Longitudinal free-water changes in dementia with Lewy bodies (P8-11.007)

Abstract

<h3>Objective:</h3> To characterize longitudinal diffusion microstructural changes in individuals with dementia with Lewy bodies (DLB). <h3>Background:</h3> Diffusion-weighted MRI (dMRI) examines tissue microstructure integrity and white matter pathways in vivo. Prior DLB studies focused on white matter or voxel-based techniques. Less is known about longitudinal white and grey matter microstructural changes in DLB. <h3>Design/Methods:</h3> dMRI scans were collected on individuals with DLB from the Mayo Clinic Longitudinal Imaging Biomarkers of DLB Program. Demographics, clinical evaluations and MRI were collected at baseline, and 12 or 24 months. Free-water (FW) and FW-corrected fractional anisotropy (FA_T) were analyzed in grey and white matter using 122 bilateral template regions and tracts of interest in Montreal Neurological Institute space. Primary outcomes were differences in FW and FA_T between baseline and 12 or 24 months. <h3>Results:</h3> We identified 23 individuals with DLB from baseline to 12 months [mean age 69.3 years (SD 9.5); 95.8% male], and 16 individuals from baseline to 24 months [mean age 67.5 years (SD 9.3); 100% male]. Participants at both time-points showed worsening in Montreal Cognitive Assessment and Movement Disorders Society Unified Parkinson’s Disease Rating Scale motor scores (<i>p</i>&lt;0.05). We found significant differences in FW, but not FA_T, from baseline to 12 months. Significant increases in FW at both time-points compared to baseline were observed in the insula, putamen, parahippocampal, and rolandic operculum regions (p&lt;0.05). We found more widespread microstructural changes from baseline to 24 months, with increased FW in the amygdala, entorhinal, mid and posterior cingulum, inferior frontal, hippocampal, pallidum, precuneus and retrosplenial regions (p&lt;0.05). We found decreased FA_T from baseline to 24 months in the cerebellar and superior occipital regions (<i>p</i>&lt;0.01). <h3>Conclusions:</h3> Longer follow-up at 24 months identified broader networks of free-water changes in individuals with DLB. More investigation is needed to evaluate the relationship of microstructural changes with clinical progression in DLB. <b>Disclosure:</b> Dr. Chiu has received research support from NIH/NIA. Mr. Chen has nothing to disclose. Dr. Wang has nothing to disclose. The institution of Dr. Armstrong has received research support from National Institute of Aging. The institution of Dr. Armstrong has received research support from Florida Department of Health. The institution of Dr. Armstrong has received research support from Lewy Body Dementia Association. Dr. Armstrong has received research support from Parkinson Foundation. Dr. Armstrong has received personal compensation in the range of $5,000-$9,999 for serving as a DSMB member with Alzheimer’s Clinical Trials Consortium. Dr. Armstrong has received personal compensation in the range of $5,000-$9,999 for serving as a DSMB member with Alzheimer’s Disease Cooperative Study. Dr. Armstrong has a non-compensated relationship as a Member, Scientific Advisory Council with Lewy Body Dementia Association that is relevant to AAN interests or activities. Dr. Boeve has received personal compensation in the range of $10,000-$49,999 for serving as an officer or member of the Board of Directors for Rainwater Charitable Foundation. The institution of Dr. Boeve has received research support from Alector. The institution of Dr. Boeve has received research support from GE Healthcare. The institution of Dr. Boeve has received research support from Transposon. The institution of Dr. Boeve has received research support from Cognition Therapeutics. Dr. Boeve has received publishing royalties from a publication relating to health care. The institution of Dr. Kantarci has received research support from Eli Lilly. The institution of Dr. Kantarci has received research support from NIH. The institution of Dr. Kantarci has received research support from ADDF. David Vaillancourt has received personal compensation for serving as an employee of Automated Imaging Diagnostics. David Vaillancourt has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Wiley. The institution of David Vaillancourt has received research support from NIH. David Vaillancourt has received intellectual property interests from a discovery or technology relating to health care.