Pilot Investigation: Older Adults With Atrial Fibrillation Demonstrate Greater Brain Leukoaraiosis in Infracortical and Deep Regions Relative to Non-Atrial Fibrillation Peers.

Margaret E Wiggins,Thomas Beaver,Catherine C Price,David J Libon,Jacob Jones,Seyed Hossein Aalaei-Andabili,Kenneth M Heilman,Ilona Schmalfuss,Jared J Tanner

doi:10.3389/fnagi.2020.00271

Abstract

BackgroundThis pilot study explored differences in distribution of white matter hyperintensities (called leukoaraiosis; LA) in older adults (mean age = 67 years) with atrial fibrillation (AF) vs. non-AF peers measured by: (1) depth distribution; (2) anterior-posterior distribution; (3) associations between LA and cortical thickness; and (4) presence of lacunae and stroke.MethodsParticipant data (AF n = 17; non-AF peers n = 17) were acquired with the same magnetic resonance imaging protocols. LA volume was quantified by cortical depth (periventricular, deep, infracortical) and in anterior and posterior regions. Cortical thickness by lobe was assessed relative to LA load.ResultsRelative to non-AF peers, the AF group had twice the total LA volume (AF = 2.1% vs. Non-AF = 0.9%), over 10 times greater infracortical LA (AF = 0.72% vs. Non-AF = 0.07%), and three times greater deep LA (AF = 2.1% vs. Non-AF = 0.6%). Examinations of the extent of LA in anterior vs. posterior regions revealed a trend for more posterior relative to anterior LA. In the entire sample, total LA and infracortical LA were negatively associated with temporal lobe thickness. Only those with AF presented with lacunae or stroke.ConclusionAging adults with AF had more total white matter disease than those without AF, particularly near the cortical mantle and deep within the cortex. Total and infracortical white matter disease in the entire sample negatively associated with temporal lobe thickness. Results suggest that those with AF have a distinct pattern of LA relative to those without AF, and that LA severity for all individuals may associate with structural changes in the cortex.

Highlights

METHODSLeukoaraiosis (LA), or white matter abnormalities seen on computed tomography (CT) or magnetic resonance imaging (MRI) scans (Hachinski et al, 1986), is a neuroimaging marker of vascular-related brain injury that can be associated with atrial fibrillation (AF)
To explore whether individuals with AF have different white matter distributions from individuals without AF, the present study examined LA quantified as a percentage of white matter by cortical depth and in anterior and posterior regions for a sample of AF and non-AF peers with a sophisticated, 3dimensional volumetric imaging and threshold measurement of LA
Statistically greater LA burden was present in infracortical and deep cortical regions in patients with AF, both groups demonstrated a trend for more LA in the posterior region of the cortex which does not align with previous findings of greater anterior relative to posterior LA (Mayasi et al, 2018)

Summary

Introduction

METHODSLeukoaraiosis (LA), or white matter abnormalities seen on computed tomography (CT) or magnetic resonance imaging (MRI) scans (Hachinski et al, 1986), is a neuroimaging marker of vascular-related brain injury that can be associated with atrial fibrillation (AF). When measured using a visual rating scale, those with AF have more LA near the cortex and in the deeper white matter relative to non-AF peers (Kobayashi et al, 2012) Another visual rating study suggests greater LA in anterior brain regions, such as around the frontal forceps, among patients with AF who present with embolic stroke (Mayasi et al, 2018). It may be that individuals with AF are vulnerable to frontal lobe cortical thinning relative to non-AF peers who have little to no LA near the cortex (Price et al, 2012; Wiggins et al, 2019) This pilot study explored differences in distribution of white matter hyperintensities (called leukoaraiosis; LA) in older adults (mean age = 67 years) with atrial fibrillation (AF) vs non-AF peers measured by: (1) depth distribution; (2) anterior-posterior distribution; (3) associations between LA and cortical thickness; and (4) presence of lacunae and stroke

Results

Discussion

Conclusion