Social cognition across bipolar disorder and behavioral-variant frontotemporal dementia: an exploratory study

Objectives: Bipolar disorder type 1 (BD1) and behavioral-variant frontotemporal dementia (bvFTD) share similar behavioral and cognitive symptoms, rendering the differential diagnosis between them a clinical challenge. We investigated the accuracy of social cognition (SC) measures to differentiate bvFTD from BD. Methods: We included three groups of participants: early-onset BD1 (in remission, n=20), bvFTD (n=18), and cognitively healthy controls (HC) (n=40), matched for age, schooling, and sex. All participants underwent cognitive assessment, including the Facial Emotion Recognition (FER) and Modified Faux-Pas (mFP) tests, which assess mentalizing. Results: Compared to HC, BD1 and bvFTD patients underperformed on both SC measures. BD1 and bvFTD did not differ regarding FER or mFP total scores, although patients with bvFTD had significantly higher difficulties than those in the BD1 group to detect social faux-pas (p < 0.001, d = 1.35). Conclusion: BD1 and bvFTD share deficits in the core SC functions. These findings should be considered in the development of tasks aiming to improve clinical differentiation between the two disorders.

Social cognition across bipolar disorder and behavioral variant frontotemporal dementia: an exploratory study.

OBJECTIVES: Bipolar disorder type 1 (BD1) and behavioral-variant frontotemporal dementia (bvFTD) share similar behavioral and cognitive symptoms, rendering the differential diagnosis between them a clinical challenge. We investigated the accuracy of social cognition (SC) measures to differentiate bvFTD from BD. METHODS: We included three groups of participants: early-onset BD1 (in remission, n=20), bvFTD (n=18), and cognitively healthy controls (HC) (n=40), matched for age, schooling, and sex. All participants underwent cognitive assessment, including the Facial Emotion Recognition (FER) and Modified Faux-Pas (mFP) tests, which assess mentalizing. RESULTS: Compared to HC, BD1 and bvFTD patients underperformed on both SC measures. BD1 and bvFTD did not differ regarding FER or mFP total scores, although patients with bvFTD had significantly higher difficulties than those in the BD1 group to detect social faux-pas (p < 0.001, d = 1.35). CONCLUSION: BD1 and bvFTD share deficits in the core SC functions. These findings should be considered in the development of tasks aiming to improve clinical differentiation between the two disorders.

I'm looking through you: Mentalizing in frontotemporal dementia and progressive supranuclear palsy.

Mentalizing and emotion recognition are impaired in behavioral variant frontotemporal dementia (bvFTD). It is not clear whether these abilities are also disturbed in other conditions with prominent frontal lobe involvement, such as progressive supranuclear palsy (PSP). Our aim was to investigate social cognition (facial emotion recognition, recognition of social norms violation and mentalizing) in bvFTD and PSP. The neural basis of these functions in PSP and bvFTD groups, by analysis of structural neuroimaging, were also investigated. Twenty-three bvFTD patients, 21 PSP patients and 23 healthy controls were included. All participants underwent 3T brain MRI and a full cognitive exam including the short version of Social and Emotional Assessment (Mini-SEA), which is composed of a facial emotion recognition test (FERT) and the faux pas test. Two components of the faux pas test were distinguished: a score assessing the recognition of social norms violation and a score assessing mentalizing. Compared to controls, bvFTD and PSP patients had significantly reduced scores in all tests of social cognition but did not differ on these measures. PSP and bvFTD had cerebral atrophy in critical regions for social cognition processes, when compared to controls. The cortical correlates of emotion recognition partially overlapped in bvFTD and PSP, with correlations retrieved within the frontal medial cortex, cingulate, insula and limbic structures. PSP and bvFTD patients also displayed similar patterns of brain correlations for the composite score of social norms, with a significant cluster in anterior temporal lobes. Mentalizing scores were associated with frontal and temporal poles bilaterally, in both bvFTD and PSP. These findings support previous observations that PSP patients exhibit impairment in complex cognitive abilities, such as mentalizing. Moreover, these data extend previous findings showing that PSP and bvFTD share key clinical, cognitive and neuroimaging features.

How to differentiate behavioral variant frontotemporal dementia from primary psychiatric disorders: practical aspects for the clinician.

BACKGROUND: Due to the early and prominent behavioral changes which characterize behavioral variant frontotemporal dementia (bvFTD), patients are more likely to seek psychiatric help and are often initially diagnosed with a primary psychiatric disorder (PPD). Differentiating these conditions is critical because of the dramatically different outcomes, differences in patient management, family counseling and caregiver education. OBJECTIVE: To propose a practical guide to distinguish between bvFTD and PDD. METHODS: We conducted a non-systematic review of the published manuscripts in the field, including some previous investigations from our own group and work on which we have collaborated, and summarized the main findings and proposals that may be useful for neurological practice. RESULTS: The reviewed literature suggests that a comprehensive clinical history, brief cognitive and neuropsychological evaluations, detailed neurological examination with special attention to motor alterations related to bvFTD, structural and functional neuroimaging evaluation, genetic investigation in selected cases, and assistance from a multidisciplinary team, including a neurologist and a psychiatrist with expertise in bvFTD, are very helpful in differentiating these conditions. CONCLUSIONS: Although the clinician may commonly face great difficulty in differentiating between bvFTD and PPD, the use of appropriate tools in a systematic way and the availability of a well-trained multidisciplinary group can significantly increase diagnostic accuracy.

How to differentiate behavioral variant frontotemporal dementia from primary psychiatric disorders: practical aspects for the clinician / Como diferenciar variante comportamental da demência frontotemporal de transtornos psiquiátricos: aspectos práticos para o clínico

ABSTRACT Background: Due to the early and prominent behavioral changes which characterize behavioral variant frontotemporal dementia (bvFTD), patients are more likely to seek psychiatric help and are often initially diagnosed with a primary psychiatric disorder (PPD). Differentiating these conditions is critical because of the dramatically different outcomes, differences in patient management, family counseling and caregiver education. Objective: To propose a practical guide to distinguish between bvFTD and PDD. Methods: We conducted a non-systematic review of the published manuscripts in the field, including some previous investigations from our own group and work on which we have collaborated, and summarized the main findings and proposals that may be useful for neurological practice. Results: The reviewed literature suggests that a comprehensive clinical history, brief cognitive and neuropsychological evaluations, detailed neurological examination with special attention to motor alterations related to bvFTD, structural and functional neuroimaging evaluation, genetic investigation in selected cases, and assistance from a multidisciplinary team, including a neurologist and a psychiatrist with expertise in bvFTD, are very helpful in differentiating these conditions. Conclusions: Although the clinician may commonly face great difficulty in differentiating between bvFTD and PPD, the use of appropriate tools in a systematic way and the availability of a well-trained multidisciplinary group can significantly increase diagnostic accuracy.

RESUMO Antecedentes: Devido às alterações comportamentais precoces e proeminentes que caracterizam a variante comportamental da demência frontotemporal (DFTvc), os pacientes são mais propensos a procurar atendimento psiquiátrico e muitas vezes são diagnosticados inicialmente com um transtorno psiquiátrico primário (TPP). Diferenciar essas condições é fundamental, devido aos desfechos significativamente diferentes, diferenças no manejo dos pacientes, no aconselhamento familiar e na educação dos cuidadores. Objetivo: Propor um guia prático para o diagnóstico diferencial entre DFTvc e TPP. Métodos: Revisão não sistemática dos manuscritos publicados na área, incluindo algumas investigações anteriores de nosso próprio grupo e trabalhos com os quais colaboramos. Os principais achados e propostas foram sintetizados para auxiliarem a prática neurológica. Resultados: A literatura revisada sugere que a história clínica abrangente, avaliação cognitiva breve e avaliação neuropsicológica, exame neurológico detalhado com especial atenção às alterações motoras relacionadas à DFTvc, exames de neuroimagem estrutural e funcional, investigação genética em casos selecionados e o atendimento por equipe multidisciplinar, incluindo um neurologista e um psiquiatra com experiência em DFTvc, são bastante úteis na diferenciação dessas condições. Conclusões: Embora o clínico possa enfrentar grande dificuldade para diferenciar DFTvc e TPP, o uso de ferramentas apropriadas de forma sistemática e a disponibilidade de uma equipe multidisciplinar bem treinada podem aumentar significativamente a acurácia diagnóstica.

Treatment of the behavioral variant of frontotemporal dementia: a narrative review.

Frontotemporal dementia (FTD) is a progressive neurodegenerative disorder accompanied by behavioral and personality changes and/or language deterioration. Its behavioral variant (bvFTD) is the main clinical presentation. OBJECTIVE: This study aims to investigate the treatment alternatives for bvFTD available so far. METHODS: We conducted a narrative review of bvFTD treatment options. We used PubMed and Lilacs databases with the terms "frontotemporal dementia" or "behavioral variant frontotemporal dementia" combined with "treatment," "pharmacological treatment," or "disease-modifying drugs." RESULTS: The articles retrieved and selected in the research pointed out that there is no specific treatment approved for bvFTD so far. The current proposals are limited to handle the cardinal behavioral symptoms of the disorder. Disease-modifying drugs are under development and may be promising, especially in the monogenic presentations of FTD. CONCLUSIONS: There are numerous approaches to treat the core symptoms of bvFTD, most of them based on low-quality research. To date, there are no drugs with a disease-specific therapeutic recommendation for bvFTD. Treatments are often investigated guided by primary psychiatric disorders with similar symptoms and should be chosen by the predominant symptom profile.

A demência frontotemporal (DFT) é um transtorno neurodegenerativo progressivo acompanhado de deterioração do comportamento e da personalidade e/ou da linguagem. A variante comportamental (DFTvc) é a principal apresentação clínica. OBJETIVOS: Investigar as alternativas de tratamento disponíveis para a DFTvc até o momento. MÉTODOS: Realizou-se uma revisão narrativa das opções de tratamento da DFTvc. Os bancos de dados PubMed e Lilacs foram utilizados com os termos "demência frontotemporal" ou "variante comportamental da demência frontotemporal" combinados com "tratamento", "tratamento farmacológico" ou "drogas modificadoras de doença". RESULTADOS: Os artigos recuperados e selecionados na pesquisa indicaram que não há nenhum tratamento específico aprovado até o momento para DFTvc. As propostas atuais são limitadas ao tratamento dos sintomas comportamentais cardinais do transtorno. As drogas modificadoras de doença estão em desenvolvimento e podem ser promissoras, especialmente nas apresentações monogênicas da DFT. CONCLUSÕES: Há inúmeras abordagens para tratar os principais sintomas DFTvc, a maioria delas baseada em pesquisas de baixa qualidade. Até o momento, não existem medicamentos com uma recomendação terapêutica específica para a DFTvc. Os tratamentos são frequentemente investigados guiados por distúrbios psiquiátricos primários com sintomas semelhantes e devem ser escolhidos pelo perfil de sintomas predominante.

Neuropsychiatric Symptoms in Behavioral Variant Frontotemporal Dementia and Alzheimer's Disease: A 12-Month Follow-Up Study.

Introduction: Neuropsychiatric symptoms in patients with frontotemporal dementia (FTD) are highly prevalent and may complicate clinical managements. Objective: To test whether the Neuropsychiatry Inventory (NPI) could detect change in neuropsychiatric symptoms and caregiver's distress in patients diagnosed with behavioral variant frontotemporal dementia (bvFTD) and Alzheimer's disease (AD) from baseline to a 12-month follow-up and to investigate possible predictors of change in NPI scores. Methods: The sample consisted of 31 patients diagnosed with bvFTD and 28 patients with AD and their caregivers. The Mini-Mental State Examination (MMSE), Addenbrooke's Cognitive Examination Revised (ACE-R), the INECO Frontal Screening (IFS), the Frontal Assessment Battery (FAB), the Executive Interview (EXIT-25) and the NPI were applied. Descriptive statistics, Mann-Whitney U test, Wilcoxon test, Chi square (χ2) test and Linear Regression Analysis were used. Results: NPI total and caregiver distress scores were statistically higher among bvFTD patients at both assessment points. MMSE, ACE-R scores significantly declined and NPI Total and Distress scores significantly increased in both groups. In the bvFTD group, age was the only independent predictor variable for the NPI total score at follow up. In the AD group, ACE-R and EXIT-25, conjunctively, were associated with the NPI total score at follow up. Conclusions: In 12 months, cognition declined and neuropsychiatric symptoms increased in bvFTD and AD groups. In the AD group only, cognitive impairment was a significant predictor of change in neuropsychiatric symptoms.

Treatment of the behavioral variant of frontotemporal dementia: a narrative review / Tratamento da variante comportamental da demência frontotemporal: uma revisão narrativa

ABSTRACT Frontotemporal dementia (FTD) is a progressive neurodegenerative disorder accompanied by behavioral and personality changes and/or language deterioration. Its behavioral variant (bvFTD) is the main clinical presentation. Objective: This study aims to investigate the treatment alternatives for bvFTD available so far. Methods: We conducted a narrative review of bvFTD treatment options. We used PubMed and Lilacs databases with the terms "frontotemporal dementia" or "behavioral variant frontotemporal dementia" combined with "treatment," "pharmacological treatment," or "disease-modifying drugs." Results: The articles retrieved and selected in the research pointed out that there is no specific treatment approved for bvFTD so far. The current proposals are limited to handle the cardinal behavioral symptoms of the disorder. Disease-modifying drugs are under development and may be promising, especially in the monogenic presentations of FTD. Conclusions: There are numerous approaches to treat the core symptoms of bvFTD, most of them based on low-quality research. To date, there are no drugs with a disease-specific therapeutic recommendation for bvFTD. Treatments are often investigated guided by primary psychiatric disorders with similar symptoms and should be chosen by the predominant symptom profile.

RESUMO A demência frontotemporal (DFT) é um transtorno neurodegenerativo progressivo acompanhado de deterioração do comportamento e da personalidade e/ou da linguagem. A variante comportamental (DFTvc) é a principal apresentação clínica. Objetivos: Investigar as alternativas de tratamento disponíveis para a DFTvc até o momento. Métodos: Realizou-se uma revisão narrativa das opções de tratamento da DFTvc. Os bancos de dados PubMed e Lilacs foram utilizados com os termos "demência frontotemporal" ou "variante comportamental da demência frontotemporal" combinados com "tratamento", "tratamento farmacológico" ou "drogas modificadoras de doença". Resultados: Os artigos recuperados e selecionados na pesquisa indicaram que não há nenhum tratamento específico aprovado até o momento para DFTvc. As propostas atuais são limitadas ao tratamento dos sintomas comportamentais cardinais do transtorno. As drogas modificadoras de doença estão em desenvolvimento e podem ser promissoras, especialmente nas apresentações monogênicas da DFT. Conclusões: Há inúmeras abordagens para tratar os principais sintomas DFTvc, a maioria delas baseada em pesquisas de baixa qualidade. Até o momento, não existem medicamentos com uma recomendação terapêutica específica para a DFTvc. Os tratamentos são frequentemente investigados guiados por distúrbios psiquiátricos primários com sintomas semelhantes e devem ser escolhidos pelo perfil de sintomas predominante.

Different patterns of gray matter atrophy in behavioral variant frontotemporal dementia with and without episodic memory impairment.

BACKGROUND: Differentiating patients with behavioral variant frontotemporal dementia (bvFTD) from Alzheimer's disease (AD) is important as these two conditions have distinct treatment and prognosis. Using episodic impairment and medial temporal lobe atrophy as a tool to make this distinction has been debatable in the recent literature, as some patients with bvFTD can also have episodic memory impairment and medial temporal lobe atrophy early in the disease. OBJECTIVES: To compare brain atrophy patterns of patients with bvFTD with and without episodic memory impairment to that of patients with AD. METHODS: We analyzed 19 patients with bvFTD, 21 with AD and 21 controls, matched by age, sex, and years of education. They underwent brain MRI and the memory test from the Brief Cognitive Battery (BCB) to assess episodic memory. We then categorized the bvFTD group into amnestic (BCB delayed recall score <7) and non-amnestic. RESULTS: The amnestic bvFTD group (n = 8) had significant gray matter atrophy in the left parahippocampal gyrus, right cingulate and precuneus regions compared with the nonamnestic group. Compared with AD, amnestic bvFTD had more atrophy in the left fusiform cortex, left insula, left inferior temporal gyrus and right temporal pole, whereas patients with AD had more atrophy in the left hippocampus, left frontal pole and left angular gyrus. CONCLUSIONS: There is a group of amnestic bvFTD patients with episodic memory dysfunction and significant atrophy in medial temporal structures, which poses a challenge in considering only these features when differentiating bvFTD from AD clinically.

Disease Progression in Frontotemporal Dementia and Alzheimer Disease: The Contribution of Staging Scales.

INTRODUCTION: There is a shortage of validated instruments to estimate disease progression in frontotemporal dementia (FTD). OBJECTIVES: To evaluate the ability of the FTD Rating Scale (FTD-FRS) to detect functional and behavioral changes in patients diagnosed with the behavioral variant of FTD (bvFTD), primary progressive aphasia (PPA), and Alzheimer disease (AD) after 12 months of the initial evaluation, compared to the Clinical Dementia Rating scale-frontotemporal lobar degeneration (CDR-FTLD) and the original Clinical Dementia Rating scale (CDR). METHODS: The sample consisted of 70 individuals, aged 40+ years, with at least 2 years of schooling, 31 with the diagnosis of bvFTD, 12 with PPA (8 with semantic variant and 4 with non-fluent variant), and 27 with AD. The FTD-FRS, the CDR, and the 2 additional CDR-FTLD items were completed by a clinician, based on the information provided by the caregiver with frequent contact with the patient. The Addenbrooke Cognitive Examination-Revised was completed by patients. After 12 months, the same protocol was applied. RESULTS: The FTD-FRS, CDR-FTLD, and CDR detected significant decline after 12 months in the 3 clinical groups (exception: FTD-FRS for PPA). The CDR was less sensitive to severe disease stages. CONCLUSIONS: The FTD-FRS and the CDR-FTLD are especially useful tools for dementia staging in AD and in the FTD spectrum.

Inside minds, beneath diseases: social cognition in amyotrophic lateral sclerosis-frontotemporal spectrum disorder.

OBJECTIVE: To compare social cognition performance between patients with amyotrophic lateral sclerosis (ALS) and those patients with behavioural variant frontotemporal dementia (bvFTD). METHODS: We included 21 participants with ALS, 20 with bvFTD and 21 healthy controls who underwent a comprehensive cognitive battery, including the short version of the Social Cognition and Emotional Assessment (Mini-SEA), which comprises the faux pas test and Facial Emotion Recognition Test (FERT); Mini-Mental State Examination; Frontal Assessment Battery; lexical fluency (F-A-S), category fluency (animals/minute), digit span (direct and backwards) tests and the Hayling test. A post hoc analysis was conducted with the patients with ALS divided into two subgroups: patients without cognitive impairment (ALScn; n=13) and patients with cognitive impairment (ALSci; n=8). RESULTS: No significant difference was noted between participant groups in terms of the age, sex and education. ALS-total group and patients with bvFTD had similar disease durations. Patients with ALSci performed poorly when compared with controls with regard to the FERT (p<0.001), the faux pas (p<0.004) and the Mini-SEA (p<0.002) total scores. Moreover, patients with bvFTD performed poorly in comparison with controls in executive and social cognition tests. The performance of patients with ALSci was similar to that of patients with bvFTD, while the performance of patients with ALScn was similar to that of controls. DISCUSSION: Our findings support a cognitive continuum between ALS and bvFTD and shed light on the cognitive heterogeneity of ALS, expanding its possible neuropsychological profiles.

Apathy in frontotemporal dementia is related to medial prefrontal atrophy and is independent of executive dysfunction.

INTRODUCTION: Apathy is the most common neuropsychiatric syndrome in behavioral variant frontotemporal dementia (bvFTD), and encompasses cognitive, behavioral and affective symptoms. The neural basis of apathy in bvFTD is not completely understood. Previous neuroimaging studies have poorly considered executive impairment and dementia severity as possible confounding factors. Herein we investigated the neural basis of apathy in bvFTD through structural neuroimaging taking into account these factors. METHODS: We included patients with probable bvFTD (n = 21) and cognitively healthy controls (HC, n = 22). Participants were matched for age, sex and schooling. All subjects underwent a thorough neuropsychological examination, including tests for executive functions and social cognition. Apathy was assessed with the Starkstein Apathy Scale (SAS). All subjects underwent 3T brain MRI. We investigated correlations between SAS scores and gray matter atrophy within the bvFTD group. Executive function (Frontal Assessment Battery) and disease severity were considered as covariates in neuroimaging analyses. RESULTS: Compared to HC, bvFTD patients had lower scores on global cognitive efficiency, executive functions and social cognition. All bvFTD had clinically relevant apathy (scores greater than 14 in the SAS). Performance in executive function tests did not correlate with apathy scores. The severity of apathy was negatively correlated with gray matter volumes in midline prefrontal regions, namely orbitofrontal cortex and both anterior and dorsal regions of cingulate cortex. CONCLUSIONS: Apathy in bvFTD is related to a specific network of prefrontal cortical areas critically involved in effort-based behavior for rewards and appears to be independent of executive dysfunction.

Can Social Cognition Measurements Differentiate Behavioral Variant Frontotemporal Dementia from Alzheimer's Disease Regardless of Apathy?

BACKGROUND: Alzheimer's disease (AD) and behavioral variant frontotemporal dementia (bvFTD) share cognitive and behavioral symptoms, such as apathy. Social cognition measurements are useful in distinguishing bvFTD from AD, but their accuracies may be affected by apathy. OBJECTIVE: To investigate whether social cognition measurements can distinguish bvFTD from either apathetic or non-apathetic AD patients. METHODS: Three groups of participants were enrolled in the present study: bvFTD (n = 22), AD (n = 20), and healthy controls (HC, n = 23). The AD group was divided into apathetic (n = 10) and non-apathetic (n = 10). All subjects underwent comprehensive neuropsychological examination, including the short version of the Social and Emotional Assessment (Mini-SEA), which comprises the facial emotion recognition test and the faux-pas recognition test (Faux-Pas Test). Apathy was assessed according to the Starkstein's Apathy (SA) Scale. RESULTS: The bvFTD and AD groups did not differ on global cognitive efficiency and on executive functions. In comparison to the whole AD group, bvFTD displayed lower Faux-Pas Test and Mini-SEA scores. Both AD subgroups, apathetic or non-apathetic, exhibited similar performance on all social cognition measurements. In comparison to either apathetic AD or non-apathetic AD, bvFTD patients underperformed on the Faux-Pas Test and on the Mini-SEA. The area under the curve values for the Mini-SEA total score were 0.87 (bvFTD versus AD), 0.90 (bvFTD versus apathetic AD), and 0.83 (bvFTD versus non-apathetic AD). CONCLUSION: Social cognition tests provide accurate distinction between bvFTD against either apathetic AD or non-apathetic AD. Social cognition measurements did not correlate with apathy severity.

Behavioral variant frontotemporal dementia in patients with previous severe mental illness: a systematic and critical review.

OBJECTIVES: To explore the relationship between severe/serious mental illness (SMI) and the behavioral variant of frontotemporal dementia (bvFTD), as the patterns of symptoms and cognitive performance that characterize both disorders share similarities. METHODS: We performed a systematic review investigating what has already been published regarding the relationship between bvFTD and SMI. Studies were selected from PubMed and LILACS databases, including those published up to February 12, 2018. The search strategy included the following terms: "frontotemporal dementia" plus "bipolar", OR "frontotemporal dementia" plus "schizophrenia", OR "frontotemporal dementia" plus "schizoaffective". Publications without abstracts, case reports with absent genetic or histopathological confirmation, reviews and non-English language papers were excluded across the search process. RESULTS: The search on PubMed retrieved 186 articles, of which 42 met eligibility criteria. On the LILACS database, none met the requirements. Generally, three major research aims were identified: 1) to look for frontotemporal lobar degeneration-associated genetic abnormalities in patients with prior SMI; 2) to compare the cognitive profile between patients affected by neurodegenerative disorders and schizophrenic patients; 3) to highlight the association between bvFTD and preceding psychiatric conditions and/or distinguish them both. The investigated mutations were found infrequently in the studied SMI samples. Cross-sectional studies comparing cognitive performance between bvFTD and psychiatric disorders mostly found no remarkable differences. There were only a few case reports identifying definite frontotemporal lobar degeneration in patients with previous psychiatric diagnoses. CONCLUSIONS: The available evidence demonstrates how fragile the current understanding is regarding the association between bvFTD and prior SMI.

Behavioral variant frontotemporal dementia in patients with previous severe mental illness: a systematic and critical review / Demência frontotemporal variante comportamental em pacientes com transtorno mental grave prévio: revisão sistemática e crítica

ABSTRACT Objectives: To explore the relationship between severe/serious mental illness (SMI) and the behavioral variant of frontotemporal dementia (bvFTD), as the patterns of symptoms and cognitive performance that characterize both disorders share similarities. Methods: We performed a systematic review investigating what has already been published regarding the relationship between bvFTD and SMI. Studies were selected from PubMed and LILACS databases, including those published up to February 12, 2018. The search strategy included the following terms: "frontotemporal dementia" plus "bipolar", OR "frontotemporal dementia" plus "schizophrenia", OR "frontotemporal dementia" plus "schizoaffective". Publications without abstracts, case reports with absent genetic or histopathological confirmation, reviews and non-English language papers were excluded across the search process. Results: The search on PubMed retrieved 186 articles, of which 42 met eligibility criteria. On the LILACS database, none met the requirements. Generally, three major research aims were identified: 1) to look for frontotemporal lobar degeneration-associated genetic abnormalities in patients with prior SMI; 2) to compare the cognitive profile between patients affected by neurodegenerative disorders and schizophrenic patients; 3) to highlight the association between bvFTD and preceding psychiatric conditions and/or distinguish them both. The investigated mutations were found infrequently in the studied SMI samples. Cross-sectional studies comparing cognitive performance between bvFTD and psychiatric disorders mostly found no remarkable differences. There were only a few case reports identifying definite frontotemporal lobar degeneration in patients with previous psychiatric diagnoses. Conclusions: The available evidence demonstrates how fragile the current understanding is regarding the association between bvFTD and prior SMI.

RESUMO Objetivos: Explorar a relação entre doença mental grave (DMG) e a variante comportamental da demência frontotemporal (DFTvc), uma vez que os padrões de sintomas e de desempenho cognitivo que caracterizam ambos os transtornos compartilham semelhanças. Métodos: Revisão sistemática investigando estudos publicados sobre a relação entre DFTvc e DMG. Os estudos foram selecionados nas bases de dados PubMed e LILACS, incluindo aqueles publicados até 12 de fevereiro de 2018. A estratégia de busca incluiu os seguintes termos: "demência frontotemporal" e "bipolar", OU "demência frontotemporal" e "esquizofrenia" OU "demência frontotemporal" e "esquizoafetivo". Publicações sem resumos, relatos de casos sem confirmação genética ou histopatológica, revisões e artigos escritos em idiomas que não fossem o inglês não foram selecionados na busca sistemática. Resultados: A pesquisa no PubMed encontrou 186 artigos, dos quais 42 alcançaram critérios de elegibilidade. Na base de dados LILACS, nenhum dos nove artigos identificados atendeu aos requisitos. Foram identificados três objetivos de pesquisa principais: buscar anormalidades genéticas associadas à degeneração lobar frontotemporal (DLFT) em pacientes com SMI prévia; comparar o perfil cognitivo entre pacientes acometidos por doenças neurodegenerativos e esquizofrênicos; destacar a associação entre DFTvc e condições psiquiátricas precedentes e/ou distinguir ambos. As mutações investigadas foram encontradas infrequentemente nas amostras estudadas. Os estudos transversais comparando o desempenho cognitivo entre DFTvc e os transtornos psiquiátricos não encontraram diferença, e houve apenas relatos de casos confirmando de DLFT em pacientes com diagnósticos psiquiátricos prévios. Conclusões: A evidência disponível demonstra quão frágil é o entendimento atual sobre a associação entre DFTvc e DMG.

Phenocopy syndrome of behavioral variant frontotemporal dementia: a systematic review.

BACKGROUND: The phenocopy syndrome of behavioral variant of frontotemporal dementia (phFTD) refers to patients presenting with neuropsychiatric symptoms mimicking the behavioral variant frontotemporal dementia (bvFTD), but lacking frontotemporal atrophy/hypometabolism on neuroimaging and not evolving to dementia during the follow-up. It is important to recognize phFTD for clinical and research purposes. OBJECTIVE: The aim of this study was to perform a systematic review of the available literature on phFTD taking into account its clinical, cognitive, imaging, genetic, and pathological features. METHODS AND RESULTS: We searched for the following terms in two electronic databases (PubMed and Scopus): "frontotemporal dementia and slowly progressive," "frontotemporal dementia and phenocopy," "frontotemporal dementia and non-progressive," "frontotemporal dementia and benign progression," and "frontotemporal dementia and benign." We did not include review articles. Papers had to be written in English, French, Portuguese, or Spanish. Overall, 235 studies were retrieved in the initial search. A total of 31 studies composed the final selection, comprising 292 patients. Patients with phFTD are predominantly male and have no major cognitive deficits, with globally preserved executive functions and episodic memory. Some cases (n = 7) of slowly progressive FTD have been associated with C9orf72 genetic expansion. There are only four reports of phFTD neuropathological data, with two patients with no neurodegenerative findings and two with frontotemporal lobar degeneration with ubiquitin-positive inclusions. CONCLUSION: The neurobiological underpinnings of phFTD remain unknown. It is controversial whether phFTD belongs to the FTD spectrum. Studies with biomarkers and pathological data are needed to solve the phFTD conundrum.

Long-Term Severe Mental Disorders Preceding Behavioral Variant Frontotemporal Dementia: Frequency and Clinical Correlates in an Outpatient Sample.

BACKGROUND: The behavioral variant frontotemporal dementia (bvFTD) shares some clinical features with severe mental disorders, such as bipolar affective disorder (BAD), schizophrenia (SCZ), and schizoaffective disorder (SZA), and at least for a small subgroup of patients, these conditions may share similar pathological genetic mutations. OBJECTIVES: To investigate the frequency of a past medical history satisfying diagnostic criteria for BAD, SCZ, and SZA in a bvFTD outpatient sample, and to compare the clinical profile of patients with and without a positive history. METHODS: Cross-sectional study in which participants were consecutively selected after receiving a diagnosis of probable bvFTD and had a caregiver interviewed with SCID-I. The sample was categorized into two groups: with (bvFTD+) or without (bvFTD-) prior medical history satisfying diagnostic criteria for BAD/SCZ/SZA. Subjects went through cognitive, functional, and neuropsychiatric evaluations. RESULTS: Overall, 46 bvFTD patients were included; bvFTD+ patients accounted for 36.9% of the sample. The main nosology fulfilling criteria was BAD (76.5%). The groups differed in Neuropsychiatric Inventory scores (p = 0.01), use of antipsychotics (p = 0.01), family history of psychosis (p = 0.01), presence of primitive reflexes (p = 0.04), Frontal Assessment Battery performance (p = 0.01), Ekman's facial emotion recognition test (p = 0.03), frequency of apathy (p = 0.03), and stereotyped behavior (p = 0.01). All these parameters were more frequent/worse in the bvFTD+ group. CONCLUSIONS: A prior medical history compatible with BAD/SCZ/SZA was found in more than 1/3 of this sample of bvFTD patients and was associated with subtle distinctive clinical features.

Kraepelin's description of chronic mania: a clinical picture that meets the behavioral variant frontotemporal dementia phenotype.

Chronic mania is an under-investigated condition and few reports have associated this disorder with an organic background. The present work examines Kraepelin's reliable description of chronic mania from a current behavioral neurology viewpoint. Kraepelin had described a cluster of symptoms that are now recognized as core manifestations of the behavioral variant frontotemporal dementia (bvFTD) clinical phenotype. We also carried out additional reviews of original manuscripts from Kraepelin's peers, in order to find any case reports that might fulfill the current diagnostic proposal for bvFTD. Even though we failed to find an ideal case, we found some scholars who seemed to agree that chronic mania should be considered a special form of dementia. The present work highlights, through historical data, the possible overlapping features between primary psychiatric disorders and neuropsychiatric symptoms secondary to neurodegenerative conditions.

Kraepelin's description of chronic mania: a clinical picture that meets the behavioral variant frontotemporal dementia phenotype / A descrição de Kraepelin de mania crônica: um quadro clínico que corresponde ao fenótipo da variante comportamental da demência fronto-temporal

ABSTRACT Chronic mania is an under-investigated condition and few reports have associated this disorder with an organic background. The present work examines Kraepelin’s reliable description of chronic mania from a current behavioral neurology viewpoint. Kraepelin had described a cluster of symptoms that are now recognized as core manifestations of the behavioral variant frontotemporal dementia (bvFTD) clinical phenotype. We also carried out additional reviews of original manuscripts from Kraepelin’s peers, in order to find any case reports that might fulfill the current diagnostic proposal for bvFTD. Even though we failed to find an ideal case, we found some scholars who seemed to agree that chronic mania should be considered a special form of dementia. The present work highlights, through historical data, the possible overlapping features between primary psychiatric disorders and neuropsychiatric symptoms secondary to neurodegenerative conditions.

RESUMO A mania crônica constitui uma condição subinvestigada e alguns trabalhos têm associado esta desordem a um substrato orgânico. O presente manuscrito analisa a descrição fidedigna de Kraepelin de mania crônica a partir de um ponto de vista atual da neurologia comportamental. Concebemos que ele havia descrito um conjunto de sintomas que atualmente é reconhecido como manifestações centrais do fenótipo clínico da variante comportamental da demência frontotemporal (bvFTD). Também realizamos uma revisão adicional de manuscritos originais de pares contemporâneos de Kraepelin, a fim de procurar por um único relato de caso que poderia preencher critério diagnóstico atual de bvFTD. Mesmo que não tenhamos conseguido encontrar um caso perfeitamente exemplar, identificamos que alguns estudiosos da época pareciam concordar que a mania crônica devesse ser considerada uma forma especial de demência. O presente trabalho destaca por meio de dados históricos a sobreposição entre transtornos psiquiátricos primários e sintomas neuropsiquiátricos secundários a doenças neurodegenerativas.