A benchmark study on current GWAS models in admixed populations

OBJECTIVE

The performances of popular genome-wide association study (GWAS) models have not been examined yet in a consistent manner under the scenario of genetic admixture, which introduces several challenging aspects: heterogeneity of minor allele frequency (MAF), wide spectrum of case-control ratio, varying effect sizes, etc.

METHODS

We generated a cohort of synthetic individuals (N = 19 234) that simulates (i) a large sample size; (ii) two-way admixture (Native American and European ancestry) and (iii) a binary phenotype. We then benchmarked three popular GWAS tools [generalized linear mixed model associated test (GMMAT), scalable and accurate implementation of generalized mixed model (SAIGE) and Tractor] by computing inflation factors and power calculations under different MAFs, case-control ratios, sample sizes and varying ancestry proportions. We also employed a cohort of Peruvians (N = 249) to further examine the performances of the testing models on (i) real genetic and phenotype data and (ii) small sample sizes.

RESULTS

In the synthetic cohort, SAIGE performed better than GMMAT and Tractor in terms of type-I error rate, especially under severe unbalanced case-control ratio. On the contrary, power analysis identified Tractor as the best method to pinpoint ancestry-specific causal variants but showed decreased power when the effect size displayed limited heterogeneity between ancestries. In the Peruvian cohort, only Tractor identified two suggestive loci (P-value $\le 1\ast{10}^{-5}$) associated with Native American ancestry.

DISCUSSION

The current study illustrates best practice and limitations for available GWAS tools under the scenario of genetic admixture. Incorporating local ancestry in GWAS analyses boosts power, although careful consideration of complex scenarios (small sample sizes, imbalance case-control ratio, MAF heterogeneity) is needed.

Epidemiology of neurocognitive disorders in adults from urban-marginalized areas: a door-to-door population-based study in Puente Piedra, Lima, Peru

Background

In Latin America (LA), the prevalence of dementia is expected to triple to 150 million people by 2050. The 2020 Lancet Commission report identified several modifiable dementia risk factors, yet few social and environmental factors, most relevant to vulnerable regions of LA, were highlighted in this report. We sought to assess the epidemiology of neurocognitive disorders (NCD) in Puente Piedra, one of the most socially and economically vulnerable districts of Lima, the capital of Peru.

Methodology

This was a cross-sectional door-to-door observational study that used two-stage household sampling. One young adult (30-59 years) and one older adult (>60 years) per household were enrolled. We collected demographic, clinical, and neurocognitive data. Addenbrooke's Cognitive Examination (young adults) and the RUDAS-PE (older adults) were used, classifying participants as cognitively normal, possible mild NCD, or possible major NCD.

Results

We enrolled 247 participants (median age 46 years; 67% female). One-fourth had not completed secondary school and more than 50% completed only secondary school. Most participants were housewives (46%) and 21% did not have health insurance. The overall prevalence of possible NCD was 30% (25.6 and 41.8% among younger adults and older adults, respectively). Among younger adults, those ages 55-59 years more frequently had NCD (70%) compared to younger age ranges. Among older adults, only 3 subjects (4.5%) had major NCD.

Conclusion

We found a high frequency of possible NCDs in a socially and economically vulnerable community in Lima, Peru, with younger adults showing levels of NCD higher than expected. Our findings support the need for health systems to incorporate cognitive screenings programs for NCD in younger ages. Future research on NCD would include younger populations, particularly in vulnerable communities.

The Memory Alteration Test Is Correlated with Clinical, Cerebrospinal Fluid, and Brain Imaging Markers of Alzheimer Disease in Lima, Peru

INTRODUCTION

As disease-modifying therapies become available for Alzheimer's disease (AD), detection of AD in early stages of illness (mild cognitive impairment [MCI], early dementia) becomes increasingly important. Biomarkers for AD in low- and middle-income countries (LMICs) are costly and not widely available; hence, it is important to identify cognitive tests that correlate well with AD biomarker status. In this study, we evaluated the memory alteration test (M@T) to detect biomarker-proven AD and quantify its correlation with neurodegeneration and cerebrospinal fluid (CSF) AD biomarkers in a cohort of participants from Lima, Peru.

METHODS

This is a secondary analysis of a cohort of 185 participants: 63 controls, 53 with amnestic MCI (aMCI), and 69 with dementia due to AD. Participants underwent testing with M@T and a gold standard neuropsychological battery. We measured total tau (t-tau), phosphorylated tau (p-tau), and beta-amyloid (β-amyloid) in CSF, and evaluated neurodegeneration via medial temporal atrophy score in MRI. We used receiver-operator curves to determine the discriminative capacity of the total M@T score and its subdomains. We used the Pearson coefficient to correlate M@T score and CSF biomarkers.

RESULTS

The M@T had an area under the curve (AUC) of 0.994 to discriminate between controls and cognitively impaired (aMCI or AD) patients, and an AUC of 0.98 to differentiate between aMCI and AD patients. Free-recall and cued recall had the highest AUCs of all subdomains. Total score was strongly correlated with t-tau (-0.77) and p-tau (-0.72), and moderately correlated with β-amyloid (0.66). The AUC for discrimination of neurodegeneration was 0.87.

CONCLUSION

The M@T had excellent discrimination of aMCI and dementia due to AD. It was strongly correlated with CSF biomarkers and had good discrimination of neurodegeneration. In LMICs, the M@T may be a cost-effective screening tool for aMCI and dementia caused by AD.

Latin American Initiative for Lifestyle Intervention to Prevent Cognitive Decline (LatAm-FINGERS): Study design and harmonization

INTRODUCTION

Latin American Initiative for Lifestyle Intervention to Prevent Cognitive Decline (LatAm-FINGERS) is the first non-pharmacological multicenter randomized clinical trial (RCT) to prevent cognitive impairment in Latin America (LA). Our aim is to present the study design and discuss the strategies used for multicultural harmonization.

METHODS

This 1-year RCT (working on a 1-year extension) investigates the feasibility of a multi-domain lifestyle intervention in LA and the efficacy of the intervention, primarily on cognitive function. An external harmonization process was carried out to follow the FINGER model, and an internal harmonization was performed to ensure this study was feasible and comparable across the 12 participating LA countries.

RESULTS

Currently, 1549 participants have been screened, and 815 randomized. Participants are ethnically diverse (56% are Nestizo) and have high cardiovascular risk (39% have metabolic syndrome).

DISCUSSION

LatAm-FINGERS overcame a significant challenge to combine the region's diversity into a multi-domain risk reduction intervention feasible across LA while preserving the original FINGER design.

A benchmark study on current GWAS models in admixed populations

Objective

The performances of popular Genome-wide association study (GWAS) models haven't been examined yet in a consistent manner under the scenario of genetic admixture, which introduces several challenging aspects such as heterogeneity of minor allele frequency (MAF), a wide spectrum of case-control ratio, and varying effect sizes etc.

Methods

We generated a cohort of synthetic individuals (N=19,234) that simulates 1) a large sample size; 2) two-way admixture [Native American-European ancestry] and 3) a binary phenotype. We then examined the inflation factors produced by three popular GWAS tools: GMMAT, SAIGE, and Tractor. We also computed power calculations under different MAFs, case-control ratios, and varying ancestry percentages. Then, we employed a cohort of Peruvians (N=249) to further examine the performances of the testing models on 1) real genetic data and 2) small sample sizes. Finally, we validated these findings using an independent Peruvian cohort (N=109) included in 1000 Genome project (1000G).

Results

In the synthetic cohort, SAIGE performed better than GMMAT and Tractor in terms of type-I error rate, especially under severe unbalanced case-control ratio. On the contrary, power analysis identified Tractor as the best method to pinpoint ancestry-specific causal variants, but showed decreased power when no adequate heterogeneity of the true effect sizes was simulated between ancestries. The real Peruvian data showed that Tractor is severely affected by small sample sizes, and produced severely inflated statistics, which we replicated in the 1000G Peruvian cohort.

Discussion

The current study illustrates the limitations of available GWAS tools under different scenarios of genetic admixture. We urge caution when interpreting results under complex population scenarios.

Impact of Covid-19 Mandatory Lockdown Measures on Cognitive and Neuropsychiatric Symptoms in Persons With Alzheimer's Disease in Lima, Peru

BACKGROUND

Neuropsychiatric symptoms (NPS) in patients with Alzheimer's disease (AD) worsened during the COVID-19 lockdowns, but their progression thereafter is unknown. We present the first longitudinal study tracking them before, during, and after restrictions.

OBJECTIVES

To describe the effect of the COVID-19 mandatory lockdowns on Cognitive and Neuropsychiatric symptoms in patients with Mild Cognitive Impairment (MCI) and Alzheimer's Disease (AD) METHODS: Cohort of 48 patients with amnestic MCI and 38 with AD in Lima, Peru. They received three rounds of cognitive (RUDAS, CDR, M@T), behavioral (NPI), and functional (ADCS-ADL) assessments. We assessed the change in score means across the time points and for each domain of NPS and tracked the changes in individual patients.

RESULTS

RUDAS declined 0.9 (SD 1.0) from baseline to lockdown and 0.7 (SD 1.0) after restrictions. M@T declined 1.0 (SD 1.5) from baseline to lockdown and 1.4 (SD 2.0) after restrictions. CDR worsened in 72 patients (83.72%) from baseline to post-lockdown. NPI worsened by 10 (SD 8.3) from baseline to lockdown but improved by 4.8 (SD 6.4) after restrictions. Proportionally, 81.3% of all patients had worsened NPS during the lockdowns, but only 10.7% saw an increase thereafter. Improvement was statistically significant for specific NPS domains except hallucinations, delusions, and appetite changes. Anxiety, irritability, apathy, and disinhibition returned to baseline levels.

CONCLUSION

Following confinement, cognition continued to decline, but NPS demonstrated either stability or improvement. This highlights the role modifiable risk factors may have on the progression of NPS.

Combining visual rating scales to identify prodromal Alzheimer's disease and Alzheimer's disease dementia in a population from a low and middle-income country

Background

Many low- and middle-income countries, including Latin America, lack access to biomarkers for the diagnosis of prodromal Alzheimer's Disease (AD; mild cognitive impairment due to AD) and AD dementia. MRI visual rating scales may serve as an ancillary diagnostic tool for identifying prodromal AD or AD in Latin America. We investigated the ability of brain MRI visual rating scales to distinguish between cognitively healthy controls, prodromal AD and AD.

Methods

A cross-sectional study was conducted from a multidisciplinary neurology clinic in Lima, Peru using neuropsychological assessments, brain MRI and cerebrospinal fluid amyloid and tau levels. Medial temporal lobe atrophy (MTA), posterior atrophy (PA), white matter hyperintensity (WMH), and MTA+PA composite MRI scores were compared. Sensitivity, specificity, and area under the curve (AUC) were determined.

Results

Fifty-three patients with prodromal AD, 69 with AD, and 63 cognitively healthy elderly individuals were enrolled. The median age was 75 (8) and 42.7% were men. Neither sex, mean age, nor years of education were significantly different between groups. The MTA was higher in patients with AD (p < 0.0001) compared with prodromal AD and controls, and MTA scores adjusted by age range (p < 0.0001) and PA scores (p < 0.0001) were each significantly associated with AD diagnosis (p < 0.0001) but not the WMH score (p=0.426). The MTA had better performance among ages <75 years (AUC 0.90 [0.85–0.95]), while adjusted MTA+PA scores performed better among ages>75 years (AUC 0.85 [0.79–0.92]). For AD diagnosis, MTA+PA had the best performance (AUC 1.00) for all age groups.

Conclusions

Combining MTA and PA scores demonstrates greater discriminative ability to differentiate controls from prodromal AD and AD, highlighting the diagnostic value of visual rating scales in daily clinical practice, particularly in Latin America where access to advanced neuroimaging and CSF biomarkers is limited in the clinical setting.

Comparative study of the word capacity and episodic memory of patients with degenerative dementia

INTRODUCTION

Although the absence of memory impairment was considered among the diagnostic criteria to differentiate Alzheimer's disease (AD) from Behavioural Variant of Frontotemporal Dementia (bvFTD), current and growing evidence indicates that a significant percentage of cases of bvFTD present with episodic memory deficits. In order to compare the performance profile of the naming capacity and episodic memory in patients with AD and bvFTD the present study was designed.

METHODS

Cross-sectional and analytical study with control group (32 people). The study included 42 people with probable AD and 22 with probable bvFTD, all over 60 years old. Uniform Data Set instruments validated in Spanish were used: Multilingual Naming Test (MINT), Craft-21 history and Benson's complex figure, among others.

RESULTS

A higher average age was observed among the patients with AD. The naming capacity was much lower in patients with bvFTD compared to patients with AD, measured according to the MINT and the nouns/verbs naming coefficient. All patients with bvFTD, 73.81% of those with AD and only 31.25% of the control group failed to recognise Benson's complex figure. All differences were statistically significant (p < 0.001).

RESULTS

This study confirms the amnesic profile of patients with AD and reveals the decrease in naming capacity in patients with bvFTD, an area of ​​language that is typically affected early on with executive functions, according to recent findings.

CONCLUSIONS

Patients with AD perform worse in verbal and visual episodic memory tasks, while patients with bvFTD perform worse in naming tasks. These findings open the possibility of exploring the mechanisms of prefrontal participation in episodic memory, typically attributed to the hippocampus.

A Functional Assessment Tool to Distinguish Controls From Alzheimer's Disease in Lima, Peru

BACKGROUND

The Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL) scale is a versatile functional assessment tool for patients with Alzheimer's disease (ad). We evaluated its performance in controls, Peruvians with MCI or AD.

METHODS

A cross-sectional study of older adults attending a neurology institute in Lima (Peru) with mild cognitive impairment (MCI), ad or cognitively healthy. Test-retest reliability (intraclass correlation coefficient, ICC; internal consistency, Cronbach's alpha) and validity were assessed.

RESULTS

We enrolled 276 individuals (ad: 113, MCI: 68, controls: 95) with no age, sex, educational level, and depressive symptom differences. Reliability was ideal (ICC: .996), and Cronbach's alpha was adequate (.937). The ADCS-ADL could not differentiate MCI from controls but did differentiate ad severity. The ADCS-ADL correlated highly with nearly all tools.

CONCLUSIONS

The ADCS-ADL scale is reliable in a population with ad in Lima, Peru. Future work may validate a tool for Peruvians with lower educational levels.

Validation of Picture Free and Cued Selective Reminding Test for Illiteracy in Lima, Peru

Dementia in Latin America is a crucial public health problem. Identifying brief cognitive screening (BCS) tools for the primary care setting is crucial, particularly for illiterate individuals. We evaluated tool performance characteristics and validated the free and total recall sections of the Free and Cued Selective Reminding Test-Picture version (FCSRT-Picture) to discriminate between 63 patients with early Alzheimer's disease dementia (ADD), 60 amnestic mild cognitive impairment (aMCI) and 64 cognitively healthy Peruvian individuals with illiteracy from an urban area. Clinical, functional, and cognitive assessments were performed. FCSRT-Picture performance was assessed using receiver operating characteristic curve analyses. The mean ± standard deviation scores were 7.7 ± 1.0 in ADD, 11.8 ± 1.6 in aMCI, and 29.5 ± 1.8 in controls. The FCSRT-Picture had better performance characteristics for distinguishing controls from aMCI compared with several other BCS tools, but similar characteristics between controls and early ADD. The FCSRT-Picture is a reliable BCS tool for illiteracy in Peru.

Diagnostic accuracy of brief cognitive screening tools to diagnose vascular cognitive impairment in Peru

INTRODUCTION

To evaluate the diagnostic accuracy of three brief cognitive screening (BCS) tools, Peruvian version of Addenbrooke's Cognitive Examination (ACE-Pe), of INECO Frontal Screening (IFS-Pe) and of the Mini-Mental State Examination (MMSE-Pe), for the diagnosis of vascular cognitive impairment (VCI) and its non-dementia stages (VCI-ND) and vascular dementia (VD) in patients with cerebral stroke in Lima-Peru.

MATERIALS AND METHODS

A cohort analysis to evaluate the diagnostic accuracy of three BCS for VCI.

RESULTS

Two hundred and four patients were evaluated: 61% Non-VCI, 30% VCI-ND and 9% VD. To discriminate patients with VCI from controls, the area under the curve (AUC) of ACE-Pe, IFS-Pe and MMs-Pe were 0.99 (95% confidence interval [CI] 0.98-0.99), 0.99 (95%CI 0.98-0.99) and 0.87 (95%CI 0.82-0.92), respectively. Of the three BCS, the IFS-Pe presented a larger AUC to discriminate VCI-ND from VD (AUC = 0.98 [95%CI 0.95-1]) compared to ACE-Pe (AUC = 0.84 [95%CI 0.74-0.95]) and MMSE-Pe (0.92 [95%CI 0.86-0.99]). The IFS-Pe presented a higher sensitivity (S), specificity (Sp), and positive (+LR) and negative likelihood ratios (-LR) (S = 96.72%, Sp = 89.47%, +LR = 9.1 and -LR = 0.03) than ACE-Pe (S = 96.72%, Sp = 63.16%, +LR = 2.62 and -LR = 0.05) and MMSE-Pe (S = 90.16%, Sp = 78.95%, +LR = 4.28 and -LR = 0.12). In the multiple regression analysis, the IFS-Pe was not affected by age, sex or years of schooling.

CONCLUSION

The IFS-Pe has the best diagnostic accuracy for detecting VCI and discriminating between pre-dementia (VCI-ND) and dementia (VD) stages.

Behavioral and psychological symptoms of Alzheimer’s disease during the COVID‐19 pandemic in underserved settings

Background

The behavioral and psychological symptoms of dementia (BPSD) are characterized by disturbances in perceptions, thought contents, moods, and behaviors. The causes for these symptoms are connected to factors related to the people with dementia (PWD), his/her caregivers, and environmental factors as well as the interrelationship between these three. Disruptions of routine due to confinements during the COVID‐19 pandemic has led to the onset/worsening of BPSD, thereby increasing distress levels in caregivers, and risks of self‐injury, hospitalization, and death for PWD. Our aim is to describe the onset/ worsening of BPSD during COVID‐19 pandemic confinement.

Method

This is a longitudinal study in patients and caregivers of people with Alzheimer’s disease from the Instituto Peruano de Neurociencias in Lima, Perú. A structured confinement interview was delivered to caregivers exploring how the caregiver's activities have been affected or modified by the confinement measures. All patients have neuropsychological, neuropsychiatric, and functional assessments performed six months before the onset of the confinement. BPSD was assessed using the neuropsychiatric inventory questionnaire (NPI).

Result

A total of 91 patients with Alzheimer’s disease and caregivers participated in the study. The average age of the patients was 73.4 years. Most patients had a CDR score of 0.5‐1. Caregivers reported that the pandemic affected their mood by 74%. Percentage of time spent caring increased from 15% to 25% (p<0.001).

Worsening and new onset of behavioral and psychological symptoms were reported. The NPI (Fig 1.) and ADCS_ADL scores increased significantly during quarantine from baseline (6.6 and 10, respectively) (p<0.001). Delusions (75%), sleep disorder (71.7%), and hallucinations were the most frequently reported worsening symptoms. Sleep disorder (71.1%), agitation (68.6%) and depression (53.3%) were the most frequently reported new symptoms (p<0.001) (Table 1). Profile of BPSD did not vary according to the CDR score.

Conclusion

Quarantine induces increases in behavioral and psychological symptoms in patients with early stages of Alzheimer’s disease. Caregivers spent more time with the patient with AD and their emotions were affected by the pandemic. We need to plan for strategies in order to address these needs.

Thyroid Dysfunction, Vitamin B12, and Folic Acid Deficiencies Are Not Associated With Cognitive Impairment in Older Adults in Lima, Peru

Background: Reversible etiologies of cognitive impairment are common and treatable, yet the majority of mild cognitive impairment (MCI) and dementia research in Latin America has focused on irreversible, neurodegenerative etiologies. Objective: We sought to determine if thyroid dysfunction and vitamin B12 and folate deficiencies are associated with cognitive disorders among older adults with memory complaints in Lima, Peru. Methods: This was a retrospective review of patients who presented for cognitive evaluations to a multidisciplinary neurology clinic in Lima, Peru from January 2014 to February 2020. We included individuals aged ≥60 years, native Spanish-speakers, with at least a primary school educational level and a complete clinical assessment. Patients had either subjective cognitive decline (SCD), MCI, or dementia. One-way ANOVA and multiple logistic regression analyses were performed. Results: We included 720 patients (330 SCD, 154 MCI, and 236 dementia); the dementia group was significantly older [mean age SCD 69.7 ± 4.1, dementia 72.4 ± 3.7 (p = 0.000)] and had lower folate levels than SCD patients. The MCI group had higher free T3 levels compared with SCD patients. Those with lower TSH had greater dementia risk (OR = 2.91, 95%CI: 1.15-6.86) but not MCI risk in unadjusted models. B12 deficiency or borderline B12 deficiency was present in 34% of the dementia group, yet no clear correlation was seen between neuropsychological test results and B12 levels in our study. There was no association between MCI or dementia and thyroid hormone, B12 nor folate levels in adjusted models. Conclusion: Our findings do not support an association between metabolic and endocrine disorders and cognitive impairment in older Peruvians from Lima despite a high prevalence of B12 deficiency. Future work may determine if cognitive decline is associated with metabolic or endocrine changes in Latin America.

Social Cognition and Behavioral Assessments Improve the Diagnosis of Behavioral Variant of Frontotemporal Dementia in Older Peruvians With Low Educational Levels

Background: The behavioral variant of frontotemporal dementia (bvFTD), characterized by early behavioral abnormalities and late memory impairment, is a neurodegenerative disorder with a detrimental impact on patients and their caregivers. bvFTD is often difficult to distinguish from other neurodegenerative diseases, such as Alzheimer's disease (AD), using brief cognitive tests. Combining brief socio-cognitive and behavioral evaluations with standard cognitive testing could better discriminate bvFTD from AD patients. We sought to evaluate the diagnostic accuracy of brief socio-cognitive tests that may differentiate bvFTD and AD patients with low educational levels. Methods: A prospective study was performed on 51 individuals over the age of 50 with low educational levels, with bvFTD or AD diagnosed using published criteria, and who were receiving neurological care at a multidisciplinary neurology clinic in Lima, Peru, between July 2017 and December 2020. All patients had a comprehensive neurological evaluation, including a full neurocognitive battery and brief tests of cognition (Addenbrooke's Cognitive Examination version III, ACE-III), social cognition (Mini-social Cognition and Emotional Assessment, Mini-SEA), and behavioral assessments (Frontal Behavioral Inventory, FBI; Interpersonal Reactivity Index-Emphatic Concern, IRI-EC; IRI-Perspective Taking, IRI-PT; and Self-Monitoring Scale-revised version, r-SMS). Receiver operating characteristic (ROC) analysis to calculate the area under the curve (AUC) was performed to compare the brief screening tests individually and combined to the gold standard of bvFTD and AD diagnoses. Results: The AD group was significantly older than the bvFTD group (p < 0.001). An analysis of the discriminatory ability of the ACE-III to distinguish between patients with AD and bvFTD (AUC = 0.85) and the INECO Frontal Screening (IFS; AUC = 0.78) shows that the former has greater discriminatory ability. Social and behavioral cognition tasks were able to appropriately discriminate bvFTD from AD. The Mini-SEA had high sensitivity and high moderate specificity (83%) for discriminating bvFTD from AD, which increased when combined with the brief screening tests ACE-III and IFS. The FBI was ideal with high sensitivity (83%), as well as the IRI-EC and IRI-PT that also were adequate for distinguishing bvFTD from AD. Conclusions: Our study supports the integration of socio-behavioral measures to the standard global cognitive and social cognition measures utilized for screening for bvFTD in a population with low levels of education.

Performance of the Rowland Universal Dementia Assessment Scale for the Detection of Mild Cognitive Impairment and Dementia in a Diverse Cohort of Illiterate Persons From Rural Communities in Peru

Background: The accurate diagnosis of neurocognitive disorders in illiterate Peruvian populations is challenging, largely owing to scarcity of brief cognitive screening tools (BCST) validated in these diverse populations. The Peruvian version of the Rowland Universal Dementia Assessment Scale (RUDAS-PE) is a BCST that relies minimally on educational attainment and has shown good diagnostic accuracy in an urban illiterate population in Peru, yet its psychometric properties in illiterate populations in rural settings of the country have not been previously investigated. Objectives: To establish the diagnostic accuracy of the RUDAS-PE compared to expert clinical diagnosis using the Clinical Dementia Rating (CDR) Scale in healthy and cognitively impaired illiterate persons living in two culturally and geographically distinct rural communities of Peru. Methods: A cross-sectional, population-based study of residents ≥ 50 years of age living in the Peruvian rural communities of Santa Clotilde and Chuquibambilla. A total of 129 subjects (76 from Santa Clotilde and 53 from Chuquibambilla) were included in this study. Gold standard diagnostic neurocognitive evaluation was based on expert neurological history and examination and administration of the CDR. Receiver operating characteristics, areas under the curve (AUC), and logistic regression analyses were conducted to determine the performance of RUDAS-PE compared to expert gold standard diagnosis. Results: Compared to gold standard diagnosis, the RUDAS-PE was better at correctly discriminating between MCI and dementia than discriminating between MCI and controls in both sites (97.0% vs. 76.2% correct classification in Chuquibambilla; 90.0% vs. 64.7% in Santa Clotilde). In Chuquibambilla, the area under the curve (AUC) of the RUDAS to discriminate between dementia and MCI was 99.4% (optimal cutoff at <18), whereas between MCI and controls it was 82.8% (optimal cutoff at <22). In Santa Clotilde, the area under the curve (AUC) of the RUDAS to discriminate between dementia and MCI was 99.1% (optimal cutoff at <17), whereas between MCI and controls it was 75.5% (optimal cutoff at <21). Conclusions: The RUDAS-PE has acceptable psychometric properties and performed well in its ability to discriminate MCI and dementia in two cohorts of illiterate older adults from two distinct rural Peruvian communities.

Dissecting the role of Amerindian genetic ancestry and the ApoE ε4 allele on Alzheimer disease in an admixed Peruvian population

Alzheimer disease (AD) is the leading cause of dementia in the elderly and occurs in all ethnic and racial groups. The apolipoprotein E (ApoE) ε4 is the most significant genetic risk factor for late-onset AD and shows the strongest effect among East Asian populations followed by non-Hispanic white populations and has a relatively lower effect in African descent populations. Admixture analysis in the African American and Puerto Rican populations showed that the variation in ε4 risk is correlated with the genetic ancestral background local to the ApoE gene. Native American populations are substantially underrepresented in AD genetic studies. The Peruvian population with up to ~80 of Amerindian (AI) ancestry provides a unique opportunity to assess the role of AI ancestry in AD. In this study, we assess the effect of the ApoE ε4 allele on AD in the Peruvian population. A total of 79 AD cases and 128 unrelated cognitive healthy controls from Peruvian population were included in the study. Genome-wide genotyping was performed using the Illumina Global screening array v2.0. Global ancestry and local ancestry analyses were assessed. The effect of the ApoE ε4 allele on AD was tested using a logistic regression model by adjusting for age, gender, and population substructure (first 3 principal components). Results showed that the genetic ancestry surrounding the ApoE gene is predominantly AI (60.6%) and the ε4 allele is significantly associated with increased risk of AD in the Peruvian population (odds ratio = 5.02, confidence interval: 2.3-12.5, p-value = 2e-4). Our results showed that the risk for AD from ApoE ε4 in Peruvians is higher than we have observed in non-Hispanic white populations. Given the high admixture of AI ancestry in the Peruvian population, it suggests that the AI genetic ancestry local to the ApoE gene is contributing to a strong risk for AD in ε4 carriers. Our data also support the findings of an interaction between the genetic risk allele ApoE ε4 and the ancestral backgrounds located around the genomic region of ApoE gene.

Dementia in Latin America: Paving the way toward a regional action plan

Across Latin American and Caribbean countries (LACs), the fight against dementia faces pressing challenges, such as heterogeneity, diversity, political instability, and socioeconomic disparities. These can be addressed more effectively in a collaborative setting that fosters open exchange of knowledge. In this work, the Latin American and Caribbean Consortium on Dementia (LAC-CD) proposes an agenda for integration to deliver a Knowledge to Action Framework (KtAF). First, we summarize evidence-based strategies (epidemiology, genetics, biomarkers, clinical trials, nonpharmacological interventions, networking, and translational research) and align them to current global strategies to translate regional knowledge into transformative actions. Then we characterize key sources of complexity (genetic isolates, admixture in populations, environmental factors, and barriers to effective interventions), map them to the above challenges, and provide the basic mosaics of knowledge toward a KtAF. Finally, we describe strategies supporting the knowledge creation stage that underpins the translational impact of KtAF.

Neuropsychiatric Symptoms in Patients With Alzheimer's Disease During SARS-COV-2 Pandemic in Peru

To evaluate neuropsychiatric symptoms in patients with Alzheimer's disease (AD) and their association with cognition and functionality during lockdown of the COVID-19's first wave. We included 91 patients and caregivers of people with AD from a memory clinic. The RUDAS, M@T, and CDR were administered to patients and NPI/ADCS-ADL to caregivers. Baseline and lockdown measurements scales were analyzed to compare the frequencies at baseline versus lockdown and conditional Odds Ratio (ORc) was calculated for the neuropsychiatric symptoms. During the pandemic, significant increase in the number of cases was observed in depression (23%), agitation (36.8%), aberrant motor activity (12%), sleep disorders (26.3%), and appetite change (12.1%). In worsening of pre-existing symptoms, the most frequent were delusions (75%), followed by sleep disorders (71.7%). Lockdown induces a rapid increase of neuropsychiatric symptoms affecting cognitive symptoms and functionality of Peruvian patients with AD.

Comparative Study of the Word Capacity and Episodic Memory of Patients with Degenerative Dementia

INTRODUCTION

Although the absence of memory impairment was considered among the diagnostic criteria to differentiate Alzheimer's disease (AD) from Behavioural Variant of Frontotemporal Dementia (bvFTD), current and growing evidence indicates that a significant percentage of cases of bvFTD present with episodic memory deficits. In order to compare the performance profile of the naming capacity and episodic memory in patients with AD and bvFTD the present study was designed.

METHODS

Cross-sectional and analytical study with control group (32 people). The study included 42 people with probable AD and 22 with probable bvFTD, all over 60 years old. Uniform Data Set instruments validated in Spanish were used: Multilingual Naming Test (MINT), Craft-21 history and Benson's complex figure, among others.

RESULTS

A higher average age was observed among the patients with AD. The naming capacity was much lower in patients with bvFTD compared to patients with AD, measured according to the MINT and the nouns/verbs naming coefficient. All patients with bvFTD, 73.81% of those with AD and only 31.25% of the control group failed to recognise Benson's complex figure. All differences were statistically significant (p <0.001).

RESULTS

This study confirms the amnesic profile of patients with AD and reveals the decrease in naming capacity in patients with bvFTD, an area of language that is typically affected early on with executive functions, according to recent findings.

CONCLUSIONS

Patients with AD perform worse in verbal and visual episodic memory tasks, while patients with bvFTD perform worse in naming tasks. These findings open the possibility of exploring the mechanisms of prefrontal participation in episodic memory, typically attributed to the hippocampus.

Systematic Review of the Diagnostic Validity of Brief Cognitive Screenings for Early Dementia Detection in Spanish-Speaking Adults in Latin America

Objectives: The aim of this study was to evaluate the validity of brief cognitive screening (BCS) tools designed to diagnose mild cognitive impairment (MCI) or dementia in Spanish-speaking individuals over the age of 50 years from Latin America (LA).

Methods: A systematic search of titles and abstracts in Medline, Biomed Central, Embase, Scopus, Scirus, PsycINFO, LILACS, and SciELO was conducted. Inclusion criteria were papers written in English or Spanish involving samples from Spanish-speaking Latin American individuals published until 2018. Standard procedures were applied for reviewing the literature. The data related to the study sample, methodology, and procedures applied, as well as the performance obtained with the corresponding BCS, were collected and systematized.

Results: Thirteen of 211 articles met the inclusion criteria. The studies primarily involved memory clinic-based samples, with the exception of two studies from an adult day-care center, one from a primary care clinic, and one from a community-based sample. All the studies originated from five of the 20 countries of LA and all used standardized diagnostic criteria for the diagnosis of dementia and MCI; however, the diagnostic protocols applied differed. Most studies reported samples with an average of 10 years of education and only one reported a sample with an average of <5 years of education. No publication to date has included an illiterate population. Although the Montreal cognitive assessment (MoCA) is the most widely-used BCS tool in LA, it is significantly influenced by education level.

Conclusions: Although evidence is still limited, the findings from studies on LA populations suggest that MoCA requires cultural adaptations and different cutoff points according to education level. Moreover, the diagnostic validity of the INECO frontal screening (IFS) test should be evaluated in populations with a low level of education. Given the heterogeneity that exists in the levels of education in LA, more studies involving illiterate and indigenous populations are required.

Depression in women with a diagnosis of breast cancer. Prevalence of symptoms of depression in Peruvian women with early breast cancer and related sociodemographic factors

We sought to review literature on the prevalence of symptoms of depression in women with a diagnosis of breast cancer (BC) and in the Peruvian population determine the prevalence of symptoms of depression and to describe the association with sociodemographic characteristics. Descriptive cross-sectional analytical study of 254 patients from the National Cancer Institute of Peru (Instituto Nacional de Enfermedades Neoplásicas) with a diagnosis of clinical stage I or II BC. The patients included women aged between 26 and 67 years old. Symptoms of depression were monitored by the Beck Depression Inventory-II. Moreover, clinical features and patient sociodemographic characteristics were analyzed and their association with depression was assessed by logistic regression. The average age of the patients was 47.8 ± 9.2 years; 5.4% of the patients were postmenopausal at the time of the questionnaire. About 55% of women were from Lima, 58.3% had completed secondary education (11 ± 3.2 years), 45.7% were not working, and 46.5% were single. The prevalence of depression was 25.6% at the time of BC diagnosis. Of those patients with symptoms of depression, 16.9% showed symptoms of mild depression, 6.3% moderate, and 2.4% severe. A multivariable logistic regression model showed that in Peruvian women with a diagnosis of BC being married or employed significantly decreased the odds of presenting depressive symptoms (P = 0.029 and 0.017, respectively). Our main limitation was the lack of evaluation of depressive symptoms before the diagnosis, during or at the end of treatment. Another limitation was that the Beck Depression Inventory-II test could only identify depressive symptoms, but not depression as a disease. We have reviewed relevant literature on depression in women with a diagnosis of BC. The data presented suggests an association between both employment and marital status with depressive symptoms among Peruvian women with a diagnosis of BC. Pre-emptive support for women at risk could influence resilience and/or motivation for compliance with antineoplastic treatments.

Validation of the RUDAS for the Identification of Dementia in Illiterate and Low-Educated Older Adults in Lima, Peru

Objectives: To evaluate the performance of the Peruvian version of the Rowland Universal Dementia Assessment Scale (RUDAS-PE) in discriminating between controls and patients with mild cognitive impairment (MCI) and dementia in an illiterate population with low-levels of education. Methods: We compared the cognitive performance of 187 elderly subjects who were illiterate (controls n = 60; MCI n = 64; dementia n = 63). Neuropsychological measures included the RUDAS-PE, Mini-Mental State Examination (MMSE), INECO Frontal Screening (IFS), and Pfeffer Functional Activities Questionnaire (PFAQ). The results were compared to a neuropsychological evaluation (gold standard), including use of Clinical Dementia Rating (CDR) scores. Results: We found a Cronbach's alpha was 0.65; Spearman's correlation coefficient was 0.79 (p < 0.01). The area under the receiver operating characteristics curve for the RUDAS to discriminate dementia from MCI was 98.0% with an optimal cut-off <19 (sensitivity 95%, specificity 97%); whereas, to differentiate MCI and controls was 98.0% with an optimal cut-off <23 (sensitivity 89%, specificity 93%). Conclusions: Based on its excellent psychometric properties, we find the RUDAS-PE suitable to aid in the opportune detection of dementia in a geriatric illiterate population with low-levels of education.

Brief cognitive tests validated in Peru for detection of cognitive impairment A systematic mapping of the scientific literature

Brief cognitive tests (BCTs) are necessary for early detection of cognitive impairment, particularly in primary care settings.

OBJECTIVE

This report describes a systematic review of BCTs evaluated in Peruvian populations.

METHODS

We used systematic mapping techniques to identify articles on screening tests for cognitive impairment involving Peruvian subjects. We included studies published in English and Spanish up to 2018. We reviewed 6 reference databases within the Virtual Health Library network, as well as the Web of Science, Scopus (MEDLINE), and EMBASE databases.

RESULTS

Ten out of 447 articles met the inclusion criteria. Studies included both outpatient (9) and community-based (2) samples. Eligibility criteria of the studies were similar. Although different protocols were applied, the diagnostic criteria were standardized. For discrimination between dementia and controls, IFS (AUC: 0.99) and ACE (AUC: 0.95 to 1.00) showed superior performance, as did the M@T (AUC: 1.00) and CDT-Mv (AUC: 0.94 to 1.00) for discriminating between Alzheimer's disease (AD) and controls.

CONCLUSION

The available evidence is limited. However, our analysis of national data suggests that the ACE may be a good choice whenever it can be applied to Peruvian patients. Alternatively, the M@T and IFS can be used for screening patients with suspected AD or FTD, respectively.

Validation of the RUDAS in Patients With a Middle-Level Education in Lima, Peru

OBJECTIVES

To assess the psychometric properties of the Peruvian version of the Rowland Universal Dementia Assessment Scale (RUDAS-PE) to discriminate controls from patients with mild cognitive impairment (MCI) and early dementia (ED) in a population with a mid-level education.

METHODS

A total of 133 patients from a memory clinic were administered the RUDAS-PE, INECO Frontal Screening, Addenbrooke's Cognitive Examination, and Mini-Mental State Examination. Results were compared against a neuropsychological evaluation (gold standard). Validity measures, internal consistency, and concurrent validity were calculated.

RESULTS

Cronbach's α was 0.68; Pearson's ratio was 0.79 (P < .01). The area under the receiver-operating characteristics curve of the RUDAS to discriminate between ED and MCI was 89.0% (optimal cutoff at <21), whereas between MCI and controls, it was 99.0% (optimal cutoff at <24).

CONCLUSIONS

The RUDAS-PE has acceptable psychometric properties performing well in its ability to discriminate controls from patients with MCI and ED.

Deterioro cognitivo en pacientes con esclerosis múltiple

La esclerosis múltiple es una enfermedad inflamatoria, autoinmune y neurodegenerativa del sistema nervioso central caracterizada por pérdida de la función motora y sensitiva; es considerada una de las principales causas de discapacidad en el adulto joven. Recientemente, se le ha dado gran importancia al deterioro cognitivo, por ser un síntoma frecuente y discapacitante. Este deterioro está presente en un 40 a 65% de los pacientes y afecta la velocidad de procesamiento de información, atención compleja, memoria de trabajo, memoria visual y verbal, fluencia verbal y funciones ejecutivas. Se puede presentar en el síndrome radiológico aislado, en el síndrome clínico aislado y en las diferentes fases de la enfermedad; además, es el responsable de la dependencia de algunos pacientes y de las dificultades para mantener o conseguir empleo. Este déficit cognitivo se asocia a atrofia del tálamo y se ha observado una correlación con las medidas de atrofia y con el volumen lesional cerebral. Existen diferentes herramientas para su evaluación; hay pruebas de cribado breves de 5 minutos de duración, hasta baterías extensas de 90 minutos. Respecto al tratamiento de las alteraciones cognitivas, no existe un tratamiento farmacológico específico; sin embargo, se considera que los fármacos modificadores de la enfermedad podrían tener una influencia favorable en la función cognitiva por sus efectos en la reducción de la actividad inflamatoria y la atrofia cerebral. En cuanto a la estimulación cognitiva, no existen datos concluyentes por las diferentes técnicas empleadas y las distintas medidas utilizadas para evaluar los resultados de las intervenciones.

Factors associated with depression in patients with Parkinson's disease A multicenter study in Lima, Peru

The diagnosis and treatment of depression in patients with Parkinson's disease (PD) is inadequate, often contributing to a reduced quality of life, rapid disease progression, higher cognitive impairment, and an increased burden of care for family members of patients with PD.

OBJECTIVE

To determine the factors associated with depression in PD and to examine the frequency of depressive symptoms among patients with PD.

METHODS

This study was an observational, analytical, multicenter study of a cross-sectional cohort, conducted between July 2016 and May 2017. PD patients were recruited from neurology clinics in Lima, Peru. All statistical analyses were performed using descriptive statistics. Bivariate and multivariate logistic regression analyses were calculated using STATA.

RESULTS

Out of 124 patients (average age: 68.7 years; 58% males) included in the study 60.5% (75/124) presented with symptoms of depression; only 20% (25/124) received antidepressants. Factors associated with depression in PD included: unemployment, falls, freezing of gait, involuntary movements micrographia, stooped posture, hyposmia, movement disorders in sleep, rapid disease progression, and the use of MAOIs. Furthermore, statistically significant differences were found in disease duration, UPDRS and MMSE scores, Hoehn and Yahr (HY) stage, and length of time taking L-dopa between PD patients with and without depressive symptoms.

CONCLUSION

Factors associated with depressive symptoms in patients with PD were hyposmia, rapid progression of the disease, the use of L-dopa, and use of MAOIs. The frequency of depressive symptoms in patients with PD is high; early diagnosis and prompt treatment are needed to improve their quality of life and the family environment.

[Performance of cognitive brief test in elderly patients with dementia in advanced stage living in an urban community of Lima, Peru]

Objectives.

Evaluate the performance of clock drawing test- Manos versión (PDR-M) and Mini Mental State Examination -Peruvian version (MMSE) to detect dementia in a sample based on urban community of Lima, Peru.

Materials and methods.

This study is a secondary analysis database, observational, analytical and cross-sectional, the gold standard was the clinical and the neuropsychological evaluations together. Performance testing individually and in combination were evaluated.. Data were obtained from prevalence study conducted in 2008 in Cercado de Lima.

Results.

MMSE performance for evaluation of patients with dementia of any kind showed sensitivity of 64,1%, specificity of 84,1%, PPV of 24.4%, NPV of 96.7%, PLR of 4,03 and NLR of 0,43. PDR-M showed sensitivity of 89,3%, specificity of 98,1%, PPV of 79.3%, NPV of 99.1%, PLR of 47,79 and NLR of 0,11. When both tests were applied, and at least one of them was positive, they showed sensitivity 98.1%, specificity 84.1%, PPV of 33.1%, NPV of 99.8%, PLR of 6,17 and NLR of 0,02. When performing separate analysis of Alzheimer-type dementia and non- Alzheimer dementia, the values of the parameters do not differ substantially from those obtained for dementia of any kind.

Conclussions.

The combination of MMSE and PDR-M show good discriminative ability to detect moderate and severe dementia in population living in urban community in Lima.

Evolution of short cognitive test performance in stroke patients with vascular cognitive impairment and vascular dementia: Baseline evaluation and follow-up

There is limited evidence about the progression of cognitive performance during the post-stroke stage.

Mixed dementia: A review of the evidence

Mixed dementia is the coexistence of Alzheimer's disease and cerebrovascular disease (CVD) in the same demented patient. Currently, its diagnosis and treatment remains a challenge for practitioners. To provide an overview of the epidemiology, pathogenesis, natural history, diagnosis, and therapy of Mixed Vascular-Alzheimer Dementia (MVAD). The literature was reviewed for articles published between 1990-2016 by using the keywords linked to MVAD. Neuropathological studies indicate that MVAD is a very common pathological finding in the elderly with a prevalence about of 22%. The distinction between Alzheimer's dementia and vascular dementia (VD) is complex because their clinical presentation can overlap. There are international criteria for the MVAD diagnosis. The pharmacologic therapy shows modest clinical benefits that are similar among all drugs used in patients with Alzheimer's dementia and VD. The non-pharmacologic therapy includes the rigorous management of cardiovascular risk factors (especially hypertension) and the promotion of a healthy diet. The diagnosis and treatment of MVAD cannot be improved without further studies. Currently available medications provide only modest clinical benefits once a patient has developed MVAD. In subjects at risk, the antihypertensive therapy and healthy diet should be recommend for preventing or slowing the progression of MVAD.

Memory Alteration Test to Detect Amnestic Mild Cognitive Impairment and Early Alzheimer's Dementia in Population with Low Educational Level

Background/Aims: Short tests to early detection of the cognitive impairment are necessary in primary care setting, particularly in populations with low educational level. The aim of this study was to assess the performance of Memory Alteration Test (M@T) to discriminate controls, patients with amnestic Mild Cognitive Impairment (aMCI) and patients with early Alzheimer’s Dementia (AD) in a sample of individuals with low level of education.

Methods: Cross-sectional study to assess the performance of the M@T (study test), compared to the neuropsychological evaluation (gold standard test) scores in 247 elderly subjects with low education level from Lima-Peru. The cognitive evaluation included three sequential stages: (1) screening (to detect cases with cognitive impairment); (2) nosological diagnosis (to determinate specific disease); and (3) classification (to differentiate disease subtypes). The subjects with negative results for all stages were considered as cognitively normal (controls). The test performance was assessed by means of area under the receiver operating characteristic (ROC) curve. We calculated validity measures (sensitivity, specificity and correctly classified percentage), the internal consistency (Cronbach’s alpha coefficient), and concurrent validity (Pearson’s ratio coefficient between the M@T and Clinical Dementia Rating (CDR) scores).

Results: The Cronbach’s alpha coefficient was 0.79 and Pearson’s ratio coefficient was 0.79 (p < 0.01). The AUC of M@T to discriminate between early AD and aMCI was 99.60% (sensitivity = 100.00%, specificity = 97.53% and correctly classified = 98.41%) and to discriminate between aMCI and controls was 99.56% (sensitivity = 99.17%, specificity = 91.11%, and correctly classified = 96.99%).

Conclusions: The M@T is a short test with a good performance to discriminate controls, aMCI and early AD in individuals with low level of education from urban settings.

Predictive model for falling in Parkinson disease patients

Background/aims

Falls are a common complication of advancing Parkinson's disease (PD). Although numerous risk factors are known, reliable predictors of future falls are still lacking. The aim of this study was to develop a multivariate model to predict falling in PD patients.

Methods

Prospective cohort with forty-nine PD patients. The area under the receiver-operating characteristic curve (AUC) was calculated to evaluate predictive performance of the purposed multivariate model.

Results

The median of PD duration and UPDRS-III score in the cohort was 6 years and 24 points, respectively. Falls occurred in 18 PD patients (30%). Predictive factors for falling identified by univariate analysis were age, PD duration, physical activity, and scores of UPDRS motor, FOG, ACE, IFS, PFAQ and GDS (p-value < 0.001), as well as fear of falling score (p-value = 0.04). The final multivariate model (PD duration, FOG, ACE, and physical activity) showed an AUC = 0.9282 (correctly classified = 89.83%; sensitivity = 92.68%; specificity = 83.33%).

Conclusions

This study showed that our multivariate model have a high performance to predict falling in a sample of PD patients.

•

In PD patients the fall rates doubles the reported rates in community welling older people without neurological disease, ranging from 35% to 90%.

•

Falls have a negative psychosocial impact creating a spiral of increased fear of falling and reduced physical activity, and increased likelihood of nursing home admission.

•

A multivariate model (PD duration, freezing of gait, Addenbrook's Cognitive Examination, and physical activity) to predict falling in our sample of PD patients showed a high performance.

Nuevos términos clínicos, prevención y tratamiento del trastorno cognitivo vascular: revisión de literatura basada en la evidencia

El trastorno cognitivo vascular agrupa todas las instancias donde el compromiso cognitivo puede ser atribuido a enfermedad vascular cerebral, es mayor que el esperado para el envejecimiento normal y que, cuando llega a afectar las actividades de la vida diaria, se denomina demencia vascular. En esta revisión, se actualizan los términos relacionados a trastorno cognitivo vascular y se plantean estrategias de prevención y tratamiento basadas en revisionessistemáticas y meta-análisis. En la primera parte se definen diversos términos relacionados a trastorno cognitivo vascular; en la segunda, se plantea el tratamiento del trastorno cognitivo vascular/demencia vascular, que incluyeun manejo orientado a prevención primaria, controlando los factores de riesgo; un tratamiento secundario para prevenir la exacerbación o la extensión de las lesiones producidas por la injuria vascular cerebral y, finalmente,untratamiento terciario o sintomático de los problemas cognitivos y/o conductuales. Damos especial énfasis y se fundamenta la conveniencia y beneficios de los tratamientos primario y secundario.

Utilidad de la batería ejecutiva y cognición social de INECO en la evaluación de funciones ejecutivas de una serie de pacientes peruanos con demencia fronto-temporal, variante conductual

Los síntomas característicos de la demencia fronto-temporal, variante conductual reflejan disfunción del cortex prefrontal ventromedial, y no existe consenso respecto a las pruebas neuropsicológicas más sensibles y específicos para evaluarlos. Objetivos: El objetivo de este estudio fue detectar alteraciones específicas de funciones ejecutivas y de cognición social en pacientes con demencia fronto-temporal variante conductual. Material y Métodos: Evaluamos la batería ejecutiva y cognición social del Instituto de Neurología Cognitiva (INECO), la cual incluye pruebas de teoría de la mente (test de la mirada y test de metida de pata), tareas del hotel, tests de diligencias multiples-versión del hospital y el Iowa Gambling Test para toma de decisiones. Los pacientes fueron divididos en dos grupos según su desempeño en el Addenbrooke´s Cognitive Examination. Resultados: Pacientes del grupo de Addenbrooke´s Cognitive Examination Bajo mostró resultados significativamente menores, respecto a los controles en muchas de las tareas de la batería ejecutiva estándar y en la batería ejecutiva y cognición social de INECO. Pero, el grupo deAddenbrooke´s Cognitive Examination Alto no difirió de los controles en muchas de las tareas de la batería ejecutiva estándar, mientras que encontramos diferencias significativas en los pacientes con demencia fronto-temporal con Addenbrooke´s Cognitive Examination Alto y los controles en la mayoría de las tareas de la batería ejecutiva y cognición social. Conclusiones: La batería ejecutiva y cognición social de INECO es más sensible para detectar alteraciones ejecutivas y de cognición social en estadios precoces de demencia fronto-temporal, variante conductual que las tareas empleadas en la batería ejecutiva estándar.

Cost-of-illness study in a retrospective cohort of patients with dementia in Lima, Peru

Dementia is a major cause of dependency and disability among older persons, and imposes huge economic burdens. Only a few cost-of-illness studies for dementia have been carried out in middle and low-income countries.

Informal caregiver burden in middle-income countries: Results from Memory Centers in Lima - Peru

Objective

The aim of this study was to evaluate caregiver burden based on Zarit Burden Interview (ZBI) and depression in caregivers on the Beck Depression Inventory-II (BDI-II).

Methods

Literate individuals, 18 years or older, who spoke Spanish as their native language were included. Demographic characteristics: Age, sex, education, relationship to person with dementia, length of time caregiving, other sources of help for caring, impact on the household economy, family support, and perception of impaired health; and Clinical data on care-recipients: type of dementia, time since diagnosis, treatment, and Global Deterioration Scale (GDS); the ZBI and BDI-II. Descriptive and analytical statistics were employed to assess caregiver burden and predictors of higher burden in caregivers.

Results

A total of 92 informal caregivers were evaluated. Regarding care-recipients, 75% were 69 years old or over, 75% had at least one year since diagnosis, 73.9% had Alzheimer's disease, 84.8% received treatment, 75% scored 5 or over on the GDS. For caregivers, 75% were 55.5 years old or over, predominantly female (81.5%), married (83.7%), the spouse of care-recipients (60.87%), had at least 10 years of education (75.0%) and one year of caregiving (75%), reduced entertainment time (90.2%) and self-perception of impaired health (83.7%). Median score on the ZBI was 37.5 (minimum value = 3; and maximum value = 74). The coefficient of BDI was 1.38 (p-value <0.001).

Conclusion

This sample of Peruvian informal caregivers showed elevated ZBI values. Self-perception of worsened health, repercussion on the family economy and time caregiving were the main determinants of ZBI, although only BDI was a consistent predictor of ZBI.

The Memory Alteration Test Discriminates between Cognitively Healthy Status, Mild Cognitive Impairment and Alzheimer's Disease

Background/Aims

Dementia is a worldwide public health problem and there are several diagnostic tools for its assessment. The aim of this study was to evaluate the performance of the Memory Alteration Test (M@T) to discriminate between patients with early Alzheimer's disease (AD), patients with amnestic mild cognitive impairment (a-MCI), and subjects with a cognitively healthy status (CHS).

Methods

The discriminative validity was assessed in a sample of 90 patients with AD, 45 patients with a-MCI, and 180 subjects with CHS. Clinical, functional, and cognitive studies were independently performed in a blinded fashion and the gold standard diagnosis was established by consensus on the basis of these results. The test performance was assessed by means of a receiver operating characteristic curve analysis as area under the curve (AUC).

Results

M@T mean scores were 17.7 (SD = 5.7) in AD, 30.8 (SD = 2.3) in a-MCI, and 44.5 (SD = 3.1) in CHS. A cutoff score of 37 points had a sensitivity of 98.3% and a specificity of 97.8% to differentiate a-MCI from CHS (AUC = 0.999). A cutoff score of 27 points had a sensitivity of 100% and a specificity of 98.9% to differentiate mild AD from a-MCI and from CHS (AUC = 1.000).

Conclusions

The M@T had a high performance in the discrimination between early AD, a-MCI and CHS.