The anatomy of spatial neglect after posterior cerebral artery stroke.

Spatial neglect is a common consequence of stroke in the territory of the right middle cerebral artery. Damage to a perisylvian fronto-temporo-parietal network has been demonstrated to underlie this disorder. Less common, stroke to the posterior cerebral artery territory may also lead to spatial neglect. This study aimed to uncover the anatomical underpinnings of spatial neglect after posterior cerebral artery infarction. A sample of 50 posterior cerebral artery infarct patients was screened for spatial neglect. Neural correlates of neglect were investigated both with voxel-based lesion behaviour mapping and with region-of-interest analyses. Brain damage neither to the splenium, nor to the parahippocampal gyrus, nor to the thalamus was predictive of spatial neglect. Only damage to the perisylvian fronto-temporo-parietal network of spatial neglect was significantly associated with neglect severity. We conclude that both posterior and middle cerebral artery stroke induce spatial neglect after damage to the same perisylvian brain network. The findings contradict previous theories that postulated neural correlates of spatial neglect specifically supplied by the posterior cerebral artery. In posterior cerebral artery stroke patients, affected parts of this network are located at the border zone between the posterior and middle cerebral artery territories. Inter-individual variability in the localization of the border between both artery territories appears to mediate the occurrence of spatial neglect after posterior cerebral artery stroke.