AUTHOR=Zhuang Xuan-Miao , Kuo Li-Wei , Lin Shih-Yen , Yang Jir-Jei , Tu Min-Chien , Hsu Yen-Hsuan 

TITLE=Prospective Memory and Regional Functional Connectivity in Subcortical Ischemic Vascular Disease

JOURNAL=Frontiers in Aging Neuroscience

VOLUME=Volume 13 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/aging-neuroscience/articles/10.3389/fnagi.2021.686040

DOI=10.3389/fnagi.2021.686040

ISSN=1663-4365

ABSTRACT=Objectives: Patients with subcortical ischemic vascular disease (SIVD) often have prominent frontal dysfunction. However, it remains unclear how SIVD affects prospective memory (PM), which strongly relies on the frontoparietal network. The present study aimed to investigate PM performance in patients with early stage SIVD as compared to those with Alzheimer’s disease (AD) and to cognitively normal older adults, and to explore the neural correlates of PM deficits. 
Method: Patients with very early to mild dementia due to SIVD or AD and normal controls (NC) aged above 60 years were recruited. Seventy-three participants (20 SIVD, 22 AD and 31 NC) underwent structural magnetic resonance imaging (MRI), cognitive screening tests and a computerized PM test. Sixty-five of these participants (19 SIVD, 20 AD and 26 NC) also received resting-state functional MRI. 
Results: The SIVD group had significantly fewer PM hits than the control group on both time-based and nonfocal event-based PM tasks. Among patients in the very early stage, only those with SIVD but not AD performed significantly worse than the controls. Correlational analyses showed that nonfocal event-based PM in SIVD was positively correlated with regional homogeneity in bilateral superior and middle frontal gyri, while time-based PM was not significantly associated with regional homogeneity in any of the regions of interest within the dorsal frontoparietal regions. 
Conclusions: The findings of this study highlight the vulnerability of nonfocal event-based PM to disruption of regional functional connectivity in bilateral superior and middle frontal gyri in patients with SIVD.