Chronic Stage Language Deficits following Dominant Hemisphere Lesions Centered on the Basal Ganglia, Internal Capsule and Thalamus

Abstract

The language abilities of a group of 14 subjects with acute stage computed tomography (CT) scan documented lesions in the region of the thalamus, internal capsule and basal ganglia of the dominant hemisphere were assessed at least six months post-onset of their cerebrovascular accident using the Western Aphasia Battery (WAB). The pattern of scores achieved on the WAB by the 14 subjects indicated the presence of two patient sub-groups. One sub-group consisted of seven subjects who performed at a level above the aphasic-non-aphasic cut-off. A second sub-group consisting of seven cases labelled as anomic aphasics by the classificatory criteria of the WAB was also indicated. Additional description of the language characteristics of the anomic subgroup suggested that the classification of anomic aphasia was inappropriate in five of the seven cases. Four of these five cases were clinically diagnosed as presenting with Broca's-type aphasia whereas one case presented with a mild transcortical motor-type aphasia clinically. The results of the current study support the suggestion that subcortical lesions (as documented by an acute stage CT scan) that result in acute aphasia may also result in long-lasting language impairments in some cases. Clinico-anatomical correlations were discussed.