title: White matter changes in dementia with Lewy bodies and Alzheimer's disease: a tractography-based study.
abstract: Dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) are different types of dementia. However, their clinical symptoms partially overlap and differential diagnosis is occasionally difficult. There is need for additional diagnostic criteria to reliably differentiate between these two conditions. Meanwhile, several imaging studies have showed inconsistent results between DLB and AD. The aim of this study was to use a tractography-based analysis to elucidate white matter alterations in subjects with DLB compared to those with AD and to controls. An understanding of the white matter connectivity differences between AD, DLB and controls will be helpful for differential diagnosis and an understanding of the pathophysiology. Twenty-six subjects with DLB, 26 with AD and 26 controls underwent magnetic resonance diffusion tensor imaging and neuropsychological assessment. Diffusion tensors were computed and fiber-tract maps were created using "dTV II" software. We measured mean fractional anisotropy (FA) values along the uncinate fasciculus (UNC), the inferior occipitofrontal fasciculus (IOFF) and the inferior longitudinal fasciculus (ILF). Both subjects with DLB and AD had lower FA values for the bilateral UNC than controls. Subjects with DLB exhibited significantly lower FA values on both sides of the IOFF and the left side of the ILF than those of controls. Although there were no significant differences between subjects with DLB and AD for any measurements, those with DLB exhibited lower FA values especially in visual-related white matter. These different changes in white matter tracts among groups could be helpful for differential diagnosis and an understanding of the pathophysiology.
authors.affiliation: Department of Psychiatry, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8522, Japan. kuniaki@naramed-u.ac.jp
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Kiuchi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Morikawa
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Taoka
authors.forename: Soichiro
authors.initials: S
authors.lastname: Kitamura
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Nagashima
authors.forename: Manabu
authors.initials: M
authors.lastname: Makinodan
authors.forename: Keiju
authors.initials: K
authors.lastname: Nakagawa
authors.forename: Masami
authors.initials: M
authors.lastname: Fukusumi
authors.forename: Katsumi
authors.initials: K
authors.lastname: Ikeshita
authors.forename: Makoto
authors.initials: M
authors.lastname: Inoue
authors.forename: Kimihiko
authors.initials: K
authors.lastname: Kichikawa
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Kishimoto
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000473:pathology*; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping; D056324:Diffusion Tensor Imaging / Q000379:methods; D005260:Female; D006801:Humans; D020961:Lewy Body Disease / Q000473:pathology*; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D009483:Neuropsychological Tests; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric