Alzheimer’s disease (AD) is strongly associated with neuropsychiatric symptoms (NPS) (such as depression, anxiety, irritability) during prodromal and clinical stages of typical and atypical presentations, often leading to psychiatric misdiagnosis and hospitalization in the psychiatric ward. Moreover, nonamnestic presentations of AD can mimic specific neurodegenerative diseases (NDD) syndromes with prominent changes in social cognition and perception, such as behavioral variant frontotemporal dementia (bvFTD) and dementia with Lewy bodies (DLB), which are also often misinterpreted as primary psychiatric disorders. Interestingly, AD has been shown to be the main or a contributing underlying pathology in bvFTD, corticobasal syndrome (CBS), DLB, and nonfluent variant primary progressive aphasia (nfvPPA) syndromes in clinicopathological studies.
This study aims to assess the frequency and clinical impact of Alzheimer’s disease clinical syndromes and plasma biomarkers in patients hospitalized in a Brazilian psychiatric ward for two years. This proposal seeks to develop a methodology that will allow in-depth neurological phenotyping of the population of patients admitted to the psychiatric ward of São Lucas Hospital in Porto Alegre, Brazil. We propose to screen all patients over 45 years of age for AD clinical syndromes and for NDD that can mimic these phenotypes (bvFTD, DLB, nfvPPA, CBS). In each of these groups, we will have the novel opportunity to screen for the presence of AD neuropathology using novel plasma-based biomarkers. This study also aims to determine whether plasma biomarkers are associated with clinical outcomes. We will collect blood at the time of admission, evaluate functional status and clinical diagnosis of AD, bvFTD, DLB, PPA, or CBS during hospitalization, and evaluate cognitive performance when neuropsychiatric stability criteria are met. Exclusion criteria include inability to collect blood and blood abnormalities. Blood samples will be sent and analyzed in the University of Pittsburgh using cutting-edge single molecule array (SIMOA) technology. This will be the first study to assess the frequency and clinical outcome of AD in psychiatric settings in Brazil, which may improve decision-making by showing unprecedented data on clinical outcome, AD frequency, and potential misdiagnosis in a psychiatric ward. In the medium term, this project will substantiate further grant funding that aims to investigate the impact of plasma AD biomarkers in decision-making and clinical outcomes in a more representative population.