title: Individual subject classification of mixed dementia from pure subcortical vascular dementia based on subcortical shape analysis.
abstract: Subcortical vascular dementia (SVaD), one of common causes of dementia, has concomitant Alzheimer's disease (AD) pathology in over 30%, termed "mixed dementia". Identifying mixed dementia from SVaD is important because potential amyloid-targeted therapies may be effective for treatment in mixed dementia. The purpose of this study was to discriminate mixed dementia from pure SVaD using magnetic resonance imaging (MRI). We measured brain amyloid deposition using the 11C-Pittsburgh compound B positron emission tomography (PiB-PET) in 68 patients with SVaD. A PiB retention ratio greater than 1.5 was considered PiB(+). Hippocampal and amygdalar shape were used in the incremental learning method to discriminate mixed dementia from pure SVaD because these structures are known to be prominently involved by AD pathologies. Among 68 patients, 23 (33.8%) patients were positive for PiB binding. With use of hippocampal shape analysis alone, PiB(+) SVaD could be discriminated from PiB(-) SVaD with 77.9% accuracy (95.7% sensitivity and 68.9% specificity). With use of amygdalar shape, the discrimination accuracy was 75.0% (87.0% sensitivity and 68.9% specificity). When hippocampal and amygdalar shape were analyzed together, accuracy increased to 82.4% (95.7% sensitivity and 75.6% specificity). An incremental learning method using hippocampal and amygdalar shape distinguishes mixed dementia from pure SVaD. Furthermore, our results suggest that amyloid pathology and vascular pathology have different effects on the shape of the hippocampus and amygdala.
authors.affiliation: Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Hee Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Jeonghun
authors.initials: J
authors.lastname: Kim
authors.forename: Hanna
authors.initials: H
authors.lastname: Cho
authors.forename: Byoung Seok
authors.initials: BS
authors.lastname: Ye
authors.forename: Cindy W
authors.initials: CW
authors.lastname: Yoon
authors.forename: Young
authors.initials: Y
authors.lastname: Noh
authors.forename: Geon Ha
authors.initials: GH
authors.lastname: Kim
authors.forename: Jae Hong
authors.initials: JH
authors.lastname: Lee
authors.forename: Jae Seung
authors.initials: JS
authors.lastname: Kim
authors.forename: Yearn Seong
authors.initials: YS
authors.lastname: Choe
authors.forename: Kyung-Han
authors.initials: KH
authors.lastname: Lee
authors.forename: Chang-Hun
authors.initials: CH
authors.lastname: Kim
authors.forename: Sang Won
authors.initials: SW
authors.lastname: Seo
authors.forename: Michael W
authors.initials: MW
authors.lastname: Weiner
authors.forename: Duk L
authors.initials: DL
authors.lastname: Na
authors.forename: Joon-Kyung
authors.initials: JK
authors.lastname: Seong
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000679:Amygdala / Q000473:pathology; D003704:Dementia / Q000145:classification / Q000473:pathology*; D015140:Dementia, Vascular / Q000145:classification / Q000473:pathology*; D005260:Female; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography