Tau pathology is associated with neuropsychiatric symptoms in a cohort of individuals of predominantly Mexican descent at risk for autosomal‐dominant Alzheimer’s disease

Abstract

AbstractBackgroundNeuropsychiatric symptoms are common in Alzheimer’s disease (AD), causing significant suffering and diminished quality of life for both individuals and caregivers. The goal of this study was to investigate the relationship between tau pathology in vivo and neuropsychiatric symptoms within a cohort of individuals of predominantly Mexican ancestry at risk for fully penetrant autosomal dominant AD (ADAD) caused by mutations in PSEN1 and APP genes (Figure 1).MethodParticipants from the Estudio de la Enfermedad de Alzheimer en Jalisciences (EEAJ) cohort were selected based on availability of demographic variables, mutation carrier status, tau PET scans (flortaucipir), and completion of the neuropsychiatric inventory (NPI). Linear regression models were used to investigate whether regional tau PET standard uptake value ratio (SUVR) predicted total score on the NPI. Models were adjusted for age, sex, and mutation carrier status. Participants were characterized as carriers if they possessed one of the following ADAD mutations: PSEN1 A431E, PSEN1 I180F, or APP V717I. Analyses were done with and without outliers. The 12‐item total NPI score was used for all analyses. The primary brain regions of interest (i.e., medial orbitofrontal, caudal anterior cingulate, rostral anterior cingulate, parahippocampal, precuneus, and lateral occipital) were selected based on previous findings. Additional analyses were conducted only on individuals who were carriers of 1 of the ADAD mutations.ResultThe sample consisted of 31 participants (45% women, mean age±SD = 37.1±11.7 years, 71% ADAD mutation carriers [81% PSEN1 A431E, 16% PSEN1 I180F, and 3% APP V717I carriers]). A significant relationship was found between regional tau pathology and neuropsychiatric symptoms for all six brain regions (Table 1), all p’s < 0.01. Within all regression models, regional tau pathology explained between 24% to 49% of the variance in neuropsychiatric symptoms. Sub‐set analyses completed on the ADAD mutation carriers sample exhibited similar results (Table 2). No significant results were found for non‐carriers.ConclusionRegional tau pathology within six distinct brain regions is strongly associated with neuropsychiatric symptoms in a cohort of individuals of predominantly Mexican ancestry at risk for fully penetrant ADAD caused by mutations in PSEN1 and APP genes.