Behavioral disturbances differentiate frontotemporal lobar degeneration subtypes and Alzheimer's disease: evidence from the Frontal Behavioral Inventory

Application of the mild behavioral impairment checklist in Chinese patients with the behavioral variant of frontotemporal dementia

BACKGROUND

The mild behavioral impairment checklist (MBI-C) designed to capture neuropsychiatric symptoms in the whole spectrum of elder with or without dementia, have been verified in mild behavioral impairment, mild cognitive impairment and Alzheimer's Disease, but never used in the behavioral variant of frontotemporal dementia (bvFTD).

METHODS

Fifty-two patients with bvFTD (mild, n = 30; moderate-severe, n = 22) and 82 community-dwelling elderly individuals (HCs) were enrolled. All subjects were assessed with a full neuropsychological scale including the MBI-C, Neuropsychiatric Inventory Questionnaire (NPI-Q), and Frontal Behavioral Inventory (FBI). Receiver operating characteristic curves were drawn to analyze the sensitivity and specificity of the MBI-C, NPI-Q, and FBI, and cutoff points were determined using the Youden index.

RESULTS

The MBI-C and domain scores in all patients with bvFTD were significantly higher than those in HCs. The most common symptoms of bvFTD were apathy (82.7%) and impulse dyscontrol (80.8%). The MBI-C score was positively correlated with the NPI-Q, FBI, and Activities of Daily Living. For differentiating patients with both bvFTD and mild bvFTD from HCs, the optimal MBI-C cutoff point was 5.5 with a sensitivity of 100% and specificity of 82%, and its sensitivity was higher than that of the NPI-Q and FBI.

CONCLUSION

The MBI-C is a sensitive tool for screening behavioral and psychological symptoms in patients with bvFTD, even in the early stages of the disease.

Screening for Executive Impairment in Patients with Frontotemporal Dementia: Evidence from the Greek Version of the Frontier Executive Screen

OBJECTIVES

The aim of the present study was to adjust the frontier executive screen (FES) for the Greek population, to develop normative data, and to investigate its ability to discriminate patients diagnosed with frontotemporal dementia from healthy individuals.

METHODS

The FES was administered to 142 community-dwelling healthy adults (age: M = 65.9, SD = 8.5; education: M = 10.8, SD = 4.3; sex: 59% female) and 32 patients diagnosed with frontotemporal dementia (age: M = 69.3, SD = 8.6; education: M = 11.7, SD = 4.8; sex: 31% female). Correlation and regression analyses were performed to determine the association between the FES scores, demographic, and clinical characteristics. Cronbach's α coefficient was used to determine internal consistency. Group differences on the FES were examined with independent samples t-test and Mann-Whitney test. Discriminant and ROC analyses were used to determine diagnostic accuracy and to identify the optimal cutoff score for the discrimination between groups.

RESULTS

Regression analyses indicated associations between demographic characteristics and FES scores (age: R2 = .08; education: R2 = .33). Internal consistency was marginally acceptable (α = .69). Patients scored lower than healthy participants on the total FES score (d = 1.91) and its three subscores (verbal fluency: η2 = .60; inhibition: η2 = .52; working memory: d = 0.90). The results indicated high diagnostic accuracy (94%) and the optimal cutoff score was 7 (91% sensitivity, 78% specificity).

CONCLUSIONS

The Greek version of the FES is a useful tool for the brief evaluation of executive functions in patients diagnosed with frontotemporal dementia.

Diagnóstico da demência frontotemporal: recomendações do Departamento Científico de Neurologia Cognitiva e do Envelhecimento da Academia Brasileira de Neurologia

RESUMO A “demência frontotemporal” (DFT) é uma síndrome clínica, cujo denominador comum é o acometimento focal dos lobos frontais e/ou temporais. A DFT tem três fenótipos clínicos distintos: a variante comportamental e dois subtipos linguísticos, a saber, a afasia progressiva primária não-fluente/agramática (APP-NF/A) e a afasia progressiva primária semântica (APP-S). A DFT é a segunda causa mais comum de demência em indivíduos com idade inferior a 65 anos, após a doença de Alzheimer. O presente artigo apresenta recomendações para diagnóstico da DFT no cenário brasileiro, considerando os três níveis de complexidade do sistema de saúde: atenção primária à saúde e níveis secundários. São propostos protocolos de investigação diagnóstica abrangendo testagem cognitiva, avaliação comportamental, avaliação fonoaudiológica, exames laboratoriais e de neuroimagem.

Diagnosis of frontotemporal dementia: recommendations of the Scientific Department of Cognitive Neurology and Aging of the Brazilian Academy of Neurology

ABSTRACT “Frontotemporal dementia” (FTD) is a clinical syndrome characterized by the focal involvement of the frontal and/or temporal lobes. FTD has three clinical phenotypes: the behavioral variant and two linguistic subtypes, namely, non-fluent/agrammatic primary progressive aphasia (PPA-NF/A) and semantic PPA (PPA-S). FTD is the second most common cause of dementia in individuals under the age of 65 years. This article presents recommendations for the diagnosis of FTD in the Brazilian scenario, considering the three levels of complexity of the health system: primary health care, secondary and tertiary levels. Diagnostic guidelines are proposed, including cognitive testing, behavioral and language assessments, laboratory tests, and neuroimaging.

Early Identification of Different Behavioral Phenotypes in the Behavioral Variant of Frontotemporal Dementia with the Aid of the Mini-Frontal Behavioral Inventory (mini-FBI)

Background: The Frontal Behavioral Inventory (FBI) is a questionnaire designed to quantify behavioral changes in frontotemporal dementia (FTD). Literature showed heterogeneous FBI profiles in FTD versus Alzheimer’s disease (AD) with variable occurrence of positive and negative symptoms. Objective: In this study, we constructed a short FBI version (i.e., mini-FBI) with the aim to provide clinicians with a short tool for the identification of early behavioral changes in behavioral variant of FTD (bvFTD), also facilitating the differential diagnosis with AD. Methods: 40 bvFTD and 33 AD patients were enrolled. FBI items were selected based on internal consistency and exploratory factor analysis. Convergent validity of mini-FBI was also assessed. A behavioral index (i.e., B-index) representing the balance between positive and negative mini-FBI symptoms was computed in order to analyze its distribution in bvFTD through a cluster analysis and to compare performance among patient groups. Results: The final version of the mini-FBI included 12 items, showing a significant convergent validity with the Neuropsychiatric Inventory scores (rp = 0.61, p < 0.001). Cluster analysis split patients in four clusters. bvFTD were included in three different clusters characterized by prevalent positive symptoms, both positive and negative symptoms, or prevalent negative behavioral alterations, similar to a subset of AD patients. A fourth cluster included only AD patients showing no positive symptoms. Conclusion: The mini-FBI is a valuable easily administrable questionnaire able to early identify symptoms effectively contributing to the bvFTD behavioral syndrome, aiding clinician in diagnosis and management.

Alzheimer's Disease or Behavioral Variant Frontotemporal Dementia? Review of Key Points Toward an Accurate Clinical and Neuropsychological Diagnosis

Alzheimer's disease (AD) and frontotemporal dementia (FTD) are the most common neurodegenerative early-onset dementias. Despite the fact that both conditions have a very distinctive clinical pattern, they present with an overlap in their cognitive and behavioral features that may lead to misdiagnosis or delay in diagnosis. The current review intends to summarize briefly the main differences at the clinical, neuropsychological, and behavioral levels, in an attempt to suggest which aspects would facilitate an adequate diagnosis in a clinical setting, especially in Latin American and low- and middle-income countries, where the resources needed for a differential diagnosis (such as MRI or biomarkers) are not always available. A timely diagnosis of AD and FTD have significant implications for the medical management and quality of life of patients and careers.

Distinguishing logopenic from semantic & nonfluent variant primary progressive aphasia: Patterns of linguistic and behavioral correlations

While language characteristics of logopenic variant primary progressive aphasia (lvPPA) are well-defined, behavioral characteristics are less understood. We investigated correlations between language and behavioral scores across three variants of primary progressive aphasia (PPA) and found language performance and behavioral disturbances are correlated in lvPPA, but not other PPA subtypes. Results suggest that unlike other PPA variants, patients diagnosed with lvPPA do not develop negative behaviors until language deficits are severe. This is consistent with the underlying neuropathology of lvPPA, Alzheimer's Disease. Such findings are crucial to clinical prognosis, especially when considering the progressive nature of this disease.

Differentiating between subtypes of primary progressive aphasia and mild cognitive impairment on a modified version of the Frontal Behavioral Inventory

Behavioral assessment has been investigated in frontotemporal lobar degeneration and Alzheimer's disease, but has not been explored extensively in subtypes of primary progressive aphasia (PPA). We explored the ability of a modified version of the Frontal Behavioral Inventory (FBI-mod) to discriminate between patients with distinct subtypes of PPA and patients with mild cognitive impairment (MCI). We hypothesized that individuals with nonfluent agrammatic PPA (nfaPPA) would have higher negative behavior scores than other groups and that individuals with semantic variant PPA (svPPA) would have higher disinhibition scores than other groups. Family members and/or caregivers of 120 individuals with PPA and MCI (mean age 69.54+8.75 years; 65 (54%) female; education 16.06±2.68 years; disease duration 46.47±34.26 months) completed the FBI-mod [logopenic PPA (lvPPA) n = 40. nfaPPA n = 29, svPPA n = 27, MCI n = 24]. The groups were not significantly different in age, gender, education, or disease duration. There were no significant differences between the groups for negative behaviors (p = 0.72) and disinhibition scores (p = 0.14). When comparing negative and disinhibition scores (in percent), negative scores were significantly higher in all groups (p < 0.001). When comparing subtest items, there was a pairwise difference between lvPPA and svPPA for restlessness (lvPPA < svPPA, p = 0.02, after adjusting for multiple between-group comparisons). There was a significant difference in the proportion of severe neglect between the groups with lvPPA having a lower proportion than the other two variants (p = 0.05), and there was a significant difference in the proportion of severe poor judgment between the groups with lvPPA also having a lower proportion than nfaPPA (p = 0.04). This study reveals the greater negative behavioral disturbance than disinhibition in the PPA and MCI groups of similar age and duration since onset and identifies different profiles for some specific behaviors for the PPA groups. These findings may have clinical and practical implications.

Frontotemporal Dementia: An Updated Clinician's Guide

Today, frontotemporal dementia (FTD) remains one of the most common forms of early-onset dementia, that is, before the age of 65, thus posing several diagnostic challenges to clinicians since symptoms are often mistaken for psychiatric or neurological diseases causing a delay in correct diagnosis, and the majority of patients with FTD present with symptoms at ages between 50 and 60. Genetic components are established risk factors for FTD, but the influence of lifestyle, comorbidity, and environmental factors on the risk of FTD is still unclear. Approximately 40% of individuals with FTD have a family history of dementia but less than 10% have a clear autosomal dominant pattern of inheritance. Lack of insight is often an early clue to FTD. A tailored treatment option at an early phase can mitigate suffering and improve patients' and caregivers' quality of life.

Correlated patterns of neuropsychological and behavioral symptoms in frontal variant of Alzheimer disease and behavioral variant frontotemporal dementia: a comparative case study

Although the neuropathologic changes and diagnostic criteria for the neurodegenerative disorder Alzheimer's disease (AD) are well-established, the clinical symptoms vary largely. Symptomatically, frontal variant of AD (fv-AD) presents very similarly to behavioral variant frontotemporal dementia (bvFTD), which creates major challenges for differential diagnosis. Here, we report two patients who present with progressive cognitive impairment, early and prominent behavioral features, and significant frontotemporal lobe atrophy on magnetic resonance imaging, consistent with an initial diagnosis of probable bvFTD. However, multimodal functional neuroimaging revealed neuropathological data consistent with a diagnosis of probable AD for one patient (pathology distributed in the frontal lobes) and a diagnosis of probable bvFTD for the other patient (hypometabolism in the bilateral frontal lobes). In addition, the fv-AD patient presented with greater executive impairment and milder behavioral symptoms relative to the bvFTD patient. These cases highlight that recognition of these atypical syndromes using detailed neuropsychological tests, biomarkers, and multimodal neuroimaging will lead to greater accuracy in diagnosis and patient management.

Identifying bvFTD Within the Wide Spectrum of Late Onset Frontal Lobe Syndrome: A Clinical Approach

OBJECTIVE

The behavioral variant of frontotemporal dementia (bvFTD) can be difficult to diagnose because of the extensive differential diagnosis, including many other diseases presenting with a frontal lobe syndrome. We aimed to identify the diagnostic spectrum causing a late onset frontal lobe syndrome and examine the quality of commonly used instruments to distinguish between bvFTD and non-bvFTD patients, within this syndrome.

METHODS

A total of 137 patients fulfilling the criteria of late onset frontal lobe syndrome, aged 45 to 75 years, were included in a prospective observational study. Diagnoses were made after clinical and neuropsychological examination, and neuroimaging and cerebral spinal fluid results were taken into account. Baseline characteristics and the scores on the Mini-Mental State Exam (MMSE), frontal assessment battery (FAB), Frontal Behavioral Inventory (FBI), and Stereotypy Rating Inventory (SRI) were compared between the bvFTD and the non-bvFTD group.

RESULTS

Fifty-five (40%) of the patients received a bvFTD diagnosis (33% probable and 7% possible bvFTD). Fifty-one patients (37%) had a psychiatric disorder, including 20 with major depressive disorder. Thirty-one patients received an alternative neurological, including neurodegenerative, diagnosis. MMSE and FAB scores were unspecific for a particular diagnosis. A score above 12 on the positive FBI subscale or a score above 5 on the SRI were indicative of a bvFTD diagnosis.

CONCLUSION

A broad spectrum of both neurological and psychiatric disorders underlies late onset frontal lobe syndrome, of which bvFTD was the most prevalent diagnosis in our cohort. The commonly used MMSE and the FAB could not successfully distinguish between bvFTD and non-bvFTD, but this could be achieved with the more specific FBI and SRI.