REMOTE CORTICAL DYSFUNCTION AS A POSSIBLE CAUSE OF SUBCORTICAL NEGLECT - A REGIONAL CEREBRAL BLOOD-FLOW STUDY

Cortical remote effects of right deep-seated lesions were studied with two cerebral blood flow measurement methods (two-dimensional xenon-13 3 inhalation and 99mTc HMPAO SPECT) in a population of 13 right-handed stroke patients. A neuropsychological battery of tests suitable for a ssessment of possible visual neglect was performed. Neglect was presen t in 7 cases. A regional cortical hypoperfusion was observed in all pa tients. However, in neglect patients it was more extended and involved the right inferior parietal region suggesting a causal relationship b etween cortical dysfunction and neuropsychological deficit. This findi ng supports the model attributing neglect to a unilateral attention-ar ousal defect in a cortico-limbic-reticular loop.