Breakdown of functional connectivity in frontoparietal networks underlies behavioral deficits in spatial neglect.
Spatial neglect is a syndrome following stroke manifesting attentional deficits in perceiving and responding to stimuli in the contralesional field. We examined brain network integrity in patients with neglect by measuring coherent fluctuations of fMRI signals (functional connectivity). Connectivity in two largely separate attention networks located in dorsal and ventral frontoparietal areas was assessed at both acute and chronic stages of recovery. Connectivity in the ventral network, part of which directly lesioned, was diffusely disrupted and showed no recovery. In the structurally intact dorsal network, interhemispheric connectivity in posterior parietal cortex was acutely disrupted but fully recovered. This acute disruption, and disrupted connectivity in specific pathways in the ventral network, strongly correlated with impaired attentional processing across subjects. Lastly, disconnection of the white matter tracts connecting frontal and parietal cortices was associated with more severe neglect and more disrupted functional connectivity. These findings support a network view in understanding neglect.
He
Biyu J
BJ
Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Snyder
Abraham Z
AZ
Vincent
Justin L
JL
Epstein
Adrian
A
Shulman
Gordon L
GL
Corbetta
Maurizio
M
D001931:Brain Mapping; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D005625:Frontal Lobe / Q000098:blood supply / Q000503:physiopathology*; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods; D008875:Middle Aged; D009434:Neural Pathways / Q000098:blood supply / Q000503:physiopathology*; D010100:Oxygen / Q000097:blood; D010296:Parietal Lobe / Q000098:blood supply / Q000503:physiopathology*; D010468:Perceptual Disorders / Q000473:pathology* / Q000503:physiopathology; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance; D013028:Space Perception / Q000502:physiology*
D010100:Oxygen