Cognitive and behavioural inhibition deficits in neurodegenerative dementias

Implementation of the Cognitive Daisy (COG-D) for improving care planning and delivery for residents with dementia in care homes: results of a feasibility randomised controlled trial

BACKGROUND

Many residents in care homes for older adults live with dementia. Understanding the unique profiles of cognitive impairments for each resident is important for person-centred care, yet information about specific cognitive problems is limited, and knowledge varies. This study explored the feasibility of implementing the Cognitive Daisy (COG-D) intervention, which provide a visual summary in the shape of a 15-petal flower derived from the scores on a neuropsychological assessment battery, in care homes for older adults.

METHODS

A parallel-group feasibility cluster randomised controlled trial (cRCT) was conducted over 24 months. Eight care homes were randomised in a 1:1 ratio to either usual care plus the Cognitive Daisy intervention (COG-D) or usual care (control). Care staff were trained on how to use Cognitive Daisies and/or on how to conduct the COG-D assessments with residents. Cognitive Daisies were displayed in residents' rooms and included in care plans. COG-D assessments were repeated after 6 months. The primary objective was to explore areas of uncertainty for a future large-scale trial including recruitment rates and intervention implementation and adherence. Secondary objectives were to explore signals of effects in candidate outcome measures for residents and staff, obtained at baseline and 6- and 9-month post-randomisation. A process evaluation explored barriers and facilitators to intervention implementation through care-plan audits (to explore recommendations in response to COG-D assessments), interviews and focus groups with staff, residents and relatives.

RESULTS

Resident recruitment (n = 115) and staff recruitment (n = 99) in 8 care homes exceeded targets (100 and 50, respectively, in 8-10 care homes). Staff training was perceived positively with high completion rates (77.1% and 83.3% for basic and advanced training, respectively). Completion rates were also high for COG-D assessments (75.5% for assessment 1, and 72.5% of these residents completed assessment 2), and COG-D scores remained stable across the two assessment points. No clear signals of effects were found for candidate outcome measures. Number of recommendations in care plans varied across care homes, and interviews/focus groups highlighted several barriers to staff's use of the Cognitive Daisies in daily practice.

CONCLUSION

Findings indicate trial delivery was feasible. However, the COG-D requires modification if it is to be feasibly implemented in care home settings.

TRIAL REGISTRATION

This trial was registered on (date) (ISRCTN15208844).

Effectiveness of the Hayling and Brixton Tests for Detecting Dementia, Progressive Cognitive Decline, and Mild Cognitive Impairment in Middle to Older Aged Adults: A Systematic Review and Meta-analysis

The aging population is increasing the prevalence of dementia, neurodegenerative disorders, and mild cognitive impairment, which are associated with cognitive declines in executive functioning. In people with these disorders, accurate tests can aid in the early detection of executive functioning decline and facilitate access to interventions. The Hayling and Brixton tests (HBTs) are popular executive functioning tests that assess inhibitory control. The HBTs may be especially effective for detecting people with disorders that are associated with disinhibition, such as behavioral-variant frontotemporal dementia (bvFTD). However, the effectiveness of the HBTs for detecting cognitive decline in dementia, neurodegenerative disorders, and mild cognitive impairment has yet to be collated. A comprehensive search of five databases identified 50 studies that compared the HBTs performances of adults aged 40 years and over with a dementia, neurodegenerative disorder, or mild cognitive impairment (e.g., Parkinson's disease, Alzheimer's dementia, bvFTD) and cognitively-healthy controls. Hedges' g effect sizes compared groups on the five HBTs scores (Inhibition Errors, Inhibition Reaction Time (RT), Automatic RT, Inhibition minus Automatic RT, and Brixton Errors). The disorders (combined) showed negative effects on all HBTs scores (g - 0.37 to - 1.13), with dementia (combined) performing the worst (g - 0.54 to - 1.56). Automatic RT and Inhibition Errors were the most effective scores for detecting cognitive decline in dementia (g - 1.55; g - 1.34). The dementia types performed similar after outliers were removed and only studies with low risk-of-bias were analyzed. Overall, the HBTs are effective for detecting cognitive decline in middle to older aged adults, especially those with dementia. However, no score type can be recommended for differentiating the dementia types, such as AD and bvFTD.

Quebec French Version of the Hayling Sentence Completion Test: Error Scoring Guidelines, Normative Data for Adults and the Elderly and Validation Study in Mild Cognitive Impairment and Alzheimer's Disease

INTRODUCTION

Deficits in inhibition have been associated with various clinical conditions, including neurodegenerative diseases. The Hayling Sentence Completion Test (HSCT) is an assessment tool commonly used in clinical settings to measure verbal initiation and prepotent verbal response inhibition. Although it is used by numerous clinical and research groups in Quebec, normative data for the HSCT are not yet available for French-Quebec speakers.

OBJECTIVES

The aims of this study were to provide error scoring guidelines and normative data in the adult population of French Quebec for the HSCT-QC (Study 1) and to determine its known-group discriminant validity (Study 2).

RESULTS

The results of Study 1, based on a sample of 214 healthy individuals aged 50 to 89, indicated that age significantly affected test performance, while educational level and sex did not. As no transformations were able to normalize the score distribution, percentile ranks for HSCT-QC performance were calculated solely based on age. Results from Study 2 demonstrated that the HSCT-QC effectively distinguishes the performance of healthy participants from those with mild cognitive impairment or Alzheimer's disease.

CONCLUSION

Norms and psychometric data for the HSCT-QC will be highly beneficial for assessing inhibitory control in French-speaking adults in Quebec, Canada.

Dementia subtypes and suicidality: A systematic review and meta-analysis

AIMS

Recent research has highlighted a link between dementia and increased risk of suicidal ideation, suicide attempts and suicide deaths. Understanding the relative risk of suicide between subtypes of dementia is important for services to offer appropriate intervention.

METHOD

We searched five databases from inception to July 2023 for peer-reviewed publications reporting suicidal ideation, suicide attempt or death by suicide for at least two dementia subtypes. Meta-analyses compared suicidality between subtypes of dementia with Alzheimer's Disease (AD).

RESULTS

From 4983 studies identified, 12 met inclusion criteria. Pooling data, people with Vascular Dementia were significantly more likely to experience suicidal ideation (OR= 2.02 [95 % CI= 1.06;3.8]) and attempt suicide (OR=1.94 [95 % CI= 1.28;2.94]) than people with AD, but not die by suicide (OR= 1.05 [95 % CI= 0.69;1.59]). People with Dementia with Lewy Bodies were significantly more likely to report suicidal ideation (OR= 1.56 [95 % CI= 1.09;2.23]) than AD but not attempt suicide (OR= 1.12 [95 % CI= 0.83;1.50]). People with Frontotemporal Dementia were significantly more likely to attempt suicide (OR= 2.42 [95 % CI= 1.02;5.72]) than people with AD but not report suicidal ideation (OR= 1.67 [95 % CI= 0.34;8.33]). People with Mixed Dementia were significantly more likely to attempt suicide (OR= 2.83 [95 % CI= 1.52;5.27]) than people with AD but not report suicidal ideation (OR = 1.65 [95 % CI= 0.5;5.46]).

CONCLUSIONS

Further research is needed to understand what underlies the increased risks of suicidal ideation and suicide attempts for rarer subtypes.

Providing appropriate health and social care for people with dementia or mild cognitive impairment in the criminal justice system of England and Wales: a thematic analysis of prisoner and staff interview data

BACKGROUND

The number of older adults entering the criminal justice system is growing. Approximately 8% of older prisoners in England and Wales have suspected dementia or mild cognitive impairment (MCI) and experience difficulties in everyday functioning, and disruption to their daily life. At present, no specific dementia/MCI care pathway has been implemented that is applicable and appropriate for use across different prisons in England and Wales. The aim of this paper is to explore the experiences of older adults with dementia/MCI in prison, and a range of key stakeholders, around the day-to-day issues faced by people with dementia/MCI and prison, healthcare, and third sector staff regarding the delivery of support for individuals with dementia/MCI.

METHODS

Thirty-two semi structured interviews were conducted with prison, local authority, and healthcare staff; peer supporters; third sector care providers; and individuals with dementia/MCI themselves, across five establishments, to provide multidimensional perspectives of dementia/MCI in criminal justice settings. The data obtained during interviews were thematically analysed.

RESULTS

From the data, six key themes emerged: (I) ethical concerns around trial, sentencing and detainment for people with dementia/MCI; (II) An unforgiving prison system, providing physical and social environments incompatible with supporting individuals with dementia/MCI; (III) An unprepared workforce requiring training in dementia/MCI. (IV) A lack of collaboration leading to sub-optimum management of the support needs of people with dementia/MCI in prison; (V) Peer support 'plugging the gap'; and (VI) staff 'hands tied behind back'.

CONCLUSIONS

Results point towards a pressing need to develop more appropriate support systems for individuals with dementia/MCI throughout the criminal justice system. Ethical concerns around the judicial process for individuals with diminished cognitive capacity must be considered. Prison governors should examine ways to make the living environment more appropriate for these individuals, and a joined-up collaborative approach to health and social care should be adopted. Staff must be appropriately trained to support and identify individuals with dementia/MCI. Peer support schemes require formal evaluation, and training/oversight of these schemes should be comprehensive.

Differential effects of social versus monetary incentives on inhibitory control under acute inflammation

While the impact of chronic, low-grade inflammation on cognitive functioning is documented in the context of neurodegenerative disease, less is known about the association between acute increases in inflammation and cognitive functioning in daily life. This study investigated how changes in interleukin-6 (IL-6) levels were associated with performance on an inhibitory control task, the go/no-go task. We further examined whether the opportunity to earn different incentive types (social or monetary) and magnitudes (high or low) was associated with differential performance on the task, depending on IL-6 levels. Using a within-participant design, individuals completed an incentivized go/no-go task before and after receiving the annual influenza vaccine. Multilevel logistic regressions were performed on the trial-level data (Nobs = 30,528). For no-go trials, we did not find significant associations in IL-6 reactivity and changes in trial accuracy between sessions. For go trials, we found significant differences in the associations between IL-6 reactivity and changes in accuracy as a function of the incentive condition. Notably, greater IL-6 reactivity was consistently associated with fewer omission errors (i.e., greater accuracy on go trials) on high-magnitude social incentives (i.e., viewing a picture of a close-other) when compared to both low-magnitude social and high-magnitude monetary incentives. Together, these results suggest that mild fluctuations in inflammation might alter the valuation of an incentive, and possibly a shift toward devoting greater attentional resources when a large social incentive is on the line. Overall, this study sheds light on how everyday, low-grade fluctuations in inflammation may influence cognitive abilities essential for daily life and effective inhibitory control.

rTMS Modulation of Behavioral and Biological Measures in 3xTg-AD Mice

BACKGROUND/OBJECTIVES

The biological basis for behavioral manifestations of Alzheimer's disease remains unclear. Emotional and behavioral alterations of Alzheimer's disease can result in substantial caregiver burden and lack effective management. This study expands upon previous work investigating behavioral alterations in mice with Alzheimer's disease and a potential treatment of increasing brain-derived neurotrophic factor (BDNF) using repetitive transcranial magnetic stimulation (rTMS).

METHODS

A total of 47 3xTg-AD (Alzheimer's) and 53 B6 (wildtype) mice were administered ANA12 (an antagonist of TrkB receptor) or Vehicle (saline) and then rTMS or Sham treatment daily. After 14 days of treatments and injections, mouse behavior was assessed under various behavioral cognitive tests. Mice were then perfused, and brain samples were processed for histology and protein assays. Brain homogenates were analyzed for BDNF and its downstream signaling molecules.

RESULTS

Open field testing demonstrated that 3xTg-AD mice spent more time in the center than B6 mice. 3xTg-AD-Sham mice injected with ANA12 were the only group to travel significantly less distance than B6-ANA12-Sham or B6-Vehicle-Sham mice (p < 0.05), while 3xTg-AD-rTMS mice (irrespective of injection) were not significantly different from B6 mice. 3xTg-AD mice had significantly greater measured levels of BDNF and TrkB than the wild-type mice.

CONCLUSIONS

Treatment of Alzheimer's disease using rTMS positively affects elements of hypoactivity, but not all behavioral abnormalities. rTMS shifted 3xTg-AD open field behavioral test measures, generating significant differences between untreated 3xTg-AD and B6 genotypes. Despite its benefit, further investigation of rTMS as a treatment for Alzheimer's disease as well as its biological underpinnings are needed.

Pharmacological inhibition of PLK2 kinase activity mitigates cognitive decline but aggravates APP pathology in a sex-dependent manner in APP/PS1 mouse model of Alzheimer's disease

Converging evidence from clinical and experimental studies suggest the potential significance of Polo-like kinase 2 (PLK2) in regulating the phosphorylation and toxicity of the Alzheimer's disease (AD)-related protein, amyloid precursor protein (APP). These findings have prompted various experimental trials aimed at inhibiting PLK2 kinase activity in different transgenic mouse models of AD. While positive impacts on cognitive decline were reported in these studies, the cellular effects remained controversial. In the present study, we sought to assess the cognitive and cellular consequences of chronic PLK2 inhibitor treatment in the APP/PS1 transgenic mouse model of AD. First, we confirmed that inhibiting PLK2 prevented cognitive decline in a sex-dependent manner, particularly by enhancing working memory in male APP/PS1 mice. Surprisingly, cellular analysis revealed that treatment with PLK2 inhibitor increased the load of amyloid plaques and elevated levels of soluble amyloid β (Aβ) 40 and Aβ42 in the cortex, as well as insoluble Aβ42 in the hippocampus of female mice, without affecting APP pathology in males. These results underscore the potential of PLK2 inhibition to mitigate cognitive symptoms in males. However, paradoxically, it intensifies amyloid pathology in females by enhancing APP amyloidogenic processing, creating a controversial aspect to its therapeutic impact. Overall, these data highlight the sex-dependent nature of the effects of PLK2 inhibition, which may also be influenced by the genetic background of the transgenic mouse model utilized.

Multimodal nonlinear correlates of behavioural symptoms in frontotemporal dementia

Studies exploring the brain correlates of behavioral symptoms in the frontotemporal dementia spectrum (FTD) have mainly searched for linear correlations with single modality neuroimaging data, either structural magnetic resonance imaging (MRI) or fluoro-deoxy-D-glucose positron emission tomography (FDG-PET). We aimed at studying the two imaging modalities in combination to identify nonlinear co-occurring patterns of atrophy and hypometabolism related to behavioral symptoms. We analyzed data from 93 FTD patients who underwent T1-weighted MRI, FDG-PET imaging, and neuropsychological assessment including the Neuropsychiatric Inventory, Frontal Systems Behavior Scale, and Neurobehavioral Rating Scale. We used a data-driven approach to identify the principal components underlying behavioral variability, then related the identified components to brain variability using a newly developed method fusing maps of grey matter volume and FDG metabolism. A component representing apathy, executive dysfunction, and emotional withdrawal was associated with atrophy in bilateral anterior insula and putamen, and with hypometabolism in the right prefrontal cortex. Another component representing the disinhibition versus depression/mutism continuum was associated with atrophy in the right striatum and ventromedial prefrontal cortex for disinhibition, and hypometabolism in the left fronto-opercular region and sensorimotor cortices for depression/mutism. A component representing psychosis was associated with hypometabolism in the prefrontal cortex and hypermetabolism in auditory and visual cortices. Behavioral symptoms in FTD are associated with atrophy and altered metabolism of specific brain regions, especially located in the frontal lobes, in a hierarchical way: apathy and disinhibition are mostly associated with grey matter atrophy, whereas psychotic symptoms are mostly associated with hyper-/hypo-metabolism.

Progress in Pharmacologic Management of Neuropsychiatric Syndromes in Neurodegenerative Disorders: A Review

Importance

Neuropsychiatric syndromes (NPSs) are common in neurodegenerative disorders (NDDs); compromise the quality of life of patients and their care partners; and are associated with faster disease progression, earlier need for nursing home care, and poorer quality of life. Advances in translational pharmacology, clinical trial design and conduct, and understanding of the pathobiology of NDDs are bringing new therapies to clinical care.

Observations

Consensus definitions have evolved for psychosis, agitation, apathy, depression, and disinhibition in NDDs. Psychosocial interventions may reduce mild behavioral symptoms in patients with NDD, and pharmacotherapy is available for NPSs in NDDs. Brexpiprazole is approved for treatment of agitation associated with Alzheimer disease dementia, and pimavanserin is approved for treatment of delusions and hallucinations associated with psychosis of Parkinson disease. Trials are being conducted across several of the NDDs, and a variety of mechanisms of action are being assessed for their effect on NPSs.

Conclusions and Relevance

Detection and characterization of NPSs in patients with NDDs is the foundation for excellent care. New definitions for NPSs in NDDs may inform choices regarding clinical trial populations and translate into clinical practice. Psychosocial and pharmacologic therapies may reduce behavioral symptoms and improve quality of life for patients and caregivers. Approved agents may establish regulatory precedents, demonstrate successful trial strategies, and provide the foundation for further advances in treatment development.

Go/No-Go Ratios Modulate Inhibition-Related Brain Activity: An Event-Related Potential Study

(1) Background: Response inhibition refers to the conscious ability to suppress behavioral responses, which is crucial for effective cognitive control. Currently, research on response inhibition remains controversial, and the neurobiological mechanisms associated with response inhibition are still being explored. The Go/No-Go task is a widely used paradigm that can be used to effectively assess response inhibition capability. While many studies have utilized equal numbers of Go and No-Go trials, how different ratios affect response inhibition remains unknown; (2) Methods: This study investigated the impact of different ratios of Go and No-Go conditions on response inhibition using the Go/No-Go task combined with event-related potential (ERP) techniques; (3) Results: The results showed that as the proportion of Go trials decreased, behavioral performance in Go trials significantly improved in terms of response time, while error rates in No-Go trials gradually decreased. Additionally, the NoGo-P3 component at the central average electrodes (Cz, C1, C2, FCz, FC1, FC2, PCz, PC1, and PC2) exhibited reduced amplitude and latency; (4) Conclusions: These findings indicate that different ratios in Go/No-Go tasks influence response inhibition, with the brain adjusting processing capabilities and rates for response inhibition. This effect may be related to the brain's predictive mechanism model.

Disinhibition in dementia related to reduced morphometric similarity of cognitive control network

Disinhibition is one of the most distressing and difficult to treat neuropsychiatric symptoms of dementia. It involves socially inappropriate behaviours, such as hypersexual comments, inappropriate approaching of strangers and excessive jocularity. Disinhibition occurs in multiple dementia syndromes, including behavioural variant frontotemporal dementia, and dementia of the Alzheimer's type. Morphometric similarity networks are a relatively new method for examining brain structure and can be used to calculate measures of network integrity on large scale brain networks and subnetworks such as the salience network and cognitive control network. In a cross-sectional study, we calculated morphometric similarity networks to determine whether disinhibition in behavioural variant frontotemporal dementia (n = 75) and dementia of the Alzheimer's type (n = 111) was associated with reduced integrity of these networks independent of diagnosis. We found that presence of disinhibition, measured by the Neuropsychiatric Inventory Questionnaire, was associated with reduced global efficiency of the cognitive control network in both dementia of the Alzheimer's type and behavioural variant frontotemporal dementia. Future research should replicate this transdiagnostic finding in other dementia diagnoses and imaging modalities, and investigate the potential for intervention at the level of the cognitive control network to target disinhibition.

The Beneficial Role of Apigenin against Cognitive and Neurobehavioural Dysfunction: A Systematic Review of Preclinical Investigations

Apigenin is a flavone widely present in different fruits and vegetables and has been suggested to possess neuroprotective effects against some neurological disorders. In this study, we systematically reviewed preclinical studies that investigated the effects of apigenin on learning and memory, locomotion activity, anxiety-like behaviour, depressive-like behaviour and sensorimotor and motor coordination in rats and mice with impaired memory and behaviour. We searched SCOPUS, Web of Science, PubMed and Google Scholar for relevant articles. A total of 34 studies were included in this review. The included studies revealed that apigenin enhanced learning and memory and locomotion activity, exhibited anxiolytic effects, attenuated depressive-like behaviour and improved sensorimotor and motor coordination in animals with cognitive impairment and neurobehavioural deficit. Some of the molecular and biochemical mechanisms of apigenin include activation of the ERK/CREB/BDNF signalling pathway; modulation of neurotransmitter levels and monoaminergic, cholinergic, dopaminergic and serotonergic systems; inhibition of pro-inflammatory cytokine production; and attenuation of oxidative neuronal damage. These results revealed the necessity for further research using established doses and short or long durations to ascertain effective and safe doses of apigenin. These results also point to the need for a clinical experiment to ascertain the therapeutic effect of apigenin.

Psychiatric burden in a cohort of adults with Niemann Pick type C disease: from psychotic symptoms to frontal lobe behavioral disorders

OBJECTIVES

To describe Niemann-Pick type C (NP-C) behavioral symptoms (focusing on psychotic symptoms) and its relation to frontal lobe functioning.

METHODS

We retrospectively reviewed medical charts of NP-C-patients followed in the Lysosomal Diseases reference center in Paris Pitié-Salpêtrière. We collected demographic data, psychiatric clinical manifestations, psychometric scales, and extended neuropsychological data including executive and behavioral frontal lobe functions evaluations.

RESULTS

Nineteen patients were included in the study with ten of them having experienced at least one acute psychotic episode, being inaugural for six of them. Most of the patients suffered from behavioral (15/17) and cognitive disorders (18/19) (including executive dysfunction (11/12), apathy (13/17), impaired social cognition (11/13) and stereotyped behaviors (5/10). For five patients, quality of life was significantly impaired by these abnormal behaviors. Concerning frontal neuropsychological evaluation, Facial emotion recognition was by far the most performed neuropsychological test (n = 8) and the score was always abnormal. It is noteworthy that psychotic symptoms were often drug resistant (8/9) and that Miglustat was associated with a better control of psychotic symptoms.

CONCLUSIONS

We report a high frequency of psychiatric symptoms in NP-C encompassing acute psychotic manifestations, often presenting early in the course of the disease with atypical features. We also report disabling behavioral manifestations related to frontal dysfunction.

Multimodal nonlinear correlates of behavioural symptoms in frontotemporal dementia

Background

Studies exploring the brain correlates of behavioural symptoms in the frontotemporal dementia spectrum (FTD) have mainly searched for linear correlations with single modality neuroimaging data, either structural magnetic resonance imaging (MRI) or fluoro-deoxy-D-glucose positron emission tomography (FDG-PET). We aimed at studying the two imaging modalities in combination to identify nonlinear co-occurring patterns of atrophy and hypometabolism related to behavioural symptoms.

Methods

We analysed data from 93 FTD patients who underwent T1-weighted MRI, FDG-PET imaging, and neuropsychological assessment including the Neuropsychiatric Inventory, Frontal Systems Behaviour Scale, and Neurobehavioral Rating Scale. We used a data-driven approach to identify the principal components underlying behavioural variability, then related the identified components to brain variability using a newly developed method fusing maps of grey matter volume and FDG metabolism.

Results

A component representing apathy, executive dysfunction, and emotional withdrawal was associated with atrophy in bilateral anterior insula and putamen, and with hypometabolism in the right prefrontal cortex. Another component representing the disinhibition versus depression/mutism continuum was associated with atrophy in the right striatum and ventromedial prefrontal cortex for disinhibition, and hypometabolism in the left fronto-opercular region and sensorimotor cortices for depression/mutism. A component representing psychosis was associated with hypometabolism in the prefrontal cortex and hypermetabolism in auditory and visual cortices.

Discussion

Behavioural symptoms in FTD are associated with atrophy and altered metabolism of specific brain regions, especially located in the frontal lobes, in a hierarchical way: apathy and disinhibition are mostly associated with grey matter atrophy, whereas psychotic symptoms are mostly associated with hyper-/hypo-metabolism.

Loneliness and risk of all-cause, Alzheimer's, vascular, and frontotemporal dementia: a prospective study of 492,322 individuals over 15 years

OBJECTIVES

This study examined the association between loneliness and risk of incident all-cause dementia and whether the association extends to specific causes of dementia.

DESIGN

Longitudinal.

SETTING

Community.

PARTICIPANTS

Participants were from the UK Biobank (N = 492,322).

INTERVENTION

None.

MEASUREMENTS

Loneliness was measured with a standard item. The diagnosis of dementia was derived from health and death records, which included all-cause dementia and the specific diagnoses of Alzheimer's disease (AD), vascular dementia (VD), and frontotemporal dementia (FTD), over 15 years of follow-up.

RESULTS

Feeling lonely was associated with a nearly 60% increased risk of all-cause dementia (HR = 1.59, 95% CI = 1.51-1.65; n = 7,475 incident all-cause). In cause-specific analyses, loneliness was a stronger predictor of VD (HR = 1.82, 95% CI = 1.62-2.03; n = 1,691 incident VD) than AD (HR = 1.40, 95% CI = 1.28-1.53; n = 3135 incident AD) and was, surprisingly, a strong predictor of FTD (HR = 1.64, 95% CI = 1.22-2.20; n = 252 incident FTD). The associations were robust to sensitivity analyses and were attenuated but remained significant accounting for clinical (e.g. diabetes) and behavioral (e.g. physical activity) risk factors, depression, social isolation, and genetic risk. The association between loneliness and all-cause and AD risk was moderated by APOE ϵ4 risk status such that the increased risk was apparent in both groups but stronger among non-carriers than carriers of the risk allele.

CONCLUSION

Loneliness is associated with increased risk of multiple types of dementia.

Impact of dysexecutive syndrome in quality of life in Alzheimer disease: What we know now and where we are headed

Alzheimer's disease (AD) is a common form of dementia that leads to multiple repercussions in the patient's life. This condition's clinical characteristics include loss of memory, temporal and spatial disorientation, language or executive dysfunction, and subsequent decline of social function. Dysexecutive syndrome (DS), the second most frequent neuropsychological dysfunction in AD, affects multiple brain areas and causes cognitive, behavioral, and emotional difficulties. We aimed to analyze the association between DS and AD and elucidate possible lack of evidence that may urge further research on this theme. Especially when dealing with such a disabling disease, where new findings can directly imply a better prognosis.

The effect of sleep disorders on dementia risk in patients with traumatic brain injury: A large-scale cohort study

INTRODUCTION

We investigated the association between sleep disorders (SDs) and incident dementia in adults with traumatic brain injury (TBI).

METHODS

Adults with a TBI between 2003 and 2013 were followed until incident dementia. Sleep disorders at TBI were predictors in Cox regression models, controlling for other dementia risks.

RESULTS

Over 52 months, 4.6% of the 712,708 adults (59% male, median age 44, <1% with SD) developed dementia. An SD was associated with a 26% and a 23% of increased risk of dementia in male and female participants (hazard ratio [HR] 1.26, 95% confidence interval [CI] 1.11-1.42 and HR 1.23, 95% CI 1.09-1.40, respectively). In male participants, SD was associated with a 93% increased risk of early-onset dementia (HR 1.93, 95% CI 1.29-2.87); this did not hold in female participants (HR 1.38, 95% CI 0.78-2.44).

DISCUSSION

In a province-wide cohort, SDs at TBI were independently associated with incident dementia. Clinical trials testing sex-specific SD care after TBI for dementia prevention are timely.

HIGHLIGHTS

TBI and sleep disorders are linked to each other, and to dementia.It is unclear if sleep disorders pose a sex-specific dementia risk in brain injury.In this study, presence of a sleep disorder increased dementia risk in both sexes.The risk differed by type of sleep disorder, which differed between the sexes.Sleep disorder awareness and care in persons with brain injury is vital for dementia prevention.

Clinical relevance of disrupted topological organization of anatomical connectivity in behavioral variant frontotemporal dementia

Graph theory is a novel approach used to examine the balance of brain connectomes. However, the clinical relevance of white matter (WM) connectome changes in the behavioral variant frontotemporal dementia (bvFTD) is not well understood. We aimed to investigate the clinical relevance of WM topological alterations in bvFTD. Thirty patients with probable bvFTD and 30 healthy controls underwent diffusion tensor imaging, structural MRI, and neuropsychological assessment. WM connectivity between 90 brain regions was calculated and the graph approach was applied to capture the individual characteristics of the anatomical network. Voxel-based morphometry and tract-based spatial statistics were used to present the gray matter atrophy and disrupted WM integrity. The topological organization was disrupted in patients with bvFTD both globally and locally. Compared to controls, bvFTD data showed a different pattern of hub region distributions. Notably, the nodal efficiency of the right superior orbital frontal gyrus was associated with apathy and disinhibition. Topological measures may be potential image markers for early diagnosis and disease severity monitoring of bvFTD.

Overlapping and unique brain responses to cognitive and response inhibition

Although cognitive inhibition and response inhibition fall under the umbrella term of inhibition, the question remains whether the two aspects of inhibition engage shared or distinct brain regions. The current study is one of the first to examine the neural underpinnings of cognitive inhibition (e.g. the Stroop incongruency effect) and response inhibition (e.g. "no-go" response) within a single task. Adult participants (n = 77) completed an adapted version of the Simon Task in a 3T MRI scanner. The results demonstrated that cognitive and response inhibition recruited a group of overlapping brain regions (inferior frontal cortex, inferior temporal lobe, precentral cortex, parietal cortex). However, a direct comparison of cognitive and response inhibition revealed that the two aspects of inhibition also engaged distinct, task-specific brain regions (voxel-wise FWE corrected p < 0.05). Cognitive inhibition was associated with increases in multiple brain regions within the prefrontal cortex. On the other hand, response inhibition was associated with increases in distinct regions of the prefrontal cortex, right superior parietal cortex, and inferior temporal lobe. Our findings advance the understanding of the brain basis of inhibition by suggesting that cognitive inhibition and response inhibition engage overlapping but distinct brain regions.

Altered delay discounting in neurodegeneration: insight into the underlying mechanisms and perspectives for clinical applications

Steeper delay discounting (i.e., the extent to which future rewards are perceived as less valuable than immediate ones) has been proposed as a transdiagnostic process across different health conditions, in particular psychiatric disorders. Impulsive decision-making is a hallmark of different neurodegenerative conditions but little is known about delay discounting in the domain of neurodegenerative conditions. We reviewed studies on delay discounting in patients with Parkinson's disease (PD) and in patients with dementia (Alzheimer's disease / AD or frontotemporal dementia / FTD). We proposed that delay discounting could be an early marker of the neurodegenerative process. We developed the idea that altered delay discounting is associated with overlapping but distinct neurocognitive mechanisms across neurodegenerative diseases: dopaminergic-related disorders of reward processing in PD, memory/projection deficits due to medial temporal atrophy in AD, modified reward processing due to orbitofrontal atrophy in FTD. Neurodegeneration could provide a framework to decipher the neuropsychological mechanisms of value-based decision-making. Further, delay discounting could become a marker of interest in clinical practice, in particular for differential diagnosis.

Behavioural disinhibition in frontotemporal dementia investigated within an ecological framework

Disinhibition is a core symptom in behavioural variant frontotemporal dementia (bvFTD) particularly affecting the daily lives of both patients and caregivers. Yet, characterisation of inhibition disorders is still unclear and management options of these disorders are limited. Questionnaires currently used to investigate behavioural disinhibition do not differentiate between several subtypes of disinhibition, encompass observation biases and lack of ecological validity. In the present work, we explored disinhibition in an original semi-ecological situation, by distinguishing three categories of disinhibition: compulsivity, impulsivity and social disinhibition. First, we measured prevalence and frequency of these disorders in 23 bvFTD patients and 24 healthy controls (HC) in order to identify the phenotypical heterogeneity of disinhibition. Then, we examined the relationships between these metrics, the neuropsychological scores and the behavioural states to propose a more comprehensive view of these neuropsychiatric manifestations. Finally, we studied the context of occurrence of these disorders by investigating environmental factors potentially promoting or reducing them. As expected, we found that patients were more compulsive, impulsive and socially disinhibited than HC. We found that 48% of patients presented compulsivity (e.g., repetitive actions), 48% impulsivity (e.g., oral production) and 100% of the patients group showed social disinhibition (e.g., disregards for rules or investigator). Compulsivity was negatively related with emotions recognition. BvFTD patients were less active if not encouraged in an activity, and their social disinhibition decreased as activity increased. Finally, impulsivity and social disinhibition decreased when patients were asked to focus on a task. Summarising, this study underlines the importance to differentiate subtypes of disinhibition as well as the setting in which they are exhibited, and points to stimulating area for non-pharmacological management.

The risk of criminal behavior in the elderly and patients with neurodegenerative disease

Behavioral changes are commonly observed in patients with dementia and can lead to criminal offenses, even without a history of criminal or antisocial behavior. Due to the growth of the aging population, this poses a rising problem to deal with for the criminal justice system and in general for society. Criminal behavior may include minor crimes such as theft or traffic violations, but also serious crimes such as physical abuse, sexual offense, or murder. In the assessment of criminal behavior among elderly (first-time) offenders, it is important to be aware of possible neurodegenerative diseases at the time of the crime. This book chapter provides an overview on criminal behavior in the elderly and specifically discusses existing literature on patients suffering from a neurodegenerative disease, including Alzheimer disease, vascular dementia, frontotemporal dementia, Parkinson disease, and Huntington disease. Each section is introduced by a true case to illustrate how the presence of a neurodegenerative disease may affect the criminal judgment. The chapter ends with a summary, multifactorial model of crime risk, future perspectives, and concluding remarks.

Social Cognition in Behavioral Variant Frontotemporal Dementia and Pathological Subtypes: A Narrative Review

Behavioral variant frontotemporal dementia (bvFTD) belongs to the spectrum of frontotemporal lobar degeneration (FTLD) and is characterized by frontal dysfunction with executive deficits and prominent socioemotional impairments. Social cognition, such as emotion processing, theory of mind, and empathy may significantly impact daily behavior in bvFTD. Abnormal protein accumulation of tau or TDP-43 are the main causes of neurodegeneration and cognitive decline. Differential diagnosis is difficult due to the heterogeneous pathology in bvFTD and the high clinicopathological overlap with other FTLD syndromes, especially in late disease stages. Despite recent advances, social cognition in bvFTD has not yet received sufficient attention, nor has its association with underlying pathology. This narrative review evaluates social behavior and social cognition in bvFTD, by relating these symptoms to neural correlates and underlying molecular pathology or genetic subtypes. Negative and positive behavioral symptoms, such as apathy and disinhibition, share similar brain atrophy and reflect social cognition. More complex social cognitive impairments are probably caused by the interference of executive impairments due to increasing neurodegeneration. Evidence suggests that underlying TDP-43 is associated with neuropsychiatric and early social cognitive dysfunction, while patients with underlying tau pathology are marked by strong cognitive dysfunction with increasing social impairments in later stages. Despite many current research gaps and controversies, finding distinct social cognitive markers in association to underlying pathology in bvFTD is essential for validating biomarkers, for clinical trials of novel therapies, and for clinical practice.

Acetylcholine deficit causes dysfunctional inhibitory control in an aging-dependent manner

Inhibitory control is a key executive function that limits unnecessary thoughts and actions, enabling an organism to appropriately execute goal-driven behaviors. The efficiency of this inhibitory capacity declines with normal aging or in neurodegenerative dementias similar to memory or other cognitive functions. Acetylcholine signaling is crucial for executive function and also diminishes with aging. Acetylcholine's contribution to the aging- or dementia-related decline in inhibitory control, however, remains elusive. We addressed this in Drosophila using a Go/No-Go task that measures inhibition capacity. Here, we report that inhibition capacity declines with aging in wild-type flies, which is mitigated by lessening acetylcholine breakdown and augmented by reducing acetylcholine biosynthesis. We identified the mushroom body (MB) γ neurons as a chief neural site for acetylcholine's contribution to the aging-associated inhibitory control deficit. In addition, we found that the MB output neurons MBON-γ2α'1 having dendrites at the MB γ2 and α'1 lobes and axons projecting to the superior medial protocerebrum and the crepine is critical for sustained movement suppression per se. This study reveals, for the first time, the central role of acetylcholine in the aging-associated loss of inhibitory control and provides a framework for further mechanistic studies.

Biosensors toward behavior detection in diagnosis of alzheimer’s disease

In recent years, a huge number of individuals all over the world, elderly people, in particular, have been suffering from Alzheimer’s disease (AD), which has had a significant negative impact on their quality of life. To intervene early in the progression of the disease, accurate, convenient, and low-cost detection technologies are gaining increased attention. As a result of their multiple merits in the detection and assessment of AD, biosensors are being frequently utilized in this field. Behavioral detection is a prospective way to diagnose AD at an early stage, which is a more objective and quantitative approach than conventional neuropsychological scales. Furthermore, it provides a safer and more comfortable environment than those invasive methods (such as blood and cerebrospinal fluid tests) and is more economical than neuroimaging tests. Behavior detection is gaining increasing attention in AD diagnosis. In this review, cutting-edge biosensor-based devices for AD diagnosis together with their measurement parameters and diagnostic effectiveness have been discussed in four application subtopics: body movement behavior detection, eye movement behavior detection, speech behavior detection, and multi-behavior detection. Finally, the characteristics of behavior detection sensors in various application scenarios are summarized and the prospects of their application in AD diagnostics are presented as well.

Behavioral Variant Frontotemporal Dementia and Social and Criminal Transgressions

OBJECTIVE

Behavioral variant frontotemporal dementia (bvFTD) is associated with social and criminal transgressions; studies from countries around the world have documented such behavior in persons with this condition. An overview and analysis of social and criminal transgressions in bvFTD and their potential neurobiological mechanisms can provide a window for understanding the relationship of antisocial behavior and the brain.

METHODS

This review evaluated the literature on the frequency of social and criminal transgressions in bvFTD and the neurobiological disturbances that underlie them.

RESULTS

There is a high frequency of transgressions among patients with bvFTD due to impairments in neurocognition, such as social perception, behavioral regulation, and theory of mind, and impairments in social emotions, such as self-conscious emotions and empathy. Additionally, there is significant evidence for a specific impairment in an innate sense of morality. Alterations in these neurobiological processes result from predominantly right-hemisphere pathology in frontal (ventromedial, orbitofrontal, inferolateral frontal), anterior temporal (amygdala, temporal pole), limbic (anterior cingulate, amygdala), and insular regions.

CONCLUSIONS

Overlapping disturbances in neurocognition, social emotions, and moral reasoning result from disease in the mostly mesial and right-sided frontotemporal network necessary for responding emotionally to others and for behavioral control. With increased sophistication in neurobiological interventions, future goals may be the routine evaluation of these processes among individuals with bvFTD who engage in social and criminal transgressions and the targeting of these neurobiological mechanisms with behavioral, pharmacological, and other interventions.

Does global positioning system-based navigation dependency make your sense of direction poor? A psychological assessment and eye-tracking study

Background

Global positioning system (GPS)-based navigation apps are very useful in our lives. However, whether and how the usage of these apps affects spatial cognition and the sense of direction is still unclear.

Methods

A total of 108 individuals were recruited and completed the GPS dependence, internet gaming behavior, and impulsivity test using scales. The eye-tracking-based general mental rotation (MR) task and target finding (TF; require individuals to find a target specified in a 3D street map in a rotated version of top 2D view map) task were used to assess their spatial cognition and the sense of direction. The correlation was used to relate GPS navigation usage, spatial cognition ability, and impulsivity. Subgroup analyses stratifying by gaming hours of individuals (&lt; 2 h or ≥ 2 h) or maps (countryside or city) in TF task were performed. The moderating and mediating effect analyses were conducted to verify these relationships.

Results

The GPS dependency score was nominal positively correlated with fixations in the TF task in the entire cohort (r = 0.202, unadjusted p = 0.036); it was significant in city (r = 0.254, p = 0.008) and gaming time of &lt; 2 h (r = 0.459, p = 0.001) subgroups. The high-score (upper 30%) group of GPS dependency had more fixations on the original target building in the training area and indicative building in the test area than the low-score (lower 30%) group. GPS dependency was not associated with the correct rate and reaction time in the TF task or any of the indicators in the MR task (p &gt; 0.05). The GPS dependency mediated the indirect effect of impulsivity on the fixations on TF. The internet gaming time moderated the association between GPS dependency and fixations on TF.

Conclusion

The dependency on GPS-based navigation apps was associated with impaired spatial cognition but may not significantly affect the sense of direction.

Design and Verbal Fluency in Alzheimer's Disease and Frontotemporal Dementia: Clinical and Metabolic Correlates

OBJECTIVE

Cognitive processes underlying verbal and design fluency, and their neural correlates in patients with Alzheimer's disease (AD) and behavioural variant Frontotemporal Dementia (bvFTD) remain unclear. We hypothesised that verbal and design fluency may be associated with distinct neuropsychological processes in AD and FTD, showing different patterns of impairment and neural basis.

METHODS

We enrolled 142 participants including patients with AD (n = 80, mean age = 74.71), bvFTD (n = 34, mean age = 68.18), and healthy controls (HCs) (n = 28, mean age = 71.14), that underwent cognitive assessment and ¹⁸F-fluorodeoxyglucose positron emission tomography imaging.

RESULTS

Semantic and phonemic fluency showed the largest effect sizes between groups, showing lower scores in bvFTD than AD and HCs, and lower scores in AD than HC. Both AD and bvFTD showed a lower number of unique designs in design fluency in comparison to HC. Semantic fluency was correlated with left frontotemporal lobe in AD, and with left frontal, caudate, and thalamus in bvFTD. Percentage of unique designs in design fluency was associated with the metabolism of the bilateral fronto-temporo-parietal cortex in AD, and the bilateral frontal cortex with right predominance in bvFTD. Repetitions in AD were correlated with bilateral frontal, temporal, and parietal lobes, and with left prefrontal cortex in bvFTD.

CONCLUSIONS

Our findings demonstrate differential underlying cognitive processes in verbal and design fluency in AD and bvFTD. While memory and executive functioning associated with fronto-temporo-parietal regions were key in AD, attention and executive functions correlated with the frontal cortex and played a more significant role in bvFTD during fluency tasks.

An ecological approach to identify distinct neural correlates of disinhibition in frontotemporal dementia

Disinhibition is a core symptom of many neurodegenerative diseases, particularly frontotemporal dementia, and is a major cause of stress for caregivers. While a distinction between behavioural and cognitive disinhibition is common, an operational definition of behavioural disinhibition is still missing. Furthermore, conventional assessment of behavioural disinhibition, based on questionnaires completed by the caregivers, often lacks ecological validity. Therefore, their neuroanatomical correlates are non-univocal. In the present work, we used an original behavioural approach in a semi-ecological situation to assess two specific dimensions of behavioural disinhibition: compulsivity and social disinhibition. First, we investigated disinhibition profile in patients compared to controls. Then, to validate our approach, compulsivity and social disinhibition scores were correlated with classic cognitive tests measuring disinhibition (Hayling Test) and social cognition (mini-Social cognition & Emotional Assessment). Finally, we disentangled the anatomical networks underlying these two subtypes of behavioural disinhibition, taking in account the grey (voxel-based morphometry) and white matter (diffusion tensor imaging tractography). We included 17 behavioural variant frontotemporal dementia patients and 18 healthy controls. We identified patients as more compulsive and socially disinhibited than controls. We found that behavioural metrics in the semi-ecological task were related to cognitive performance: compulsivity correlated with the Hayling test and both compulsivity and social disinhibition were associated with the emotion recognition test. Based on voxel-based morphometry and tractography, compulsivity correlated with atrophy in the bilateral orbitofrontal cortex, the right temporal region and subcortical structures, as well as with alterations of the bilateral cingulum and uncinate fasciculus, the right inferior longitudinal fasciculus and the right arcuate fasciculus. Thus, the network of regions related to compulsivity matched the "semantic appraisal" network. Social disinhibition was associated with bilateral frontal atrophy and impairments in the forceps minor, the bilateral cingulum and the left uncinate fasciculus, regions corresponding to the frontal component of the "salience" network. Summarizing, this study validates our semi-ecological approach, through the identification of two subtypes of behavioural disinhibition, and highlights different neural networks underlying compulsivity and social disinhibition. Taken together, these findings are promising for clinical practice by providing a better characterisation of inhibition disorders, promoting their detection and consequently a more adapted management of patients.

THE IMPLICATIONS OF FRONTOTEMPORAL DEMENTIA FOR BRAIN DYSFUNCTION IN PSYCHOPATHY

Understanding how psychopathy compares with brain disease can help clarify its underlying mechanisms. This literature review is a broad overview of the neurobiology of psychopathic traits in comparison to behavioral variant frontotemporal dementia (bvFTD), a disorder uniquely associated with criminal behavior. In addition to violation of social norms, both psychopathy and bvFTD result in impaired socioemotional perception and empathy, impulsivity, and altered moral judgment. Despite wide areas of decreased function in psychopathy, structural changes are primarily evident in amygdala and, to a lesser extent, anterior insula, whereas in bvFTD neuropathology involves a wider paralimbic region. In psychopathy, relatively intact medial prefrontal and anterior cingulate cortices facilitate theory of mind and psychopathic traits such as deceitfulness and manipulation, bold fearlessness, and risk-taking behavior. In conclusion, many frontotemporal areas are hypoactive in psychopathy and bvFTD, but differences in dysfunctional connectivity in psychopathy vs. direct involvement in bvFTD potentially explain similarities and differences between these two conditions.

A transdiagnostic review of neuroimaging studies of apathy and disinhibition in dementia

Apathy and disinhibition are common and highly distressing neuropsychiatric symptoms associated with negative outcomes in persons with dementia. This paper is a critical review of functional and structural neuroimaging studies of these symptoms transdiagnostically in dementia of the Alzheimer type, which is characterized by prominent amnesia early in the disease course, and behavioural variant frontotemporal dementia, characterized by early social-comportmental deficits. We describe the prevalence and clinical correlates of these symptoms and describe methodological issues, including difficulties with symptom definition and different measurement instruments. We highlight the heterogeneity of findings, noting however, a striking similarity of the set of brain regions implicated across clinical diagnoses and symptoms. These regions involve several key nodes of the salience network, and we describe the functions and anatomical connectivity of these brain areas, as well as present a new theoretical account of disinhibition in dementia. Future avenues for research are discussed, including the importance of transdiagnostic studies, measuring subdomains of apathy and disinhibition, and examining different units of analysis for deepening our understanding of the networks and mechanisms underlying these extremely distressing symptoms.

Identification of the main components of spontaneous speech in primary progressive aphasia and their neural underpinnings using multimodal MRI and FDG-PET imaging

BACKGROUND

Primary progressive aphasia (PPA) is a clinical syndrome characterized by gradual loss of language skills. This study aimed to evaluate the diagnostic capacity of a connected speech task for the diagnosis of PPA and its variants, to determine the main components of spontaneous speech, and to examine their neural correlates.

METHODS

A total of 118 participants (31 patients with nfvPPA, 11 with svPPA, 45 with lvPPA, and 31 healthy controls) were evaluated with the Cookie Theft picture description task and a comprehensive language assessment protocol. Patients also underwent ¹⁸F-fluorodeoxyglucose positron emission tomography and magnetic resonance imaging studies. Principal component analysis and machine learning were used to evaluate the main components of connected speech and the accuracy of connected speech parameters for diagnosing PPA. Voxel-based analyses were conducted to evaluate the correlation between spontaneous speech components and brain metabolism, brain volumes, and white matter microstructure.

RESULTS

Discrimination between patients with PPA and controls was 91.67%, with 77.78% discrimination between PPA variants. Parameters related to speech rate and lexical variables were the most discriminative for classification. Three main components were identified: lexical features, fluency, and syntax. The lexical component was associated with ventrolateral frontal regions, while the fluency component was associated with the medial superior prefrontal cortex. Number of pauses was more related with the left parietotemporal region, while pauses duration with the bilateral frontal lobe. The lexical component was correlated with several tracts in the language network (left frontal aslant tract, left superior longitudinal fasciculus I, II, and III, left arcuate fasciculus, and left uncinate fasciculus), and fluency was linked to the frontal aslant tract.

CONCLUSION

Spontaneous speech assessment is a useful, brief approach for the diagnosis of PPA and its variants. Neuroimaging correlates suggested a subspecialization within the left frontal lobe, with ventrolateral regions being more associated with lexical production and the medial superior prefrontal cortex with speech rate.

Multimodal Capture of Patient Behaviour for Improved Detection of Early Dementia: Clinical Feasibility and Preliminary Results

Non-invasive automatic screening for Alzheimer’s disease has the potential to improve diagnostic accuracy while lowering healthcare costs. Previous research has shown that patterns in speech, language, gaze, and drawing can help detect early signs of cognitive decline. In this paper, we describe a highly multimodal system for unobtrusively capturing data during real clinical interviews conducted as part of cognitive assessments for Alzheimer’s disease. The system uses nine different sensor devices (smartphones, a tablet, an eye tracker, a microphone array, and a wristband) to record interaction data during a specialist’s first clinical interview with a patient, and is currently in use at Karolinska University Hospital in Stockholm, Sweden. Furthermore, complementary information in the form of brain imaging, psychological tests, speech therapist assessment, and clinical meta-data is also available for each patient. We detail our data-collection and analysis procedure and present preliminary findings that relate measures extracted from the multimodal recordings to clinical assessments and established biomarkers, based on data from 25 patients gathered thus far. Our findings demonstrate feasibility for our proposed methodology and indicate that the collected data can be used to improve clinical assessments of early dementia.

Frontotemporal dementia subtypes based on behavioral inhibition deficits

INTRODUCTION

We aimed to investigate phenotypic heterogeneity in the behavioral variant of frontotemporal dementia (bvFTD) through assessment of inhibition deficits.

METHODS

We assessed occurrences of 16 behavioral inhibition deficits from video recordings of 15 bvFTD patients (early stage) and 15 healthy controls (HC) in an ecological setting. We extracted dimensions of inhibition deficit and analyzed their correlations with cognitive and clinical measures. Using these dimensions, we isolated patient clusters whose atrophy patterns were explored.

RESULTS

After identifying two patterns of inhibition deficit (compulsive automatic behaviors and socially unconventional behaviors), we isolated three behavioral clusters with distinct atrophy patterns. BvFTD-G0 (N = 3), an outlier group, showed severe behavioral disturbances and more severe ventromedial prefrontal cortex/orbitofrontal cortex atrophy. Compared to bvFTD-G1 (N = 6), bvFTD-G2 (N = 6) presented higher anxiety and depression along with less diffuse atrophy especially in midline regions.

DISCUSSION

Identifying clinico-anatomical profiles through behavior observation could help to stratify bvFTD patients for adapted treatments.