Search

ABSTRACT Transient global amnesia (TGA) is a rare, temporary, sudden-onset disturbance in anterograde episodic memory with unclear pathophysiology. Previous brain volumetric analysis in TGA patients showed varied results. Objective: To explore brain morphometry, hypothesizing that patients with TGA exhibit structural alterations. Methods: A case-control study was performed involving TGA subjects (n=50) and matched healthy controls (n=50). Both groups underwent a 3D-T1 weighted structural MRI on a 3T scanner, and voxel-based morphometry (VBM), region-based morphometry (RBM), and surface-based morphometry (SBM) were analyzed. Results: After performing the VBM, RBM, and SBM analyses, no consistent and statistically significant differences were found after applying multiple corrections. Conclusion: Despite previous studies showing volumetric changes in TGA patients, our results differ from this. The discrepancy could be due to sample size and timing of MRI scans. While our findings do not explain TGA pathophysiology, they support a network dysfunction as a possible mechanism and discards a structural alteration as a predisposing factor for TGA.

ABSTRACT The COVID-19 pandemic has affected the continuity of cognitive rehabilitation worldwide. However, the use of teleneuropsychology to provide cognitive rehabilitation has contributed significantly to the continuity of the treatment. Objectives: To measure the effects of cognitive telerehabilitation on cognition, neuropsychiatric symptoms, and memory strategies in a cohort of patients with mild cognitive impairment. Methods: A sample of 60 patients with mild cognitive impairment according to Petersen’s criteria was randomly divided into two groups: 30 treatment cases and 30 controls (waiting list group). Subjects were matched by age, sex, and Montreal Cognitive Assessment. The treatment group received ten cognitive telerehabilitation sessions of 45 minutes duration once a week. Pre-treatment (week 0) and post-treatment (week 10) measures were assessed for both groups. Different linear mixed models were estimated to test treatment effect (cognitive telerehabilitation vs. controls) on each outcome of interest over time (pre/post-intervention). Results: A significant group (control/treatment) x time (pre/post) interaction revealed that the treatment group at week 10 had better scores in cognitive variables: memory (RAVLT learning trials p=0.030; RAVLT delayed recall p=0.029), phonological fluency (p=0.001), activities of daily living (FAQ p=0.001), satisfaction with memory performance (MMQ satisfaction p=0.004) and use of memory strategies (MMQ strategy p=0.000), as well as, and a significant reduction of affective symptomatology: depression (GDS p=0.000), neuropsychiatric symptoms (NPI-Q p=0.045), forgetfulness (EDO-10 p=0.000), and stress (DAS stress p=0.000). Conclusions: Our study suggests that CTR is an effective intervention.

ABSTRACT. Normal aging usually brings age-related cognitive decline. However, there is a group of aged individuals who have exceptional memory performance: the superagers. Objective: Our aim was to identify the environmental factors that could influence exceptional memory performance in a cohort of Argentine individuals. Methods: Forty healthy volunteers >80 years of age were classified into two groups, superagers (SA, n=20) and normal agers (NA, n=20), according to the Northwestern SuperAging Program criteria. Participants were neuropsychologically tested and evaluated on environmental aspects: working status, education, bilingualism, cognitive reserve, physical activity, social networking, clinical comorbidities, and longevity of parents and siblings. Results: Both groups were highly educated (NA=16.3±3 years; SA 15.85±2.6; p=0.6), 11.8% of the sample was still working without differences between groups. There were no differences in cognitive reserve inventory (p=0.7), physical activity engagement (p=0.423), or social network index (p=0.73). As for longevity, 44% of the siblings lived longer than 80 years of age (p=0.432) and maternal longevity was linked to SA (NA=46.7%; SA=80%; p=0.045). Conclusions: This study is a pilot approximation to the superaging population in Argentina. Our results suggest that environmental factors related to successful aging do not differentiate superaging. SA may depend on variables yet to be identified, probably of a genetic/metabolic order.

ABSTRACT. Neurodegenerative dementias have been described based on their phenotype, in relation to selective degeneration occurring in a particular neuroanatomical system. More recently however, the term proteinopathy has been introduced to describe diseases in which one or more altered proteins can be detected. Neurodegenerative diseases can be produced by more than one abnormal protein and each proteinopathy can determine different clinical phenotypes. Specific biomarkers have now been linked to certain molecular pathologies in live patients. In 2016, a new biomarker-based classification, currently only approved for research in Alzheimer’s disease, was introduced. It is based on the evaluation three biomarkers: amyloid (A) detected on amyloid-PET or amyloid- beta 42 assay in CSF; tau (T) measured in CSF as phosphorylated tau or on tau PET imaging; and neuronal injury/neurodegeneration (N), detected by total T-tau in CSF, FDG PET hypometabolism and on MRI brain scan. Results of clinical research using the ATN biomarkers at FLENI, a Neurological Institute in Buenos Aires, Argentina have, since 2011, contributed to ongoing efforts to move away from the concept of neurodegenerative dementias and more towards one of cognitive proteinopathies. Today, clinical diagnosis in dementia can only tell us “where” abnormal tissue is found but not “what” molecular mechanisms are involved.

ABSTRACT As life expectancy increases, there is a marked increase in the elderly population eager to continue driving. A large proportion of these elderly drive safely, however, patients with mild dementia are high-risk drivers. Objective: to identify the cognitive tests that best predict driving ability in subjects with mild dementia. Methods: 28 drivers with mild dementia and 28 healthy elderly subjects underwent an extensive cognitive assessment (NACC Uniform Data Set Neuropsychological Battery), completed an adapted On Road Driving Test (ORDT) and a Driving Simulator assessment. Results: drivers with mild dementia made more mistakes on the ORDT and had slower responses in the simulator tasks. Cognitive tests correlated strongly with on road and simulator driving performance. Age, the Digit Symbol Modalities Test and Boston Naming Test scores were the variables that best predicted performance on the ORDT and were included in a logistic regression model. Conclusion: the strong correlation between driving performance and performance on specific cognitive tests supports the importance of cognitive assessment as a useful tool for deciding whether patients with mild dementia can drive safely. The algorithm including these three variables could be used as a screening tool for the detection of unsafe driving in elderly subjects with cognitive decline.

Abstract Mild cognitive impairment (MCI) was defined by Petersen et al. (1999) as progressive memory loss, a prodrome of Alzheimer's disease. MCI is a well-established entity that can be both a diagnosis in medical practice and a valid target of Alzheimer's prevention therapy. More recently MCI has expanded to include other cognitive domains with other potential causes: amnestic MCI, multiple domains MCI, and single domain non-amnestic MCI. Behavioral symptoms in MCI are associated with a higher risk of dementia, but their association with dementia risk in patients without MCI is unknown. The objective of our paper was to address the question of whether aging patients with behavioral symptoms with or without cognitive impairment represent a population at risk for dementia. Mild Behavioral Impairment (MBI) defines a late life syndrome with prominent psychiatric and related behavioral symptoms in the absence of major cognitive symptoms. MBI also appears to be a transitional state between normal aging and dementia. MBI may carry a higher risk for dementia than MCI. A subgroup of MBI patients is likely to exhibit symptoms of a frontotemporal dementia (FTD) prodrome. We proposed 4 subtypes of patients at risk for dementia: amnestic MCI (which is said to progress preferentially to Alzheimer's disease), multiple domain MCI (which may represent normal aging or may progress to vascular cognitive impairment or a neurodegenerative disorder), single domain non-amnestic MCI, and MBI (which may progress to frontotemporal dementia, Lewy Body dementia or Alzheimer's disease). We concluded that MBI is a counterpart of MCI as a transitional state between normal aging and dementia. These findings have implications for early detection, prevention, and treatment of patients with late-life dementia.

Epidemiological data on dementia and cognitive impairment are scarce in South America. In Argentina, no dementia/cognitive impairment population-based epidemiological studies are available. The Ceibo Study is a population-based epidemiological study of dementia and cognitive impairment in individuals over 60 to be conducted. The present paper reports the results of the pilot phase (survey of cognitive impairment) conducted in Cañuelas (province of Buenos Aires). METHODS: In a door-to-door survey, trained high school students evaluated 1453 individuals aged 60 years and over in one day using a demographic data and risk factors questionnaire, the Mini-Mental State Examination (MMSE) and the 15-item Geriatric Depression Scale (GDS). RESULTS: Mean age of the individuals was 70.9 (±7.5) years, 61.4% were women, mean schooling was 5.5 (±3.5) years. Mean MMSE score was 24.5 (±4.7) and mean GDS 3.1 (±2.7). Risk factors of higher prevalence in the population under study were: hypertension (40.6%), smoking (35.1%), alcohol consumption (32.8%), high cholesterol (16.1%), diabetes (12.5%), cranial trauma with loss of consciousness (12.5%), 7 points or more on the GDS (11.7%). Prevalence of cognitive impairment for the whole sample was 23%, and 16.9% in subjects aged 60-69, 23.3% in 70-79 and 42.5% in subjects aged 80 or over . A significant correlation of cognitive impairment with age, functional illiteracy, cranial trauma, high blood pressure, inactivity and depression was found. CONCLUSION: In this pilot study, the prevalence of cognitive impairment was comparable with previous international studies.

Abstract In this paper, we investigated two subjects with superior memory, or hyper memory: Solomon Shereshevsky, who was followed clinically for years by A. R. Luria, and Funes the Memorious, a fictional character created by J. L. Borges. The subjects possessed hyper memory, synaesthesia and symptoms of what we now call autistic spectrum disorder (ASD). We will discuss interactions of these characteristics and their possible role in hyper memory. Our study suggests that the hyper memory in our synaesthetes may have been due to their ASD-savant syndrome characteristics. However, this talent was markedly diminished by their severe deficit in categorization, abstraction and metaphorical functions. As investigated by previous studies, we suggest that there is altered connectivity between the medial temporal lobe and its connections to the prefrontal cingulate and amygdala, either due to lack of specific neurons or to a more general neuronal dysfunction.

Population aging has taken place intensively worldwide, even in developing countries. These countries have population groups with low resources and basic unmet needs that are frequently omitted from epidemiological studies. OBJECTIVE: The purpose of this study was to determine the prevalence of cognitive impairment (CI) and dementia in an economic and socially vulnerable population from Argentina. METHODS: A door-to-door observational population-based survey among adults over 60 years of cognitive impairment and dementia in the social vulnerable area of the Matanza Riachuelo Basin, in the suburban area of Buenos Aires, Argentina was conducted. Trained psychologists interviewed subjects and a proxy informant. A standardized protocol including a socio-demographic questionnaire, the Mini-Mental State Examination, the Geriatric Depression Scale and a functional inventory for IADL and ADL was administered. Diagnoses were divided into three general categories: normal cognitive function, cognitive impairment-no dementia (CIND) and dementia. RESULTS AND CONCLUSIONS: A total of 2437 elderly persons were assessed, of which 73.6% fulfilled inclusion criteria. The prevalence of CI among those over 60 was 26.4% (18.1% CIND and 8.3% dementia) with higher prevalence of dementia in younger individuals than rates reported in developed counties, probably due to low control of vascular risk factors. This information can help inform health public decisions in the generation of programs and plans for the prevention, diagnosis and treatment of cognitive impairment in this type of socially vulnerable population.

Abstract The recently developed Phototest is a simple, easy and very brief test for detecting cognitive impairment or dementia. Objective: To evaluate the diagnostic accuracy of the Phototest for detecting cognitive impairment or dementia. Methods: We used a manually created database to search for studies evaluating the Phototest diagnostic yield and performed an initial meta-analysis to determine sensitivity (Sn) and specificity (Sp) of diagnostic parameters. We also performed a second meta-analysis of individual participant data. Results: In total, 6 studies were included in the meta-analysis. For dementia, Sn was 0.85 (95% CI, 0.82-0.88) and Sp 0.87 (95% CI, 0.85-0.99); for cognitive impairment, Sn was 0.80 (95% CI, 0.77-0.92) and Sp 0.88 (95% CI, 0.86-0.90). In the individual data meta-analysis, 1565 subjects were included, where best cut-off points for dementia and for cognitive impairment were 26/27 (Sn=0.89 (95% CI 0.85-0.91), Sp=0.84 (95% CI, 0.82-0.91)) and 28/29 (Sn=0.79 (95% CI, 0.76-0.81), Sp=0.88 (95% CI, 0.86-0.90)), respectively. Conclusion: Phototest has good diagnostic accuracy for dementia and cognitive impairment. It is brief, simple and can be used in illiterate persons. This makes it suitable for use in primary care settings and/or in subjects with low educational level.

Abstract Cognitive reserve is the ability to optimize performance through differential recruitment of brain networks, which may reflect the use of alternative cognitive strategies. Objectives: To identify factors related to cognitive reserve associated with progression from mild cognitive impairment (MCI) to degenerative dementia. Methods: A cohort of 239 subjects with MCI (age: 72.2±8.1 years, 58% women, education: 12 years) was assessed and followed for five years (2001 to 2006). Results: In the first year, 13.7% of MCI converted to dementia and 34.7% converted within three years (78.3% converted to Alzheimer's dementia). Risk factors for those who converted were education less than 12 years, MMSE score less than 27, Boston naming test score less than 51, IQ (Intelligence Quotient) less than 111, age over 75 years, lack of occupation at retirement, and presence of intrusions in memory recall (all account for 56% of the variability of conversion). Conclusions: MCI patients are a population at high risk for dementia. The study of risk factors (e.g. IQ, education and occupation), particularly those related to cognitive reserve, can contribute important evidence to guide the decision-making process in routine clinical activity and public health policy.

ABSTRACT Background: "Forgetfulness" is frequent in normal aging and characteristic of the early stages of dementia syndromes. The episodic memory test is central for detecting amnestic mild cognitive impairment (MCI). The Memory Binding Test (MBT) is a simple, easy and brief memory test to detect the early stage of episodic memory impairment. Objective: To validate the Argentine version of the MBT in a Latin American population and to estimate the diagnostic accuracy as a tool for early detection of MCI. Methods: 88 subjects (46 healthy controls and 42 patients with amnestic MCI) matched for age and educational level were evaluated by an extensive neuropsychological battery and the memory binding test. Results: A significantly better performance was detected in the control group; all MBT scales were predictive of MCI diagnosis (p

Abstract Mild cognitive impairment (MCI) is the transitional stage between normal aging and Alzheimer's disease (AD). Impairments in semantic memory have been demonstrated to be a critical factor in early AD. The Boston Naming Test (BNT) is a straightforward method of examining semantic or visuo-perceptual processing and therefore represents a potential diagnostic tool. The objective of this study was to examine naming ability and identify error types in patients with amnestic mild cognitive impairment (aMCI). Methods: Twenty aMCI patients, twenty AD patients and twenty-one normal controls, matched by age, sex and education level were evaluated. As part of a further neuropsychological evaluation, all subjects performed the BNT. A comprehensive classification of error types was devised in order to compare performance and ascertain semantic or perceptual origin of errors. Results: AD patients obtained significantly lower total scores on the BNT than aMCI patients and controls. aMCI patients did not obtain significant differences in total scores, but showed significantly higher semantic errors compared to controls. Conclusion: This study reveals that semantic processing is impaired during confrontation naming in aMCI.

Abstract Alzheimer's disease (AD) patients suffer progressive cognitive, behavioral and functional impairment which result in a heavy burden to patients, families, and the public-health system. AD entails both direct and indirect costs. Indirect costs (such as loss or reduction of income by the patient or family members) are the most important costs in early and community-dwelling AD patients. Direct costs (such as medical treatment or social services) increase when the disorder progresses, and the patient is institutionalized or a formal caregiver is required. Drug therapies represent an increase in direct cost but can reduce some other direct or indirect costs involved. Several studies have projected overall savings to society when using drug therapies and all relevant cost are considered, where results depend on specific patient and care setting characteristics. Dementia should be the focus of analysis when public health policies are being devised. South American countries should strengthen their policy and planning capabilities by gathering more local evidence about the burden of AD and how it can be shaped by treatment options.