WHITE MATTER VASOGENIC EDEMA AND ITS ASSOCIATION WITH NEUROPSYCHOLOGICAL MEASURES IN ALZHEIMER’S DISEASE

Abstract

Cerebral vasogenic edema is a pathological phenomena involved in the disease progression of Alzheimer disease (AD). A diffusion based MRI method - neuro-inflammation imaging (NII) has recently demonstrated its feasibility in detecting not only the axon integrity but also inflammation and edema in WM. This study aims to quantify the vasogenic edema in preclinical and early symptomatic AD and investigate its association with neuropsychological measures. Participants (n=121 amyloid negative healthy controls (HC), n=31 amyloid positive w/ normal cognition (PC) and n=20 individuals diagnosed as incipient AD with Clinical Dementia Rating of 0.5 (iAD)) enrolled in ongoing studies at the Knight Alzheimer's Disease Research Center at Washington University in Saint Louis were used for NII measures and a cognitive test battery. Cognitive tests common to all participants include Animal Naming (ANIMAL), Trail Making A test (TMA), the Selective Reminding Test containing the Free Recall (SRTFREE) and the Mini-Mental State Examination (MMSE). NII was acquired with multi-b value scheme (bmax =1400s/mm2 and 25 directions). NII derived edema fraction (reflecting WM vasogenic edema) was quantified and correlated with cognitive tests using tract-based spatial statistics. There is an elevation of NII derived edema fraction in the iAD group but not in the PC group when compared to the HC group (Figure 1). The significant correlations between NII edema fraction and ANIMAL, TMA and MMSE, but not SRTFREE have been observed (Figure 2). Scatter plots demonstrated those associations on corpus callosum tract as a representative example (Figure 3).