Clinical Phenotypes of Behavioral Variant Frontotemporal Dementia by Age at Onset

The pursuit for markers of disease progression in behavioral variant frontotemporal dementia: a scoping review to optimize outcome measures for clinical trials

Behavioral variant frontotemporal dementia (bvFTD) is a neurodegenerative disorder characterized by diverse and prominent changes in behavior and personality. One of the greatest challenges in bvFTD is to capture, measure and predict its disease progression, due to clinical, pathological and genetic heterogeneity. Availability of reliable outcome measures is pivotal for future clinical trials and disease monitoring. Detection of change should be objective, clinically meaningful and easily assessed, preferably associated with a biological process. The purpose of this scoping review is to examine the status of longitudinal studies in bvFTD, evaluate current assessment tools and propose potential progression markers. A systematic literature search (in PubMed and Embase.com) was performed. Literature on disease trajectories and longitudinal validity of frequently-used measures was organized in five domains: global functioning, behavior, (social) cognition, neuroimaging and fluid biomarkers. Evaluating current longitudinal data, we propose an adaptive battery, combining a set of sensitive clinical, neuroimaging and fluid markers, adjusted for genetic and sporadic variants, for adequate detection of disease progression in bvFTD.

Diagnostic Instability Over Time in the Late-Onset Frontal Lobe Syndrome: When Can We Say it's FTD?

OBJECTIVES

Distinguishing sporadic behavioral variant of frontotemporal dementia (bvFTD) from late-onset primary psychiatric disorders (PPD) remains challenging with the lack of robust biomarkers. An early bvFTD misdiagnosis in PPD cases and vice-versa is common. Little is known about diagnostic (in)stability over longer period of time. We investigated diagnostic instability in a neuropsychiatric cohort up to 8 years after baseline visit and identified which clinical hallmarks contribute to diagnostic instability.

DESIGN

Diagnoses of participants of the late-onset frontal lobe (LOF) study were collected from the baseline visit (T0) and the 2-year follow-up visit (T2). Clinical outcomes were retrieved 5-8 years after baseline visit (Tfinal). Endpoint diagnoses were categorized into bvFTD, PPD and other neurological disorders (OND). We calculated the total amount of participants that switched diagnosis between T0-T2 and T2-Tfinal. Clinical records of participants that switched diagnosis were assessed.

RESULTS

Of the 137 patients that were included in the study, the final diagnoses at Tfinal were bvFTD 24.1% (n = 33), PPD 39.4% (n = 54), OND 33.6% (n = 46) and unknown 2.9% (n = 4). Between T0 and T2, a total of 29 (21.2%) patients switched diagnosis. Between T2 and Tfinal, 8 (5.8%) patients switched diagnosis. Prolonged follow-up identified few cases with diagnostic instability. Major contributors to diagnostic instability where a nonconverting diagnosis of possible bvFTD and a probable bvFTD diagnosis based on informant-based history and an abnormal FDG-PET scan whilst having a normal MRI.

CONCLUSION

Considering these lessons, a FTD diagnosis remains stable enough to conclude that 2 years is sufficient to say if a patient with late-life behavioral disorder has FTD.

Weight Change and Neuropsychiatric Symptoms in Alzheimer's Disease and Frontotemporal Dementia: Associations with Cognitive Decline

Weight changes, neuropsychiatric symptoms (NPS), and cognitive decline often coincide in Alzheimer's disease (AD) and frontotemporal dementia (FTD); however, the direction of their relationship remains unclear. This study aims to clarify the connection between weight changes, NPS, and cognition in AD and FTD. We found that cognitive decline was associated with decreased body mass index (BMI) in AD, while BMI gain was associated with increased conversion to FTD. Elevated NPS were associated with decreased BMI in AD and increased BMI in FTD. Identifying early changes in NPS and BMI may facilitate the detection of cognitive decline, providing an opportunity for early intervention.

[Rare forms of dementia-Atypical variants of Alzheimer's dementia]

In Germany, around 1.8 million people currently suffer from dementia and the numbers are increasing. The main cause of dementia is Alzheimer's disease. This is classically manifested in the form of an amnestic syndrome but also encompasses various atypical variants, especially in younger patients and in the clinical routine are not always easy to recognize. These are described in this narrative review with case studies. Posterior cortical atrophy (PCA) presents with visual disorders, in the logopenic variants of primary progressive aphasia (lvPPA) impaired word retrieval is the main symptom, in the frontal variant of Alzheimer's disease behavioral disorders are prominent and in corticobasal syndrome (CBS) an akinetic rigid Parkinson's syndrome with alien limb phenomenon. As the clinical presentation of these atypical variants shows an overlap with other dementia disorders, the differential diagnosis is often challenging. In this context amyloid biomarkers can provide valuable services.

Knowledge and Attitudes for the Management of Behavioral Variant of Frontotemporal Dementia

Background: The diagnosis of the behavioral variant of frontotemporal dementia (bvFTD) can be especially challenging and is relatively underdiagnosed. There is scarce information on training and attitudes from care providers facing bvFTD in settings with limited resources. We aim to describe clinical knowledge and attitudes facing bvFTD from neurologists, psychiatrists, and residents in Peru.

Methods: Potential participants received invitations by email to complete an online questionnaire. In addition, we reviewed 21 curricula from undergraduate medical schools' programs offered by the main schools of medicine in Peru during 2020 and 2021.

Results: A total of 145 participants completed the survey. The responders were neurologists (51%), psychiatrists (25%), and residents in neurology or psychiatry (24%). Only 26% of the respondents acknowledged receiving at least one class on bvFTD in undergraduate medical training, but 66.6% received at least some training during postgraduate study. Participants identified isolated supportive symptoms for bvFTD; however, only 25% identified the possible criteria and 18% the probable bvFTD criteria. They identified MoCA in 44% and Frontal Assessment Battery (39%) as the most frequently used screening test to assess bvFTD patients. Memantine and Acetylcholinesterase inhibitors were incorrectly indicated by 40.8% of participants. Seventy six percentage of participants indicated that they did not provide education and support to the caregiver. The dementia topic was available on 95.2%, but FTD in only 19%.

Conclusion: Neuropsychiatry medical specialists in Peru receive limited training in FTD. Their clinical attitudes for treating bvFTD require appropriate training focused on diagnostic criteria, assessment tools, and pharmacological and non-pharmacological management.

Hyperorality in Frontotemporal Dementia: Cognitive and Psychiatric Symptom Profiles in Early-Stage Disease

Hyperorality is a distinctive feature of the behavioral variant of frontotemporal dementia (bvFTD), but little is known about its significance in early-stage disease. This study examined the cognitive and psychiatric symptom profiles associated with hyperorality, using data from subjects with early-stage bvFTD enrolled in Alzheimer's Disease Research Centers. We found that hyperorality was not associated with cognitive performance, but was associated with psychosis, elation, and disinhibition. Hyperorality may share neurobiology with a subset of early psychiatric symptoms, a finding which could help identify targets for future treatment.

Risk factors to mortality and causes of death in frontotemporal dementia: An Australian perspective

OBJECTIVES

Frontotemporal dementia (FTD) is a common cause of dementia in younger people. There is less information known about risk factors to mortality such as the type of symptom onset and cause of death in this group.

METHOD

This was a retrospective file review of inpatients with FTD admitted to a tertiary neuropsychiatry unit located in Australia from 1992 to 2014. Mortality information including linkage of names and causes of death were obtained from the Australian Institute Health and Welfare National Death Index.

RESULTS

One hundred inpatients were diagnosed with FTD, including behavioural-variant, language-variant FTDs and FTD-motor neuron disease (FTD-MND). Mean age was 52.8 years (SD = 10, range 31-76 years). Sixty-seven of them had died at linkage. Median survival of the sample was 10.5 years and FTD-MND had the shortest survival, 3.5 years. Increasing age of onset and FTD-MND were found to be significant predictors of association for mortality. Compared to the general population, having a FTD had an 8× increased risk of death. Females had double the standardised mortality ratio compared to males.

DISCUSSION

This study provides important prognostic information for people diagnosed with FTD living in Australia. It highlights the importance of obtaining a definitive diagnosis as early as possible for future planning. More investigation into the relationship of symptom onset type and sex differences in FTD is required.