Can visuospatial measures improve the diagnosis of Alzheimer's disease?

Alterations of resting-state network dynamics in Alzheimer's disease based on leading eigenvector dynamics analysis

Alzheimer's disease (AD) is a neurodegenerative disease, and mild cognitive impairment (MCI) is considered a transitional stage between healthy aging and dementia. Early detection of MCI can help slow down the progression of AD. At present, there are few studies exploring the characteristics of abnormal dynamic brain activity in AD. This article uses a method called leading eigenvector dynamics analysis (LEiDA) to study resting-state functional magnetic resonance imaging (rs-fMRI) data of AD, MCI, and cognitively normal (CN) participants. By identifying repetitive states of phase coherence, intergroup differences in brain dynamic activity indicators are examined, and the neurobehavioral scales were used to assess the relationship between abnormal dynamic activities and cognitive function. The results showed that in the indicators of occurrence probability and lifetime, the globally synchronized state of the patient group decreased. The activity state of the limbic regions significantly detected the difference between AD and the other two groups. Compared to CN, AD and MCI have varying degrees of increase in default and visual region activity states. In addition, in the analysis related to the cognitive scales, it was found that individuals with poorer cognitive abilities were less active in the globally synchronized state and more active in limbic region activity state and visual region activity state. Taken together, these findings reveal abnormal dynamic activity of resting-state networks in patients with AD and MCI, provide new insights into the dynamic analysis of brain networks, and contribute to a deeper understanding of abnormal spatial dynamic patterns in AD patients.NEW & NOTEWORTHY Alzheimer's disease (AD) is a neurodegenerative disease, but few studies have explored the characteristics of abnormal dynamic brain activity in AD patients. Here, our report reveals the abnormal dynamic activity of the patients' resting-state network, providing new insights into the dynamic analysis of brain networks and helping to gain a deeper understanding of the abnormal spatial dynamic patterns in AD patients.

Assessment of visuospatial functions in post-Covid 19 patients: Beyond the traditional paradigm

Several studies indicate that some cognitive changes occur after COVID-19. Visuospatial alterations have been reported in 24-40 %. These alterations may be useful as early biomarkers of neurodegenerative disease. Thus, we can emphasize the importance of visuospatial processes in cognition through quantitative and qualitative analysis of performance on the Clock Test (CDT) and the Rey-Osterrieth Complex Figure (FCRO). Our objective was to describe the performance of post COVID 19 patients in visuospatial tests, with different degrees of respiratory impairment and to perform a qualitative analysis of the performance to check its relationship with alterations in attention and executive functions. This will allow highlighting the executive component of the performance of the CDT and ROCF and differentiate patients with possible cognitive impairment. 77 patients with SARS-CoV-2 infection were evaluated (3 months post-infection) with a complete neuropsychological battery and MRI. Overall, there is a significant difference between FCRO and CDT, with FCRO having only 9 % change and CDT having 51.9 % change. Regarding the correlations observed between groups (VM Inv, VM non I and non hospitalized) the highest correlations were observed between Boston with FCRO copy (r=0.497; p=0.001) and with FCRO memory (r=0.429; p=0.001). Comparing the performance between groups by severity, significant differences were observed only in the TMT A (13.706 p=0.001) and B (9.583 p=0.008) tests and in the phonological fluency letter A (13.445 p=0.001), we observed that the group of non-hospitalized patients had a better performance. Neuropsychological deficits often have a direct impact on daily life by affecting the ability to learn and adapt. Thus, a useful strategy for the neuropsychological characterization of post-COVID-19 patients is the qualitative analysis of visuospatial abilities in conjunction with executive functions that cannot be analyzed in isolation.

Visuospatial working memory in behavioural variant frontotemporal dementia: a comparative analysis with Alzheimer's disease using the box task

OBJECTIVE

This study investigated the visuospatial working memory profiles of behavioural variant frontotemporal dementia (bvFTD) and Alzheimer's disease (AD) using a novel computerised test of visuospatial working memory: the Box Task.

METHODS

Twenty-eight bvFTD and 28 AD patients, as well as 32 age-matched control participants were recruited. All participants completed the Box Task and conventional neuropsychological tests of working memory, episodic memory, and visuospatial function.

RESULTS

Both the bvFTD and AD groups exhibited significantly more Box Task between-search errors than the control group across all set sizes. Notably, the AD group demonstrated a significantly higher error rate compared to the bvFTD group. Regression analysis revealed that whilst episodic memory impairment significantly predicted Box Task error performance in AD, this was not the case for bvFTD. Additionally, a noticeable trend was observed for attention in predicting Box Task errors in both bvFTD and AD groups. The Box Task demonstrated high utility in differentiating between bvFTD and AD, with a decision tree correctly classifying 82.1% of bvFTD patients and 75% of AD patients.

CONCLUSIONS

Our findings reveal significant visuospatial working memory impairments in bvFTD, albeit of lesser severity compared to disease-matched AD patients. The Box Task, a novel measure of visuospatial working memory, proved effective in differentiating between bvFTD and AD, outperforming many traditional neuropsychological measures. Overall, our findings highlight the utility of assessing visuospatial memory when differentiating between bvFTD and AD in the clinical setting.

The effect of apolipoprotein E genotype on spatial processing in humans: A meta-analysis and systematic review

The ε4 allele of the apolipoprotein E (APOE4) gene is an established risk factor for Alzheimer's disease but its impact on cognition in healthy adults across the lifespan is unclear. One cognitive domain that is affected early in the course of Alzheimer's disease is spatial cognition, yet the evidence for APOE-related changes in spatial cognition is mixed. In this meta-analysis we assessed the impact of carrying the APOE4 allele on five subdomains of spatial cognition across the lifespan. We included studies of healthy human participants where an APOE4-carrier group (heterozygous or homozygous) could be compared to a homozygous group of APOE3-carriers. We identified 156 studies in total from three databases (Pubmed, Scopus and Web of Science) as well as through searching cited literature and contacting authors for unpublished data. 122 studies involving 32,547 participants were included in a meta-analysis, and the remaining studies are included in a descriptive review. APOE4 carriers scored significantly lower than APOE3 carriers (θˆ = -.08 [-.14, -.02]) on tests of spatial long-term memory; this effect was very small and was not modulated by age. On other subdomains of spatial cognition (spatial construction, spatial working memory, spatial reasoning, navigation) there were no effects of genotype. Overall, our results demonstrate that the APOE4 allele exerts little influence on spatial cognitive abilities in healthy adults.

Learning ratio performance on a brief visual learning and memory test moderates cognitive training gains in Double Decision task in healthy older adults

Cognitive training using a visual speed-of-processing task, called the Useful Field of View (UFOV) task, reduced dementia risk and reduced decline in activities of daily living at a 10-year follow-up in older adults. However, there was variability in the achievement of cognitive gains after cognitive training across studies, suggesting moderating factors. Learning trials of visual and verbal learning tasks recruit similar cognitive abilities and have overlapping neural correlates with speed-of-processing/working memory tasks and therefore could serve as potential moderators of cognitive training gains. This study explored the association between the Hopkins Verbal Learning Test-Revised (HVLT-R) and Brief Visuospatial Memory Test-Revised (BVMT-R) learning with a commercial UFOV task called Double Decision. Through a secondary analysis of a clinical trial, we assessed the moderation of HVLT-R and BVMT-R learning on Double Decision improvement after a 3-month speed-of-processing/attention and working memory cognitive training intervention in a sample of 75 cognitively healthy older adults. Multiple linear regressions showed that better baseline Double Decision performance was significantly associated with better BVMT-R learning (β =  - .303). This association was not significant for HVLT-R learning (β =  - .142). Moderation analysis showed that those with poorer BVMT-R learning improved the most on the Double Decision task after cognitive training. This suggests that healthy older adults who perform below expectations on cognitive tasks related to the training task may show the greatest training gains. Future cognitive training research studying visual speed-of-processing interventions should account for differing levels of visuospatial learning at baseline, as this could impact the magnitude of training outcomes and efficacy of the intervention.

Associations of cerebral amyloid beta and tau with cognition from midlife

INTRODUCTION

Understanding early neuropathological changes and their associations with cognition may aid dementia prevention. This study investigated associations of cerebral amyloid and tau positron emission tomography (PET) retention with cognition in a predominately middle-aged community-based cohort and examined factors that may modify these relationships.

METHODS

11C-Pittsburgh compound B amyloid and 18F-flortaucipir tau PET imaging were performed. Associations of amyloid and tau PET with cognition were evaluated using linear regression. Interactions with age, apolipoprotein E (APOE) ε4 status, and education were examined.

RESULTS

Amyloid and tau PET were not associated with cognition in the overall sample (N = 423; mean: 57 ± 10 years; 50% female). However, younger age (< 55 years) and APOE ε4 were significant effect modifiers, worsening cognition in the presence of higher amyloid and tau.

DISCUSSION

Higher levels of Aβ and tau may have a pernicious effect on cognition among APOE ε4 carriers and younger adults, suggesting a potential role for targeted early interventions.

HIGHLIGHTS

Risk and resilience factors influenced cognitive vulnerability due to Aβ and tau. Higher fusiform tau associated with poorer visuospatial skills in younger adults. APOE ε4 interacted with Aβ and tau to worsen cognition across multiple domains.

The discriminant validity of Rey Complex Figure Test (RCFT) in subjective cognitive decline, mild cognitive impairment (multiple domain) and Alzheimer's disease dementia (ADD; mild stage) in Greek older adults

Aim: The goal of this study was to determine the discriminant potential of the Rey Complex Figure Test (RCFT) in older adults with Mild Cognitive Impairment multiple domain (mdMCI) and Alzheimer's Disease Dementia (ADD; mild subtype) as compared to older adults with Subjective Cognitive Decline (SCD).Materials and methods: We administered RCFT in 608 older adults, dividing them in three groups (217 individuals with SCD; 304 mdMCI population; 106 people with mild ADD, aged 50-90 years; M = 66.9, SD = 8.4) and a mean education of 10.20 (SD 4.3) years.Results: RCFT subtests have excellent discriminant validity, mainly between people with SCD and those with mild ADD. However, its discriminant validity in detecting older adults with SCD among mdMCI population is still questionable.Discussion: The use of RFCT in discriminating older adults with SCD from those with mild ADD both in research as well as in clinical practice is highly recommended.

Human restricted CHRFAM7A gene increases brain efficiency

Introduction

CHRFAM7A, a uniquely human fusion gene, has been associated with neuropsychiatric disorders including Alzheimer's disease, schizophrenia, anxiety, and attention deficit disorder. Understanding the physiological function of CHRFAM7A in the human brain is the first step to uncovering its role in disease. CHRFAM7A was identified as a potent modulator of intracellular calcium and an upstream regulator of Rac1 leading to actin cytoskeleton reorganization and a switch from filopodia to lamellipodia implicating a more efficient neuronal structure. We performed a neurocognitive-MRI correlation exploratory study on 46 normal human subjects to explore the effect of CHRFAM7A on human brain.

Methods

Dual locus specific genotyping of CHRFAM7A was performed on genomic DNA to determine copy number (TaqMan assay) and orientation (capillary sequencing) of the CHRFAM7A alleles. As only the direct allele is expressed at the protein level and affects α7 nAChR function, direct allele carriers and non-carriers are compared for neuropsychological and MRI measures. Subjects underwent neuropsychological testing to measure motor (Timed 25-foot walk test, 9-hole peg test), cognitive processing speed (Symbol Digit Modalities Test), Learning and memory (California Verbal Learning Test immediate and delayed recall, Brief Visuospatial Memory Test-Revised immediate and delayed recall) and Beck Depression Inventory-Fast Screen, Fatigue Severity Scale. All subjects underwent MRI scanning on the same 3 T GE scanner using the same protocol. Global and tissue-specific volumes were determined using validated cross-sectional algorithms including FSL's Structural Image Evaluation, using Normalization, of Atrophy (SIENAX) and FSL's Integrated Registration and Segmentation Tool (FIRST) on lesion-inpainted images. The cognitive tests were age and years of education-adjusted using analysis of covariance (ANCOVA). Age-adjusted analysis of covariance (ANCOVA) was performed on the MRI data.

Results

CHRFAM7A direct allele carrier and non-carrier groups included 33 and 13 individuals, respectively. Demographic variables (age and years of education) were comparable. CHRFAM7A direct allele carriers demonstrated an upward shift in cognitive performance including cognitive processing speed, learning and memory, reaching statistical significance in visual immediate recall (FDR corrected p = 0.018). The shift in cognitive performance was associated with smaller whole brain volume (uncorrected p = 0.046) and lower connectivity by resting state functional MRI in the visual network (FDR corrected p = 0.027) accentuating the cognitive findings.

Conclusion

These data suggest that direct allele carriers harbor a more efficient brain consistent with the cellular biology of actin cytoskeleton and synaptic gain of function. Further larger human studies of cognitive measures correlated with MRI and functional imaging are needed to decipher the impact of CHRFAM7A on brain function.

Genetic modifiers of cognitive decline in PSEN1 E280A Alzheimer's disease

INTRODUCTION

Rate of cognitive decline (RCD) in Alzheimer's disease (AD) determines the degree of impairment for patients and of burden for caretakers. We studied the association of RCD with genetic variants in AD.

METHODS

RCD was evaluated in 62 familial AD (FAD) and 53 sporadic AD (SAD) cases, and analyzed by whole-exome sequencing for association with common exonic functional variants. Findings were validated in post mortem brain tissue.

RESULTS

One hundred seventy-two gene variants in FAD, and 227 gene variants in SAD associated with RCD. In FAD, performance decline of the immediate recall of the Rey-Osterrieth figure test associated with 122 genetic variants. Olfactory receptor OR51B6 showed the highest number of associated variants. Its expression was detected in temporal cortex neurons.

DISCUSSION

Impaired olfactory function has been associated with cognitive impairment in AD. Genetic variants in these or other genes could help to identify risk of faster memory decline in FAD and SAD patients.

A tablet-based multi-dimensional drawing system can effectively distinguish patients with amnestic MCI from healthy individuals

The population with dementia is expected to rise to 152 million in 2050 due to the aging population worldwide. Therefore, it is significant to identify and intervene in the early stage of dementia. The Rey-Osterreth complex figure (ROCF) test is a visuospatial test scale. Its scoring methods are numerous, time-consuming, and inconsistent, which is unsuitable for wide application as required by the high number of people at risk. Therefore, there is an urgent need for a rapid, objective, and sensitive digital scoring method to detect cognitive dysfunction in the early stage accurately. This study aims to clarify the organizational strategy of aMCI patients to draw complex figures through a multi-dimensional digital evaluation system. At the same time, a rapid, objective, and sensitive digital scoring method is established to replace traditional scoring. The data of 64 subjects (38 aMCI patients and 26 NC individuals) were analyzed in this study. All subjects completed the tablet's Geriatric Complex Figure (GCF) test, including copying, 3-min recall, and 20-min delayed recall, and also underwent a standardized neuropsychological test battery and classic ROCF test. Digital GCF (dGCF) variables and conventional GCF (cGCF) scores were input into the forward stepwise logistic regression model to construct classification models. Finally, ROC curves were made to visualize the difference in the diagnostic value of dGCF variables vs. cGCF scores in categorizing the diagnostic groups. In 20-min delayed recall, aMCI patients' time in air and pause time were longer than NC individuals. Patients with aMCI had more short strokes and poorer ability of detail integration (all p < 0.05). The diagnostic sensitivity of dGCF variables for aMCI patients was 89.47%, slightly higher than cGCF scores (sensitivity: 84.21%). The diagnostic accuracy of both was comparable (dGCF: 70.3%; cGCF: 73.4%). Moreover, combining dGCF variables and cGCF scores could significantly improve the diagnostic accuracy and specificity (accuracy: 78.1%, specificity: 84.62%). At the same time, we construct the regression equations of the two models. Our study shows that dGCF equipment can quantitatively evaluate drawing performance, and its performance is comparable to the time-consuming cGCF score. The regression equation of the model we constructed can well identify patients with aMCI in clinical application. We believe this new technique can be a highly effective screening tool for patients with MCI.

Contributions of hippocampal subfields and subregions to episodic memory performance in healthy cognitive aging

In the present study we investigated whether hippocampal subfield (cornu ammonis 1-3, dentate gyrus, and subiculum) and anteroposterior hippocampal subregion (head,body, and tail) volumes can predict episodic memory function using high-field high resolution structural magnetic resonance imaging (MRI). We recruited 126 healthy participants (18-85 years). MRI datasets were collected on a 4.7 T system. Participants were administered the Wechsler Memory Scale (WMS-IV) to evaluate episodic memory function. Structural equation modeling was used to test the relationship between studied variables. We found that the volume of the dentate gyrus subfield and posterior hippocampus (body) showed a significant direct effect on visuospatial memory performance; additionally, an indirect effect of age on visuospatial memory mediated through these hippocampal subfield/subregion was significant. Logical and verbal memory were not significantly associated with hippocampal subfield or subregion volumes.

Application and validation of an algorithmic classification of early impairment in cognitive performance

OBJECTIVE

Due to the long prodromal period for dementia pathology, approaches are needed to detect cases before clinically recognizable symptoms are apparent, by which time it is likely too late to intervene. This study contrasted two theoretically-based algorithms for classifying early cognitive impairment (ECI) in adults aged ≥50 enrolled in the Baltimore Longitudinal Study of Aging.

METHOD

Two ECI algorithms were defined as poor performance (1 standard deviation [SD] below age-, sex-, race-, and education-specific means) in: (1) Card Rotations or California Verbal Learning Test (CVLT) immediate recall and (2) ≥1 (out of 2) memory or ≥3 (out of 6) non-memory tests. We evaluated concurrent criterion validity against consensus diagnoses of mild cognitive impairment (MCI) or dementia and global cognitive scores using receiver operating characteristic (ROC) curve analysis. Predictive criterion validity was evaluated using Cox proportional hazards models to examine the associations between algorithmic status and future adjudicated MCI/dementia.

RESULTS

Among 1,851 participants (mean age = 65.2 ± 11.8 years, 50% women, 74% white), the two ECI algorithms yielded comparably moderate concurrent criterion validity with adjudicated MCI/dementia. For predictive criterion validity, the algorithm based on impairment in Card Rotations or CVLT immediate recall was the better predictor of MCI/dementia (HR = 3.53, 95%CI: 1.59-7.84) over 12.3 follow-up years.

CONCLUSIONS

Impairment in visuospatial ability or memory may be capable of detecting early cognitive changes in the preclinical phase among cognitively normal individuals.

Striatal dopamine transporter uptake, parkinsonism and cognition in Alzheimer's disease

BACKGROUND AND PURPOSE

The correlates of motor parkinsonism in Alzheimer's disease (AD) remain controversial. The effects of nigrostriatal dopaminergic degeneration on parkinsonism and cognition in biomarker-validated patients with AD were evaluated.

METHODS

This study recruited 116 patients with AD who underwent dual-phase 18 F-N-(3-fluoropropyl)-2β-carbon ethoxy-3β-(4-iodophenyl) nortropane positron emission tomography, 18 F-florbetaben positron emission tomography, 3 T brain magnetic resonance imaging, and Unified Parkinson's Disease Rating Scale (UPDRS) and neuropsychological tests. The mean cortical thickness in the frontal, temporal, parietal and occipital cortices, and the dopamine transporter (DAT) uptake in the caudate, anterior/posterior putamen and substantia nigra were quantified. The relationship between DAT uptake, mean lobar cortical thickness, UPDRS motor score and cognition was investigated using general linear models (GLMs) after controlling for age, sex, education, intracranial volume, and deep and periventricular white matter hyperintensities. A path analysis was performed for the UPDRS motor score with the same covariates.

RESULTS

Path analysis and multivariable GLMs for UPDRS motor score showed that lower caudate DAT uptake was directly associated with a higher UPDRS motor score, whereas caudate DAT uptake confounded the association between mean frontal/parietal thickness and UPDRS motor score. Multivariable GLMs for cognitive scores showed that lower caudate DAT uptake was associated with visuospatial/executive dysfunction independent of mean frontal or parietal thickness.

CONCLUSIONS

Nigrostriatal dopaminergic dysfunction is associated with parkinsonism and visuospatial/executive dysfunction in patients with AD.

A graph theoretic approach to neurodegeneration: five data-driven neuropsychological subtypes in mild cognitive impairment

Mild cognitive Impairment (MCI) is notoriously heterogenous in terms of clinical presentation, neuroimaging correlates, and subsequent progression. Predicting who will progress to dementia, which type of dementia, and over what timeframe is challenging. Previous work has attempted to identify MCI subtypes using neuropsychological measures in an effort to address this challenge; however, there is no consensus on approach, which may account for some of the variability. Using a hierarchical community detection approach, we examined cognitive subtypes within an MCI sample (from the Alzheimer's Disease Neuroimaging Initiative [ADNI] study). We then examined whether these subtypes were related to biomarkers (e.g., cortical volumes, fluorodeoxyglucose (FDG)-positron emission tomography (PET) hypometabolism) or clinical progression. We identified five communities (i.e., cognitive subtypes) within the MCI sample: 1) predominantly memory impairment, 2) predominantly language impairment, 3) cognitively normal, 4) multidomain, with notable executive dysfunction, 5) multidomain, with notable processing speed impairment. Community membership was significantly associated with 1) cortical volume in the hippocampus, entorhinal cortex, and fusiform cortex; 2) FDG PET hypometabolism in the posterior cingulate, angular gyrus, and inferior/middle temporal gyrus; and 3) conversion to dementia at follow up. Overall, community detection as an approach appears a viable method for identifying unique cognitive subtypes in a neurodegenerative sample that were linked to several meaningful biomarkers and modestly with progression at one year follow up.

The cerebellum and cognitive neural networks

Cognitive function represents a complex neurophysiological capacity of the human brain, encompassing a higher level of neural processing and integration. It is widely acknowledged that the cerebrum plays a commanding role in the regulation of cognitive functions. However, the specific role of the cerebellum in cognitive processes has become a subject of considerable scholarly intrigue. In 1998, Schmahmann first proposed the concept of "cognitive affective syndrome (CCAS)," linking cerebellar damage to cognitive and emotional impairments. Since then, a substantial body of literature has emerged, exploring the role of the cerebellum in cognitive neurological function. The cerebellum's adjacency to the cerebral cortex, brainstem, and spinal cord suggests that the cerebral-cerebellar network loops play a crucial role in the cerebellum's participation in cognitive neurological functions. In this review, we comprehensively examine the recent literature on the involvement of the cerebellum in cognitive functions from three perspectives: the cytological basis of the cerebellum and its anatomical functions, the cerebellum and cognitive functions, and Crossed cerebellar diaschisis. Our aim is to shed light on the role and mechanisms of the cerebellum in cognitive neurobrain networks.

Machine Learning and Eye Movements Give Insights into Neurodegenerative Disease Mechanisms

Humans are a vision-dominated species; what we perceive depends on where we look. Therefore, eye movements (EMs) are essential to our interactions with the environment, and experimental findings show EMs are affected in neurodegenerative disorders (ND). This could be a reason for some cognitive and movement disorders in ND. Therefore, we aim to establish whether changes in EM-evoked responses can tell us about the progression of ND, such as Alzheimer's (AD) and Parkinson's diseases (PD), in different stages. In the present review, we have analyzed the results of psychological, neurological, and EM (saccades, antisaccades, pursuit) tests to predict disease progression with machine learning (ML) methods. Thanks to ML algorithms, from the high-dimensional parameter space, we were able to find significant EM changes related to ND symptoms that gave us insights into ND mechanisms. The predictive algorithms described use various approaches, including granular computing, Naive Bayes, Decision Trees/Tables, logistic regression, C-/Linear SVC, KNC, and Random Forest. We demonstrated that EM is a robust biomarker for assessing symptom progression in PD and AD. There are navigation problems in 3D space in both diseases. Consequently, we investigated EM experiments in the virtual space and how they may help find neurodegeneration-related brain changes, e.g., related to place or/and orientation problems. In conclusion, EM parameters with clinical symptoms are powerful precision instruments that, in addition to their potential for predictions of ND progression with the help of ML, could be used to indicate the different preclinical stages of both diseases.

Application and validation of an algorithmic classification of early impairment in cognitive performance

Objective

Due to the long prodromal period for dementia pathology, approaches are needed to detect cases before clinically recognizable symptoms are apparent, by which time it is likely too late to intervene. This study contrasted two theoretically-based algorithms for classifying early cognitive impairment (ECI) in adults aged ≥50 enrolled in the Baltimore Longitudinal Study of Aging.

Method

Two ECI algorithms were defined as poor performance (1 standard deviation [SD] below age-, sex-, race-, and education-specific means) in: (1) Card Rotations or California Verbal Learning Test (CVLT) immediate recall and (2) ≥1 (out of 2) memory or ≥3 (out of 6) non- memory tests. We evaluated concurrent criterion validity against consensus diagnoses of mild cognitive impairment (MCI) or dementia and global cognitive scores using receiver operating characteristic (ROC) curve analysis. Predictive criterion validity was evaluated using Cox proportional hazards models to examine the associations between algorithmic status and future adjudicated MCI/dementia.

Results

Among 1,851 participants (mean age=65.2±11.8 years, 50% women, 74% white), the two ECI algorithms yielded comparably moderate concurrent criterion validity with adjudicated MCI/dementia. For predictive criterion validity, the algorithm based on impairment in Card Rotations or CVLT immediate recall was the better predictor of MCI/dementia (HR=3.53, 95%CI: 1.59-7.84) over 12.3 follow-up years.

Conclusions

Impairment in visuospatial ability or memory may be capable of detecting early cognitive changes in the preclinical phase among cognitively normal individuals.

The Benton Visual Form Discrimination Test as a Predictor of Neurocognitive Disorder in Older Veterans

OBJECTIVE

The Benton Visual Form Discrimination Test (VFDT) is a commonly used measure of visual discrimination and visual recognition memory and has shown promise in distinguishing between different levels of cognitive impairment. We assess the predictive diagnostic utility of the VFDT in a sample of older Veterans with cognitive concerns.

METHOD

Subjects included a total of 172 mostly male Veterans over the age of 64 (mean = 76.0; SD = 7.6) recruited from a VA clinic specializing in neuropsychological assessment of older Veterans. The clinical sample included 56 subjects diagnosed with Major Neurocognitive Disorder, 74 diagnosed with Mild Neurocognitive Disorder, and 42 with No Neurocognitive Impairment. Impairment categories were modeled in separate multinomial logistic regressions with two versions of the VFDT as predictors: the Visual Form Discrimination Test-Recognition Subtest (VFDT-Rec) test (visual recognition memory) and the Visual Form Discrimination Test-Matching Subtest VFDT-Mat test (visual form discrimination). Years of education were included as a covariate.

RESULTS

After adjusting for education, higher VFDT-Rec total scores were associated with lower odds of being categorized with a greater degree of cognitive/functional impairment (OR 0.66-0.83, p < .001). VFDT-Mat scores showed a similar pattern, but only reached statistical significance for the Major versus No Neurocognitive Impairment (OR = 0.77, p = .0010) and Major versus Mild comparisons (OR = 0.89, p = .0233).

CONCLUSIONS

The VFDT may enhance the confidence of differential diagnosis of dementia in older adult Veterans. Formal education-adjusted norms need to be established for clinical use.

Tracking cognition with the T-MoCA in a racially/ethnically diverse older adult cohort

Introduction

We investigated the utility of the Telephone-Montreal Cognitive Assessment (T-MoCA) to track cognition in a diverse sample from the Einstein Aging Study.

Methods

Telephone and in-person MoCA data, collected annually, were used to evaluate longitudinal cognitive performance. Joint models of T-MoCA and in-person MoCA compared changes, variance, and test-retest reliability measured by intraclass correlation coefficient by racial/ethnic group.

Results

There were no significant differences in baseline performance or longitudinal changes across three study waves for both MoCA formats. T-MoCA performance improved over waves 1-3 but declined afterward. Test-retest reliability was lower for the T-MoCA than for the in-person MoCA. In comparison with non-Hispanic Whites, non-Hispanic Blacks and Hispanics performed worse at baseline on both MoCA formats and showed lower correlations between T-MoCA and in-person versions.

Conclusions

The T-MoCA provides valuable information on cognitive change, despite racial/ethnic disparities and practice effects. We discuss implications for health disparity populations.

Highlights

We assessed the comparability of Telephone-Montreal Cognitive Assessment (T-MoCA) and in-person MoCA for tracking cognition.Changes within 3 years in T-MoCA were similar to that for the in-person MoCA.T-MoCA is subject to practice effects and shows difference in performance by race/ethnicity.Test-retest reliability of T-MoCA is lower than that for in-person MoCA.

Effects of different virtual reality technology driven dual-tasking paradigms on posture and saccadic eye movements in healthy older adults

Postural sway and eye movements are potential biomarkers for dementia screening. Assessing the two movements comprehensively could improve the understanding of complicated syndrome for more accurate screening. The purpose of this research is to evaluate the effects of comprehensive assessment in healthy older adults (OA), using a novel concurrent comprehensive assessment system consisting of stabilometer and virtual reality headset. 20 healthy OA (70.4 ± 4.9 years) were recruited. Using a cross-sectional study design, this study investigated the effects of various dual-tasking paradigms with integrated tasks of visuospatial memory (VM), spatial orientation (SO), and visual challenge on posture and saccades. Dual-task paradigms with VM and SO affected the saccadic eye movements significantly. Two highly intensive tests of anti-saccade with VM task and pro-saccade with SO task also influenced postural sway significantly. Strong associations were seen between postural sway and eye movements for the conditions where the two movements theoretically shared common neural pathways in the brain, and vice versa. This study suggests that assessing posture and saccades with the integrated tasks comprehensively and simultaneously could be useful to explain different functions of the brain. The results warrant a cross-sectional study in OA with and without dementia to explore differences between these groups.

Cognitive training modified age-related brain changes in older adults with subjective memory decline

OBJECTIVES

Neuroimaging findings suggest that older adults with subjective memory decline (SMD) demonstrate some neurodegenerative brain changes and have high risk of developing dementia, but relatively little is known about the effectiveness of interventions for SMD. This study aimed to examine the effects of cognitive training on resting-state brain activity in SMD.

METHOD

This study employed the amplitude of low frequency fluctuations (ALFF) and resting state functional connectivity (rs-FC) analyses. After baseline evaluations, participants were randomly allocated to the intervention and control group to receive a four-week cognitive training and lectures on health and aging, respectively. All participants were scanned before and after training with an interval of about three months.

RESULTS

(1) Participants in the intervention group showed significant improvements on the Associative Learning Test (ALT) and the Digit Span Forward task compared to the control group; (2) ALFF in the occipital lobe for the control group increased significantly, while that for the intervention group remained the same; ALFF changes were negatively correlated with ALT performance in the control group; (3) The mean value of rs-FC for the intervention group decreased, while that for the control group showed a trend of increase; rs-FC changes were also negatively correlated with ALT performance in the control group.

CONCLUSIONS

Resting-state brain activities in occipital region increased with aging. The cognitive training could counteract this brain function changes associated with aging or even reverse the changes. These findings provide new insights into the understanding of brain plasticity in posterior areas in SMD.

TRIAL REGISTRATION

ChiCTR-IOR-15006165 in the Chinese Clinical Trial Registry.

In Vivo Parieto-Occipital White Matter Metabolism Is Correlated with Visuospatial Deficits in Adult DM1 Patients

Myotonic dystrophy type 1 (DM1) is a genetic disorder caused by a (CTG) expansion in the DM protein kinase (DMPK) gene, representing the most common adult muscular dystrophy, characterized by a multisystem involvement with predominantly skeletal muscle and brain affection. Neuroimaging studies showed widespread white matter changes and brain atrophy in DM1, but only a few studies investigated the role of white matter metabolism in the pathophysiology of central nervous system impairment. We aim to reveal the relationship between the metabolic profile of parieto-occipital white matter (POWM) as evaluated with proton MR spectroscopy technique, with the visuoperceptual and visuoconstructional dysfunctions in DM1 patients. MR spectroscopy (3 Tesla) and neuropsychological evaluations were performed in 34 DM1 patients (19 F, age: 46.4 ± 12.1 years, disease duration: 18.7 ± 11.6 years). The content of neuro-axonal marker N-acetyl-aspartate, both relative to Creatine (NAA/Cr) and to myo-Inositol (NAA/mI) resulted significantly lower in DM1 patients compared to HC (p-values < 0.0001). NAA/Cr and NAA/mI correlated with the copy of the Rey-Osterrieth complex figure (r = 0.366, p = 0.033; r = 0.401, p = 0.019, respectively) and with Street’s completion tests scores (r = 0.409, p = 0.016; r = 0.341, p = 0.048 respectively). The proportion of white matter hyperintensities within the MR spectroscopy voxel did not correlate with the metabolite content. In this study, POWM metabolic alterations in DM1 patients were not associated with the white matter morphological changes and correlated with specific neuropsychological deficits.

Linking cognitive functioning and postural balance control through virtual reality environmental manipulations

Background

Dementia is becoming a relevant problem worldwide. A simple screening at an early stage will be important to detect the risk of developing dementia. Vestibular dysfunction is likely to be associated with cognitive impairment. Since head-mounted display (HMD) virtual reality (VR) technology has the potential to activate the vestibular function, assessing postural sway with visual stimulation using HMD VR technology could be potentially useful for dementia screening.

Objective

The purpose of this study is to evaluate the effect of HMD-based VR visual stimuli on posture in older adults and the relationship between the stimulated body sway behaviors and cognitive performance.

Method

Using a cross-sectional study design, we investigated the effect of an optokinetic design-based room with stripes (OKR) VR environment oscillating forwards and backwards at 23/60Hz. Center of pressure (COP) displacement was measured in older adults aged 65 years and over in the OKR VR environment. The frequency response of COP was compared to the cognitive performance of the Montreal Cognitive Assessment (MoCA).

Results

20 healthy older adults (70.4 ± 4.9 years; 27.2 ± 1.6 MoCA score) and 3 people with mild cognitive impairment (74.7 ± 4.0 years; 20.3 ± 2.1 MoCA score) were assessed. The results reveal that the oscillating OKR VR environment induced different postural sway in the anterior-posterior direction in the real world. Correlation analysis shows that the cognitive test score was associated with the frequency response of stimulated postural sway in the anterior-posterior direction (frequency Band 1 of 0−0.5Hz related to the visual and vestibular systems: r_s = 0.45, P = 0.03).

Conclusion

Outcomes would suggest that a potential link may emerge between cognition and posture when the HMD-based VR visual stimuli are applied. The simple screening of stimulated postural sway could explain cognitive functioning. Further studies are warranted to clarify the vestibular system and spatial cognitive function more specifically in the proposed assessment system.

Prevalence, demographics, and cognitive dysfunction among methamphetamine-dependent individuals with childhood maltreatment

Previous studies have shown that dependent individuals (DIs) have higher rates of childhood maltreatment and poorer cognitive performance compared with healthy controls. However, little attention has been paid to the cognitive dysfunction of DIs with childhood maltreatment. The purpose of this study was to explore the cognitive deficits of maltreated methamphetamine-dependent individuals (METH-DIs) using a cross-sectional and case-control design. In addition, we aimed to examine the prevalence of childhood maltreatment and the demographic and clinical characteristics of Chinese male METH-DIs. 330 METH-DIs and 143 healthy controls were recruited and completed a detailed questionnaire on demographic and drug-related variables. Childhood abuse data were collected from the Childhood Trauma Questionnaire-Short Form (CTQ-SF). Cognitive function was assessed by the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). The Beck Depression Inventory, Beck Anxiety Inventory, and Visual Analogue Scale (VAS) were used to assess the clinical state of the METH-DIs. 166 of 326 (50.9%) METH-DIs had experienced at least one type of childhood maltreatment. Maltreated METH-DIs were more likely to have a lower level of education (t₃₂₄ = 5.81, p < 0.001), a higher level of depression(t₃₂₄ = －2.68, p < 0.01), and a younger onset age of drug use (t₃₂₄ = 3.58, p < 0.01) than METH-DIs who had no experience of childhood maltreatment. Maltreated METH-DIs also performed worse on the RBANS attention score than METH-DIs who did not experience maltreatment (F_1,324 = 15.41, p < 0.001, partial η² = 0.05). Our findings revealed that some demographic and clinical variables were associated with maltreatment among METH-DIs. Moreover, attention dysfunction was found in maltreated METH-DIs, which conforms to the theory of latent vulnerability.

Neural basis of visuospatial tests in behavioral variant frontotemporal dementia

Background

Recent models of visuospatial functioning suggest the existence of three main circuits emerging from the dorsal (“where”) route: parieto-prefrontal pathway, parieto-premotor, and parieto-medial temporal. Neural underpinnings of visuospatial task performance and the sparing of visuospatial functioning in bvFTD are unclear. We hypothesized different neural and cognitive mechanisms in visuospatial tasks performance in bvFTD and AD.

Methods

Two hundred and sixteen participants were enrolled for this study: 72 patients with bvFTD dementia and 144 patients with AD. Visual Object and Space Perception Battery Position Discrimination and Number Location (VOSP-PD and VOSP-NL) and Rey-Osterrieth Complex Figure (ROCF) were administered to examine visuospatial functioning, together with a comprehensive neuropsychological battery. FDG-PET was acquired to evaluate brain metabolism. Voxel-based brain mapping analyses were conducted to evaluate the brain regions associated with visuospatial function in bvFTD and AD.

Results

Patients with AD performed worst in visuospatial tasks in mild dementia, but not at prodromal stage. Attention and executive functioning tests showed higher correlations in bvFTD than AD with ROCF, but not VOSP subtests. Visuospatial performance in patients with bvFTD was associated with bilateral frontal regions, including the superior and medial frontal gyri, supplementary motor area, insula and middle cingulate gyrus.

Conclusion

These findings support the role of prefrontal and premotor regions in visuospatial processing through the connection with the posterior parietal cortex and other posterior cortical regions. Visuospatial deficits should be interpreted with caution in patients with bvFTD, and should not be regarded as hallmarks of posterior cortical dysfunction.

Development of the Colorado posterior cortical questionnaire within an Alzheimer's disease study cohort

INTRODUCTION

Non-amnestic presentations of neurodegenerative dementias, including posterior- and visual-predominant cognitive forms, are under-recognized. Specific screening measures for posterior cortical symptoms could allow for earlier, more accurate diagnosis and directed treatment.

METHODS

Based on clinical experience with posterior cortical atrophy evaluations, high-yield screening questions were collected and organized into a 15-item self-report questionnaire, titled the Colorado Posterior Cortical Questionnaire (CPC-Q). The CPC-Q was then piloted within a longitudinal cohort of cognitive aging, including 63 older adults, including healthy older adults (n = 33) and adults with either amnestic Alzheimer's disease (n = 21) or posterior cortical atrophy (PCA, n = 9).

RESULTS

The CPC-Q demonstrated acceptable psychometric properties (internal consistency, α = 0.89; mean item-total correlation = 0.62), correlated strongly with visuospatial measures on cognitive testing (p < 0.001), and could distinguish PCA from non-PCA groups (p < 0.001; AUC 0.95 (95% CI 0.88, 1.0)).

CONCLUSIONS

The CPC-Q captured posterior cortical symptoms in older adults, using a gold standard of expert consensus PCA diagnosis. Future studies will validate the CPC-Q in a larger cohort, with recruitment of additional PCA participants, to evaluate its convergent and discriminant validity more thoroughly. As a short, self-report tool, the CPC-Q demonstrates potential to improve detection of non-amnestic neurodegenerative dementias in the clinical setting.

Exploring Information Flow from Posteromedial Cortex during Visuospatial Working Memory: A Magnetoencephalography Study

The posteromedial cortex (PMC) is a major hub of the brain's default mode network, and is implicated in a broad range of internally driven cognitions, including visuospatial working memory. However, its precise contribution to these cognitive processes remains unclear. Using MEG, we measured PMC activity in healthy human participants (young adults of both sexes) while they performed a visuospatial working memory task. Multivariate pattern classification analyses revealed stimulus-related information during encoding and retrieval in a set of a priori defined cortical ROIs, including prefrontal, occipital, and ventrotemporal cortices, in addition to PMC. We measured the extent to which this stimulus information was exchanged between areas in an information flow analysis, measuring Granger-causal relationships between areas over time. Consistent with the visual nature of the task, information from occipital cortex shaped other regions across most epochs. However, the PMC shaped object representations in occipital and prefrontal cortices during visuospatial working memory, influencing occipital cortex during retrieval and PFC across all task epochs. Our findings are consistent with a proposed role for the PMC in the representation of internal content, including remembered information, and in the comparison of external stimuli with remembered material.SIGNIFICANCE STATEMENT The human brain operates as a collection of highly interconnected regions. Mapping the function of this interconnectivity, as well as the specializations within different regions, is central to understanding the neural processes underlying cognition. The posteromedial cortex (PMC) is a highly connected cortical region, implicated in visuospatial working memory, although its precise contribution remains unclear. We measured the activity of PMC during a visuospatial working memory task, testing how different regions represented the stimuli, and whether these representations were driven by other cortical regions. We found that PMC influenced stimulus information in other regions across all task phases, suggesting that PMC plays a key role in shaping stimulus representations during visuospatial working memory.

Diagnostic Accuracy of the Overlapping Infinity Loops, Wire Cube, and Clock Drawing Tests in Subjective Cognitive Decline, Mild Cognitive Impairment and Dementia

Figure drawing tasks are commonly used standalone or as part of broader screening tests to detect cognitive impairment. Only one study has compared the classification accuracy of three common drawing tasks—overlapping infinity loops, wire cube, and the clock drawing task (CDT)—in mild cognitive impairment (MCI) and dementia, but age and education, which impact performance, were not accounted for. We replicated the research, adjusting for age and education and, for the first time, assessed subjective cognitive decline (SCD) too. Participants were recruited from the Tasmanian ISLAND Cognitive Clinic and healthy controls from a community sample. All participants completed the three figure drawing tasks. The clinic patients were categorised according to interdisciplinary consensus diagnosis. Binomial logistic regression and area under ROC curves (AUC) were calculated to determine the discriminatory ability of each drawing task. Overall, 112 adults were recruited; 51 had normal cognition (NC), 21 SCD, 24 MCI, and 16 had dementia. The infinity loops test did not discriminate any of the groups, casting some doubt on its usefulness. The wire cube discriminated NC from dementia (AUC 0.7; p < 0.05). The CDT discriminated NC from dementia (AUC 0.77; p < 0.01), NC from cognitive impairment (dementia + MCI; AUC 0.59; p < 0.05), and MCI from dementia (AUC 0.76; p < 0.01). None of the tests discriminated NC from MCI or NC from SCD. The CDT was the most discriminatory test, followed by the wire cube. This may help guide clinicians who often choose just one figure drawing task due to time constraints or patient fatigue.

Utility of the Addenbrooke’s Cognitive Examination III online calculator to differentiate the primary progressive aphasia variants

The Addenbrooke’s Cognitive Examination III is a brief cognitive screening tool that is widely used for the detection and monitoring of dementia. Recent findings suggest that the three variants of primary progressive aphasia can be distinguished based on their distinct profiles on the five subdomain scores of this test. Here, we investigated the utility of the Addenbrooke’s Cognitive Examination III to differentiate the primary progressive aphasia variants based on their item-by-item performance profiles on this test. From these results, we created an interactive primary progressive aphasia Addenbrooke’s Cognitive Examination III calculator which predicts the variant based on a patient’s unique item-by-item profile. Twenty-eight logopenic variant, 25 non-fluent variant and 37 semantic variant primary progressive aphasia patients and 104 healthy controls completed the Addenbrooke’s Cognitive Examination III at first clinical presentation. Multinomial regression analyses were conducted to establish performance profiles among groups, and R Shiny from RStudio was used to create the interactive Addenbrooke’s Cognitive Examination III diagnostic calculator. To verify its accuracy, probability values of the regression model were derived based on a 5-fold cross-validation of cases. The calculator’s accuracy was then verified in an independent sample of 17 logopenic, 19 non-fluent and 13 semantic variant primary progressive aphasia patients and 68 Alzheimer’s disease patients who had completed the Addenbrooke’s Cognitive Examination III (or an older version of this test: Revised) and had in vivo amyloid-PET imaging and/or brain autopsy pathological confirmation. Cross-validation of cases in the calculator model revealed different rates of sensitivity in classifying variants: semantic = 100%, non-fluent = 80.6% and logopenic = 79.9%; healthy controls were distinguished from primary progressive aphasia patients with 100% sensitivity. Verification of in vivo amyloid and/or autopsy-confirmed patients showed that the calculator correctly classified 10/13 (77%) semantic variant, 3/19 (16%) non-fluent variant and 4/17 (24%) logopenic variant patients. Importantly, for patients who were not classified, diagnostic probability values mostly pointed toward the correct clinical diagnosis. Furthermore, misclassified diagnoses of the primary progressive aphasia cohort were rare (1/49; 2%). Although 22 of the 68 Alzheimer’s disease patients (32%) were misclassified with primary progressive aphasia, 19/22 were misclassified with the logopenic variant (i.e. falling within the same neuropathological entity). The Addenbrooke’s Cognitive Examination III primary progressive aphasia diagnostic calculator demonstrates sound accuracy in differentiating the variants based on an item-by-item Addenbrooke’s Cognitive Examination III profile. This calculator represents a new frontier in using data-driven approaches to differentiate the primary progressive aphasia variants.

Older Adults Get Lost in Virtual Reality: Visuospatial Disorder Detection in Dementia Using a Voting Approach Based on Machine Learning Algorithms

As the age of an individual progresses, they are prone to more diseases; dementia is one of these age-related diseases. Regarding the detection of dementia, traditional cognitive testing is currently one of the most accurate tests. Nevertheless, it has many disadvantages, e.g., it does not measure the extent of the brain damage and does not take the patient’s intelligence into consideration. In addition, traditional assessment does not measure dementia under real-world conditions and in daily tasks. It is therefore advisable to investigate the newest, more powerful applications that combine cognitive techniques with computerized techniques. Virtual reality worlds are one example, and allow patients to immerse themselves in a controlled environment. This study created the Medical Visuospatial Dementia Test (referred to as the “MVD Test”) as a non-invasive, semi-immersive, and cognitive computerized test. It uses a 3D virtual environment platform based on medical tasks combined with AI algorithms. The objective is to evaluate two cognitive domains: visuospatial assessment and memory assessment. Using multiple machine learning algorithms (MLAs), based on different voting approaches, a 3D system classifies patients into three classes: patients with normal cognition, patients with mild cognitive impairment (MCI), and patients with severe cognitive impairment (dementia). The model with the highest performance was derived from voting approach named Ensemble Vote, where accuracy was 97.22%. Cross-validation accuracy of Extra Tree and Random Forest classifiers, which was greater than 99%, indicated a greater discriminate capacity than that of other classes.

Associations between Time Processing Ability, Daily Time Management, and Dementia Severity

This study investigated associations between time processing ability (TPA), daily time management (DTM), and dementia severity. Persons with dementia (PwDs) (n = 53) and their significant others (n = 49) participated in this cross-sectional study. Bivariate analyses were used to investigate associations between TPA and DTM and the dementia severity. Linear regression models were used to further predict the contribution of the subtests in the Mini Mental State Examination (MMSE) for TPA results. The results showed significant correlations between TPA and dementia severity, where visuospatial functions were the most highly correlated. TPA also showed a significant correlation to proxy-rated DTM. In addition, proxy-rated DTM was significantly correlated with dementia severity and PwDs' own self-ratings of their DTM. Knowledge of the association between TPA, dementia severity, and visuospatial functions can enable early detection of TPA impairments. For a comprehensive assessment of TPA and DTM, objective measures should be used in combination with self-ratings and proxy-ratings. The findings can be used in clinical research and healthcare settings to develop methods to compensate for impaired TPA and support DTM in PwDs.

Multidimensional Clinical Assessment in Frontotemporal Dementia and Its Spectrum in Latin America and the Caribbean: A Narrative Review and a Glance at Future Challenges

Frontotemporal dementia (FTD) is the third most common form of dementia across all age groups and is a leading cause of early-onset dementia. The Frontotemporal dementia (FTD) includes a spectrum of diseases that are classified according to their clinical presentation and patterns of neurodegeneration. There are two main types of FTD: behavioral FTD variant (bvFTD), characterized by a deterioration in social function, behavior, and personality; and primary progressive aphasias (PPA), characterized by a deficit in language skills. There are other types of FTD-related disorders that present motor impairment and/or parkinsonism, including FTD with motor neuron disease (FTD-MND), progressive supranuclear palsy (PSP), and corticobasal syndrome (CBS). The FTD and its associated disorders present great clinical heterogeneity. The diagnosis of FTD is based on the identification through clinical assessments of a specific clinical phenotype of impairments in different domains, complemented by an evaluation through instruments, i.e., tests and questionnaires, validated for the population under study, thus, achieving timely detection and treatment. While the prevalence of dementia in Latin America and the Caribbean (LAC) is increasing rapidly, there is still a lack of standardized instruments and consensus for FTD diagnosis. In this context, it is important to review the published tests and questionnaires adapted and/or validated in LAC for the assessment of cognition, behavior, functionality, and gait in FTD and its spectrum. Therefore, our paper has three main goals. First, to present a narrative review of the main tests and questionnaires published in LAC for the assessment of FTD and its spectrum in six dimensions: (i) Cognitive screening; (ii) Neuropsychological assessment divided by cognitive domain; (iii) Gait assessment; (iv) Behavioral and neuropsychiatric symptoms; (v) Functional assessment; and (vi) Global Rating Scale. Second, to propose a multidimensional clinical assessment of FTD in LAC identifying the main gaps. Lastly, it is proposed to create a LAC consortium that will discuss strategies to address the current challenges in the field.

Distinct roles of right temporoparietal cortex in pentagon copying test

Pentagon Copying Test (PCT) is commonly used to assess visuospatial deficits, but the neural substrates underlying pentagon copying are not well understood. The Qualitative Scoring Pentagon Test (QSPT), an optimized scoring system, classifies five categories of errors patients make in pentagons copying and grades them depending on the errors' severity. To determine the strategic brain regions involved in the PCT, we applied the QSPT system to evaluate the visuospatial impairment of 136 acute ischemic stroke patients on the PCT and used Support Vector Regression Lesion-Symptom Mapping to investigate relevant brain regions. The total QSPT score was correlated with the right supramarginal gyrus. The angle number errors and closure errors were principally associated with lesions of the posterior temporoparietal cortex, including the right middle occipital gyrus and middle temporal gyrus, while the intersection errors and rotation errors were related to the more anterior part of the right temporoparietal lobe with the additional frontal cortex. In conclusion, the right temporoparietal cortex is the strategic region for pentagon copying tasks. The angle number and closure represent the visuospatial processing of within-object features, while intersection and rotation require between-object manipulation. The posterior-anterior distinction in the right temporoparietal region underlies the differences of within-object and between-object processing.

The Assessment of Visuospatial Skills and Verbal Fluency in the Diagnosis of Alzheimer's Disease

BACKGROUND

In the diagnosis of Alzheimer's disease (AD), examining memory is predominant. Our aim was to analyze the potential role of various cognitive domains in the cognitive evaluation of AD.

METHODS

In total, 110 individuals with clinically defined AD and 45 healthy control participants underwent neuropsychological evaluation including Addenbrooke's Cognitive Examination (ACE). Patients with AD were selected in three groups based on disease duration in years (Group 1: ≤2 years, n = 36; Group 2: 2-4 years, n = 44; Group 3: ≥4 years, n = 30). Covariance-weighted intergroup comparison was performed on the global cognitive score and subscores of cognitive domains. Spearman's rho was applied to study the correlation between cognitive subscores and disease duration. The Wilcoxon signed-rank test was used for within-group analysis among ACE cognitive subscores.

RESULTS

Significant difference was found between ACE total scores among groups (χ2 = 119.1; p < 0.001) with a high negative correlation (p < 0.001; r = -0.643). With a longer disease duration, all the subscores of ACE significantly decreased (p-values < 0.001). The visuospatial score showed the strongest negative correlation with disease duration with a linear trajectory in decline (r = -0.85). In the early phase of cognitive decline, verbal fluency was the most impaired cognitive subdomain (normalized value = 0.64), and it was significantly reduced compared to all other subdomains (p-values < 0.05).

CONCLUSION

We found that the impairment of verbal fluency is the most characteristic feature of early cognitive decline; therefore, it might have crucial importance in the early detection of AD. Based on our results, the visuospatial assessment might be an ideal marker to monitor the progression of cognitive decline in AD.

Try to see it my way - Examining the relationship between visual perspective taking and theory of mind in frontotemporal dementia

The behavioural variant of frontotemporal dementia (bvFTD) is characterised by pronounced alterations in social functioning, including the understanding of others' thoughts and feelings via theory of mind. The emergence of such impairments in other social disorders such as autism and schizophrenia is suggested to reflect an inability to imagine the other person's visual perspective of the world. To our knowledge, relationships between visual perspective taking and theory of mind have not previously been explored in bvFTD. Here, we sought to examine the capacity for visual perspective taking and theory of mind in bvFTD, and to establish their inter-relationships and underlying neural correlates. Fifteen bvFTD patients and 15 healthy Controls completed a comprehensive battery of perspective taking measures, comprising Level 1 ('what') and Level 2 ('how') visual perspective taking tasks, a cartoon task capturing theory of mind, and a questionnaire assessing subjective perspective taking in daily life. Compared with Controls, bvFTD patients displayed significant impairments across all perspective taking measures. These perspective taking impairments, however, were not correlated with one another in bvFTD. Region-of-interest voxel-based morphometry analyses suggested distinct neural correlates for visual perspective taking (inferior frontal gyrus) versus theory of mind (medial prefrontal cortex, precuneus), which appeared to partially overlap with those implicated in subjective perspective taking (inferior frontal gyrus, precuneus, temporoparietal junction). Despite pervasive impairments in all aspects of perspective taking in bvFTD, these did not appear to relate to one another at the behavioural or neural level in our study. Future large-scale studies manipulating discrete aspects of the tasks will help to clarify the neurocognitive mechanisms of, and relationships between, visual perspective taking and theory of mind in bvFTD, along with their real-world implications.

Putting the Pieces Together: Mental Construction of Semantically Congruent and Incongruent Scenes in Dementia

Scene construction refers to the process by which humans generate richly detailed and spatially cohesive scenes in the mind’s eye. The cognitive processes that underwrite this capacity remain unclear, particularly when the envisaged scene calls for the integration of various types of contextual information. Here, we explored social and non-social forms of scene construction in Alzheimer’s disease (AD; n = 11) and the behavioural variant of frontotemporal dementia (bvFTD; n = 15) relative to healthy older control participants (n = 16) using a novel adaptation of the scene construction task. Participants mentally constructed detailed scenes in response to scene–object cues that varied in terms of their sociality (social; non-social) and congruence (congruent; incongruent). A significant group × sociality × congruence interaction was found whereby performance on the incongruent social scene condition was significantly disrupted in both patient groups relative to controls. Moreover, bvFTD patients produced significantly less contextual detail in social relative to non-social incongruent scenes. Construction of social and non-social incongruent scenes in the patient groups combined was significantly associated with independent measures of semantic processing and visuospatial memory. Our findings demonstrate the influence of schema-incongruency on scene construction performance and reinforce the importance of episodic–semantic interactions during novel event construction.

Spatio-Semantic Graphs From Picture Description: Applications to Detection of Cognitive Impairment

Clinical assessments often use complex picture description tasks to elicit natural speech patterns and magnify changes occurring in brain regions implicated in Alzheimer's disease and dementia. As The Cookie Theft picture description task is used in the largest Alzheimer's disease and dementia cohort studies available, we aimed to create algorithms that could characterize the visual narrative path a participant takes in describing what is happening in this image. We proposed spatio-semantic graphs, models based on graph theory that transform the participants' narratives into graphs that retain semantic order and encode the visuospatial information between content units in the image. The resulting graphs differ between Cognitively Impaired and Unimpaired participants in several important ways. Cognitively Impaired participants consistently scored higher on features that are heavily associated with symptoms of cognitive decline, including repetition, evidence of short-term memory lapses, and generally disorganized narrative descriptions, while Cognitively Unimpaired participants produced more efficient narrative paths. These results provide evidence that spatio-semantic graph analysis of these tasks can generate important insights into a participant's cognitive performance that cannot be generated from semantic analysis alone.

The Visuospatial and Sensorimotor Functions of Posterior Parietal Cortex in Drawing Tasks: A Review

Drawing is a comprehensive skill that primarily involves visuospatial processing, eye-hand coordination, and other higher-order cognitive functions. Various drawing tasks are widely used to assess brain function. The neuropsychological basis of drawing is extremely sophisticated. Previous work has addressed the critical role of the posterior parietal cortex (PPC) in drawing, but the specific functions of the PPC in drawing remain unclear. Functional magnetic resonance imaging and electrophysiological studies found that drawing activates the PPC. Lesion-symptom mapping studies have shown an association between PPC injury and drawing deficits in patients with global and focal cerebral pathology. These findings depicted a core framework of the fronto-parietal network in drawing tasks. Here, we review neuroimaging and electrophysiological studies applying drawing paradigms and discuss the specific functions of the PPC in visuospatial and sensorimotor aspects. Ultimately, we proposed a hypothetical model based on the dorsal stream. It demonstrates the organization of a PPC-centered network for drawing and provides systematic insights into drawing for future neuropsychological research.

Early Impairment in the Ventral Visual Pathway Can Predict Conversion to Dementia in Patients With Amyloid-negative Amnestic Mild Cognitive Impairment

BACKGROUND

Around 15% to 20% of patients with clinically probable Alzheimer disease have been found to have no significant Alzheimer pathology on amyloid positron emission tomography. A previous study showed that conversion to dementia from amyloid-negative mild cognitive impairment (MCI) was observed in up to 11% of patients, drawing attention to this condition.

OBJECT

We gathered the detailed neuropsychological and neuroimaging data of this population to elucidate factors for conversion to dementia from amyloid-negative amnestic MCI.

METHODS

This study was a single-institutional, retrospective cohort study of amyloid-negative MCI patients over age 50 with at least 36 months of follow-up. All subjects underwent detailed neuropsychological testing, 3 tesla brain magnetic resonance imaging), and fluorine-18(18F)-florbetaben amyloid positron emission tomography scans.

RESULTS

During the follow-up period, 39 of 107 (36.4%) patients converted to dementia from amnestic MCI. The converter group had more severe impairment in all visual memory tasks. The volumetric analysis revealed that the converter group had significantly reduced total hippocampal volume on the right side, gray matter volume in the right lateral temporal, lingual gyri, and occipital pole.

CONCLUSION

Our study showed that reduced gray matter volume related to visual memory processing may predict clinical progression in this amyloid-negative MCI population.

Overview of the Complex Figure Test and Its Clinical Application in Neuropsychiatric Disorders, Including Copying and Recall

The Rey–Osterrieth Complex Figure (ROCF) test is a commonly used neuropsychological assessment tool. It is widely used to assess the visuo-constructional ability and visual memory of neuropsychiatric disorders, including copying and recall tests. By drawing the complex figure, the functional decline of a patient in multiple cognitive dimensions can be assessed, including attention and concentration, fine-motor coordination, visuospatial perception, non-verbal memory, planning and organization, and spatial orientation. This review first describes the different versions and scoring methods of ROCF. It then reviews the application of ROCF in the assessment of visuo-constructional ability in patients with dementia, other brain diseases, and psychiatric disorders. Finally, based on the scoring method of the digital system, future research hopes to develop a new digital ROCF scoring method combined with machine learning algorithms to standardize clinical practice and explore the characteristic neuropsychological structure information of different disorders.

Visuospatial alpha and gamma oscillations scale with the severity of cognitive dysfunction in patients on the Alzheimer's disease spectrum

Background

Entrainment of neural oscillations in occipital cortices by external rhythmic visual stimuli has been proposed as a novel therapy for patients with Alzheimer’s disease (AD). Despite this increased interest in visual neural oscillations in AD, little is known regarding their role in AD-related cognitive impairment and in particular during visuospatial processing.

Methods

We used source-imaged magnetoencephalography (MEG) and an established visuospatial processing task to elicit multi-spectral neuronal responses in 35 biomarker-confirmed patients on the AD spectrum and 20 biomarker-negative older adults. Neuronal oscillatory responses were imaged to the level of the cortex, and group classifications and neurocognitive relationships were modeled using logistic and linear regression, respectively.

Results

Visuospatial neuronal oscillations in the theta, alpha, and gamma ranges significantly predicted the classification of patients on the AD spectrum. Importantly, the direction of these effects differed by response frequency, such that patients on the AD spectrum exhibited weaker alpha-frequency responses in lateral occipital regions, and stronger gamma-frequency responses in the primary visual cortex, as compared to biomarker-negative older adults. In addition, alpha and gamma, but not theta, oscillations robustly predicted cognitive status (i.e., MoCA and MMSE scores), such that patients with neural responses that deviated more from those of healthy older adults exhibited poorer cognitive performance.

Conclusions

We find that the multi-spectral neural dynamics supporting visuospatial processing differentiate patients on the AD spectrum from cognitively normal, biomarker-negative older adults. Oscillations in the alpha and gamma bands also relate to cognitive status in ways that are informative for emerging clinical interventions.

The Box Task: A novel tool to differentiate the primary progressive aphasias

OBJECTIVE

Differentiating the primary progressive aphasia (PPA) variants in clinical settings remains complex and challenging, especially for the logopenic (lv-PPA) and non-fluent variants (nfv-PPA). Recent studies suggest that visuospatial memory is more compromised in lv-PPA than in nfv-PPA and is relatively spared in the semantic variant (sv-PPA). Accordingly, assessment of visuospatial memory performance may assist in the differential diagnosis of PPA variants. Here, we investigated the utility of a novel computerised visuospatial working memory test-the Box Task-to differentiate the three PPA variants and typical Alzheimer's disease (AD).

METHODS

Eighteen lv-PPA, 14 nfv-PPA, 23 sv-PPA, 33 AD patients, and 32 healthy controls matched for age and education were recruited. All participants completed the computerised Box Task and WMS-III Spatial Span as measures of visuospatial working memory.

RESULTS

The lv-PPA group made significantly more Box Task between-search errors than nfv-PPA, sv-PPA and control groups. The AD group, however, displayed the greatest impairments on this measure relative to the PPA variants. Logistic regression analyses in lv-PPA and nfv-PPA demonstrated that the combination of Box Task between-search error variables (i.e., 4- and 6-box levels) could correctly classify 72% of lv-PPA patients and nearly 79% of nfv-PPA patients. Area under the receiver operator characteristics curve (AUC) analyses revealed the Box Task was more sensitive than Spatial Span at differentiating lv-PPA from nfv-PPA.

CONCLUSIONS

Our findings suggest that a simple, computerised measure of visuospatial working memory-the Box Task-shows potential diagnostic utility in differentiating lv-PPA from the other PPA variants.

A matter of quality: Kurt Goldstein's assessment of the abstract attitude after brain damage

Neurologist and psychiatrist Kurt Goldstein (1878-1965) made substantial contributions to neuropsychology in general and to the development of tests for the assessment of brain damage sequelae in particular. Unlike present-day neuropsychology's psychometric orientation, Goldstein kept a critical distance to a mere quantitative evaluation. Eighty years ago, he impressively demonstrated his own, qualitatively oriented diagnostic approach both in a remarkable monograph and in a didactic film, in collaboration with psychologist Martin Scheerer (1900-1961). By modifying a classical paradigm for the assessment of deficits in visuospatial construction, the Block Design Test, the two authors developed the Goldstein-Scheerer Cube Test. This version characterizes itself by offering the patient different types of cues in order to reveal the nature of the deficit at stake. The test remains an impressive illustration of Goldstein's most famous neuropsychological concept, viz. the human ability to abstract from a concrete situation: the abstract (or categorial) attitude.

To Explore the Predictive Power of Visuomotor Network Dysfunctions in Mild Cognitive Impairment and Alzheimer's Disease

Background

Research into Alzheimer’s disease has shifted toward the identification of minimally invasive and less time-consuming modalities to define preclinical stages of Alzheimer’s disease.

Method

Here, we propose visuomotor network dysfunctions as a potential biomarker in AD and its prodromal stage, mild cognitive impairment with underlying the Alzheimer’s disease pathology. The functionality of this network was tested in terms of timing, accuracy, and speed with goal-directed eye-hand tasks. The predictive power was determined by comparing the classification performance of a zero-rule algorithm (baseline), a decision tree, a support vector machine, and a neural network using functional parameters to classify controls without cognitive disorders, mild cognitive impaired patients, and Alzheimer’s disease patients.

Results

Fair to good classification was achieved between controls and patients, controls and mild cognitive impaired patients, and between controls and Alzheimer’s disease patients with the support vector machine (77–82% accuracy, 57–93% sensitivity, 63–90% specificity, 0.74–0.78 area under the curve). Classification between mild cognitive impaired patients and Alzheimer’s disease patients was poor, as no algorithm outperformed the baseline (63% accuracy, 0% sensitivity, 100% specificity, 0.50 area under the curve).

Comparison with Existing Method(s)

The classification performance found in the present study is comparable to that of the existing CSF and MRI biomarkers.

Conclusion

The data suggest that visuomotor network dysfunctions have potential in biomarker research and the proposed eye-hand tasks could add to existing tests to form a clear definition of the preclinical phenotype of AD.

Smart Health System to Detect Dementia Disorders Using Virtual Reality

Smart health technology includes physical sensors, intelligent sensors, and output advice to help monitor patients’ health and adjust their behavior. Virtual reality (VR) plays an increasingly larger role to improve health outcomes, being used in a variety of medical specialties including robotic surgery, diagnosis of some difficult diseases, and virtual reality pain distraction for severe burn patients. Smart VR health technology acts as a decision support system in the diseases diagnostic test of patients as they perform real world tasks in virtual reality (e.g., navigation). In this study, a non-invasive, cognitive computerized test based on 3D virtual environments for detecting the main symptoms of dementia (memory loss, visuospatial defects, and spatial navigation) is proposed. In a recent study, the system was tested on 115 real patients of which thirty had a dementia, sixty-five were cognitively healthy, and twenty had a mild cognitive impairment (MCI). The performance of the VR system was compared with Mini-Cog test, where the latter is used to measure cognitive impaired patients in the traditional diagnosis system at the clinic. It was observed that visuospatial and memory recall scores in both clinical diagnosis and VR system of dementia patients were less than those of MCI patients, and the scores of MCI patients were less than those of the control group. Furthermore, there is a perfect agreement between the standard methods in functional evaluation and navigational ability in our system where P-value in weighted Kappa statistic= 100% and between Mini-Cog-clinical diagnosis vs. VR scores where P-value in weighted Kappa statistic= 93%.

Reliability of Telephone and Videoconference Methods of Cognitive Assessment in Older Adults with and without Dementia

BACKGROUND

Telephone and videoconference administration of cognitive tests introduce additional sources of variance compared to in-person testing. Reviews of test-retest reliability have included mixed neurocognitive and psychiatric populations with limited consideration of methodological and statistical contributions.

OBJECTIVE

We reviewed reliability estimates from comparison studies of older adults with and without dementia, considering test-retest analyses and study methods.

METHODS

Medline, Embase, PsycINFO, and Web of Science were systematically searched from 1 January 2000 to 9 June 2020 for original articles comparing telephone or videoconference administered cognitive instruments to in-person administration in older adults with and without dementia or mild cognitive impairment.

RESULTS

Of 4,125 articles, 23 were included: 11 telephone (N = 2 dementia cohorts) and 12 videoconference (N = 4 dementia cohorts). Telephone administered subtest scores trended in the same direction as in-person with comparable means. Person-level data were scarce. Data on dementia was only available for MMSE, with resulting subtle modality bias. MMSE, SMMSE, Letter Fluency, and HVLT-R in healthy to mild-moderate Alzheimer's disease were particularly reliable for videoconference administration. Other tests show promise but require more observations and comprehensive analyses. Most studies used high-speed stable videoconferencing hardware resulting in a lack of ecological validity for home administration.

CONCLUSION

Remote administration is often consistent with in-person administration but variable and limited at the person/test level. Improved statistical design and inclusion of dementia related cohorts in telephone studies is recommended. Reliability evidence is stronger for videoconferencing but with limited applicability to home administration and severe dementia. Improved reporting of administrative procedures is recommended.

Alzheimer's Disease or Behavioral Variant Frontotemporal Dementia? Review of Key Points Toward an Accurate Clinical and Neuropsychological Diagnosis

Alzheimer's disease (AD) and frontotemporal dementia (FTD) are the most common neurodegenerative early-onset dementias. Despite the fact that both conditions have a very distinctive clinical pattern, they present with an overlap in their cognitive and behavioral features that may lead to misdiagnosis or delay in diagnosis. The current review intends to summarize briefly the main differences at the clinical, neuropsychological, and behavioral levels, in an attempt to suggest which aspects would facilitate an adequate diagnosis in a clinical setting, especially in Latin American and low- and middle-income countries, where the resources needed for a differential diagnosis (such as MRI or biomarkers) are not always available. A timely diagnosis of AD and FTD have significant implications for the medical management and quality of life of patients and careers.

Neuropsychological profile in the preclinical stages of dementia: principal component analysis approach

The preclinical stages of dementia include subtle neurocognitive changes that are not easily detected in standard clinical evaluations. Neuropsychological evaluation is important for the classification and prediction of deterioration in all the phases of dementia.

Harnessing Visual Imagery and Oculomotor Behaviour to Understand Prospection

Much of the rich internal world constructed by humans is derived from, and experienced through, visual mental imagery. Despite growing appreciation of visual exploration in guiding episodic memory processes, extant theories of prospection have yet to accommodate the precise role of visual mental imagery in the service of future-oriented thinking. We propose that the construction of future events relies on the assimilation of perceptual details originally experienced, and subsequently reinstantiated, predominantly in the visual domain. Individual differences in the capacity to summon discrete aspects of visual imagery can therefore account for the diversity of content generated by humans during future simulation. Our integrative framework provides a novel testbed to query alterations in future thinking in health and disease.