How preserved is emotion recognition in Alzheimer disease compared with behavioral variant frontotemporal dementia?

Background: Emotion deficits are a recognised biomarker for behavioural variant frontotemporal dementia (bvFTD), but recent studies have reported emotion deficits also in Alzheimer’s disease (AD). Methods: A hundred and twenty-three participants (33 AD, 60 bvFTD, 30 controls) were administered a facial emotion recognition test, to investigate the clinical factors influencing the diagnostic distinction on this measure. Binomial regression analysis revealed that facial emotion recognition in AD was influenced by disease duration and MMSE, whereas the same was not true for bvFTD. Based on this information, we median-split the AD group on disease duration (3 years) or MMSE (24) and compared the facial emotion recognition performance of mild-AD, moderate-AD, bvFTD patients and controls. Results: Results showed that very mild-AD performed consistently at control levels for all emotions. By contrast, mild/moderate-AD and bvFTD were impaired compared to controls on most emotions. Interestingly, mild/moderate-AD were significantly impaired compared to very mild-AD on total score, anger and sadness subscores. Logistic regression analyses corroborated these findings with ~94% of very mild-AD being successfully distinguished from bvFTD at presentation, while this distinction was reduced to ~78% for mild/moderate-AD. Conclusions: Facial emotion recognition in AD is influenced by disease progression, with very mild-AD being virtually intact for emotion performance. Mild/moderate-AD and bvFTD show consistent impairment in emotion recognition, with bvFTD being worse. A disease progression of over 3 years or a MMSE lower than 24 should warrant caution to put too much emphasis on emotion recognition performance in the diagnostic distinction of AD and bvFTD

In two minds: executive functioning versus theory of mind in behavioural variant frontotemporal dementia

Background: The relationship of executive function (EF) and theory of mind (ToM) deficits in neurodegeneration is still debated. There is contradicting evidence as to whether these cognitive processes are overlapping or distinct, which has clear clinical relevance for the evaluation of their associated clinical symptoms. Aim: To investigate the relationship of EF and ToM deficits via a data-driven approach in a large sample of patients with behavioural variant frontotemporal dementia (bvFTD). Methods: Data of 46 patients with bvFTD were employed in a hierarchical cluster analysis to determine the similarity of variance between different EF measures (verbal abstraction, verbal initiation, motor programming, sensitivity to interference, inhibitory control, visual abstraction, flexibility, working memory/attention) and ToM (faux pas). Results: Overall results showed that EF measures were clustered separately from the ToM measure. A post hoc analysis revealed a more complex picture where selected ToM subcomponents (empathy; intention) showed a relationship to specific EF measures (verbal abstraction; working memory/attention), whereas the remaining EF and ToM subcomponents were separate. Conclusions: Taken together, these findings suggest that EF and ToM are distinct components; however, ToM empathy and intention subcomponents might share some functions with specific EF processes. This has important implications for guiding diagnostic assessment of these deficits in clinical conditions

Social cognition deficits: the key to discriminate behavioral variant frontotemporal dementia from Alzheimer’s disease regardless of amnesia?

Relative sparing of episodic memory is a diagnostic criterion of behavioral variant frontotemporal dementia (bvFTD). However, increasing evidence suggests that bvFTD patients can show episodic memory deficits at a similar level as Alzheimer’s disease (AD). Social cognition tasks have been proposed to distinguish bvFTD, but no study to date has explored the utility of such tasks for the diagnosis of amnestic bvFTD. Here, we contrasted social cognition performance of amnestic and non-amnestic bvFTD from AD, with a subgroup having confirmed in vivo pathology markers. Ninety-six participants (38 bvFTD and 28 AD patients as well as 30 controls) performed the short Social-cognition and Emotional Assessment (mini-SEA). BvFTD patients were divided into amnestic versus non-amnestic presentation using the validated Free and Cued Selective Reminding Test (FCSRT) assessing episodic memory. As expected, the accuracy of the FCSRT to distinguish the overall bvFTD group from AD was low (69.7% ) with ∼50% of bvFTD patients being amnestic. By contrast, the diagnostic accuracy of the mini-SEA was high (87.9% ). When bvFTD patients were split on the level of amnesia, mini-SEA diagnostic accuracy remained high (85.1% ) for amnestic bvFTD versus AD and increased to very high (93.9% ) for non-amnestic bvFTD versus AD. Social cognition deficits can distinguish bvFTD and AD regardless of amnesia to a high degree and provide a simple way to distinguish both diseases at presentation. These findings have clear implications for the diagnostic criteria of bvFTD. They suggest that the emphasis should be on social cognition deficits with episodic memory deficits not being a helpful diagnostic criterion in bvFTD

A comparison of magnetic resonance imaging and neuropsychological examination in the diagnostic distinction of Alzheimer’s disease and behavioral variant frontotemporal dementia

The clinical distinction between Alzheimer's disease (AD) and behavioral variant frontotemporal dementia (bvFTD) remains challenging and largely dependent on the experience of the clinician. This study investigates whether objective machine learning algorithms using supportive neuroimaging and neuropsychological clinical features can aid the distinction between both diseases. Retrospective neuroimaging and neuropsychological data of 166 participants (54 AD; 55 bvFTD; 57 healthy controls) was analyzed via a Naïve Bayes classification model. A subgroup of patients (n = 22) had pathologically-confirmed diagnoses. Results show that a combination of gray matter atrophy and neuropsychological features allowed a correct classification of 61.47% of cases at clinical presentation. More importantly, there was a clear dissociation between imaging and neuropsychological features, with the latter having the greater diagnostic accuracy (respectively 51.38 vs. 62.39%). These findings indicate that, at presentation, machine learning classification of bvFTD and AD is mostly based on cognitive and not imaging features. This clearly highlights the urgent need to develop better biomarkers for both diseases, but also emphasizes the value of machine learning in determining the predictive diagnostic features in neurodegeneration

Judgments about moral responsibility and determinism in patients with behavioural variant of frontotemporal dementia: Still compatibilists

Do laypeople think that moral responsibility is compatible with determinism? Recently, philosophers and psychologists trying to answer this question have found contradictory results: while some experiments reveal people to have compatibilist intuitions, others suggest that people could in fact be incompatibilist. To account for this contradictory answers, Nichols and Knobe (2007) have advanced a 'performance error model' according to which people are genuine incompatibilist that are sometimes biased to give compatibilist answers by emotional reactions. To test for this hypothesis, we investigated intuitions about determinism and moral responsibility in patients suffering from behavioural frontotemporal dementia. Patients suffering from bvFTD have impoverished emotional reaction. Thus, the 'performance error model' should predict that bvFTD patients will give less compatibilist answers. However, we found that bvFTD patients give answers quite similar to subjects in control group and were mostly compatibilist. Thus, we conclude that the 'performance error model' should be abandoned in favour of other available model that best fit our data

Determinants of Theory of Mind performance in Alzheimer’s disease: A data-mining study

Whether theory of mind (ToM) is preserved in Alzheimer’s disease (AD) remains a controversial subject. Recent studies have showed that performance on some ToM tests might be altered in AD, though to a lesser extent than in behavioural-variant Frontotemporal Dementia (bvFTD). It is however, unclear if this reflects a genuine impairment of ToM or a deficit secondary to the general cognitive decline observed in AD. Aiming to investigate the cognitive determinants of ToM performance in AD, a data-mining study was conducted in 29 AD patients then replicated in an independent age-matched group of 19 AD patients to perform an independent replication of the results. 44 bvFTD patients were included as a comparison group. All patients had an extensive neuropsychological examination. Hierarchical clustering analyses showed that ToM performance clustered with measures of executive functioning in AD. ToM performance was also specifically correlated with the executive component extracted from a principal component analysis. In a final step, automated linear modelling conducted to determine the predictors of ToM performance showed that 48.8% of ToM performance was significantly predicted by executive measures. Similar findings across analyses were observed in the independent group of AD patients, thereby replicating our results. Conversely, ToM impairments in bvFTD appeared independent of other cognitive impairments. These results suggest that difficulties of AD patients on ToM tests do not reflect a genuine ToM deficit, rather mediated by general (and particularly executive) cognitive decline. They also suggest that executive functioning has a key role in mental state attribution, which support interacting models of ToM functioning. Finally, our study highlights the relevancy of data-mining statistical approaches in clinical and cognitive neurosciences

Fronto-striatal atrophy in behavioural variant frontotemporal dementia & Alzheimer’s disease

Behavioral variant frontotemporal dementia (bvFTD) has only recently been associated with significant striatal atrophy, whereas the striatum appears to be relatively preserved in Alzheimer’s disease (AD). Considering the critical role the striatum has in cognition and behavior, striatal degeneration, together with frontal atrophy, could be responsible of some characteristic symptoms in bvFTD and emerges therefore as promising novel diagnostic biomarker to distinguish bvFTD and AD. Previous studies have, however, only taken either cortical or striatal atrophy into account when comparing the two diseases. In this study, we establish for the first time a profile of fronto-striatal atrophy in 23 bvFTD and 29 AD patients at presentation, based on the structural connectivity of striatal and cortical regions. Patients are compared to 50 healthy controls by using a novel probabilistic connectivity atlas, which defines striatal regions by their cortical white-matter connectivity, allowing us to explore the degeneration of the frontal and striatal regions that are functionally linked. Comparisons with controls revealed that bvFTD showed substantial fronto-striatal atrophy affecting the ventral as well as anterior and posterior dorso-lateral prefrontal cortices and the related striatal subregions. In contrast, AD showed few frontostriatal atrophy, despite having significant posterior dorso-lateral prefrontal degeneration. Direct comparison between bvFTD and AD revealed significantly more atrophy in the ventral striatal–ventromedial prefrontal cortex regions in bvFTD. Consequently, deficits in ventral fronto-striatal regions emerge as promising novel and efficient diagnosis biomarker for bvFTD. Future investigations into the contributions of these fronto-striatal loops on bvFTD symptomology are needed to develop simple diagnostic and disease tracking algorithms

Urban vulnerability and resilience to climate change: The case of the Guadalajara metropolitan area, Mexico

México participa en iniciativas y acuerdos relativos al cambio climático. Se han elaborado estudios e instrumentos legislativos para enfrentar el fenómeno. En la Zona Metropolitana de Guadalajara (ZMG), segunda área urbana de México, se han realizado estudios meteorológicos y geográficos de vulnerabilidad del territorio que ofrecen un panorama de dicha condición, la cual depende de las características físicas de la zona expuesta a los riesgos, como también de la vulnerabilidad estructural propia de las infraestructuras y equipamientos. Como consecuencia de eventos catastróficos se ven implicados los ámbitos de lo social y lo organizacional, la vinculación pública y privada; y la intersección entre ellos genera vulnerabilidad de interdependencia, por proximidades, interacciones e interfaces entre la ocupación de los espacios, los usos de suelo y las actividades en el territorio. La resiliencia urbana es comprendida aquí como la resistencia de un sistema que absorbe perturbaciones, se adapta y organiza para recobrar equilibrio similar y anterior al evento extremo.Mexico participates in initiatives and agreements on climate change. Studies have been carried out and legislation produced to address this phenomenon. In the Guadalajara Metropolitan Area (ZMG in Spanish), the second-largest urban area in Mexico, meteorological and geographical vulnerability studies of the territory have been done that offer an overview of the situation, which depends on the physical characteristics of the area at risk, as well as the structural vulnerability of the infrastructure and equipment. As a result of catastrophic events, social and organizational spheres become involved, public and private connect; and their intersection creates vulnerability interdependence, due to proximity, interactions and interfaces in the occupation of spaces, land use and activities in the territory. Urban resilience is understood here as the resistance of a system that absorbs disruptions, and adapts and organizes itself to regain a balance similar to that experienced prior to the extreme event

Categorization and Aging as measured by an adapted version of Wechsler’s similarities test

L’objectif de cette recherche est d’étudier l’évolution avec le vieillissement du processus taxonomique impliqué dans une version adaptée du test des Similitudes de Wechsler, qui distingue la catégorisation des mots concrets versus abstraits. Deux groupes ont été constitués : 20 adultes jeunes (M =20ans, SD=1.36) et 20 adultes âgés (M =70ans, SD=4.66). Les résultats montrent un déclin de la catégorisation taxonomique avec l’âge, notamment pour les mots abstraits. L’effet de concrétude est donc observé mais seulement chez les âgés du fait d’un effet « plafond » des performances chez les jeunes adultes. De plus, il s’avère que la moyenne des réponses taxonomiques des âgés est à peu près équivalente à celle d’enfants de 9 ans d’une étude antérieure. La courbe curvilinéaire du développement de la catégorisation taxonomique observée par de nombreux auteurs est donc retrouvée. Néanmoins, une analyse plus précise des items et des réponses montre que les âgés ont davantage de difficultés avec des mots faciles qu’avec des mots difficiles. Ce résultat suggère que le processus de catégorisation serait préservé mais que des variables affectives viendraient moduler l’activation du processus taxonomique.We used an adapted version of the Wechsler Similarities subtest to study taxonomic processing, the superordinate categorization of concrete and abstract words, in 20 young adult (M =20 years, SD=1.36) and 20 elderly (M =70 years, SD=4.66) subjects. Young adults performed near ceiling on both categorization tasks. Elderly subjects performed less well, especially with abstract words. Our results are consistent with the curvilinear function reported by many authors, which describes an increase in taxonomic processing from childhood to adulthood and then a decline as aging progresses. The mean performances of  the elderly adults studied here were about similar to the mean taxonomic scores in a group of 9 year-olds (Rozencwajg & Corroyer, 2007). An item analysis of the child and elderly data suggests that taxonomic processing is preserved in the elderly but that affective variables modulate response strategies