Characterizing biomarker features of cognitively normal individuals with ventriculomegaly

Abstract

Abstract 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 [18F]fluorodeoxyglucose standardized uptake value ratio but higher amyloid burden represented by higher [18F]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.

Keywords

• Ventriculomegaly
• Neuropsychological test
• Biomarker
• Alzheimer's disease
• Idiopathic normal pressure hydrocephalus