Journal Article

Normalized perfusion MRI to identify common areas of dysfunction: patients with basal ganglia neglect

Hans-Otto Karnath, Regine Zopf, Leif Johannsen, Monika Fruhmann Berger, Thomas Nägele and Uwe Klose

in Brain

Published on behalf of The Guarantors of Brain

Volume 128, issue 10, pages 2462-2469
Published in print October 2005 | ISSN: 0006-8950
Published online September 2005 | e-ISSN: 1460-2156 | DOI: http://dx.doi.org/10.1093/brain/awh629
Normalized perfusion MRI to identify common areas of dysfunction: patients with basal ganglia neglect

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Perfusion-weighted imaging (PWI) is used to identify brain regions that are receiving enough blood supply to remain structurally intact, but not enough to function normally. Previous observations suggest that spatial neglect due to subcortical stroke can be explained by dysfunction of cortical areas rather than through the neuronal loss in the subcortical structures itself. The present study aimed to identify the dysfunctional cortical regions induced by basal ganglia stroke in patients with spatial neglect. In a patient group with stroke lesions centring on the basal ganglia, we examined the common area(s) of structurally intact but dysfunctional cortical tissue by using spatial normalization of PWI maps as well as symmetric voxel-wise inter-hemispheric comparisons. These new techniques allow comparison of the structurally intact but abnormally perfused areas of different individuals in the same stereotaxic space, and at the same time avoid problems due to regional perfusion differences and to possible observer-dependent biases. We found that strokes centring on the right basal ganglia which provoke spatial neglect induce abnormal perfusion in a circumscribed area of intact cortex that typically involves those three regions that have previously been described to provoke spatial neglect when damaged directly by cortical infarction: the superior temporal gyrus, the inferior parietal lobule and the inferior frontal gyrus. The data suggest that spatial neglect following a right basal ganglia lesion typically is caused by the dysfunction of (part of) these specific cortical areas.

Keywords: spatial neglect; basal ganglia; attention; visual search; exploration; perfusion-weighted imaging; human; PWI = perfusion-weighted imaging; DWI = diffusion-weighted imaging; FLAIR = fluid-attenuated inversion-recovery

Journal Article.  5994 words.  Illustrated.

Subjects: Neurology ; Neuroscience

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