title: Heterogeneity in mild cognitive impairment: differences in neuropsychological profile and associated white matter lesion pathology.
abstract: This study examined whether distinct neuropsychological profiles could be delineated in a sample with Mild Cognitive Impairment (MCI) and whether white matter lesion (WML) burden contributed to MCI group differences. A heterogeneous, clinical sample of 70 older adults diagnosed with MCI was assessed using cognitive scores, and WML was quantified using a semi-automated, volumetric approach on T2-weighted fluid-attenuated inversion recovery (FLAIR) images. Using cluster and discriminant analyses, three distinct groups (Memory/Language, Executive/Processing Speed, and Pure Memory) were empirically derived based on cognitive scores. Results also showed a dose dependent relationship of WML burden to MCI subgroup, with the Executive/Processing Speed subgroup demonstrating significantly higher levels of WML pathology when compared to the other subgroups. In addition, there was a dissociation of lesion type by the two most impaired subgroups (Memory/Language and Executive/Processing Speed) such that the Memory/Language subgroup showed higher periventricular lesion (PVL) and lower deep white matter lesion (DWML) volumes, whereas the Executive/Processing Speed demonstrated higher DWML and lower PVL volumes. Results demonstrate that distinct MCI subgroups can be empirically derived and reliably differentiated from a heterogeneous MCI sample, and that these profiles differ according to WML burden. Overall, findings suggest different underlying pathologies within MCI and contribute to our understanding of MCI subtypes.
authors.affiliation: Department of Psychiatry, School of Medicine, University of California-San Diego, La Jolla, CA 92161, USA. ldelano@ucsd.edu
authors.forename: Lisa
authors.initials: L
authors.lastname: Delano-Wood
authors.forename: Mark W
authors.initials: MW
authors.lastname: Bondi
authors.forename: Joshua
authors.initials: J
authors.lastname: Sacco
authors.forename: Norm
authors.initials: N
authors.lastname: Abeles
authors.forename: Amy J
authors.initials: AJ
authors.lastname: Jak
authors.forename: David J
authors.initials: DJ
authors.lastname: Libon
authors.forename: Andrea
authors.initials: A
authors.lastname: Bozoki
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001921:Brain / Q000473:pathology*; D003072:Cognition Disorders / Q000473:pathology* / Q000503:physiopathology; D016002:Discriminant Analysis; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D009483:Neuropsychological Tests; D014796:Visual Perception / Q000502:physiology