Since its first implementation in 1998, significant evidence has been presented of the positive impact of the TimeSlips creative expression method for people with dementia in long-term care (LTC) settings. Our research with people with dementia in Colombia extends this evidence in important new directions: it is the longest TimeSlips study to date (at 32 consecutive weeks); it is the first to evaluate the feasibility of the online delivery of the method (in response to the strict COVID-19 quarantine in Colombia); it is the first study to investigate the impact of the TimeSlips method on the personhood, quality of life and psychological well- being of Spanish-speaking participants in non-LTC settings in the Global South.

Trained facilitators provided weekly, one-hour TimeSlips group storytelling sessions via Zoom over 32 consecutive weeks to eight participants with dementia. Semi- structured interviews of participants and care partners were conducted within one week of the final intervention. Thematic analysis evaluated the resultant qualitative data.

Our online implementation of the TimeSlips creative expression method reinforced key facets of participants’ personhood (self-expression and self-perception, which led in turn to increased care partner appreciation), had a positive impact on key domains of quality of life (mood, energy levels and cognitive function) and stimulated a key aspect of psychological well-being (the formation and maintenance of social ties).

Our study demonstrated that the online delivery of the TimeSlips method to participants who remain in their own homes is both feasible and effective. With more than 2.5 million people with dementia in Latin America (most of whom remain at home post-diagnosis) and a predicted 180% increase in prevalence to 2050 (compared with a 70% increase in Europe), our pioneering study offers important precedents for future, related research, in which a direct comparison between the benefits of online versus face-to-face delivery of the method would be important next step.

Associative memory is impacted early in Alzheimer’s disease (AD). Poorer performance on associative memory tests has been related to greater amyloid and regional tau burden in preclinical AD. Our group previously examined the association of brain pathology and performance on the Free and Cued Selective Reminding Test (FCSRT) in Autosomal Dominant Alzheimer’s Disease (ADAD), finding that associative memory summary scores distinguished non-demented mutation carriers from non-carriers several years before clinical onset of cognitive impairment. In the current study, we examined whether FCSRT learning slopes were associated with brain pathology in a sample of ADAD carriers and non-carriers.

There were 119 participants including 57 non-demented carriers of the Colombian kindred with the Presenilin1 E280A mutation and 62 non-carrier family members (mean age= 36.3, 60% female). Participants were administered the Mini-Mental State Examination (MMSE), a measure of global cognitive status, and the FCSRT, which consists of three trials in which participants are asked to freely recall the same list of 16 items. It is a well-established measure known to be sensitive to early changes in AD. A subsample of 69 participants (32 carriers and 37 non-carriers) underwent positron emission tomography (PET) to measure in vivo cortical amyloid-beta (Pittsburgh compound B, PiB), and regional tau (Flortaucipir, FTP) burden in entorhinal and precuneus regions, which are among the earliest sites of tau accumulation in this ADAD population. Mann Whitney U tests, Spearman correlations, and chi-square tests were used to examine group differences and relations among variables of interest. Learning slope was calculated by subtracting the number of items freely recalled in FCSRT Trial 1 from the number of items freely recalled in Trial 3.

Compared to non-carriers, carriers had greater cortical amyloid-ß and regional tau burden, lower MMSE scores (mean [SD]: carriers= 27.5 [2.7]; non-carriers= 28.8 [1.0]), and lower scores on total immediate/ delayed free/ cued recall scores on the FCSRT (all p<.01). The groups did not differ on age, sex, or education level (all p> 0.05). In the whole sample and in carriers only, we found that higher MMSE scores were associated with higher learning slope, meaning faster learning (whole group p= 0.25, p= 0.006; carriers p= 0.30, p=0.029). In the whole sample, we found that lower learning slope was associated with higher levels of amyloid (p=-.34, p=.006) and tau in the left, right, and bilateral precuneus region (p=-.43, p<.001; p=-.46, p<.001; p=-.45, p<.001). In carriers only, lower learning slope was associated with higher tau burden in the left, right, and bilateral precuneus specifically (p=-.43, p=.017; p=-.48, p=.008; p=-.46, p=.010, respectively). No significant associations were found in non-carriers.

These findings suggest that learning curves on an associative memory test may be sensitive to preclinical pathological changes in AD, specifically within the precuneus, a brain region known to be involved in cue reactivity, episodic memory retrieval, and mental imagery strategies. Future studies with larger samples are warranted to further examine associations between the FCSRT learning curves and regional tau accumulation in individuals with ADAD.

Contextual memory, which refers to the ability to remember spatial or temporal circumstances related to an event, is affected early in Alzheimer’s Disease (AD). Computerized cognitive tasks have been suggested to be an ecological way to assess memory, but there are few studies that utilize these tools. Studying contextual memory via a computerized task in a Colombian kindred with autosomal dominant AD due to the Presenilin-1 (PSEN1) E280A mutation and a well-characterized disease progression may help us understand contextual memory changes in the preclinical AD stage. In this study we investigated whether a novel computerized task examining contextual memory can help identify those at increased risk for dementia.

A group of 31 non-carriers (mean age=38.97±6.11; mean education=11.45±4.34) and 15 cognitively unimpaired PSEN1E280A mutation carriers from the Colombia-Boston (COLBOS) Biomarker Study (mean age=35.67±5.50), mean education=10.60±3.83) performed the “MAPP Room Memory Task” on a computer. As part of this task, participants are asked to remember ten rooms and the specific location of a few objects for later recall. During the immediate recall phase, participants are asked to recognize the objects presented in each room (Immediate Object Recognition) and their location (Immediate Object Placement). During the subsequent delay phase of the task, participants are asked to select the correct room in which an object was first presented (Delayed Room Recognition) and place the objects previously seen in each room (Delayed Object Placement). We conducted Mann Whitney U tests to analyze differences between groups and Spearman Rho correlations to examine associations among the Room Memory Task performance, age, education, and Mini Mental State Examination (MMSE).

There were no differences in age or education between carriers and non-carriers (p>0.05, for both). Carriers had worse Delayed Room Recognition than non-carriers (Carriers mean score=0.893±0.18, non-carriers mean score=0.987±0.05; U=168.0, p=0.02), while there were no differences in the other task conditions (all p>0.05). In carriers, education was positively associated with Immediate Object Placement (rs=0.61, p=0.02), Delayed Object Placement (rs=0.76, p=0.001), and Delayed Room Recognition (rs=0.68, p=0.006). There were no significant associations between Room Memory Task conditions and age or MMSE scores in carriers. Further, no significant associations were observed between Room Memory Task performance, and age, education or MMSE scores in non-carriers.

Our preliminary findings show that the MAPP Room Memory Task, in particular the Delayed Room Recognition condition, may be helpful to discriminate those at increased risk of dementia. Future studies with larger samples using the Room Memory Task and AD-related biomarkers are needed to examine whether this task can be sensitive to early preclinical changes associated with AD and can potentially help track disease progression in those at risk.

High levels of stress may increase risk for Alzheimer’s disease (AD) dementia. Religious coping practices to deal with stress (i.e., prayer, having faith, attending religious services) may reduce risk of dementia. Studying religious stress coping in cognitively unimpaired individuals with autosomal-dominant AD (ADAD), who will develop dementia later in life, may inform us about the role of religious coping in modifying the clinical trajectory from preclinical to clinical stages of the disease. We examined religious stress coping in cognitively unimpaired mutation carriers from the world’s largest ADAD kindred and its relation to markers of brain pathology and memory.

16 cognitively unimpaired Presenilin-1 E280A mutation carriers and 19 age and education-matched noncarrier family members from the Colombia-Boston (COLBOS) Biomarker Study were included. A subsample (n=26; 13 cognitively unimpaired carriers) underwent amyloid and tau PET imaging. Participants completed the Coping Strategies Questionnaire (CAE) that includes a subscale used to assess religious stress coping, where a higher score indicates more coping, and underwent memory testing using the Free and Cued Selective Reminding Test (FCSRT). The Geriatric Depression Scale (GDS) was used to assess depression. Mann-Whitney U tests were used to examine group differences in religious stress coping, brain pathology (i.e., cortical amyloid-beta, entorhinal and precuneus tau), memory, and depression. Nonparametric correlations were used to examine associations among religious stress coping, age, education, depression, memory, and pathology.

Carriers had poorer FCSRT immediate free recall than noncarriers (U=84.5, p=.024). There was no difference between groups in CAE religious stress coping, other FCSRT memory scores, nor GDS score (all p>.05). Compared to non-carriers, carriers had more cortical amyloid (U=152.0, p<.001) and more precuneus tau (U=123.0, p=.05). In carriers, religious stress coping was positively associated with education (r=.57, p=.022), FCSRT immediate free recall (a=.75, p<.001), FCSRT cued recall (a=.50, p=.047), and FCSRT delayed recall (r=.52, p=.038). After controlling for education, religious stress coping remained positively associated with FCSRT immediate free recall (r=.65, p=.009), but not other FCSRT memory scores (all p>.05). Religious stress coping was not associated with age or GDS score regardless of controlling for education (all p>.05). In carriers, religious stress coping was negatively associated with entorhinal tau (r=-.73, p=.005) and precuneus tau burden (r=-.58, p=.037). The association between religious stress coping and entorhinal tau remained significant after controlling for education (r=-.67, p=.016), but not precuneus tau (p>.05). Religious stress coping was not associated with cortical amyloid regardless of controlling for education in carriers (all p>.05). None of the associations with brain pathology or memory were significant in the non-carrier group.

Religious stress coping was associated with better memory performance and a low AD pathology burden in individuals at genetic risk for developing AD dementia. Future studies with independent and larger samples should further examine religious stress coping strategies and their associations with other AD-related biomarkers, as well as with other risk and protective factors to better understand their role at the preclinical and prodromal stages of Alzheimer’s disease.

Semantic processing dysfunction has been shown to be an early indicator of cognitive decline in Alzheimer's disease (AD) and has been linked to early accumulation of AD-pathology. We examined semantic processing and its relation to AD pathology in non-demented individuals from a Colombian kindred with autosomal dominant AD due to the Presenilin1 E280A mutation (PSEN1).

A total of 13 cognitively unimpaired PSEN1 mutation carriers (mean age: 36.92± 4.94), 7 carriers with mild cognitive impairment (MCI; mean age: 45±2.65), and 17 family non-carriers (mean age: 36±6.38) from the Colombia-Boston (COLBOS) longitudinal biomarker study were included. We used the Bateria IV Woodcock-Munoz verbal analogies and text comprehension subtests to examine semantic processing, the Mini-Mental State Examination (MMSE) to assess global cognition and the CERAD word list delayed recall task to measure verbal memory. Participants also underwent PiB and flortaucipir-PET to measure mean cortical amyloid and regional tau burden (entorhinal cortex and precuneus), respectively. Mann-Whitney U tests and Spearman's Rho correlations compared group differences in semantic processing, and its associations with age and pathological markers. Post-hoc analyses excluded carriers with MCI and controlled for education.

Carriers (including cognitively unimpaired and symptomatic individuals) performed significantly worse on the MMSE (carriers: 14.55, non-carriers: 24.24; U=81.00, p=.006), CERAD word list delayed recall (carriers: 13.63, non-carriers: 25.32; U=48.00, p=.001), and text comprehension (carriers: 16.36, non-carriers: 23.81; l/=107.00, p=.042,) than non-carriers, and showed a trend towards worse performance on verbal analogies (carriers: 17.16, non-carriers: 23.68; U=124.50, p=.077). There were no differences in text comprehension or verbal analogies performance between cognitively-unimpaired carriers and non-carriers.Across the whole sample, age was negatively associated with performance on verbal analogies (r=-.341, p=.039), but not text comprehension (r=-.136, p=.428). Among carriers only, better MMSE and CERAD delayed recall performance was associated with higher verbal analogies (r=.561, p=<.001; r=.662, p=<.001, respectively) and text comprehension scores (r=.468, p=.004; r=.480, p=.003, respectively). Greater amyloid burden was associated with worse verbal analogies performance (r=-.432, p=.007) and text comprehension (r=-.430, p=.008). Greater entorhinal cortex (r=-.384, p=.016) and precuneus tau burden (r=-.318, p=.049) was associated with worse performance on verbal analogies, but not text comprehension. These associations did not survive when excluding carriers with MCI or controlling for education.

Preliminary results show that non-demented mutation carriers had worse performance in semantic processing than non-carriers and performance was associated with markers of AD pathology. These findings suggest that changes in semantic processing may be early indicators of disease progression in individuals at increased risk for Alzheimer's disease dementia. Future studies with larger samples need to examine the role of education and the longitudinal trajectory of semantic processing dysfunction in AD.

Sleep contributes to memory retention and recall. Alzheimer’s disease (AD) patients experience decreased slow wave activity (SWA) during sleep. This decrease in SWA is associated with impaired memory consolidation (Lee et al., 2020). Long-term forgetting (LTF) over days or weeks has been linked to memory consolidation deficits and has been suggested as an early marker of AD that could be useful for identifying at-risk individuals for preclinical AD trials (Weston et al., 2018). Here, we examined associations between LTF and SWA in a sample of Presenilin-1 (PSEN1) E280A mutation carriers with autosomal dominant Alzheimer’s disease and non-carrier family members. Carriers of this mutation usually develop dementia in their forties (Fuller et al., 2019).

Fourteen cognitively unimpaired PSEN1-E280A mutation carriers and sixteen age-matched non-carriers (mean age: 34.2 years) from the Colombia-Boston (COLBOS) biomarker study were included. Participants completed an overnight polysomnogram (PSG) and memory testing (NEUROPSI Word List) at 3-time points: 1) the night before PSG: immediate recall (Day1-ImmRecall) and a 20-minute delayed recall (Day1-DelayedRecall), 2) recall the following day (Day2-recall), and 3) recall one week later (Day7-recall). SWA was measured as the ratio 0. 6-1Hz/0.6-4Hz in frontopolar and frontotemporal regions and was calculated for sleep stages N2+N3 (slow wave sleep) based on an automated staging algorithm. Each participant’s LTF was calculated as the percent retention between Day 1 immediate recall and Day 7 recall (Butler, 2009). Mann-Whitney U tests were used to compare differences in recall, SWA, and LTF between groups. Spearman’s correlation was used to examine the associations between memory recall at different time points and SWA, as well as between LTF and SWA.

On Day 1, carriers had lower performance in immediate recall (p=0.02), compared to non-carriers, but there were no group differences in the 20-minute delayed recall. Carriers also recalled fewer words on Day 2 (p=0.03) and Day 7 (p=0.009) and had greater LTF (p=0.03). There were no group differences in SWA. In our overall sample, worse performance on word list delayed recall on Day 1, Day 2, and Day 7 was associated with less SWA across both frontotemporal (Day1: p=0.04, Day2: p=0.02, Day7: p=0.02) and frontopolar (all Ps<0.01) regions. In carriers, only worse performance on Day 1 delayed recall was associated with lower SWA in the frontopolar region (r= 0.535; p=0.049). Memory recall on other days was not associated with SWA in any brain regions. Additionally, greater LTF was associated with less SWA across both frontopolar (r= 0.507; p=0.005) and frontotemporal regions (r= 0.463 p= 0.01).

Preliminary findings suggest that long-term forgetting is associated with less slow- wave activity in preclinical autosomal dominant Alzheimer’s disease. These results also suggest that SWA may be related to pre-sleep learning and subsequent overnight memory consolidation processes. LTF testing may be useful in selecting individuals for preclinical AD trials. Future research on the impact of slow wave activity on LTF may be useful in identifying ways to enhance short- and long-term memory consolidation in individuals at greater risk for dementia.

Neurofilament light chain (NfL), a plasma-based biomarker for neurodegeneration, is a promising marker for early Alzheimer disease (AD) detection in individuals at increased risk. We previously reported that Presenilin1 (PSEN1) E280A carriers have increased levels of plasma NfL relative to non-carrier family members twenty years before the onset of clinical symptoms. Abstract reasoning is one of the first cognitive abilities to deteriorate in AD. Here, we examined whether levels of plasma NfL were associated with non-verbal abstract reasoning performance in non-demented PSEN1-E280A carriers and non-carriers.

A total of 798 members of the Colombian kindred with the PSEN1 E280A mutation (462 cognitively-unimpaired and 336 non-carriers; mean age= 34.02 (10.53), mean education= 8.23(4.60), 57% females and 43% males) were included in the study. Participants completed the Raven’s Progressive Matrices (RPM), Mini Mental State Examination (MMSE), and underwent blood sampling. Plasma NfL concentrations were measured with a single molecule array (Simoa) method. Mann-Whitney U test and education-adjusted Spearman partial correlation were used to examine group differences and associations between abstract reasoning performance and NfL levels.

Non-carriers were older (p<.001) and had higher levels of education than carriers (p=.025). Compared to non-carriers, carriers had higher levels of NfL (p=.014), lower performance on the MMSE (p<.001) and on the RPM (p=.001). In the whole sample, performance on the RPM was significantly associated with age (r= -.144, p<.001), and MMSE score (r=.198, p<.001). In carriers only, performance on the RPM was negatively associated with NfL levels (r=-.121, p=.009). This association was not significant in non-carriers.

Our findings support the hypothesis that plasma NfL levels may be indicators of disease progression and early cognitive dysfunction in autosomal dominant AD. Future work with NfL, abstract reasoning and memory with larger samples across the preclinical/prodromal spectrum will allow a more comprehensive examination of these associations.

Alzheimer’s disease (AD) is known to impact semantic access, which is frequently evaluated using the Category Fluency (Animals) test. Recent studies have suggested that in addition to overall category fluency scores (total number of words produced over time), poor clustering could signal AD-related cognitive difficulties. In this study, we examined the association between category fluency clustering performance (i.e., stating words sequentially that are all contained within a subcategory, such as domestic animals) and brain pathology in individuals with autosomal dominant Alzheimer’s disease (ADAD).

A total of 29 non-demented carriers of the Presenilin1 E280A ADAD mutation and 32 noncarrier family members completed the category fluency test (Animals) and the Mini-Mental State Examination (MMSE). The participants also underwent positron emission tomography (PET) scans to evaluate in vivo amyloid-beta in the neocortex and tau in medial temporal lobe regions. Differences between carriers and noncarriers on cognitive tests were assessed with Mann-Whitney tests; associations between cognitive test performance and brain pathology were assessed with Spearman correlations.

Animal fluency scores did not differ between carriers and noncarriers. Carriers, however, showed a stronger association between animal fluency clustering and in vivo AD brain pathology (neocortical amyloid and entorhinal tau) relative to noncarriers.

This study indicates that using category fluency clustering, but not total score, is related to AD pathophysiology in the preclinical and early stages of the disease.

Subjective Cognitive Decline (SCD) may be an early indicator of risk for Alzheimer’s disease (AD). Findings regarding sex differences in SCD are inconsistent. Studying sex differences in SCD within cognitively unimpaired individuals with autosomal-dominant AD (ADAD), who will develop dementia, may inform sex-related SCD variations in preclinical AD. We examined sex differences in SCD within cognitively unimpaired mutation carriers from the world’s largest ADAD kindred and sex differences in the relationship between SCD and memory performance.

We included 310 cognitively unimpaired Presenilin-1 (PSEN-1) E280A mutation carriers (51% females) and 1998 noncarrier family members (56% females) in the study. Subjects and their study partners completed SCD questionnaires and the CERAD word list delayed recall test. ANCOVAs were conducted to examine group differences in SCD, sex, and memory performance. In carriers, partial correlations were used to examine associations between SCD and memory performance covarying for education.

Females in both groups had greater self-reported and study partner-reported SCD than males (all p < 0.001). In female mutation carriers, greater self-reported (p = 0.02) and study partner-reported SCD (p < 0.001) were associated with worse verbal memory. In male mutation carriers, greater self-reported (p = 0.03), but not study partner-reported SCD (p = 0.11) was associated with worse verbal memory.

Study partner-reported SCD may be a stronger indicator of memory decline in females versus males in individuals at risk for developing dementia. Future studies with independent samples and preclinical trials should consider sex differences when recruiting based on SCD criteria.

Visual memory (ViM) declines early in Alzheimer’s disease (AD). However, it is unclear whether ViM impairment is evident in the preclinical stage and relates to markers of AD pathology. We examined the relationship between ViM performance and in vivo markers of brain pathology in individuals with autosomal dominant AD (ADAD).

Forty-five cognitively unimpaired individuals from a Colombian kindred with the Presenilin 1 (PSEN1) E280A ADAD mutation (19 carriers and 26 noncarriers) completed the Rey–Osterrieth Complex Figure immediate recall test, a measure of ViM. Cortical amyloid burden and regional tau deposition in the entorhinal cortex (EC) and inferior temporal cortex (IT) were measured using 11C-Pittsburgh compound B positron emission tomography (PET) and 11F-flortaucipir PET, respectively.

Cognitively unimpaired carriers and noncarriers did not differ on ViM performance. Compared to noncarriers, carriers had higher levels of cortical amyloid and regional tau in both the EC and IT. In cognitively unimpaired carriers, greater cortical amyloid burden, higher levels of regional tau, and greater age were associated with worse ViM performance. Only a moderate correlation between regional tau and ViM performance remained after adjusting for verbal memory scores. None of these correlations were observed in noncarriers.

Results suggest that AD pathology and greater age are associated with worse ViM performance in ADAD before the onset of clinical symptoms. Further investigation with larger samples and longitudinal follow-up is needed to examine the utility of ViM measures for identifying individuals at high risk of developing dementia later in life.

Executive dysfunction is a predominant cognitive symptom in cerebral small vessel disease (SVD). The Institute of Cognitive Neurology Frontal Screening (IFS) is a well-validated screening tool allowing the rapid assessment of multiple components of executive function in Spanish-speaking individuals. In this study, we examined performance on the IFS in subjects with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), an inherited condition leading to the early onset of SVD. We further explored associations between performance on the IFS and magnetic resonance imaging (MRI) markers of SVD.

We recruited 24 asymptomatic CADASIL subjects and 23 noncarriers from Colombia. All subjects underwent a research MRI and a neuropsychological evaluation, including the IFS. Structural MRI markers of SVD were quantified in each subject, together with an SVD Sum Score representing the overall burden of cerebrovascular alterations. General linear model, correlation, and receiver operating characteristic curve analyses were used to explore group differences on the IFS and relationships with MRI markers of SVD.

CADASIL subjects had a significantly reduced performance on the IFS Total Score. Performance on the IFS correlated with all quantified markers of SVD, except for brain atrophy and perivascular spaces enlargement. Finally, while the IFS Total Score was not able to accurately discriminate between carriers and noncarriers, it showed adequate sensitivity and specificity in detecting the presence of multiple MRI markers of SVD.

These results suggest that the IFS may be a useful screening tool to assess executive function and disease severity in the context of SVD.

This study aimed to determine Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Neuropsychological Assessment Battery total score diagnostic accuracy in the diagnosis of mild cognitive impairment (MCI) and dementia in familial Alzheimer's disease (FAD) with E280A mutation on presenilin-1 gene (PSEN1).

A cross-sectional study was conducted in a cohort of PSEN1 E280A carriers and non-carriers assessed between January 1995 and February 2013. During the first neuropsychological assessment, 76 were having dementia, 46 had MCI, and 1,576 were asymptomatic. CERAD cut-off points were established for MCI and dementia using a Receiver Operating Characteristics (ROC) analysis, and were further analyzed according to education level in two groups: low education level (eight years or less), and high education level (over eight years).

The area under curve–ROC CERAD total score for dementia was 0.994 (95% CI = 0.989–0.999), and that for MCI was 0.862 (95% CI = 0.816–0.908). The dementia diagnosis cut-off point for the low education group was 54, (98.4% sensitivity, 92.6% specificity), and that for the high education group was 67 (100% sensitivity, 94.1% specificity). The MCI diagnosis cut-off point for the low education group was 66 (91.2% sensitivity, 56.4% specificity), and that for the high education group was 72 (91.7% sensitivity, 76.3% specificity).

The CERAD total score is a useful screening tool for dementia and MCI in a population at risk of FAD.