Global spatial disorientation. Clinico-pathologic correlations.
Two patients presenting with the acute onset of bilateral parietal lobe damage showed initially the features of Balint's syndrome. After most of its manifestations had cleared, both patients exhibited severe disorders of spatial orientation: acoustic ataxia, inability to localize objects in space. In addition, 1 patient showed a topographical disorientation and abnormalities of whole body movements. This patient came to post-mortem examination, which revealed bilateral and fairly symmetrical old and recent infarctions of the superior parietal lobules. In the light of these observations and previous reports, it is suggested that the reported abnormalities of whole body movements can be explained on the basis of a visuo-motor intrahemispheric disconnection due to the bilateral lesion of the dorsal parietal lobe. In addition, the global spatial disorientation is analysed and is thought to be the manifestation of a derangement of a specific function centered in the parietal lobe. Moreover, it is pointed out that topographic disorientation does not require the concomitant failure of oculomotor mechanisms for its production. The topography of the anatomical lesion is considered in relation to current concepts on brain damage after severe hypotension and cardiac arrest. It is concluded that this group of patients is most likely at risk of developing behavioural abnormalities akin to the ones here reported.