Association of brain amyloidosis with the incidence and frequency of neuropsychiatric symptoms in ADNI: a multisite observational cohort study

• Authors: Naira Goukasian, Robert Larner College of Medicine, Burlington; Kristy S Hwang, Emory University; Tamineh Romero, University of California Los Angeles; Jonathan Grotts, University of California Los Angeles; Triet M Do, Tulane University School of Medicine; Jenna R Groh, Indiana University School of Medicine; Daniel R Bateman, Indiana University School of Medicine; Liana G Apostolova, Indiana University School of Medicine
• Journal Title: BMJ Open
• Volume: Volume 9, Number 12
• Publisher: BMJ Journals | 2019-12-18
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1136/bmjopen-2019-031947
• Subjects: Health Sciences, Medicine and Surgery
• Keywords: Amyloidosis; Mild Cognitive Impairment (MCI); Alzheimer’s disease (AD); Neuropsychiatric Symptoms (NPS); Alzheimer’s Disease Neuroimaging Initiative (ADNI)

Abstract

Objective To investigate the relationship between amyloid burden and frequency of existing and incidence of new neuropsychiatric symptoms (NPS) in elderly with and without cognitive decline. Methods 275 cognitively normal controls (NC), 100 subjective memory complaint (SMC), 559 mild cognitive impairment (MCI) and 143 Alzheimer’s disease dementia subjects from the Alzheimer’s Disease Neuroimaging Initiative received (18F)-florbetapir positron emission tomography (PET) scans. Yearly neuropsychiatric inventory (Neuropsychiatric Inventory (NPI)/NPI-Questionnaire) data were collected from the study partners at each visit. Mean standard uptake volume ratios (SUVR) normalised to whole cerebellum were obtained. Positive amyloid PET scan was defined as mean SUVR ≥1.17. Fisher’s exact test was used to compare frequency and incidence between amyloid positive and amyloid negative subjects. Survival analyses were used to estimate of neuropsychiatric symptoms (NPS) between amyloid positive and amyloid negative subjects. Survival analyses were used to estimate hazard ratios for developing the most common NPS by amyloid status. Results No differences in NPS frequency were seen between amyloid positive and amyloid negative NC, SMC, MCI or dementia groups. MCI subjects with amyloid pathology however tended to have greater frequency x severity (FxS) of anxiety, hallucinations, delusions, apathy, disinhibition, irritability, aberrant motor behavior, and appetite, but not agitation, depression, night-time disturbances, or elation. MCI subjects with amyloid pathology were at greater risk for developing apathy, anxiety and agitation over time. Baseline presence of agitation and apathy and new onset agitation, irritability and apathy predicted faster conversion to dementia among MCI subjects. Conclusions Amyloid pathology is associated with greater rate of development of new NPS in MCI. Anxiety and delusions are significant predictors of amyloid pathology. Agitation, irritability and apathy are significant predictors for conversion from MCI to dementia.