Deficits in Everyday Function Differ in AD and FTD

Validation of the Short Form of Korean-Everyday Cognition (K-ECog)

BACKGROUND

Evaluating the activities of daily living (ADL) is an important factor for diagnosing dementia. The Everyday Cognition (ECog) scale was developed to measure ADL changes that were correlated with specific neuropsychological impairments. A short form of the ECog (ECog-12) was also developed, consisting of 12 items, two from each of the six cognitive domains of the ECog. The Korean full version of ECog (K-ECog) has recently been standardized, but the need for a shortened version has been raised in clinical practice. The purpose of this study was to develop a Korean version of ECog-12 (K-ECog-12) and to verify its reliability and validity by comparing those to the full version of K-ECog.

METHODS

The participants were 267 cognitively normal older adults (CN), 183 patients with mild cognitive impairment (MCI), and 89 patients with dementia. The Korean-Mini Mental State Examination (K-MMSE), Korean-Montreal Cognitive Assessment (K-MoCA), and Short form of Geriatric Depression Scale (SGDS) were administered to all participants. The K-ECog and Korean-Instrumental Activities of Daily Living (K-IADL) were rated by the informants of patients.

RESULTS

K-ECog-12 was newly constructed by replacing one item for the visuospatial function in the original ECog-12 with another one through an item response theory analysis on Korean data. The internal consistencies (Cronbach's α) of K-ECog-12 and K-ECog were 0.95 and 0.99, respectively. The test-retest reliabilities (Pearson's r) were 0.67 for K-ECog-12 and 0.73 for K-ECog. The K-ECog-12 was significantly correlated with K-ECog as well as K-IADL, K-MMSE, and K-MoCA. The K-ECog-12 scores differed significantly between the CN, MCI, and dementia groups, as did the K-ECog scores. Receiver operating characteristic curve analyses showed that K-ECog-12, like K-ECog, could differentiate MCI and dementia patients from CN as well.

CONCLUSION

The K-ECog-12 is as reliable and valid as the K-ECog in assessing ADL. Therefore, K-ECog-12 can be used as an alternative to the K-ECog in clinical and community settings in Korea.

Pathological (Dis)Similarities in Neuronal Exosome-Derived Synaptic and Organellar Marker Levels Between Alzheimer's Disease and Frontotemporal Dementia

BACKGROUND

Alzheimer's disease (AD) and frontotemporal dementia (FTD) are pathologically distinct neurodegenerative disorders with certain overlap in cognitive and behavioral symptoms. Both AD and FTD are characterized by synaptic loss and accumulation of misfolded proteins, albeit, in different regions of the brain.

OBJECTIVE

To investigate the synaptic and organellar markers in AD and FTD through assessment of the levels of synaptic protein, neurogranin (Ng) and organellar proteins, mitofusin-2 (MFN-2), lysosomal associated membrane protein-2 (LAMP-2), and golgin A4 from neuronal exosomes.

METHODS

Exosomes isolated from the plasma of healthy controls (HC), AD and FTD subjects were characterized using transmission electron microscopy. Neurodegenerative status was assessed by measurement of neurofilament light chain (NfL) using Simoa. The pooled exosomal extracts from each group were analyzed for Ng, MFN-2, LAMP-2, and golgin A4 by western blot analysis using enhanced chemiluminescence method of detection.

RESULTS

The densitometric analysis of immunoreactive bands demonstrated a 65% reduction of Ng in AD and 53% in FTD. Mitochondrial protein MFN-2 showed a significant reduction by 32% in AD and 46% in FTD. Lysosomal LAMP-2 and Golgi complex associated golgin A4 were considerably increased in both AD and FTD.

CONCLUSION

Changes in Ng may reflect the ongoing synaptic degeneration that are linked to cognitive disturbances in AD and FTD. Importantly, the rate of synaptic degeneration was more pronounced in AD. Changes to a similar extent in both the dementia groups in organellar proteins indicates shared mechanisms of protein accumulation/degradation common to both AD and FTD.

Classification of Alzheimer's disease and frontotemporal dementia using routine clinical and cognitive measures across multicentric underrepresented samples: A cross sectional observational study

Background

Global brain health initiatives call for improving methods for the diagnosis of Alzheimer's disease (AD) and frontotemporal dementia (FTD) in underrepresented populations. However, diagnostic procedures in upper-middle-income countries (UMICs) and lower-middle income countries (LMICs), such as Latin American countries (LAC), face multiple challenges. These include the heterogeneity in diagnostic methods, lack of clinical harmonisation, and limited access to biomarkers.

Methods

This cross-sectional observational study aimed to identify the best combination of predictors to discriminate between AD and FTD using demographic, clinical and cognitive data among 1794 participants [904 diagnosed with AD, 282 diagnosed with FTD, and 606 healthy controls (HCs)] collected in 11 clinical centres across five LAC (ReDLat cohort).

Findings

A fully automated computational approach included classical statistical methods, support vector machine procedures, and machine learning techniques (random forest and sequential feature selection procedures). Results demonstrated an accurate classification of patients with AD and FTD and HCs. A machine learning model produced the best values to differentiate AD from FTD patients with an accuracy = 0.91. The top features included social cognition, neuropsychiatric symptoms, executive functioning performance, and cognitive screening; with secondary contributions from age, educational attainment, and sex.

Interpretation

Results demonstrate that data-driven techniques applied in archival clinical datasets could enhance diagnostic procedures in regions with limited resources. These results also suggest specific fine-grained cognitive and behavioural measures may aid in the diagnosis of AD and FTD in LAC. Moreover, our results highlight an opportunity for harmonisation of clinical tools for dementia diagnosis in the region.

Funding

This work was supported by the Multi-Partner Consortium to Expand Dementia Research in Latin America (ReDLat), funded by NIA/NIH (R01AG057234), Alzheimer's Association (SG-20-725707-ReDLat), Rainwater Foundation, Takeda (CW2680521), Global Brain Health Institute; as well as CONICET; FONCYT-PICT (2017-1818, 2017-1820); PIIECC, Facultad de Humanidades, Usach; Sistema General de Regalías de Colombia (BPIN2018000100059), Universidad del Valle (CI 5316); ANID/FONDECYT Regular (1210195, 1210176, 1210176); ANID/FONDAP (15150012); ANID/PIA/ANILLOS ACT210096; and Alzheimer's Association GBHI ALZ UK-22-865742.

Diminished Visual Attention to Emotional Faces Is Associated with Poor Emotional Valence Perception in Frontotemporal Dementia

AIM

The current study examined whether visual attention to emotional facial expressions is lower in individuals with frontotemporal dementia (FTD) compared to healthy controls, and whether visual attention to emotional facial expressions is associated with the ability to perceive others' emotional valence accurately.

METHODS

Participants with FTD (n = 17) and healthy controls (n = 23) passively viewed pairs of emotional and neutral faces while their visual attention was measured using eye-tracking. A subsample of participants (n = 28) also completed an emotional valence perception task.

RESULTS

Individuals with FTD spent less time looking at emotional faces than healthy controls. However, there was no difference in the amount of time individuals with FTD spent looking at neutral faces as compared to healthy controls. In the subsample, less time spent looking at emotional faces (but not neutral faces) was associated with a less accurate perception of others' emotional valence.

CONCLUSION

Individuals with FTD displayed diminished visual attention to emotional facial expressions compared to healthy controls. Reduced attention towards emotional faces was associated with poorer emotional valence perception. Findings point toward diminished visual attention as potentially relevant for understanding oft-observed impairments in socioemotional functioning in FTD.

The Measurement of Everyday Cognition (ECog): Revisions and Updates

INTRODUCTION

The Everyday Cognition scale (ECog), a measure of everyday functioning developed in 2008, is sensitive to early detection and progression of neurodegenerative disease. The goal was to update ECog item content to ensure relevancy to contemporary older adults from diverse backgrounds.

METHODS

Participants included 44 culturally diverse older adults (18 with normal cognition, 11 with mild cognitive impairment) and their study partners. Item understandability and relevance was evaluated using iterative interviewing methods that were analyzed using standard qualitative methods. On the basis of this information, items were modified, deleted, or developed as needed.

RESULTS

Of the 39 original items, 19 were revised, 3 new items were added (primarily to cover contemporary activities such as the use of technology), and 1 was deleted. The revised version (ECog-II) includes 41 items.

DISCUSSION

To ensure strong psychometric properties, and to facilitate harmonization of previously collected data, we preserved well over half of the items. Future work will validate the revised ECog by measuring associations with neuropsychological performance, external measures of disease, and other functional measures. Overall, the revised ECog will continue to be a useful tool for measuring cognitively relevant everyday abilities in clinical settings and intervention clinical trials.

Tremor Distribution and the Variable Clinical Presentation of Essential Tremor

In addition to having postural and kinetic tremor of the upper limbs, some patients with essential tremor (ET) may have head tremor as well as cognitive and psychiatric disorders. We aimed to investigate whether the variable clinical presentation in ET patients, including motor and non-motor symptoms, differs in patients with and without head tremor. We consecutively enrolled 70 patients with a diagnosis of ET. Tremor severity was assessed by means of clinical rating scales. Patients also underwent kinematic recordings of postural and kinetic tremor of the upper limbs based on an optoelectronic system. Several neuropsychological tests were also administered. Finally, we adopted the structured interviews for DSM-IV, SCID-I, and SCID-II to investigate psychiatric and personality disorders. ET patients with upper limb tremor plus head tremor exhibited more severe kinetic tremor of the upper limbs and a higher occurrence of axis I psychiatric disorders than ET patients with upper limb tremor only. Cognitive and other motor and psychiatric features did not differ significantly with respect to tremor distribution. The study findings support the hypothesis that body tremor distribution, i.e., the presence of head tremor, influences the variable clinical presentation of ET. The study results support the notion that cases with head tremor may represent a distinct ET subtype, characterized by a prominent cerebellar involvement, and that psychiatric disorders should be considered as a specific manifestation of ET.

A meta-analysis of neuropsychological, social cognitive, and olfactory functioning in the behavioral and language variants of frontotemporal dementia

BACKGROUND

Though meta-analyses of neuropsychological and social cognitive deficits in behavioral variant frontotemporal dementia (bvFTD) have been conducted, no study has comprehensively characterized and compared the neuropsychological, social cognitive, and olfactory profiles in the behavioral and language variants of FTD.

METHODS

Our search yielded 470 publications meeting inclusion criteria representing 11 782 FTD patients and 19 451 controls. For each domain, we calculated Hedges' g effect sizes, which represent the mean difference between the patient and control group divided by the pooled standard deviation. The heterogeneity of these effects was assessed with Cochran's Q-statistic using a random-effects model. Meta-regressions were employed to analyze the influence of demographic and disease characteristics.

RESULTS

Though semantic variant primary progressive aphasia patients showed the greatest impairment across all task types, the three groups showed similar cognitive effect sizes once contributions from the language subdomain were excluded from analysis. Contrary to expectation, the magnitude of deficits in executive functioning, social cognition and olfaction were comparable between the three subgroups. Among indices, a metric of executive errors distinguished the behavioral variant of FTD from the language phenotypes.

CONCLUSIONS

These data indicate that social cognitive and traditional executive functioning measures may not capture differences between FTD syndromes. These results have important implications for the interpretation of neuropsychological assessments, particularly when applied to the differential diagnosis of FTD. It is hoped that these findings will guide clinical and research assessments and spur new studies focused on improving the measurement of FTD syndromes.

Everyday Language Difficulties in Parkinson's Disease: Caregiver Description and Relationship With Cognition, Activities of Daily Living, and Motor Disability

Purpose Parkinson's disease (PD) impacts language in multiple ways, though important questions remain. The current article explores 2 main issues: what type of everyday language difficulties (ELDs) are noted by care partners and how do ELDs relate to cognition, daily activities, and motor disability in PD. Method Care partner reports of ELD were collected in 42 community-dwelling individuals with PD. Descriptive information of ELD was tallied, and the relationship of cognitive decline, activities of daily living (ADLs), and motor disability with ELD was evaluated. Results Forty-two percent of patients were described by care partners as having at least 1 consistent ELD, and the frequency of ELD increased in the presence of dementia, χ²(2) = 14.37, p = .0008. The most commonly described ELDs by caregivers were related to comprehension of instructions and deriving the point of conversations. ELD was correlated with worse cognition ( r _s = -.524, p < .001), increased difficulty with daily activities ( r _s = .634, p < .001), and increased motor dysfunction ( r _s = .554, p < .001). Mild ADL decline (Functional Assessment Questionnaire score of 4); an area under the curve of .81 ( SE = .07) was highly specific to the presence of ELD (95.4%). Conclusions Care partners note a variety of ELDs in patients with PD, most commonly comprehension difficulties. These difficulties increase with overall cognitive decline but are described in 30%-40% of those without significant cognitive deficits. ADL difficulties correlate with functional, motoric, and cognitive status, with even mild functional declines predictive of the presence of ELD. Implications for research and practice in this population are discussed.

Executive functioning: perspectives on neurotrophic activity and pharmacology

Executive functioning is a high-level cognitive ability, regulating other abilities and behaviors to achieve desired goals. A typical executive task can be defined as the capacity to maintain one's attention on the current task, that is, responding only to the correct but not to distractive stimuli. Impairments of executive functions, or executive dysfunctions, have a growing impact on everyday life and academic achievement and are usually an early feature, and one of the core features, in brain injury and memory and behavioral disorders. Furthermore, emerging evidence indicates that memory therapeutics cannot achieve their clinical benefits in cognition if executive dysfunction is not effectively and simultaneously treated. Improvement of executive functions might be achieved through targeting some signaling pathways in the brain, including the brain-derived neurotrophic factor signaling pathways. These agents may be useful either as stand-alone interventions for patients with executive dysfunction and/or psychiatric and memory disorders or as essential adjuncts to drugs that target the underlying pathology in various brain injury and memory and behavioral disorders.

The Everyday Cognition Scale in Parkinson's disease

This brief report describes caregiver ratings on the Everyday Cognition (ECog) scale, a psychometrically robust measure of cognitively driven daily activities that was initially designed for other neurodegenerative conditions, in individuals with Parkinson's disease (PD). In 49 individuals with PD, those with suspected PD dementia had more difficulties across ECog domains than those with normal cognition or mild cognitive impairment. Results from multiple regression analyses revealed that activities captured by the ECog were related to measured cognitive ability, over and above disease duration and demographic factors. The lack of floor and ceiling effects speaks to the potential utility of the instrument in practice and research regarding this population. Preliminary data support the utility of the ECog as a marker of functional impact of cognitive problems in PD, though further research will be required to validate the instrument in this population.

Everyday cognition scales are related to cognitive function in the early stage of probable Alzheimer's disease and FDG-PET findings

We applied the Everyday Cognition (ECog) scale in normal aging adults and patients with Alzheimer’s disease (AD) to investigate associations between neuropsychological tests and neuroimaging markers. A total of 160 normal aging adults and 40 patients with the early stage of probable AD were included. Neuropsychological performance was assessed using the Consortium to Establish a Registry for Alzheimer’s Disease Neuropsychological Assessment Battery (CERAD-NAB). ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) scans were used to measure AD-related hypometabolism. Nonparametric Spearman correlation analysis was used to study associations between ECog and z-transformed total CERAD-NAB scores in both groups. The results revealed a significant correlation between total ECog and CERAD-NAB scores (rho = −0.28, p < 0.01), and category verbal fluency test with the executive domain of the ECog scale (rho = −0.20, p < 0.01). The CERAD-NAB scores were also significantly correlated with AD-related hypometabolism (rho = −0.49, p < 0.01). The memory domain of the ECog scale was significantly correlated with FDG uptake in the angular gyrus and posterior cingulum gyrus (rho = −0.41 and −0.46, P < 0.01). In conclusion, both total and memory domain ECog scores were correlated with the neuropsychological tests and neuroimaging biomarkers.