Normative data stratified by age and education for a Spanish neuropsychological test battery: Results from the Colombian Alzheimer's prevention initiative registry

Is language translation enough in cross-cultural neuropsychological assessments of patients from Latin America?

OBJECTIVE

The purpose of this review was to highlight the need to consider factors other than language when adapting tests across cultural groups and to offer a list of tests that have been adapted for use among patients from or descended from Latin American Countries. Despite efforts in the field through publications and workshops, the authors were aware of continued errors in cross-cultural assessment of these patients, resulting in misdiagnosis and unintentional inequitable care. Thus, we sought to reinforce the existing literature.

METHOD

We reviewed the literature pertaining to cross-cultural adaptation of neuropsychological measures. Relevant papers were identified by our institution's Academic Enhanced Search Option (AcESO) Database, PubMed, and Google Scholar.

RESULTS

102 papers, articles, and other published literature were reviewed describing issues related to the adaptation of tests for groups originally from or descended from Latin American Countries residing in the United States.

CONCLUSIONS

It is imperative that tests be appropriately developed or adapted for the target population with appropriate normative data available, and ideally administered by a fluent speaker trained in assessment. Inappropriate use of tests not adapted for a particular patient's language and country of origin can result in misdiagnosis, potentially resulting in harm to the individual.

APOE3 Christchurch Heterozygosity and Autosomal Dominant Alzheimer's Disease

BACKGROUND

Variants in APOE and PSEN1 (encoding apolipoprotein E and presenilin 1, respectively) alter the risk of Alzheimer's disease. We previously reported a delay of cognitive impairment in a person with autosomal dominant Alzheimer's disease caused by the PSEN1 E280A variant who also had two copies of the apolipoprotein E3 Christchurch variant (APOE3 Ch). Heterozygosity for the APOE3 Ch variant may influence the age at which the onset of cognitive impairment occurs. We assessed this hypothesis in a population in which the PSEN1 E280A variant is prevalent.

METHODS

We analyzed data from 27 participants with one copy of the APOE3 Ch variant among 1077 carriers of the PSEN1 E280A variant in a kindred from Antioquia, Colombia, to estimate the age at the onset of cognitive impairment and dementia in this group as compared with persons without the APOE3 Ch variant. Two participants underwent brain imaging, and autopsy was performed in four participants.

RESULTS

Among carriers of PSEN1 E280A who were heterozygous for the APOE3 Ch variant, the median age at the onset of cognitive impairment was 52 years (95% confidence interval [CI], 51 to 58), in contrast to a matched group of PSEN1 E280A carriers without the APOE3 Ch variant, among whom the median age at the onset was 47 years (95% CI, 47 to 49). In two participants with the APOE3 Ch and PSEN1 E280A variants who underwent brain imaging, 18F-fluorodeoxyglucose positron-emission tomographic (PET) imaging showed relatively preserved metabolic activity in areas typically involved in Alzheimer's disease. In one of these participants, who underwent 18F-flortaucipir PET imaging, tau findings were limited as compared with persons with PSEN1 E280A in whom cognitive impairment occurred at the typical age in this kindred. Four studies of autopsy material obtained from persons with the APOE3 Ch and PSEN1 E280A variants showed fewer vascular amyloid pathologic features than were seen in material obtained from persons who had the PSEN1 E280A variant but not the APOE3 Ch variant.

CONCLUSIONS

Clinical data supported a delayed onset of cognitive impairment in persons who were heterozygous for the APOE3 Ch variant in a kindred with a high prevalence of autosomal dominant Alzheimer's disease. (Funded by Good Ventures and others.).

Prevalence of Mild Cognitive Impairment in Southern Regions of Colombia

Background

Recent reports suggest that by 2050 there will be an increase of around 310% of cases affected by dementia in Latin American countries. A previous study in a Southern region reported one of the highest prevalences of dementia in Latin America.

Objective

To investigate the prevalence of mild cognitive impairment associated with low education, rurality, and demographic characteristics.

Methods

A cross-sectional study recruited a community-dwelling sample of 823 adults from rural and urban areas of two Southern provinces of Colombia from 2020-2022. Participants were assessed with a neuropsychological protocol validated in Colombia. To obtain general and region-specific prevalence rates, age, sex, schooling, and socioeconomic level were considered and controlled for.

Results

Most of the participants reported low education and socioeconomic level, the participation of women was higher. It was determined that the prevalence of mild cognitive impairment (MCI) was 53.6%, with 56.6% in the province of Caquetá followed by 51.9% in the province of Huila. The amnestic MCI represented 42.6%, the amnestic multi-domain was 39%, the non-amnestic 16.55%, and the non-amnestic multi-domain 1.81%. Our participants reported comorbidities such as diabetes and hypertension. We also observed a relationship between exposure to pesticides and MCI.

Conclusions

We observed one of the highest prevalences of MCI in Latin America reported to date. Variables such as age, gender, and education proved risk factors for MCI in the explored regions. Our findings are very much in line with recent studies that highlight the influence of non-canonical risk factors of dementia in underrepresented countries from Latin America.

Linear and Nonlinear Effect of Years of Schooling, Sex, and Age on the CERAD-MX and Complementary Tasks in a Mexican Sample: A Cross-Sectional Study

OBJECTIVE

Since evidence of adults' cognition decline is based on standardized testing, we developed regression-based continuous norms by linear regression (LR) and nonlinear quantile regression (NQR) with years of schooling (YoS), age, and sex as covariates on the Mexican adaptation of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD-MX) and complementary tasks.

METHODS

392 healthy, Spanish-speaking Mexican adults (50.25% women) aged 18-59 completed the 15 CERAD-MX cognitive tasks and complementary tasks. We used raw scores and examined YoS-related effects considering sex and age as covariates. For the NQR, we used calibrated scores for sex and age. While LR represents one line across the performance, NQR differentiated several nonlinear performance bands by quantiles.

RESULTS

LR showed positive relationships between YoS and cognitive performance with a funnel variance pattern. Therefore, this relationship is better represented with NQR than LR. A small, but significant, negative effect of age was found for this age range (18-59 years). The band with fewer years of schooling (1-6) showed greater variability in the cognitive measures than those with more years of schooling (16-22).

CONCLUSION

This study shows that NQR is useful for accurately positioning participants' performance relative to their peers. NQR accounts more than LR for the inconsistent variability of cognitive performance as a function of YoS by identifying the variability according to YoS (low, medium, high). Thus, NQR represents an appropriate way to construct norms for the cognitive performance of adults.

Plasma p-tau217 predicts in vivo brain pathology and cognition in autosomal dominant Alzheimer's disease

INTRODUCTION

Plasma-measured tau phosphorylated at threonine 217 (p-tau217) is a potential non-invasive biomarker of Alzheimer's disease (AD). We investigated whether plasma p-tau217 predicts subsequent cognition and positron emission tomography (PET) markers of pathology in autosomal dominant AD.

METHODS

We analyzed baseline levels of plasma p-tau217 and its associations with amyloid PET, tau PET, and word list delayed recall measured 7.61 years later in non-demented age- and education-matched presenilin-1 E280A carriers (n = 24) and non-carrier (n = 20) family members.

RESULTS

Carriers had higher plasma p-tau217 levels than non-carriers. Baseline plasma p-tau217 was associated with subsequent amyloid and tau PET pathology levels and cognitive function.

DISCUSSION

Our findings suggest that plasma p-tau217 predicts subsequent brain pathological burden and memory performance in presenilin-1 E280A carriers. These results provide support for plasma p-tau217 as a minimally invasive diagnostic and prognostic biomarker for AD, with potential utility in clinical practice and trials.

HIGHLIGHTS

Non-demented presenilin-1 E280A carriers have higher plasma tau phosphorylated at threonine 217 (p-tau217) than do age-matched non-carriers. Higher baseline p-tau217 is associated with greater future amyloid positron emission tomography (PET) pathology burden. Higher baseline p-tau217 is associated with greater future tau PET pathology burden. Higher baseline p-tau217 is associated with worse future memory performance.

Validation of the Norma Latina Neuropsychological Assessment Battery in Patients with Alzheimer's Disease in Mexico

To our knowledge, this is the first study reported in the literature that has validated the Norma Latina Battery in a population of people with Alzheimer's disease (AD) in Mexico. The objective of the study was to determine the discriminant validity of the Norma Latina Battery in a group of Mexican individuals with AD and a group of heathy controls (HC). The Norma Latina Battery was administered to 234 Mexican participants (117 HC and 117 individuals with AD). Results show that: (1) the Norma Latina Battery has high discriminative capacity between groups in all domains; (2) participants with AD presented worse scores in each of the cognitive domains compared to the HC and a greater number of low scores in each of the established thresholds or cut-off points; and finally, (3) the Norma Latina Battery had optimal sensitivity and specificity, especially when a set was observed ≥5 scores below the 10th percentile or ≥4 scores below the 5th percentile. In conclusion, it is recommended that both clinicians and researchers use this battery in the evaluation of Mexican people with AD to better understand the prognosis of the disease and its subsequent treatment.

A cultural approach to dementia - insights from US Latino and other minoritized groups

Alzheimer disease and related dementias present considerable challenges to health-care and medical systems worldwide. In the USA, older Black and Latino individuals are more likely than older white individuals to have Alzheimer disease and related dementias. In this Perspective, we leverage our experience and expertise with older US Latino groups to review and discuss the need to integrate cultural factors into dementia research and care. We examine the importance of considering the effects of cultural factors on clinical presentation and diagnosis, dementia risk, clinical research and recruitment, and caregiving practices, with a focus on minoritized groups in the USA. We highlight critical gaps in the literature to stimulate future research aimed at improving the prevention and early detection of Alzheimer disease and related dementias and developing novel treatments and interventions across ethnoracially diverse populations. In addition, we briefly discuss some of our own initiatives to promote research and clinical care among Latino populations living in the USA.

Automatic Classification of Subjects of the PSEN1-E280A Family at Risk of Developing Alzheimer’s Disease Using Machine Learning and Resting State Electroencephalography

Background: The study of genetic variant carriers provides an opportunity to identify neurophysiological changes in preclinical stages. Electroencephalography (EEG) is a low-cost and minimally invasive technique which, together with machine learning, provide the possibility to construct systems that classify subjects that might develop Alzheimer’s disease (AD). Objective: The aim of this paper is to evaluate the capacity of the machine learning techniques to classify healthy Non-Carriers (NonCr) from Asymptomatic Carriers (ACr) of PSEN1-E280A variant for autosomal dominant Alzheimer’s disease (ADAD), using spectral features from EEG channels and brain-related independent components (ICs) obtained using independent component analysis (ICA). Methods: EEG was recorded in 27 ACr and 33 NonCr. Statistical significance analysis was applied to spectral information from channels and group ICA (gICA), standardized low-resolution tomography (sLORETA) analysis was applied over the IC as well. Strategies for feature selection and classification like Chi-square, mutual informationm and support vector machines (SVM) were evaluated over the dataset. Results: A test accuracy up to 83% was obtained by implementing a SVM with spectral features derived from gICA. The main findings are related to theta and beta rhythms, generated in the parietal and occipital regions, like the precuneus and superior parietal lobule. Conclusion: Promising models for classification of preclinical AD due to PSEN-1-E280A variant can be trained using spectral features, and the importance of the beta band and precuneus region is highlighted in asymptomatic stages, opening up the possibility of its use as a screening methodology.

Muscular Function as an Alternative to Identify Cognitive Impairment: A Secondary Analysis From SABE Colombia

BACKGROUND

Identification of cognitive impairment is based traditionally on the neuropsychological tests and biomarkers that are not available widely. This study aimed to establish the association between motor function (gait speed and handgrip strength) and cognitive performance in the Mini-Mental State Examination, globally and by domains. A secondary goal was calculating a cut-off point for gait speed and handgrip strength to classify older adults as cognitively impaired.

METHODS

This is a secondary analysis of SABE Colombia (Salud, Bienestar & Envejecimiento), a survey that was conducted in 2015 on health, wellbeing, and aging in Colombia. This study used linear regression models to search for an association between motor function and cognitive performance. The accuracy of motor function measurements in identifying cognitive impairment was assessed with receiver operating characteristic (ROC) curves. This study also analyzed other clinical and sociodemographical variables.

RESULTS

Gait speed was associated with orientation (r 2 = 0.16), language (r 2 = 0.15), recall memory (r 2 = 0.14), and counting (r 2 = 0.08). Similarly, handgrip strength was associated with orientation (r 2 = 0.175), language (r 2 = 0.164), recall memory (r 2 = 0.137), and counting (r 2 = 0.08). To differentiate older adults with and without cognitive impairment, a gait speed cut-off point of 0.59 m/s had an area under the curve (AUC) of 0.629 (0.613-0.646), and a weak handgrip (strength below 17.5 kg) had an AUC of 0.653 (0.645-0.661). The cut-off points for handgrip strength and gait speed were significantly higher in male participants.

CONCLUSIONS

Gait speed and handgrip strength are similarly associated with the cognitive performance, exhibiting the most extensive association with orientation and language domains of the Mini-Mental State Examination. Gait speed and handgrip strength can easily be measured by any clinician, and they prove to be useful screening tools to detect cognitive impairment.

Quality of life in early-onset Alzheimer's disease due to a PSEN1-E280A mutation

PURPOSE

The present study aims to explore the association between the quality of life (QoL) score and the clinical and sociodemographic variables in patients with the PSEN1-E280A mutation. We also seek to evaluate the differences between the QoL reported by the patients (P-QoL) and the scores reported by the caregivers (C-QoL).

METHODS

An analysis of 75 patients with the PSEN1-E280A mutation with mild cognitive impairment and dementia was performed. We used the Quality of Life in Alzheimer Disease (QoL-AD) survey to evaluate QoL as an outcome and evaluated its association with sociodemographic, lifestyle, clinical, and past medical history variables.

RESULTS

The largest difference in the median of the QoL-AD score was in those who needed help to eat, those with moderate or severe dementia, those classified as frail or pre-frail, those with moderate social risk, and those with depression. Also, C-QoL was lower than the P-QoL, and the QoL-AD of individuals with severe dementia was lower than for milder forms of the disease. Not needing help to eat, not having a stressful situation in the past 3 months, and the years of education were positively correlated with QoL-AD in the linear model.

CONCLUSION

As studies in similar populations with AD, factors with more impact on QoL are those related to loss of functionality and independence. These factors are also associated with variables related to the current literature with the burden of the disease for the caregivers.

Regression-Based Normative Data for Independent and Cognitively Active Spanish Older Adults: Digit Span, Letters and Numbers, Trail Making Test and Symbol Digit Modalities Test

In this work, we developed normative data for the neuropsychological assessment of independent and cognitively active Spanish older adults over 55 years of age.

METHOD

Regression-based normative data were calculated from a sample of 103 non-depressed independent community-dwelling adults aged 55 or older (67% women). Raw data for Digit Span (DS), Letters and Numbers (LN), the Trail Making Test (TMT), and the Symbol Digit Modalities Test (SDMT) were regressed on age, sex, and education. The model predicting TMT-B scores also included TMT-A scores. Z-scores for the discrepancy between observed and predicted scores were used to identify low scores. The base rate of low scores for SABIEX normative data was compared to the base rate of low scores using published normative data obtained from the general population.

RESULTS

The effects of age, sex, and education varied across neuropsychological measures. Although the proportion of low scores was similar between normative datasets, there was no agreement in the identification of cognitively impaired individuals.

CONCLUSIONS

Normative data obtained from the general population might not be sensitive to identify low scores in cognitively active older adults, incorrectly classifying them as cognitively normal compared to the less-active population. We provide a friendly calculator for use in neuropsychological assessment in cognitively active Spanish people aged 55 or older.

Neuroticism Is Associated with Tau Pathology in Cognitively Unimpaired Individuals with Autosomal Dominant Alzheimer's Disease

BACKGROUND

Greater neuroticism has been associated with higher risk for Alzheimer's disease (AD) dementia. However, the directionality of this association is unclear. We examined whether personality traits differ between cognitively-unimpaired carriers of autosomal-dominant AD (ADAD) and non-carriers, and are associated with in vivo AD pathology.

OBJECTIVE

To determine whether personality traits differ between cognitively unimpaired ADAD mutation carriers and non-carriers, and whether the traits are related to age and AD biomarkers.

METHODS

A total of 33 cognitively-unimpaired Presenilin-1 E280A mutation carriers and 41 non-carriers (ages 27-46) completed neuropsychological testing and the NEO Five-Factor Personality Inventory. A subsample (n = 46; 20 carriers) also underwent tau and amyloid PET imaging.

RESULTS

Carriers reported higher neuroticism relative to non-carriers, although this difference was not significant after controlling for sex. Neuroticism was positively correlated with entorhinal tau levels only in carriers, but not with amyloid levels.

CONCLUSION

The finding of higher neuroticism in carriers and the association of this trait with tau pathology in preclinical stages of AD highlights the importance of including personality measures in the evaluation of individuals at increased risk for cognitive impairment and dementia. Further research is needed to characterize the mechanisms of these relationships.

Nutritional Assessment in Patients with Early-Onset Autosomal Dominant Alzheimer's Disease Due to PSEN1- E280A Genetic Variant: A Cross-Sectional Study

Background

Weight loss and malnutrition are frequent findings in late-onset and sporadic presentations of Alzheimer's Disease (AD). However, less is known about nutritional status in Early-Onset Autosomal Dominant AD (EO-ADAD).

Objective

To analyze the association between nutritional status and other clinical and sociodemographic characteristics in individuals with a genetic form of EO-ADAD.

Design settings and participants

Cross-sectional study with 75 non-institutionalized participants from a cohort of Autosomal Dominant AD (13 with mild cognitive impairment and 61 with dementia, ages from 38 to 67 years) underwent a structured clinical assessment with emphasis on nutritional status.

Measurements

Primary outcome was nutritional status and it was measured using the Mini Nutritional Assessment (MNA). Patients were categorized according to MNA total score, as undernourished (MNA ≤23.5) and well-nourished (MNA ≥ 24). Sociodemographic and clinical variables identified as potential predictors or confounders of nutritional status were also collected.

Results

Undernourishment by MNA was present in 57.3% of the sample. Forty-two percent of participants had abnormal BMI values considered lower than 18.5 or higher than 24.9 kg/m2. Total BMI values were similar in well and undernourished patients (median 24.2 IQR 3.59 and median 23.9 IQR 4.42, respectively, p=0.476). When comparing well and undernourished groups, we found statistically significant differences for variables: severity of dementia (p=0.034), frailty (p=0.001), multimorbidity (p=0.035) and, polymedication (p=0.045). Neither adjusted logistic regression nor the Poisson regression showed that any clinical or sociodemographic variables explained undernourishment.

Conclusions

Undernourishment was a frequent finding in our sample of EO-ADAD, especially in later stages of the disease. Patients with polymedication, multimorbidity, frailty and severe dementia show differences in their nutritional status with a tendency to be more frequently undernourished. Further studies with larger sample sizes are needed to establish this association.

Association Between Visual Memory and In Vivo Amyloid and Tau Pathology in Preclinical Autosomal Dominant Alzheimer's Disease

OBJECTIVE

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).

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.