Differences and similarities between familial and sporadic frontotemporal dementia: An Italian single-center cohort study

Plasma p-tau217 and neurofilament/p-tau217 ratio in differentiating Alzheimer's disease from syndromes associated with frontotemporal lobar degeneration

INTRODUCTION

Plasma-based biomarkers have shown promise for clinical implementation, but their accuracy in differentiating Alzheimer's disease (AD) from syndromes associated with frontotemporal lobar degeneration (FTLD) has yet to be fully investigated. This study assessed the potential of plasma biomarkers for differential diagnosis.

METHODS

This cohort study included 374 participants (96 AD, 278 FTLD). Plasma phosphorylated tau (p-tau)217, neurofilament light chain (NfL), brain-derived tau, glial fibrillary acidic protein, and the amyloid beta1-42/1-40 ratio were measured. Receiver operating characteristic curve analyses assessed diagnostic accuracy, and a three-range threshold approach was used to stratify patients based on the most accurate biomarker.

RESULTS

Plasma p-tau217 effectively distinguished AD from FTLD, with the NfL/p-tau217 ratio showing superior accuracy. The three-range approach identified thresholds with 95% and 97.5% sensitivity and specificity, reducing the need for cerebrospinal fluid testing by 75% and 54%, respectively.

DISCUSSION

Plasma p-tau217 and the NfL/p-tau217 ratio are promising non-invasive biomarkers for differentiating AD from FTLD, suggesting their use as a potential alternative to traditional diagnostic methods.

HIGHLIGHTS

Plasma phosphorylated tau (p-tau)217 distinguishes Alzheimer's disease (AD) from frontotemporal lobar degeneration (FTLD) with high accuracy. The neurofilament light chain/p-tau217 ratio showed the highest accuracy for differentiating AD from FTLD. A three-range threshold reduces the need for invasive cerebrospinal fluid testing or amyloid positron emission tomography imaging.

Psychotropic medication usage in sporadic versus genetic behavioral-variant frontotemporal dementia

INTRODUCTION

Psychotropic medication (PM) use in behavioral-variant frontotemporal dementia (bvFTD) is higher than in other dementias. However, no information exists on whether PM use differs between sporadic and genetic bvFTD.

METHODS

We analyzed data from sporadic and genetic bvFTD participants with PM prescriptions in the Advancing Research and Treatment in Frontotemporal Lobar Degeneration/Longitudinal Evaluation of Familial Frontotemporal Dementia Subjects study. We estimated ordinal odds ratio (OOR) of having more PM comparing sporadic and genetic bvFTD. Finally, we explored the neuropsychiatric symptom (NPS) combinations using classification and regression trees (CART).

RESULTS

We included 263 with sporadic and 193 with genetic bvFTD. The OOR for sporadic bvFTD to be on PM was 1.75 (95% confidence interval: 1.21 to 2.53) for the fully adjusted model. CART revealed the most common NPS combination was apathy + personality changes in 18% of participants.

DISCUSSION

Participants with sporadic bvFTD were twice as likely to be on PM compared to genetic bvFTD. The reason for increased PM usage in sporadic bvFTD participants should be further investigated.

HIGHLIGHTS

We report on patients with behavioral variant frontotemporal dementia (bvFTD). We evaluated the psychotropic medication (PM) prescription at baseline in the cohort. Patients with sporadic bvFTD had more prescriptions for PM than genetic patients. The frequency of symptoms combination was different in sporadic and genetic bvFTD.

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.

Examining the relation between bilingualism and age of symptom onset in frontotemporal dementia

Bilingualism is thought to confer advantages in executive functioning, thereby contributing to cognitive reserve and a later age of dementia symptom onset. While the relation between bilingualism and age of onset has been explored in Alzheimer's dementia, there are few studies examining bilingualism as a contributor to cognitive reserve in frontotemporal dementia (FTD). In line with previous findings, we hypothesized that bilinguals with behavioral variant FTD would be older at symptom onset compared to monolinguals, but that no such effect would be found in patients with nonfluent/agrammatic variant primary progressive aphasia (PPA) or semantic variant PPA. Contrary to our hypothesis, we found no significant difference in age at symptom onset between monolingual and bilingual speakers within any of the FTD variants, and there were no notable differences on neuropsychological measures. Overall, our results do not support a protective effect of bilingualism in patients with FTD-spectrum disease in a U.S. based cohort.

Diagnostic accuracy of research criteria for prodromal frontotemporal dementia

BACKGROUND

The Genetic Frontotemporal Initiative Staging Group has proposed clinical criteria for the diagnosis of prodromal frontotemporal dementia (FTD), termed mild cognitive and/or behavioral and/or motor impairment (MCBMI). The objective of the study was to validate the proposed research criteria for MCBMI-FTD in a cohort of genetically confirmed FTD cases against healthy controls.

METHODS

A total of 398 participants were enrolled, 117 of whom were carriers of an FTD pathogenic variant with mild clinical symptoms, while 281 were non-carrier family members (healthy controls (HC)). A subgroup of patients underwent blood neurofilament light (NfL) levels and anterior cingulate atrophy assessment.

RESULTS

The core clinical criteria correctly classified MCBMI vs HC with an AUC of 0.79 (p < 0.001), while the addition of either blood NfL or anterior cingulate atrophy significantly increased the AUC to 0.84 and 0.82, respectively (p < 0.001). The addition of both markers further increased the AUC to 0.90 (p < 0.001).

CONCLUSIONS

The proposed MCBMI criteria showed very good classification accuracy for identifying the prodromal stage of FTD.