A scale of socioemotional dysfunction in frontotemporal dementia

Socioemotional Dysfunction From Temporal Lobe Involvement in Frontotemporal Dementia: A Preliminary Report

OBJECTIVE

Socioemotional changes, rather than cognitive impairments, are the feature that defines behavioral variant frontotemporal dementia (bvFTD). Investigators have attributed the socioemotional changes in bvFTD and other dementias to frontal lobe dysfunction; however, recent work implies a further contribution from right anterior temporal disease. The authors evaluated relationships between regional brain atrophy and socioemotional changes in both bvFTD and early-onset Alzheimer's disease (EOAD).

METHODS

This study explored the neuroanatomical correlations of performance on the Socioemotional Dysfunction Scale (SDS), an instrument previously shown to document socioemotional changes in bvFTD, among 13 patients with bvFTD not preselected for anterior temporal involvement and 16 age-matched patients with early-onset Alzheimer's disease (EOAD). SDS scores were correlated with volumes of regions of interest assessed with tensor-based morphometric analysis of MRI images.

RESULTS

As expected, the bvFTD group had significantly higher SDS scores overall and smaller frontal regions compared with the EOAD group, which in turn had smaller volumes in temporoparietal regions. SDS scores significantly correlated with lateral anterior temporal lobe (ATL) atrophy, and a regression analysis that controlled for diagnosis indicated that SDS scores predicted lateral ATL volume. Within the bvFTD group, higher SDS scores were associated with smaller lateral and right ATL regions, as well as a smaller orbitofrontal cortex. Within the EOAD group, higher SDS scores were associated with a smaller right parietal cortex.

CONCLUSIONS

This study confirms that, in addition to orbitofrontal disease, there is a prominent right and lateral ATL origin of socioemotional changes in bvFTD and further suggests that right parietal involvement contributes to socioemotional changes in EOAD.

A systematic review of cognitive and behavioral tools to differentiate behavioral variant frontotemporal dementia from other conditions

The behavioral variant of frontotemporal dementia (bvFTD) is thought to be the commonest clinical presentation of frontotemporal lobar degeneration and is predominantly characterized by changes in behavior. In patients lacking unequivocal biomarker evidence of frontotemporal neurodegeneration, the clinical diagnosis of bvFTD is often unstable. In response, we conducted a systematic review and critical appraisal of cognitive and behavioral tools that have sought to differentiate bvFTD from other conditions. A systematic literature review of PubMed, Scopus, and Web of Science was conducted on December 31, 2023 for cognitive and behavioral tools that differentiated bvFTD from other cohorts. Ninety-six studies were included. The quality appraisal of almost all studies was low and introduced a high risk of bias. The few studies that were of high quality had a prospective study design and recruited patients suspected (but not yet confirmed) to have bvFTD. These studies reported that behavioral tools (e.g., the Frontal Behavioral Inventory) and social cognition tests (e.g., the Ekman's Faces Test) had good test performance in differentiating bvFTD from a broad range of psychiatric and neurological conditions. Importantly, the review highlighted the extreme paucity of studies that have evaluated methods where, in Bayesian terms, there is genuine clinical uncertainty regarding a diagnosis of bvFTD. Most studies used healthy controls of typical Alzheimer's disease as comparators-groups that often have negligible pretest probability of bvFTD. In response, we propose a study design checklist for studies seeking to develop diagnostic algorithms in bvFTD research.

Pilot Randomized, Double-Blind, Placebo-Controlled Crossover Trial Evaluating the Feasibility of an Intranasal Oxytocin in Improving Social Cognition in Individuals Living with Alzheimer's Disease

Background

Individuals living with Alzheimer's disease (AD) demonstrate extensive deficits in social cognition. To date, no studies have investigated the feasibility of an intranasal oxytocin (INOT) treatment to improve social cognition in individuals living with AD.

Objective

We conducted a pilot trial to determine recruitment feasibility, enrolment acceptability, and adherence to an INOT treatment to inform on the subsequent design of a future randomized controlled trial (RCT). We also estimated the effect sizes of potential social cognitive function outcome measures related to participants and their caregivers.

Methods

Four individuals with AD were enrolled in a single-center, randomized, double-blind, placebo-controlled crossover trial involving a one-week treatment period with both INOT (72 IU twice daily) and placebo.

Results

All participants reported no treatment-causative or serious adverse events following repeated INOT administration. While enrolment acceptability (100%) and INOT adherence (placebo, 95%; INOT, 98%) were excellent, feasibility of recruitment was not acceptable (i.e., n = 4/58 individuals screened met inclusion criteria). However, positive/large effects were associated with secondary outcomes of self-reported health and wellbeing, caregiver 'burden', intimacy and interpersonal-bonding, following repeated INOT administration. No positive effects were associated with participant outcomes of social cognition.

Conclusion

This pilot RCT provides first evidence that INOT administration in individuals living with AD is safe and well-tolerated. Despite limitations in sample size, moderate-to-large effect size improvements were identified in participant health outcomes as well as core social cognitive functions and 'burden' as reported by a caregiver. This suggests potential broad-ranging beneficial effects of INOT which should be assessed in future RCTs.

Social Frailty in Late Adulthood: Social Cognitive and Psychological Well-Being Correlates

OBJECTIVES

Social frailty poses a major threat to successful aging, but its social cognitive and psychological well-being correlates remain poorly understood. This cross-sectional study provides initial insights into whether social cognitive difficulties in older age are associated with social frailty, as well as how social frailty is linked to psychological characteristics known to be important for health and well-being.

METHOD

Ninety community-dwelling older adults completed measures of social frailty and social cognition (social perception, theory of mind, affective empathy, and informant-rated social behavior) as well as measures of psychological function known to be important for health and well-being, both positively (resilience and life satisfaction) and negatively (demoralization, social anxiety, and apathy). Measures of cognitive frailty, physical frailty, and depression were also administered to test the specificity of any observed relationships with social frailty.

RESULTS

Both affective empathy and social behavior were predictive of increased social frailty, but social behavior emerged as the only unique predictor after controlling for covariates. Social frailty also predicted unique variance in all five measures of psychological well-being, and for three of these measures (demoralization, resilience, and life satisfaction), the effects remained significant even after adjusting for covariates.

DISCUSSION

Findings are discussed in relation to models of socioemotional aging and frailty. Potential mechanisms linking social behavior to social capital in older age are identified, as well as how loss of social resources might both directly and indirectly impact well-being.

Aging Is Associated With Multidirectional Changes in Social Cognition: Findings From an Adult Life-Span Sample Ranging From 18 to 101 Years

OBJECTIVES

Normal adult aging is associated with changes in social cognition. Although 4 social cognitive domains have been identified (social perception, theory of mind [ToM], affective empathy, and social behavior), no study has tested all 4 domains concurrently in a life-span sample, limiting understanding of the relative magnitude of age-related changes across domains. This study addresses this gap by providing the first assessment of all 4 social cognitive domains in an adult life-span sample.

METHODS

Three hundred and seventy-two participants ranging from 18 to 101 years of age took part in this study. Participants completed a testing battery that assessed social perception, ToM, affective empathy, and social behavior, as well as broader cognitive function and well-being.

RESULTS

The results showed that adult aging is associated with multidirectional changes in social cognitive abilities, with ToM and social perception showing nonlinear decline across much of the life-span, and affective empathy and social behavior showing improvement. Age remained a significant predictor of all 4 social cognitive domains, even after accounting for broader cognitive function. Weak associations emerged between some of the social cognitive abilities and and indices of broader well-being.

DISCUSSION

These findings provide novel and important evidence that normative aging is associated with both gains and losses in social cognition that occur at distinct points of the adult life-span, and that are at least partially independent of general age-related cognitive decline.

Empathy and Impaired Socioemotional Self-Perception in Frontotemporal Dementia

OBJECTIVE

Impaired empathy is a core feature of behavioral variant frontotemporal dementia (bvFTD). Patients with bvFTD are also prominently impaired in experiencing self-conscious emotions. The investigators explored whether impaired empathy in bvFTD, such as self-conscious emotions, may result from impaired self-consciousness in social situations (socioemotional self-perception).

METHODS

This pilot study evaluated 25 patients with bvFTD and compared them with 25 patients with Alzheimer's disease who had comparable dementia severity. Their caregivers completed the Social Dysfunction Scale (SDS), which quantifies empathy, and an extensive intake interview that included questions regarding self-consciousness and insight. The patients completed two measures of self-perception in social situations, the Schutte Self-Report Emotional Intelligence Test (SSEIT) scale and the Embarrassability Scale (EMB).

RESULTS

Caregivers of patients with bvFTD, but not of patients with Alzheimer's disease, reported a high correlation between significantly decreased empathy (SDS) and decreased self-consciousness (intake interview questions). Consistent with lack of insight, the patients with bvFTD, unlike the patients with Alzheimer's disease, did not report decreases on the SSEIT and EMB measures.

CONCLUSIONS

These preliminary findings suggest that impaired socioemotional self-perception plays a role in the loss of empathy among patients with bvFTD. A lack of self-consciousness in social situations may contribute to a loss of empathy resulting from an inability to co-represent another's emotion in relation to oneself.

Profiling Social Cognition in Premanifest Huntington's Disease

OBJECTIVE

Discrepancies exist in reports of social cognition deficits in individuals with premanifest Huntington's disease (HD); however, the reason for this variability has not been investigated. The aims of this study were to (1) evaluate group- and individual-level social cognitive performance and (2) examine intra-individual variability (dispersion) across social cognitive domains in individuals with premanifest HD.

METHOD

Theory of mind (ToM), social perception, empathy, and social connectedness were evaluated in 35 individuals with premanifest HD and 29 healthy controls. Cut-off values beneath the median and 1.5 × the interquartile range below the 25th percentile (P25 - 1.5 × IQR) of healthy controls for each variable were established for a profiling method. Dispersion between social cognitive domains was also calculated.

RESULTS

Compared to healthy controls, individuals with premanifest HD performed worse on all social cognitive domains except empathy. Application of the profiling method revealed a large proportion of people with premanifest HD fell below healthy control median values across ToM (>80%), social perception (>57%), empathy (>54%), and social behaviour (>40%), with a percentage of these individuals displaying more pronounced impairments in empathy (20%) and ToM (22%). Social cognition dispersion did not differ between groups. No significant correlations were found between social cognitive domains and mood, sleep, and neurocognitive outcomes.

CONCLUSIONS

Significant group-level social cognition deficits were observed in the premanifest HD cohort. However, our profiling method showed that only a small percentage of these individuals experienced marked difficulties in social cognition, indicating the importance of individual-level assessments, particularly regarding future personalised treatments.

Instruments to Assess Social Functioning in Individuals with Dementia: A Systematic Review

BACKGROUND

Social functioning is an important parameter for the early detection and diagnosis of dementia, as well as the description of its course and the assessment of intervention effects. Therefore, valid and reliable instruments to measure social functioning in individuals with dementia are needed.

OBJECTIVE

We aimed to provide an overview of such instruments including information on feasibility and psychometric properties.

METHODS

The review is informed by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Relevant literature was identified using a pre-specified search string in the databases MEDLINE, PsycINFO, and Web of Science. Information on the characteristics, feasibility, and psychometric properties of the identified instruments were extracted, summarized, and discussed.

RESULTS

Out of 5,307 articles, 8 were selected to be included in the study, describing a total of three instruments for measuring social functioning in individuals with dementia: the Nurses' Observation Scale for Geriatric Patients (NOSGER; dimension "social behavior"), the Socioemotional Dysfunction Scale (SDS), and the Social Functioning in Dementia Scale (SF-DEM). The validity of all the three instruments was overall acceptable. Reliability was high for the NOSGER scale "social behavior" and the SF-DEM. Information on the usability of the instruments tended to be scarce.

CONCLUSION

There are a few valid and reliable instruments to assess social functioning in individuals with dementia. Further considerations could comprise their feasibility with regard to measuring changes in social functioning over time, in additional target groups, e.g., different types and stages of dementia, and adaptions to different languages and cultural backgrounds.

Using a second-person approach to identify disease-specific profiles of social behavior in frontotemporal dementia and Alzheimer's disease

Changes in social behavior are recognized as potential symptoms of behavioral-variant frontotemporal dementia (bvFTD) and semantic dementia (SD), yet objective ways to assess these behaviors in natural social situations are lacking. This study takes a truly social (or second-person) approach and examines changes in real-world social behavior in different dementia syndromes, by analyzing non-scripted social interactions in bvFTD patients (n = 20) and SD patients (n = 20), compared to patients with Alzheimer's disease (AD) (n = 20). Video recordings of 10-min conversations between patients and behavioral neurologists were analyzed for the presence of socially engaging (e.g., nodding, smiling, gesturing) and disengaging behavior (e.g., avoiding eye contact, self-grooming, interrupting). Results demonstrated disease-specific profiles, with bvFTD patients showing less nodding and more looking away than AD, and SD patients showing more gesturing than AD. A principal components analysis revealed the presence of four unobserved components, showing atypical disengaging patterns of behavior. Whole-brain voxel-based morphometry analyses revealed distinct neurobiological bases for each of these components, with the brain regions identified previously associated with behavior selection, abstract mentalization and processing of multi-sensory and socially-relevant information, in mediating socially engaging and disengaging behavior. This study demonstrates the utility of systematic behavioral observation of social interactions in the differential diagnosis of dementia.

Impaired Empathy Versus General Hypoemotionality in Frontotemporal Dementia

OBJECTIVE

Impaired empathy is a diagnostic feature of behavioral variant frontotemporal dementia (bvFTD), but it is not clear whether it is caused by a primary impairment in empathy or by general emotional blunting.

METHODS

Patients with bvFTD who met criteria for loss of empathy (N=10) and patients with Alzheimer's disease (N=15) were assessed with a measure for empathy (Socioemotional Dysfunction Scale [SDS]) and a measure for general emotion (Scale for Emotional Blunting [SEB]). All patients underwent neuroimaging. Both patient groups and a healthy control group (N=18) were evaluated by using autonomic responses (skin conductance responses [SCR]) to pictures from the Internal Affective Picture System (IAPS) (presence or absence of empathy stimuli and high versus low emotion).

RESULTS

All participants reported understanding the content and others' perspectives on the empathy pictures; however, only patients with bvFTD showed impaired empathic behavior on the SDS, which persisted after adjusting for measures from the emotion scale (SEB). Patients with bvFTD had significantly lower SCR for all the IAPS stimuli, including for empathy pictures, which also persisted after adjusting for emotional content. On MRI analysis, SCR across groups significantly correlated with the volume of the dorsal anterior cingulate gyrus (dACC).

CONCLUSIONS

These results indicate that patients with bvFTD have decreased empathic behavior with or without emotional blunting, and they exhibit decreased psychophysiological responses to empathy stimuli, independent of general emotion. These preliminary findings suggest a specific impairment in emotional empathy, possibly related to impairment of the emotional appraisal role of the dACC.

Vicarious Embarrassment or "Fremdscham": Overendorsement in Frontotemporal Dementia

OBJECTIVE

The experience of embarrassment signals violations in social norms, and impairment in this social emotion may underlie much of the social dysfunction in behavioral variant frontotemporal dementia (bvFTD). The authors investigated whether impaired self-awareness of embarrassment may distinguish patients with bvFTD early in the course of disease from healthy control subjects (HCs).

METHODS

Self-reported embarrassment was examined among 18 patients with early bvFTD and 23 HCs by using the 36-item Embarrassability Scale, which includes items of situations eliciting embarrassment for oneself ("self-embarrassment") and embarrassment for others ("vicarious embarrassment"). The two study groups were also compared with the Social Norms Questionnaire (SNQ). The analyses included correlations of SNQ results (total score, violations or "break" errors, and overendorsement of social rules or "overadhere" errors) with Embarrassability Scale scores.

RESULTS

Patients with bvFTD did not differ from HCs on total or self-embarrassment scores but did have significantly higher vicarious embarrassment scores. Unlike in the HC group, reports of vicarious embarrassment did not differ from reports of self-embarrassment among patients in the bvFTD group. The Embarrassability Score further correlated with overadherence to norms on the SNQ.

CONCLUSIONS

In the presence of social dysfunction and emotional blunting, these findings suggest that patients with bvFTD rely on their own perspective for a rule-based application of social norms in reporting vicarious embarrassment. The assessment of reports of embarrassment for others may indicate an early and previously unrecognized clinical measure for detecting bvFTD.

Frontotemporal asymmetry in socioemotional behavior: A pilot study in frontotemporal dementia

Clinical studies report abnormal socioemotional behavior in patients with right frontotemporal disease, but neuroimaging studies of socioemotional behavior usually show bilateral activations in normal subjects. This discrepancy suggests that impaired interhemispheric collaboration for socioemotional functions results from asymmetric frontotemporal disease. Behavioral variant frontotemporal dementia (bvFTD) can clarify the contribution of direction-independent frontotemporal asymmetry. In a two-part study, we evaluated bvFTD patients using socioemotional scales and magnetic and resonance imaging measures. Part A compared 18 patients on scales of social dysfunction and emotional intelligence with degree of asymmetry in frontal lobe volumes and analyzed differences between lower and higher asymmetry groups. Part B compared 24 patients on scales of social observation and emotional blunting with degree of asymmetry in frontotemporal cortical thickness using multiple linear regression. Both results showed that left or right hemispheric-specific contributions did not account for all socioemotional differences and that frontal lobe and frontotemporal differences in atrophy between the hemispheres accounted for significant variance in abnormalities in social and emotional behavior. These preliminary results indicate that the degree of frontal lobe and frontotemporal asymmetric involvement, regardless of direction or laterality, significantly contribute to socioemotional dysfunction and support the hypothesis that interhemispheric collaboration is important for complex socioemotional behavior.

Network Architecture Underlying Basal Autonomic Outflow: Evidence from Frontotemporal Dementia

The salience network is a distributed neural system that maintains homeostasis by regulating autonomic nervous system activity and social-emotional function. Here we examined how within-network connectivity relates to individual differences in human (including males and females) baseline parasympathetic and sympathetic nervous activity. We measured resting autonomic nervous system physiology in 24 healthy controls and 23 patients with behavioral variant frontotemporal dementia (bvFTD), a neurodegenerative disease characterized by baseline autonomic deficits. Participants also underwent structural and task-free fMRI. First, we used voxel-based morphometry to determine whether salience network atrophy was associated with lower baseline respiratory sinus arrhythmia (a parasympathetic measure) and skin conductance level (a sympathetic measure) in bvFTD. Next, we examined whether functional connectivity deficits in 21 autonomic-relevant, salience network node-pairs related to baseline autonomic dysfunction. Lower baseline respiratory sinus arrhythmia was associated with smaller volume in left ventral anterior insula (vAI), weaker connectivity between bilateral vAI and bilateral anterior cingulate cortex (ACC), and stronger connectivity between bilateral ACC and bilateral hypothalamus/amygdala. Lower baseline skin conductance level, in contrast, was associated with smaller volume in inferior temporal gyrus, dorsal mid-insula, and hypothalamus; weaker connectivity between bilateral ACC and right hypothalamus/amygdala; and stronger connectivity between bilateral dorsal anterior insula and periaqueductal gray. Our results suggest that baseline parasympathetic and sympathetic tone depends on the integrity of lateralized salience network hubs (left vAI for parasympathetic and right hypothalamus/amygdala for sympathetic) and highly calibrated ipsilateral and contralateral network connections. In bvFTD, deficits in this system may underlie resting parasympathetic and sympathetic disruption.SIGNIFICANCE STATEMENT The salience network maintains homeostasis and regulates autonomic nervous system activity. Whether within-network connectivity patterns underlie individual differences in resting parasympathetic and sympathetic nervous system activity, however, is not well understood. We measured baseline autonomic nervous system activity in healthy controls and patients with behavioral variant frontotemporal dementia, a neurodegenerative disease characterized by resting autonomic deficits, and probed how salience network dysfunction relates to diminished parasympathetic and sympathetic outflow. Our results indicate that baseline parasympathetic and sympathetic tone are the product of complex, opposing intranetwork nodal interactions and depend on the integrity of highly tuned, lateralized salience network hubs (i.e., left ventral anterior insula for parasympathetic activity and right hypothalamus/amygdala for sympathetic activity).

Meta-analytic Review of Memory Impairment in Behavioral Variant Frontotemporal Dementia

OBJECTIVES

A meta-analysis of the extent, nature and pattern of memory performance in behavioral variant frontotemporal dementia (bvFTD). Multiple observational studies have challenged the relative sparing of memory in bvFTD as stated in the current diagnostic criteria.

METHODS

We performed a meta-analytic review covering the period 1967 to February 2017 of case-control studies on episodic memory in bvFTD versus control participants (16 studies, 383 patients, 603 control participants), and patients with bvFTD versus those with Alzheimer's disease (AD) (20 studies, 452 bvFTD, 874 AD). Differences between both verbal and non-verbal working memory, episodic memory learning and recall, and recognition memory were examined. Data were extracted from the papers and combined into a common metric measure of effect, Hedges' d.

RESULTS

Patients with bvFTD show large deficits in memory performance compared to controls (Hedges' d -1.10; 95% confidence interval [CI] [-1.23, -0.95]), but perform significantly better than patients with AD (Hedges' d 0.85; 95% CI [0.69, 1.03]). Learning and recall tests differentiate best between patients with bvFTD and AD (p<.01). There is 37-62% overlap in test scores between the two groups.

CONCLUSIONS

This study points to memory disorders in patients with bvFTD, with performance at an intermediate level between controls and patients with AD. This indicates that, instead of being an exclusion criterion for bvFTD diagnosis, memory deficits should be regarded as a potential integral part of the clinical spectrum. (JINS, 2018, 24, 593-605).

Social Cognition Dysfunctions in Neurodegenerative Diseases: Neuroanatomical Correlates and Clinical Implications

Social cognitive function, involved in the perception, processing, and interpretation of social information, has been shown to be crucial for successful communication and interpersonal relationships, thereby significantly impacting mental health, well-being, and quality of life. In this regard, assessment of social cognition, mainly focusing on four key domains, such as theory of mind (ToM), emotional empathy, and social perception and behavior, has been increasingly evaluated in clinical settings, given the potential implications of impairments of these skills for therapeutic decision-making. With regard to neurodegenerative diseases (NDs), most disorders, characterized by variable disease phenotypes and progression, although similar for the unfavorable prognosis, are associated to impairments of social cognitive function, with consequent negative effects on patients' management. Specifically, in some NDs these deficits may represent core diagnostic criteria, such as for behavioral variant frontotemporal dementia (bvFTD), or may emerge during the disease course as critical aspects, such as for Parkinson's and Alzheimer's diseases. On this background, we aimed to revise the most updated evidence on the neurobiological hypotheses derived from network-based approaches, clinical manifestations, and assessment tools of social cognitive dysfunctions in NDs, also prospecting potential benefits on patients' well-being, quality of life, and outcome derived from potential therapeutic perspectives of these deficits.

Looking but not seeing: Increased eye fixations in behavioural-variant frontotemporal dementia

Face processing plays a central role in human communication, with the eye region a particularly important cue for discriminating emotions. Indeed, reduced attention to the eyes has been argued to underlie social deficits in a number of clinical populations. Despite well-established impairments in facial affect recognition in behavioural-variant frontotemporal dementia, whether these patients also have perturbed facial scanning is yet to be investigated. The current study employed eye tracking to record visual scanning of faces in 20 behavioural-variant frontotemporal dementia patients and 21 controls. Remarkably, behavioural-variant frontotemporal dementia patients displayed more fixations to the eyes of emotional faces, compared to controls. Neural regions associated with fixations to the eyes included the left inferior frontal gyrus, right cerebellum and middle temporal gyrus. Our study is the first to show such compensatory functions in behavioural-variant frontotemporal dementia and suggest a feedback-style network, including anterior and posterior brain regions, is involved in early face processing.

Prolonged Visual Facial Grasp in Frontotemporal Dementia

BACKGROUND

Gaze and eye contact is a critical aspect of social interaction. Patients with behavioral variant frontotemporal dementia (bvFTD) may exhibit abnormally prolonged stare toward human faces.

OBJECTIVE

To study characteristics of social gaze in patients with bvFTD compared to age and education matched-patients with early-onset Alzheimer's disease (eAD) and healthy controls (HC).

METHOD

Fifty picture stimuli were presented to each participant (bvFTD = 12, eAD = 18, HC = 13). Each stimuli contained two properties: face (facial versus non-facial) and valence (positive, negative, and neutral). The "facial" stimuli contained human faces. The participants Visual Fixation Time (VFT) was measured for each picture stimuli of interest (per facial expressions on the Facial Action Coding System). A linear mixed-effects regression model with participant-level of random effects was used to compare VFTs between groups.

RESULTS

The patients with bvFTD showed significantly prolonged VFTs to faces than the patients with eAD and the HC, regardless of valence (all p < 0.01). There were no differences in VFTs for non-facial stimuli between patients with bvFTD and eAD. However, patients with bvFTD and eAD had significantly prolonged VFTs to negative non-facial stimuli than the HC (p = 0.006 and 0.019, respectively).

CONCLUSION

Patients with bvFTD exhibited a prolonged stare toward human faces. This prolonged visual facial grasp may contribute to the disturbed social interactions of patients with bvFTD and can help distinguish them from those with Alzheimer's disease and other conditions. Additionally, both dementia groups tended to stare at negative stimuli whether faces or non-faces.

Progranulin haploinsufficiency causes biphasic social dominance abnormalities in the tube test

Loss-of-function mutations in progranulin (GRN) are a major autosomal dominant cause of frontotemporal dementia (FTD), a neurodegenerative disorder in which social behavior is disrupted. Progranulin-insufficient mice, both Grn(+/-) and Grn(-/-) , are used as models of FTD due to GRN mutations, with Grn(+/-) mice mimicking the progranulin haploinsufficiency of FTD patients with GRN mutations. Grn(+/-) mice have increased social dominance in the tube test at 6 months of age, although this phenotype has not been reported in Grn(-/-) mice. In this study, we investigated how the tube test phenotype of progranulin-insufficient mice changes with age, determined its robustness under several testing conditions, and explored the associated cellular mechanisms. We observed biphasic social dominance abnormalities in Grn(+/-) mice: at 6-8 months, Grn(+/-) mice were more dominant than wild-type littermates, while after 9 months of age, Grn(+/-) mice were less dominant. In contrast, Grn(-/-) mice did not exhibit abnormal social dominance, suggesting that progranulin haploinsufficiency has distinct effects from complete progranulin deficiency. The biphasic tube test phenotype of Grn(+/-) mice was associated with abnormal cellular signaling and neuronal morphology in the amygdala and prefrontal cortex. At 6-9 months, Grn(+/-) mice exhibited increased mTORC2/Akt signaling in the amygdala and enhanced dendritic arbors in the basomedial amygdala, and at 9-16 months Grn(+/-) mice exhibited diminished basal dendritic arbors in the prelimbic cortex. These data show a progressive change in tube test dominance in Grn(+/-) mice and highlight potential underlying mechanisms by which progranulin insufficiency may disrupt social behavior.

The attribution of animacy and agency in frontotemporal dementia versus Alzheimer's disease

Impaired attribution of animacy (state of living or being sentient) and of agency (capability of intrinsically-driven action) may underlie social behavior disturbances in behavioral variant frontotemporal dementia (bvFTD). We presented the Heider and Simmel film of moving geometric shapes to 11 bvFTD patients, 11 Alzheimer's disease (AD) patients, and 12 healthy controls (HCs) and rated their recorded verbal responses for animacy attribution and agency attribution. All participants had skin conductance (SC) continuously recorded while viewing the film, and all dementia participants underwent magnetic resonance imaging (MRI) for regions of interest. The bvFTD patients, but not the AD patients, were impaired in animacy attribution, compared to the HCs. In contrast, both bvFTD and AD groups were impaired in agency attribution, compared to the HCs, and only the HCs had increasing SC responsiveness during viewing of the film. On MRI analysis of cortical thicknesses, animacy scores significantly correlated across groups with the right pars orbitalis and opercularis; agency scores with the left inferior and superior parietal cortices and the supramarginal gyrus; and both scores with the left cingulate isthmus involved in visuospatial context. These findings suggest that bvFTD is specifically associated with impaired animacy attribution from right inferior frontal atrophy. In contrast, both dementias may have impaired agency attribution from left parietal cortical atrophy and absent SC increases during the film, a sympathetic indicator of attribution of a social "story" to the moving shapes. These findings clarify disease-related changes in social attribution and corroborate the neuroanatomical origins of animacy and agency.

Emotional quotient in frontotemporal dementia vs. Alzheimer's disease: the role of socioemotional agnosia

INTRODUCTION

Socioemotional dysfunction distinguishes behavioural variant frontotemporal dementia (bvFTD) from other dementias. Patients with bvFTD not only have early social impairment and emotional blunting, but they also have agnosia of their socioemotional dysfunction.

METHODS

To investigate the relationship between agnosia and dysfunction, we assessed self-knowledge of socioemotional dysfunction with an emotional quotient (EQ) scale administered to 12 patients with bvFTD and a comparison group of 12 age-matched patients with Alzheimer's disease (AD), and compared these self-ratings to caregiver ratings of social dysfunction and emotional blunting.

RESULTS

The bvFTD patients self-rated as having higher EQs than the AD patients, particularly higher self-ratings of their Social Skills, an EQ subscale which correlated with increased emotional blunting. On within-groups analysis, the bvFTD patients' high self-ratings of their EQ Appraisal of Emotions correlated with increased socioemotional dysfunction, whereas all of the AD patients' self-ratings correlated appropriately with their degree of dysfunction.

CONCLUSIONS

Large socioemotional agnosia scores (EQ minus function) distinguishes bvFTD from AD. Additionally, in bvFTD, agnosia specifically for their ability to appreciate others' emotions correlates with the degree of socioemotional dysfunction, suggesting a role for socioemotional agnosia in increasing socioemotional dysfunction.

Neuropsychological and Neuroanatomical Correlates of the Social Norms Questionnaire in Frontotemporal Dementia Versus Alzheimer's Disease

Traditional neuropsychological batteries may not distinguish early behavioral variant frontotemporal dementia (bvFTD) from Alzheimer's disease (AD) without the inclusion of a social behavioral measure. We compared 33 participants, 15 bvFTD, and 18 matched patients with early-onset AD (eAD), on the Social Norms Questionnaire (SNQ), neuropsychological tests and 3-dimensional T1-weighted magnetic resonance imaging (MRI). The analyses included correlations of SNQ results (total score, overendorsement or "overadhere" errors, and violations or "break" errors) with neuropsychological results and tensor-based morphometry regions of interest. Patients with BvFTD had significantly lower SNQ total scores and higher overadhere errors than patients with eAD. On neuropsychological measures, the SNQ total scores correlated significantly with semantic knowledge and the overadhere subscores with executive dysfunction. On MRI analysis, the break subscores significantly correlated with lower volume of lateral anterior temporal lobes (aTL). The results also suggest that endorsement of social norm violations corresponds to the role of the right aTL in social semantic knowledge.