Characterizing biomarker features of cognitively normal individuals with ventriculomegaly

INTRODUCTION: The clinical significance of ventriculomegaly in cognitively normal elderly individuals remains unclear. METHODS: We selected cognitively normal individuals (n = 425) from the Alzheimer's Disease Neuroimaging Initiative database and calculated Evans index (EI) based on the ratio of the frontal horn and skull diameter. We defined ventriculomegaly as EI ≥ 0.30, and the participants were stratified into EI ≥ 0.30 group and EI < 0.30 group. Neuropsychological, imaging, and fluid biomarker profiles between the two groups were then compared using regression models. RESULTS: A total of 96 (22.5%) individuals who had ventriculomegaly performed worse on the cognitive tests; showed smaller hippocampal volume but larger caudate, cingulate, and paracentral gyrus volumes; and displayed lower positron emission tomography [(18)F]fluorodeoxyglucose standardized uptake value ratio but higher amyloid burden represented by higher [(18)F]florbetapir standardized uptake value ratio and lower cerebrospinal fluid amyloid β 1–42 levels compared to those without ventriculomegaly. DISCUSSION: Asymptomatic ventriculomegaly might be an early imaging signature of preclinical Alzheimer's disease and/or normal pressure hydrocephalus.