Data Availability StatementData for all your analyses and results reported in this article were acquired from The 90+ Study. 1.11C1.42; 0.001). HS was more likely in participants with a history of autoimmune diseases (rheumatoid arthritis or thyroid disease, OR 3.15; 95% CI 1.30C7.62; = 0.011), high thyroid-stimulating hormone (OR 4.94; 95% CI 1.40C17.46; = 0.013), or high thyroid antibodies (OR 3.45; 95% Metformin HCl CI 1.09C10.88; = 0.035). Lewy body disease (LBD) pathology was also associated with an increased likelihood of HS (OR 5.70; 95% CI 1.22C26.4; = 0.027). Conclusion We identified autoimmune conditions (rheumatoid arthritis and thyroid disease) as potential risk factors for HS in our cohort. LBD was the only pathology that was associated with increased odds of HS and those harboring HS pathology had a longer duration of dementia. This suggests multiple pathways of HS pathology among the oldest-old. People over the age of 90 are the fastest growing age group in much of the world and in the United States.1 Dementia is very common in the oldest old, with an overall prevalence of all-cause dementia in this age group of 41.2%.2 Hippocampal sclerosis (HS) is strongly associated with dementia in the oldest old.3 HS is a neuropathologically defined condition characterized by severe and disproportionate gliosis and neuronal loss in the CA1 region of the hippocampus and subiculum.3,C6 The prevalence of HS pathology in the elderly population has been reported to be up to 26% in previous studies,6,C12 making Metformin HCl HS an important condition to investigate in the oldest old.13 Despite its importance,14 the clinical characteristics, neuropathologic comorbidities, and risk factors of HS remain poorly understood.15,16 To overcome these knowledge gaps, we studied data from 134 participants with dementia from The 90+ Study, a population-based study of people aged 90 years and older.17 The aim of this scholarly study was to review, within a combined band of individuals with dementia, characteristics of these with HS at autopsy to individuals without HS. Individuals were compared with regards to medical histories and neuropathologic results to recognize risk elements and neuropathologic features of HS in TAN1 the oldest outdated. Strategies Individuals Individuals who got decided to longitudinal in-person assessments and postmortem human brain evaluation originated from The 90+ Study, a population-based epidemiologic study of individuals aged 90 years and over in Laguna Woods, California. The 90+ Study began in 2003 to study the physical and mental health of the fastest-growing age group in the United States. As of September 30, 2015, 421 participants had enrolled in the autopsy program, representing Metformin HCl 39% of those invited, and 264 had come to autopsy (93% autopsy rate) (physique). The inclusion criteria for the present study were (1) postmortem analysis (autopsy) of the brain and (2) clinical diagnosis of dementia at the time of death from a multidisciplinary case conference as described below. The focus of the study was on individuals with dementia as almost all participants who had HS at postmortem had a diagnosis of dementia. Inclusion of participants without dementia would have only added 3 cases to the HS group at the expense of subjecting the study to confounding effect of a cognitively heterogeneous sample. However, to ensure that restricting the analysis to only participants with dementia did not lead to obtaining of spurious associations, we also performed the analyses on the full autopsied cohort (n = 264) for variables with significant associations in the dementia group. Open in a separate window Figure Flow chart for participant inclusion Standard protocol approvals, registrations, and patient consents All participants or their designated surrogates provided consent to participate in the study. Procedures were reviewed and approved by the Institutional Review Board at the University of California, Irvine. Assessments The cognitive and physical status of the participants was evaluated in-person every 6 months. Clinical evaluation included a battery of neuropsychological assessments, neurologic examination, and self or informant.