PATHOGENESIS OF SUBCORTICAL VISUOSPATIAL NEGLECT - A HMPAO SPECT STUDY

The pathophysiology of neuropsychological disorders due to right deep- seated hemispheric lesions remains a debated point. We undertook this study to check the hypothesis according to which remote cortical dysfu nction could be responsible :or the occurrence of neglect. Twenty-eigh t patients presenting with a right sided subcortical stroke were studi ed. A neuropsychological battery of tests suitable for assessment of p ossible visuo-spatial neglect was performed as well as HMPAO SPECT. Ne glect was observed in 15 cases out of 28. The lesion's site (at CT and /or MRI) did not allow discrimination between patients without neglect and patients with neglect. The latter however could be distinguished from the former by the presence of a remote decrease in cortical blood flow in the right temporo-parietal region. By suggesting that cortica l involvement is necessary for the occurrence of neglect, the results were interpreted according to a network approach in which subcortical neglect is attributed to a cortical deprivation from afferent input in the posterior part of the brain. (C) 1997 Elsevier Science Ltd.