Background: Neuropsychiatric symptoms (NPS) are increasingly recognized as early non-cognitive manifestations in the Alzheimer's disease (AD) continuum. However, the role of NPS as an early marker of pathophysiological progression in AD remains unclear. Dominantly inherited AD (DIAD) mutation carriers are young individuals who are destined to develop AD in future due to the full penetrance of the genetic mutation. Hence, the study of DIAD mutation carriers enables the evaluation of the associations between pure AD pathophysiology and metabolic correlates of NPS without the confounding effects of co-existing pathologies. In this longitudinal study, we aimed to identify regional brain metabolic dysfunctions associated with NPS in cognitively intact DIAD mutation carriers.
Methods: We stratified 221 cognitively intact participants from the Dominantly Inherited Alzheimer's Network according to their mutation carrier status. The interactions of NPS measured by the Neuropsychiatric Inventory-Questionnaire (NPI-Q), age, and estimated years to symptom onset (EYO) as a function of metabolism measured by [F]flurodeoxyglucose ([F]FDG) positron emission tomography, were evaluated by the mixed-effects regression model with family-level random effects in DIAD mutation carriers and non-carriers. Exploratory factor analysis was performed to identify the neuropsychiatric subsyndromes in DIAD mutation carriers using the NPI-Q sub-components. Then the effects of interactions between specific neuropsychiatric subsyndromes and EYO on metabolism were evaluated with the mixed-effects regression model.
Results: A total of 119 mutation carriers and 102 non-carriers were studied. The interaction of higher NPI-Q and shorter EYO was associated with more rapid declines of global and regional [F]FDG uptake in the posterior cingulate and ventromedial prefrontal cortices, the bilateral parietal lobes and the right insula in DIAD mutation carriers. The neuropsychiatric subsyndromes of agitation, disinhibition, irritability and depression interacted with the EYO to drive the [F]FDG uptake decline in the DIAD mutation carriers. The interaction of NPI and EYO was not associated with [F]FDG uptake in DIAD mutation non-carriers.
Conclusions: The NPS in cognitively intact DIAD mutation carriers may be a clinical indicator of subsequent metabolic decline in brain networks vulnerable to AD, which supports the emerging conceptual framework that NPS represent early manifestations of neuronal injury in AD. Further studies using different methodological approaches to identify NPS in preclinical AD are needed to validate our findings.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7780680 | PMC |
http://dx.doi.org/10.1186/s40035-020-00225-y | DOI Listing |
Acta Neuropathol
August 2024
Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, 635 Barnhill Dr., MSB A136, Indianapolis, IN, 46202, USA.
Cotton wool plaques (CWPs) have been described as features of the neuropathologic phenotype of dominantly inherited Alzheimer disease (DIAD) caused by some missense and deletion mutations in the presenilin 1 (PSEN1) gene. CWPs are round, eosinophilic amyloid-β (Aβ) plaques that lack an amyloid core and are recognizable, but not fluorescent, in Thioflavin S (ThS) preparations. Amino-terminally truncated and post-translationally modified Aβ peptide species are the main component of CWPs.
View Article and Find Full Text PDFThis study explored the role of the ubiquitin-proteasome system (UPS) in dominantly inherited Alzheimer's disease (DIAD) by examining changes in cerebrospinal fluid (CSF) levels of UPS proteins along with disease progression, AD imaging biomarkers (PiB PET, tau PET), neurodegeneration imaging measures (MRI, FDG PET), and Clinical Dementia Rating (CDR). Using the SOMAscan assay, we detected subtle increases in specific ubiquitin enzymes associated with proteostasis in mutation carriers (MCs) up to two decades before the estimated symptom onset. This was followed by more pronounced elevations of UPS-activating enzymes, including E2 and E3 proteins, and ubiquitin-related modifiers.
View Article and Find Full Text PDFAlzheimers Dement
April 2024
Washington University School of Medicine in Saint Louis, St. Louis, Missouri, USA.
Introduction: Amyloidosis, including cerebral amyloid angiopathy, and markers of small vessel disease (SVD) vary across dominantly inherited Alzheimer's disease (DIAD) presenilin-1 (PSEN1) mutation carriers. We investigated how mutation position relative to codon 200 (pre-/postcodon 200) influences these pathologic features and dementia at different stages.
Methods: Individuals from families with known PSEN1 mutations (n = 393) underwent neuroimaging and clinical assessments.
Int J Mol Sci
September 2023
Oncogenetics Laboratory, Oncopole Claudius Regaud, IUCT-Oncopole, Toulouse, France.
Even though male breast cancer (MBC) risk encompasses both genetic and environmental aetiologies, the primary risk factor is a germline pathogenic variant (PV) or likely pathogenic variant (LPV) in and/or genes. To identify new potential MBC-specific predisposition genes, we sequenced a panel of 585 carcinogenesis genes in an MBC cohort without PV/LPV. We identified 14 genes carrying rare PVs/LPVs in the MBC population versus noncancer non-Finnish European men, predominantly coding for DNA repair and maintenance of genomic stability proteins.
View Article and Find Full Text PDFAlzheimers Dement
January 2024
Department of Neurology, Washington University St. Louis, St. Louis, Missouri, USA.
Introduction: Studies suggest distinct differences in the development, presentation, progression, and response to treatment of Alzheimer's disease (AD) between females and males. We investigated sex differences in cognition, neuroimaging, and fluid biomarkers in dominantly inherited AD (DIAD).
Methods: Three hundred twenty-five mutation carriers (55% female) and one hundred eighty-six non-carriers (58% female) of the Dominantly Inherited Alzheimer Network Observational Study were analyzed.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!