title: Structural connectivity in spatial attention network: reconstruction from left hemispatial neglect.
abstract: Left hemispatial neglect (neglect) is an impaired state of spatial attention. We aimed to reconstruct structural connectivity in the spatial attention network and to identify disconnection patterns underlying neglect. We enrolled 59 right-handed patients who had their first-ever infarction in the right hemisphere and classified them into neglect group (34 patients with neglect) and control group (25 patients without neglect). The neglect group was further subcategorized into 6 subgroups based on infarcted vascular territories. Diffusion tensor imaging data were obtained from all patients. Fractional anisotropy maps were compared between neglect group/subgroups and the control group by using non-parametric voxel-based analysis, generating a lesion path mask. Probabilistic tractography analysis using the lesion path mask reconstructed the following structural connectivity in the spatial attention network, which is specifically damaged in neglect patients: (1) superior longitudinal fasciculus (SLF) I connecting the superior parietal lobule/intraparietal sulcus with the superior frontal gyrus/frontal eye field (SFG/FEF) (dorsal attention network); (2) SLF III/the arcuate fasciculus (AF) and the extreme capsule/inferior fronto-occipital fasciculus (IFOF) connecting the right inferior parietal lobule/temporoparietal junction/superior temporal gyrus (IPL/TPJ/STG) with the middle frontal gyrus/inferior frontal gyrus (ventral attention network); (3) the thalamic radiations to the spatial attention-related cortices; and (4) SLF II and IFOF interconnecting dorsal and ventral attention networks. Individual analysis indicated that isolated damage in SLF I, SLF II, SLF III/AF or the thalamic radiations to IPL/TPJ/STG due to posterior cerebral artery infarction, or simultaneous damage in four thalamic radiations due to anterior choroidal artery infarction, underlies different phenotypes of neglect.
authors.affiliation: Department of Neurology and Neurological Science, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan. takaaki-hattori@umin.ac.jp.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Hattori
authors.affiliation: Division of Ultra-High Field MRI, Institute for Biomedical Sciences, Iwate Medical University, Iwate, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Ito
authors.affiliation: Department of Rehabilitation, JA Toride Medical Center, Ibaraki, Japan.
authors.forename: Chika
authors.initials: C
authors.lastname: Nakazawa
authors.affiliation: Department of Neurology and Neurological Science, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Numasawa
authors.affiliation: Department of Rehabilitation, JA Toride Medical Center, Ibaraki, Japan.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Watanabe
authors.affiliation: Department of Radiology, Juntendo University, Tokyo, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Aoki
authors.affiliation: National Center of Neurology and Psychiatry, Tokyo, Japan.
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Mizusawa
authors.affiliation: Department for Rehabilitation, Sapporo Medical University, Sapporo, Japan.
authors.forename: Sumio
authors.initials: S
authors.lastname: Ishiai
authors.affiliation: Department of Neurology and Neurological Science, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Yokota
mesh_terms: D000368:Aged; D001288:Attention; D020520:Brain Infarction / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology; D056324:Diffusion Tensor Imaging; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D009434:Neural Pathways / Q000000981:diagnostic imaging / Q000473:pathology; D010468:Perceptual Disorders / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology; D013028:Space Perception
keywords: Diffusion tensor imaging; Left hemispatial neglect; Structural connectivity