ANATOMICAL CORRELATES OF VISUAL AND TACTILE EXTINCTION IN HUMANS - A CLINICAL CT SCAN STUDY

The anatomical correlates of tactile and visual extinction with double simultaneous stimulation were investigated in a series of 159 patient s with right brain damage caused by stroke. Forty six patients showed extinction (22 tactile, 14 visual, 10 tactile and visual). Over 50% of the patients with extinction had deep lesions, which were found in ab out 25% of the patients with visuospatial neglect not associated with extinction. In the patients with extinction and cortico-subcortical da mage the paraventricular occipital white matter and the dorsolateral f rontal cortex were most often involved. By contrast, when neglect was also present, the lesions clustered in the inferior parietal lobule. T hese data suggest, from an anatomical perspective, that partly differe nt neural mechanisms may under-lie neglect and extinction. The compara tively high frequency of subcortical lesions involving the ascending p athways may be a neural correlate of a sensory component of extinction .