Right-sided neglect following a left subcortical lesion.

Unilateral spatial neglect is, in humans, typically consequent to lesions of the right hemisphere and pertains to the left hemispace. Although neglect is maximally frequent after right cortical lesions, it may also ensue from lesions confined to right subcortical structures. By contrast, hemispatial neglect consequent to left hemispheric lesions occurs less frequently. Reports of neglect following lesions to left subcortical structures are even more rare and largely anecdotal. Here we report on a right-handed man who had two successive left-sided brain lesions at an interval of 10 years from one another. The first lesion, centered upon the occipital lobe, induced a contralateral hemianopia, but no signs of hemispatial neglect; by contrast, the second lesion, a capsulo-thalamic hemorrhage, did induce a florid and persistent right-sided neglect. This finding would suggest that left subcortical structures may be important nodes in the network subserving spatial representations.