Publications by authors named "Seelaar H"
A subpopulation of astrocytes expressing WD Repeat Domain 49 (WDR49) was recently identified in frontotemporal lobar degeneration (FTLD) with GRN pathogenic variants. This is the first study to investigate their expression and relation to pathology in other FTLD subtypes and Alzheimer's disease (AD). In a postmortem cohort of TDP-43 proteinopathies (12 GRN, 11 C9orf72, 9 sporadic TDP-43), tauopathies (13 MAPT, 8 sporadic tau), 10 AD, and four controls, immunohistochemistry and immunofluorescence were performed for WDR49 and pathological inclusions on frontal, temporal, and occipital cortical sections.
View Article and Find Full Text PDFBackground: Frontotemporal lobar degeneration (FTLD) is one of the leading causes of early onset dementia. Pathogenic variants in GRN have been reported to cause 5-25% of familial and 5% of sporadic FTLD. Here, we present two novel, likely pathogenic variants in GRN.
View Article and Find Full Text PDFBackground: Primary lateral sclerosis (PLS) is a rare motor neuron disease characterized by upper motor neuron degeneration, diagnosed clinically due to the absence of a (neuropathological) gold standard. Post-mortem studies, particularly TDP-43 pathology analysis, are limited.
Methods: This study reports on 5 cases in which the diagnostic criteria for PLS were met, but in which neuropathology findings showed (partially) conflicting results.
Background And Objectives: Sleep dysfunction is common in patients with neurodegenerative disorders; however, its neural underpinnings remain poorly characterized in genetic frontotemporal dementia (FTD). Hypothalamic nuclei important for sleep regulation may be related to this dysfunction. Thus, we examined changes in hypothalamic structure across the lifespan in patients with genetic FTD and whether these changes related to sleep dysfunction.
View Article and Find Full Text PDFBackground And Objectives: Pathogenic variants in the gene cause frontotemporal dementia (FTD-) with marked brain asymmetry. This study aims to assess whether the disease progression of FTD- depends on the initial side of the atrophy. We also investigated the potential use of brain asymmetry as a biomarker of the disease.
View Article and Find Full Text PDFCharacterization of cognitive profiles across genetic FTD gene mutations is crucial for the identification of sensitive endpoints for clinical trials targeting specific pathologies. However, no systematic overview of the literature describing cognitive profiles in different FTD gene mutations has been made thus far. We performed a meta-analysis and systematic review to characterize cognitive profiles across the different FTD gene mutations and clinical disease stages of familial frontotemporal dementia (FTD).
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- Tau-PET is a diagnostic tool for Alzheimer's disease that shows promise in research, but its effectiveness in everyday clinical settings is still unclear.
- The TAP-TAU study will include 300 patients with mild cognitive impairments from five Dutch memory clinics to assess how tau-PET affects diagnosis, patient management, and anxiety levels.
- The study has received ethics approval and aims to begin participant enrollment in October 2024, with potential findings that could enhance understanding of tau-PET's real-world clinical value.
Introduction: Genetic mutation carriers of frontotemporal dementia can remain cognitively well despite neurodegeneration. A better understanding of brain structural, perfusion, and functional patterns in the pre-symptomatic stage could inform accurate staging and potential mechanisms.
Methods: We included 207 pre-symptomatic genetic mutation carriers and 188 relatives without mutations.
Background And Objectives: Behavioral and neuropsychiatric symptoms are frequent in patients with genetic frontotemporal dementia (FTD). We aimed to describe behavioral and neuropsychiatric phenotypes in genetic FTD, quantify their temporal association, and investigate their regional association with brain atrophy.
Methods: We analyzed data of pathogenic variant carriers in the chromosome 9 open reading frame 72 (), progranulin (), or microtubule-associated protein tau () gene from the Genetic Frontotemporal dementia Initiative cohort study that enrolls both symptomatic pathogenic variant carriers and first-degree relatives of known carriers.
Introduction: We aimed to assess the knowledge of social norms in patients with behavioral variant frontotemporal dementia (bvFTD) with the Dutch version of the Social Norms Questionnaire (SNQ-NL).
Methods: The SNQ-NL was administered in 34 patients with bvFTD, 20 prodromal mutation carriers, 76 presymptomatic mutation carriers, and 56 controls. Group differences and correlations with other neuropsychological tests and gray matter volume were examined.
Background And Objectives: Data on care home admission and survival rates of patients with syndromes associated with frontotemporal lobar degeneration (FTLD) are limited. However, their estimation is essential to plan trials and assess the efficacy of intervention. Population-based registers provide unique samples for this estimate.
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- Mutations in the tau gene can cause a type of brain disease called frontotemporal dementia and parkinsonism, leading to changes in behavior and thinking.
- The study focused on two specific mutations, P301L and P301T, found in different people, revealing unique structures of tau proteins in their brains.
- The researchers suggest that these mutations create special kinds of tau-related brain diseases that should be treated differently in research studies about similar conditions.
Background: Inflammation has been proposed as a crucial player in neurodegeneration, including Frontotemporal Dementia (FTD). A few studies on sporadic FTD lead to inconclusive results, whereas large studies on genetic FTD are lacking. The aim of this study is to determine cytokine and chemokine plasma circulating levels in a large cohort of genetic FTD, collected within the GENetic Frontotemporal dementia Initiative (GENFI).
View Article and Find Full Text PDFBackground: Long non-coding RNAs (lncRNAs) play crucial roles in gene regulation and are implicated in neurodegenerative diseases, including frontotemporal dementia (FTD). However, their expression patterns and potential as biomarkers in genetic FTD involving Chromosome 9 Open Reading Frame (C9ORF72), Microtubule Associated Protein Tau (MAPT), and Progranulin (GRN) genes are not well understood.
Objective: This study aimed to profile the expression levels of lncRNAs in peripheral blood mononuclear cells collected within the GENetic Frontotemporal dementia Initiative (GENFI).
The glymphatic system is an emerging target in neurodegenerative disorders. Here, we investigated the activity of the glymphatic system in genetic frontotemporal dementia with a diffusion-based technique called diffusion tensor image analysis along the perivascular space. We investigated 291 subjects with symptomatic or presymptomatic frontotemporal dementia (112 with [] expansion, 119 with [] mutations and 60 with [] mutations) and 83 non-carriers (including 50 young and 33 old non-carriers).
View Article and Find Full Text PDFFrontotemporal lobar degeneration with neuronal inclusions of the TAR DNA-binding protein 43 (FTLD-TDP) is a fatal neurodegenerative disorder with only a limited number of risk loci identified. We report our comprehensive genome-wide association study as part of the International FTLD-TDP Whole-Genome Sequencing Consortium, including 985 cases and 3,153 controls, and meta-analysis with the Dementia-seq cohort, compiled from 26 institutions/brain banks in the United States, Europe and Australia. We confirm as the strongest overall FTLD-TDP risk factor and identify as a novel FTLD-TDP risk factor.
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- * A study analyzed 4,685 sporadic FTD cases and found significant genetic variants at the MAPT and APOE loci that increase the risk for the disease, indicating potential genetic overlap with other neurodegenerative diseases.
- * The genetic risk factors appear to vary by population, with MAPT and APOE associations predominantly found in Central/Nordic and Mediterranean Europeans, suggesting a need for further research into these population-specific features for better understanding of sporadic FTD.
Article Synopsis
- Effective longitudinal biomarkers, like cerebral perfusion, are crucial for tracking disease progression in presymptomatic genetic frontotemporal dementia (FTD) carriers.
- The study examined cerebral perfusion in various genetic FTD groups using advanced MRI techniques and found declines in gray matter perfusion across all groups, with specific regional patterns.
- Results suggest that monitoring cerebral perfusion could serve as an early biomarker for detecting FTD before symptoms appear, especially highlighting differences among genetic subgroups.
Introduction: We aimed to expand the range of the frontotemporal dementia (FTD) phenotypes assessed by the Clinical Dementia Rating Dementia Staging Instrument plus National Alzheimer's Coordinating Center Behavior and Language Domains (CDR plus NACC FTLD).
Methods: Neuropsychiatric and motor domains were added to the standard CDR plus NACC FTLD generating a new CDR plus NACC FTLD-NM scale. This was assessed in 522 mutation carriers and 310 mutation-negative controls from the Genetic Frontotemporal dementia Initiative (GENFI).
Background: Cognitive reserve is a potential mechanism to cope with brain damage as a result of dementia, which can be defined by indirect proxies, including education level, leisure time activities, and occupational attainment. In this study we explored the association between dementia diagnosis and type of occupation in a retrospective Dutch outpatient memory clinic sample of patients with primary progressive aphasia (PPA), behavioral variant frontotemporal dementia (bvFTD), and Alzheimer's Dementia (AD).
Methods: We included data from 427 patients (bvFTD = 87, PPA = 148, AD = 192) and compared the frequency of occupations (11 categories) between patients and data from the Dutch census using Pearson tests and we calculated odds ratios (OR) by means of multinomial logistic regression analyses.
Article Synopsis
- Pathogenic heterozygous mutations in the GRN gene are a significant cause of frontotemporal dementia (FTD), leading to lower levels of the progranulin protein in biofluids, which has sparked therapeutic trials aimed at increasing these levels.
- A systematic review of literature on biofluid PGRN concentrations included data from 7071 individuals, primarily focusing on plasma PGRN levels derived from a single assay type, which accounted for variations based on mutation type, age, sex, and clinical diagnosis.
- Key findings established specific concentration cut-offs for plasma (74.8 ng/mL) and CSF (3.43 ng/mL) and indicated that plasma PGRN levels vary by mutation type,
Objective: Methylation of plasma cell-free DNA (cfDNA) has potential as a marker of brain damage in neurodegenerative diseases such as frontotemporal dementia (FTD). Here, we study methylation of cfDNA in presymptomatic and symptomatic carriers of genetic FTD pathogenic variants, next to healthy controls.
Methods: cfDNA was isolated from cross-sectional plasma of 10 presymptomatic carriers (4 C9orf72, 4 GRN, and 2 MAPT), 10 symptomatic carriers (4 C9orf72, 4 GRN, and 2 MAPT), and 9 healthy controls.
Background: Blood neurofilament light chain (NfL) is increasingly considered as a key trial biomarker in genetic frontotemporal dementia (gFTD). We aimed to facilitate the use of NfL in gFTD multicentre trials by testing its (1) reliability across labs; (2) reliability to stratify gFTD disease stages; (3) comparability between blood matrices and (4) stability across recruiting sites.
Methods: Comparative analysis of blood NfL levels in a large gFTD cohort (GENFI) for (1)-(4), with n=344 samples (n=148 presymptomatic, n=11 converter, n=46 symptomatic subjects, with mutations in , or ; and n=139 within-family controls), each measured in three different international labs by Simoa HD-1 analyzer.
Article Synopsis
- The study aimed to validate clinical criteria for diagnosing mild cognitive and/or behavioral and/or motor impairment (MCBMI) in cases suspected of frontotemporal dementia (FTD).
- A total of 398 participants were studied, including 117 FTD variant carriers with mild symptoms and 281 healthy controls, with some undergoing additional neurobiological assessments.
- The MCBMI criteria effectively distinguished between affected individuals and healthy controls, with classification accuracy improving significantly when incorporating blood neurofilament light levels and anterior cingulate atrophy measurements.
Background: Plasma biomarkers reflecting the pathology of frontotemporal dementia would add significant value to clinical practice, to the design and implementation of treatment trials as well as our understanding of disease mechanisms. The aim of this study was to explore the levels of multiple plasma proteins in individuals from families with genetic frontotemporal dementia.
Methods: Blood samples from 693 participants in the GENetic Frontotemporal Dementia Initiative study were analysed using a multiplexed antibody array targeting 158 proteins.