Publications by authors named "A. Campbell Sullivan"

Although Alzheimer disease neuropathologic change (ADNC) is the most common pathology underlying clinical dementia, the presence of multiple comorbid neuropathologies is increasingly being recognized as a major contributor to the worldwide dementia burden. We analyzed 1051 subjects with specific combinations of isolated and mixed pathologies and conducted multivariate logistic regression analysis on a cohort of 4624 cases with mixed pathologies to systematically explore the independent cognitive contributions of each pathology. Alzheimer disease neuropathologic change and limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC) were both associated with a primary clinical diagnosis of Alzheimer disease (AD) and were characterized by an amnestic dementia phenotype, while only ADNC associated with logopenic variant primary progressive aphasia (PPA).

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Article Synopsis
  • The study investigates the role of the genetic variant rs1990622 as a potential modifier of disease risk in frontotemporal lobar degeneration (FTLD), particularly among those with pathogenic variants.
  • Researchers enrolled participants from the ALLFTD study, analyzing the impact of rs1990622 on gray matter volume and cognitive function across various genetic groups related to FTD.
  • Results indicate that carriers of the minor allele of rs1990622 show increased gray matter volume and better cognitive performance, especially in the thalamus and among presymptomatic individuals.
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Article Synopsis
  • The study investigates the effect of a specific genetic modifier on gray matter volume and cognitive function in patients with Frontotemporal Lobar Degeneration (FTLD), including both mutation carriers and sporadic cases.
  • Participants were recruited from the ALLFTD study and were genotyped for the rs1990622 SNP to assess the relationship between this genetic variant and cognitive outcomes across different genetic groups.
  • Findings indicate that the minor allele of rs1990622 is associated with increased gray matter volume and better cognitive scores in mutation carriers, especially affecting the thalamus, suggesting it may play a role in modifying the risk and impact of FTLD.
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The pathophysiological mechanisms driving disease progression of frontotemporal lobar degeneration (FTLD) and corresponding biomarkers are not fully understood. We leveraged aptamer-based proteomics (> 4,000 proteins) to identify dysregulated communities of co-expressed cerebrospinal fluid proteins in 116 adults carrying autosomal dominant FTLD mutations () compared to 39 noncarrier controls. Network analysis identified 31 protein co-expression modules.

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Retrotransposons are viral-like DNA sequences that constitute approximately 41% of the human genome. Studies in mice, cultured cells, and human brain indicate that retrotransposons are activated in settings of tauopathy, including Alzheimer's disease, and causally drive neurodegeneration. The anti-retroviral medication 3TC (lamivudine), a nucleoside analog reverse transcriptase inhibitor, limits retrotransposon activation and suppresses neurodegeneration in tau transgenic two mouse models of tauopathy, and in brain assembloids derived from patients with sporadic Alzheimer's disease.

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Background: Posterior cortical atrophy is a rare syndrome characterised by early, prominent, and progressive impairment in visuoperceptual and visuospatial processing. The disorder has been associated with underlying neuropathological features of Alzheimer's disease, but large-scale biomarker and neuropathological studies are scarce. We aimed to describe demographic, clinical, biomarker, and neuropathological correlates of posterior cortical atrophy in a large international cohort.

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Objective: Approximately 50% of patients with amyotrophic lateral sclerosis (ALS) experience cognitive decline, with frontotemporal dementia (FTD) accounting for up to 15% of these cases. Despite this, there is considerable delay in diagnosis, which affects patient care.

Methods: We report longitudinal results of neuropsychological evaluations in a patient diagnosed with non-fluent/agrammatic primary progressive aphasia (nfvPPA) and amyotrophic lateral sclerosis (ALS).

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The Functional Activities Questionnaire (FAQ) is a collateral-report measure of difficulties in activities of daily living. Despite its widespread use, psychometric analyses have been limited in scope, piecemeal across samples, and limited primarily to classical test theory. This article consolidated and expanded psychometric analyses using tools from generalizability and item response theories among 27,916 individuals from the National Alzheimer's Coordinating Center database who completed the FAQ.

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There are currently no disease-modifying therapies for the treatment of tauopathies, a group of progressive neurodegenerative disorders that are pathologically defined by the presence of tau protein aggregates in the brain. Current challenges for the treatment of tauopathies include the inability to diagnose early and to confidently discriminate between distinct tauopathies in patients, alongside an incomplete understanding of the cellular mechanisms involved in pathogenic tau-induced neuronal death and dysfunction. In this review, we describe current diagnostic and therapeutic strategies, known drivers of pathogenic tau formation, recent contributions to our current mechanistic understanding of how pathogenic tau induces neuronal death, and potential diagnostic and therapeutic approaches.

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