Authors:

Mummery, C.J., PATTERSON, K., Price, C.J., Ashburner, J., Frackowiak, R.S.J. & HODGES, J.R.

Reference:

Year of publication:

2000

CBU number:

3913

Abstract:

The cortical anatomy of six patients with semantic dementia (the temporal lobe variant of fronto-temporal dementia) was contrasted with that of a group of age-matched normals using voxel-based morphometry, a technique that identifies changes in grey matter volume on a voxel-by-voxel basis. Among the circumscribed regions of neuronal loss, the left temporal pole (BA 38) was the most significantly and consistently affected region. Cortical atrophy in the left hemisphere also involved the infero-lateral temporal lobe (BA 20/21) and fusiform gyrus. In addition, the right temporal pole (BA 38), the ventromedial frontal cortex (BA 11/32) bilaterally and the amygdaloid complex were affected, but no significant atrophy was measured in the hippocampus, entorhinal or caudal perirhinal cortex. The degree of semantic memory impairment across the six cases correlated significantly with the extent of atrophy of the left anterior temporal lobe but not with atrophy in the adjacent ventromedial frontal cortex. These results confirm the view that the anterior temporal lobe is critically involved in semantic processing, and dissociate its function from that of the adjacent frontal region.