, compared with controls, only improved in 6.9% of cognitive measures after CT. PD-H and PD-MCI, alone or together, somehow improved information processing speed, attention, working memory, executive functions, and visual episodic memory. PD-MCI improved better than PD-H in global cognition and planning abilities. The outcomes suggest some efficacy of cognitive interventions in PD. However, small samples, lack of information regarding standardization of interventions, and poor methodological quality limit results validity and prevent firm conclusions.     

Age- and education-adjusted normative data for the Montreal Cognitive Assessment (MoCA) in older adults age 70–99

The original validation study for the Montreal Cognitive Assessment (MoCA) suggests a cutoff score of 26; however, this may be too stringent for older adults, particularly for those with less education. Given the rapidly increasing number of older adults and associated risk of dementia, this study aims to provide appropriate age- and education-adjusted norms for the MoCA. Data from 205 participants in an ongoing longevity study were used to derive normative data. Individuals were grouped based on age (70–79, 80–89, 90–99) and education level (≤12 Years, 13–15, ≥16 Years). There were significant differences between age and education groups with younger and more educated participants outperforming their counterparts. Forty-six percent of our sample scored below the suggested cutoff of 26. These normative data may provide a more accurate representation of MoCA performance in older adults for specific age and education stratifications.     

Examining the reliability of ADAS-Cog change scores

The purpose of this study was to estimate and examine ways to improve the reliability of change scores on the Alzheimer’s Disease Assessment Scale, Cognitive Subtest (ADAS-Cog). The sample, provided by the Alzheimer’s Disease Neuroimaging Initiative, included individuals with Alzheimer’s disease (AD) (n = 153) and individuals with mild cognitive impairment (MCI) (n = 352). All participants were administered the ADAS-Cog at baseline and 1 year, and change scores were calculated as the difference in scores over the 1-year period. Three types of change score reliabilities were estimated using multivariate generalizability. Two methods to increase change score reliability were evaluated: reweighting the subtests of the scale and adding more subtests. Reliability of ADAS-Cog change scores over 1 year was low for both the AD sample (ranging from .53 to .64) and the MCI sample (.39 to .61). Reweighting the change scores from the AD sample improved reliability (.68 to .76), but lengthening provided no useful improvement for either sample. The MCI change scores had low reliability, even with reweighting and adding additional subtests. The ADAS-Cog scores had low reliability for measuring change. Researchers using the ADAS-Cog should estimate and report reliability for their use of the change scores. The ADAS-Cog change scores are not recommended for assessment of meaningful clinical change.     

Macro-event recognition in healthy ageing,Alzheimer’s disease,and mild cognitive impairment

Event perception and cognition is integral to our everyday experience and functional ability. A commonly reported complaint in Alzheimer’s disease (AD) is the inability to follow narratives – be it textual, conversational, video, or pictures. This phenomenon has received little systematic research so far. In the current study, we developed a novel paradigm to examine macro-event recognition in individuals with AD in the early stage and its preceding stage of mild cognitive impairment (MCI) in comparison with cognitively healthy older adults, using pictures depicting events. In Experiment 1, we examined participants’ ability to integrate pictorially depicted sub-events into macro-events. The pictures were presented in a scrambled order, and participants were expected to arrange them in the temporally and causally appropriate sequence, as dictated by the macro-event schema. Additionally, we investigated the effect of cueing the appropriate event schema by providing a word cue (verb). In Experiment 2, macro-event recognition was examined again using a cognitively less taxing paradigm, where pictures depicting sub-events were presented in correct order, but staggered, and recognition speed was measured. We observed significant deficits in the AD and MCI groups’ performance compared with the cognitively healthy older adults, across both experiments, suggesting event perception and cognition is impaired early in the course of AD. There was no effect of cueing on the performance of any of the groups. The theoretical and clinical implications of these findings are discussed.     

Visual associations to retrieve episodic memory across healthy elderly,mild cognitive impairment,and patients with Alzheimer’s disease

Episodic memory tests need to determine the degree to which patients with moderate to severe memory deficits can still benefit from retrieval support. Especially in the case of Alzheimer’s disease (AD), this may support health care to be more closely aligned with patients’ memory capacities. We investigated whether the different measures of episodic memory of the Visual Association Test-Extended (VAT-E) can provide a more detailed and informative assessment on memory disturbances across a broad range of cognitive decline, from normal to severe impairment as seen in AD, by examining differences in floor effects. The VAT-E consists of 24 pairs of black-and-white line drawings. In a within-group design, we compared score distributions of VAT-E subtests in healthy elderly controls, mild cognitive impairment (MCI), and AD (n = 144), as well as in relation to global cognitive impairment. Paired associate recall showed a floor effect in 41% of MCI patients and 62% of AD patients. Free recall showed a floor effect in 73% of MCI patients and 84% of AD patients. Multiple-choice cued recognition did not show a floor effect in either of the patient groups. We conclude that the VAT-E covers a broad range of episodic memory decline in patients. As expected, paired associate recall was of intermediate difficulty, free recall was most difficult, and multiple-choice cued recognition was least difficult for patients. These varying levels of difficulty enable a more accurate determination of the level of retrieval support that can still benefit patients across a broad range of cognitive decline.     

Exploring mechanisms that affect retrograde memory for public events in amnestic mild cognitive impairment: A longitudinal update

Here, we examined mechanisms that affect retrograde memory in amnestic mild cognitive impairment (a-MCI) as a function of longitudinal clinical outcome. 8 a-MCI who converted to Alzheimer's dementia (AD) during the subsequent 3-year follow-up (converter a-MCI) and 10 a-MCI who remained clinically stable during the same period (stable a-MCI) were compared at the baseline evaluation (i.e., when they were diagnosed as a-MCI) using a remote memory questionnaire for public events that allows disentangling the differential contribution of storage and retrieval mechanisms to performance accuracy. Results suggest that deficits in remote memory are primarily explained by impaired retrieval abilities in stable a-MCI and by impaired storage in converter-to-AD a-MCI. This distinction between retrograde amnesia due to defective trace utilisation in stable a-MCI and trace storage in converter a-MCI is consistent with the temporal unfolding of declining anterograde memory over the course of disease progression to AD.     

Relationship of cognitive strategy use to prospective memory performance in a diverse sample of nondemented older adults with varying degrees of cognitive complaints and impairment

Although older adults typically have better performance on prospective memory (PM) tasks carried out in naturalistic settings, a paucity of research directly assesses older adults’ use of compensatory strategies on such tasks. The current study investigates external memory strategy use during performance of a clinical PM test that features both short-term (in laboratory) and long-term (out of laboratory) subtasks (i.e., the Royal Prince Alfred Prospective Memory Test – RPA-ProMem. Nondemented, community-dwelling older adults (n = 214; mean age = 80.5; 68.2% female; 39.7% non-white) with mild cognitive impairment, subjective cognitive decline, and healthy controls completed the RPA-ProMem while external strategy use was permitted and recorded. Overall, participants utilized external strategies 41% of the time on the RPA-ProMem. Increased utilization of external memory strategies was significantly associated with better PM performance. Additionally, better performance on executive functioning tasks was associated with increased use of external memory strategies. Results are discussed in relation to how memory strategy use can be enhanced to improve everyday memory ability in older adults at risk for dementia.     

Neuropsychological predictors of conversion to probable Alzheimer disease in elderly with mild cognitive impairment

In the field of neuropsychology, it is essential to determine which neuropsychological tests predict Alzheimer's disease (AD) in people with mild cognitive impairment (MCI) and which cut‐off points should be used to identify people at greater risk for converting to dementia. The aim of the present study was to analyse the predictive value of the cognitive tests included in a neuropsychological battery for conversion to AD among MCI participants and to analyse the influence of some sociodemographic variables – sex, age, schooling – and others, such as follow‐up time and emotional state. A total of 105 participants were assessed with a neuropsychological battery at baseline and during a 3‐year follow‐up period. For the present study, the data were analysed at baseline. During the follow‐up period, 24 participants (22.85%) converted to dementia (2.79 ± 1.14 years) and 81 (77.14%) remained as MCI. The logistic regression analysis determined that the long delay cued recall and the performance time of the Rey figure test were the best predictive tests of conversion to dementia after an MCI diagnosis. Concerning the sociodemographic factors, sex had the highest predictive power. The results reveal the relevance of the neuropsychological data obtained in the first assessment. Specifically, the data obtained in the episodic verbal memory tests and tests that assess visuospatial and executive components may help to identify people with MCI who may develop AD in an interval not longer than 4 years, with the masculine gender being an added risk factor.     

Measuring emotion recognition: Added value in diagnosing dementia of the Alzheimer’s disease type

Neuropsychological tests, particularly for episodic memory, are used to classify patients in memory clinics. Still, the differential diagnosis between dementia of the Alzheimer’s disease type (Dementia-AD), mild cognitive impairment (MCI), or major depressive disorder (MDD) is challenging. However, impairments in other domains, such as emotion recognition, an aspect of social cognition, might have additional value in distinguishing Dementia-AD from MCI and MDD and hence signal progression of neurodegeneration. We evaluated this in patients visiting a memory clinic. Sixty healthy controls (HC) and 143 first time attendants of an academic hospital memory clinic who were eventually classified as Dementia-AD (n = 45), MCI (n = 47), MDD (n = 27), or No Impairment (NI, n = 24) were included. We assessed group differences in Emotion Recognition (Ekman 60 Faces Test (EFT)) and episodic memory (Dutch Rey Auditory Verbal Learning Test (RAVLT)). With multinomial and binomial regression analysis, we assessed whether EFT was added to RAVLT in distinguishing patient groups. Dementia-AD patients had significantly worse emotion recognition than HC, MCI, MDD, and NI groups, but no other between-group differences were found. Episodic memory was impaired in Dementia-AD and MCI patients. We found no memory impairments in the MDD and NI groups. Emotion recognition in addition to episodic memory was significantly better in predicting group membership than episodic memory alone. In conclusion, emotion recognition measurement had added value for differentiation between patients first visiting memory clinics, in particular in distinguishing Dementia-AD from MCI. We recommend the standard inclusion of emotion recognition testing in neuropsychological assessment in memory clinics.     

Assessment of apathy in neurological patients using the Apathy Motivation Index caregiver version

Apathy is a common, disabling neuropsychiatric syndrome that occurs across many brain disorders and may be associated with diminished motivation in behavioural, cognitive, emotional and social domains. Assessment is complicated by the variability of symptoms across apathy domains and self-report from patients, which can be misleading due to their lack of insight. Independent evaluation by clinicians also has limitations though if it has to be performed with limited time. Caregiver reports are a viable alternative, but current assessments for them either do not distinguish between different apathy domains or are interview-based and take long to administer. In this study, we developed a brief caregiver questionnaire version of the recently developed Apathy Motivation Index (AMI), which is a self-report tool. We confirmed three apathy factors in this new caregiver measure (AMI-CG) that were also present in the AMI: Behavioural Activation, Emotional Sensitivity and Social Motivation. Furthermore, we validated the scores against more extensive caregiver interviews using the established Lillle apathy rating scale as well as patient self-reports of apathy, measures of depression, anhedonia, cognition, activities of daily living and caregiver burden across four different neurological conditions: Parkinson's disease, Alzheimer's disease, subjective cognitive impairment and limbic encephalitis. The AMI-CG showed good internal reliability, external validity and diagnostic accuracy. It also uncovered cases of social apathy overlooked by traditional instruments. Crucially, patients who under-rated their apathy compared to informants were more likely to have difficulties performing everyday activities and to be a greater burden to caregivers. The findings provide evidence for a multidimensional conceptualization of apathy and an instrument for efficient detection of apathy based on caregiver reports for use in clinical practice.     

The association between cognitive ability across the lifespan and health literacy in old age: The Lothian Birth Cohort 1936

Three hundred and four participants in the Lothian Birth Cohort 1936 study took a validated IQ-type test at age 11 years and a battery of cognitive tests at age 70 years. Three tests of health literacy were completed at age 72 years; the Rapid Estimate of Adult Literacy in Medicine (REALM), the Test of Functional Health Literacy in Adults (S-TOFHLA), and the Newest Vital Sign (NVS). Participants who had a lower childhood IQ exhibited poorer performance on all three tests of health literacy taken in older adulthood. Relative cognitive change from age 11 to 70 and education were also important factors influencing performance on health literacy tasks, independent of childhood cognitive ability. It is important to understand the determinants of low health literacy in order to support individuals in managing their own health.     

Dysexecutive syndrome in Parkinson’s disease: the GREFEX study

The objectives of this study were to characterize the frequencies and profiles of behavioral and cognitive dysexecutive syndromes in PD (based on validated battery and diagnostic criteria) and to develop a shortened diagnostic battery. Eighty-eight non-demented patients with a diagnosis of PD were examined with an executive validated battery. Using a validated framework, the patients’ test results were interpreted with respect to normative data from 780 controls. A dysexecutive syndrome was observed in 80.6% of the patients [95% confidence interval: 71.1–90.1]. The dysexecutive profile was characterized by prominent impairments in deduction, flexibility, inhibition and initiation in the cognitive domain, and by global hypoactivity with apathy and hyperactivity in the behavioral domain. This finding implies that patients with PD should be assessed with cognitive tests and a validated inventory for behavioral dysexecutive syndromes. A shortened battery (based on three cognitive tests and three behavioral domains) provided high diagnostic accuracy.     

Performance of an Adapted Version of the Timed Up-and-Go Test in People with Cognitive Impairments

In clinical practice, older people with cognitive impairment may have difficulties to understand the instructions of the Timed Up-and-Go (TUGT) test and present a bad performance. The purpose of this study was to identify differences in the TUGT performance, in an adapted version, between older adults with preserved cognition (PC), mild cognitive impairment (MCI) and Alzheimer's disease (AD), and to identify the association between the adapted TUGT performance and cognition among groups. A cross-sectional study was conducted with 118 community-dwelling older adults divided in three groups: PC (n?=?40), MCI (n?=?40) and AD (n?=?38). The evaluation was composed by the adapted TUGT and cognitive assessment (Addenbrooke's Cognitive Examination and Frontal Assessment Battery). Only the cadence of TUGT presented significant difference between groups, specifically between AD versus MCI and PC groups. The main correlations were found between time of TUGT with fluency domain and global cognitive function, especially in the AD Group. The findings contribute to the understanding of how cognition interferes on functional mobility in older people with MCI and AD. The adapted TUGT is easy to perform in clinical practice and can be useful when assessing mobility in people with cognitive impairment.     

Differences in cognitive performance between informal caregivers and non-caregivers

ABSTRACT

Extensive literature exists documenting the relationship between stress and cognition. Caregiving for an individual with Alzheimer’s disease can be aunique and chronic stress experience due to the increasing dependency of the care-recipient as the disease progresses. The current study examines the relationship between stress and cognitive performance in 47 dementia caregivers compared to 47 noncaregiver control participants matched on age, gender, and education. Participants completed measures assessing stress (measured via the Perceived Stress Scale) and seven domains of cognition including episodic memory, working memory, executive functioning, attention, visuospatial processing, processing speed, and implicit memory. Results showed that caregivers had poorer performance than non-caregivers on certain measures of episodic memory, working memory, and executive functioning; while no significant differences were observed on measures of attention, visuospatial processing, processing speed, or implicit memory. In addition, when controlling for general stress, caregiver performance on measures of processing speed and visuospatial processing was also poorer than non-caregivers. By controlling for levels of general stress that may not be related to caregiving, these results show that differences in cognitive performance are unlikely to be explained by general stress alone.     

The free and cued selective reminding test for predicting progression to Alzheimer's disease in patients with mild cognitive impairment: A prospective longitudinal study

Amnestic mild cognitive impairment (aMCI) patients carry a greater risk of conversion to Alzheimer's disease (AD). Therefore, the International Working Group (IWG) on AD aims to consider some cases of aMCI as symptomatic prodromal AD. The core diagnostic marker of AD is a significant and progressive memory deficit, and the Free and Cued Selective Reminding Test (FCSRT) was recommended by the IWG to test memory in cases of possible prodromal AD. This study aims to investigate whether the performance on the FCSRT would enhance the ability to predict conversion to AD in an aMCI group. A longitudinal study was conducted on 88 aMCI patients, and neuropsychological tests were analysed on the relative risk of conversion to AD. During follow‐up (23.82 months), 33% of the aMCI population converted to AD. An impaired FCSRT TR was significantly associated with the risk of conversion to dementia, with a mean time to conversion of 25 months. The FCSRT demonstrates utility for detecting AD at its prodromal stage, thus supporting its use as a valid clinical marker.     

Alterations in working memory networks in amnestic mild cognitive impairment

Patients with amnestic mild cognitive impairment (aMCI) show preserved or mildly impaired working memory, despite their deficits in episodic memory. We aimed to identify performance and/or neural differences between aMCI patients and matched controls on a standard working memory fMRI task. Neuropsychological assessment demonstrated aMCI impairments in verbal and visual episodic long-term memory, with intact IQ and executive function. Participants completed a standard three-level N-back task where patients were unimpaired. Functional activations in the control group were found in expected areas, including the inferior parietal lobule and dorsolateral prefrontal cortex. Group differences were found in the insula and lingual gyrus and, in a region of interest analysis, in the hippocampus. In all cases, these were caused by an absence of task-related deactivations in the aMCI group. The results are consistent with reports of failure in task-related deacivations in aMCI and could be early indications of pathology.     

The importance of impaired physical health and age in normal cognitive aging

The objective of this study was to investigate the importance of impaired physical health and age in normal cognitive aging. In our cross-sectional, clinical and explorative study, medical and neuropsychological data from 118 voluntary healthy controls aged 26-91 years were collected from five recruitment occasions. Health was assessed according to a criterion reflecting clinical and subclinical severity. The examinations included a clinical investigation, brain neuroimaging, and a comprehensive neuropsychological assessment. Regression analyses showed a significant incidence of clinical and subclinical medical disorders that explained 10.8% of the variation in cognitive performance, while age-related impairment explained 5.6%. Findings of the central nervous system were important but various other medical findings explained about half of the health-related variation. Cognitively demanding tasks were more susceptible to impaired physical health while tasks comprising salient motor- and visual spatial elements were more prone to be impaired by age. Our findings suggest (1) that impaired physical health is more important than chronological age in accounting for cognitive impairment across the adult lifespan, (2) that age and health dissociate with regard to cognitive functions affected, and (3) that selection for so-called "super healthy" elderly people might be justified in cognitive research. Because the prevalent diseases in normal aging are potentially preventable, the present findings promise good prospect for prevention of future cognitive disability among elderly people.