title: Attention-network specific alterations of structural connectivity in the undamaged white matter in acute neglect.
abstract: Visual neglect results from dysfunction within the spatial attention network. The structural connectivity in undamaged brain tissue in neglect has barely been investigated until now. In the present study, we explored the microstructural white matter characteristics of the contralesional hemisphere in relation to neglect severity and recovery in acute stroke patients. We compared age-matched healthy subjects and three groups of acute stroke patients (9 ± 0.5 days after stroke): (i) patients with nonrecovered neglect (n = 12); (ii) patients with rapid recovery from initial neglect (within the first week post-stroke, n = 7), (iii) stroke patients without neglect (n = 17). We analyzed the differences between groups in grey and white matter density and fractional anisotropy (FA) and used fiber tracking to identify the affected fibers. Patients with nonrecovered neglect differed from those with rapid recovery by FA-reduction in the left inferior parietal lobe. Fibers passing through this region connect the left-hemispheric analogues of the ventral attention system. Compared with healthy subjects, neglect patients with persisting neglect had FA-reduction in the left superior parietal lobe, optic radiation, and left corpus callosum/cingulum. Fibers passing through these regions connect centers of the left dorsal attention system. FA-reduction in the identified regions correlated with neglect severity. The study shows for the first time white matter changes within the spatial attention system remote from the lesion and correlating with the extent and persistence of neglect. The data support the concept of neglect as disintegration within the whole attention system and illustrate the dynamics of structural-functional correlates in acute stroke.
authors.affiliation: Department of Neurology, University Medical Centre Freiburg, Freiburg, Germany; Freiburg Brain Imaging, University Medical Centre Freiburg, Freiburg, Germany; BrainLinks-BrainTools Cluster of Excellence, University of, Freiburg, Germany.
authors.forename: Roza M
authors.initials: RM
authors.lastname: Umarova
authors.forename: Marco
authors.initials: M
authors.lastname: Reisert
authors.forename: Tanja-Ute
authors.initials: TU
authors.lastname: Beier
authors.forename: Valerij G
authors.initials: VG
authors.lastname: Kiselev
authors.forename: Stefan
authors.initials: S
authors.lastname: Klöppel
authors.forename: Christoph P
authors.initials: CP
authors.lastname: Kaller
authors.forename: Volkmar
authors.initials: V
authors.lastname: Glauche
authors.forename: Irina
authors.initials: I
authors.lastname: Mader
authors.forename: Lena
authors.initials: L
authors.lastname: Beume
authors.forename: Jürgen
authors.initials: J
authors.lastname: Hennig
authors.forename: Cornelius
authors.initials: C
authors.lastname: Weiller
mesh_terms: D000368:Aged; D016880:Anisotropy; D001288:Attention; D001921:Brain / Q000473:pathology*; D056324:Diffusion Tensor Imaging; D066128:Gray Matter / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000473:pathology; D009483:Neuropsychological Tests; D010468:Perceptual Disorders / Q000209:etiology / Q000473:pathology*; D020127:Recovery of Function; D012720:Severity of Illness Index; D020521:Stroke / Q000150:complications* / Q000473:pathology; D066127:White Matter / Q000473:pathology*
keywords: diffusion-tensor imaging (DTI); fractional anisotropy (FA); recovery from neglect; structural connectivity; visual neglect; white matter remodeling