Subcortical aphasia: two clinical-CT scan correlation studies.

Two clinical-CT scan studies were undertaken in order to investigate the frequency and the characteristics of aphasia following strictly subcortical left hemisphere lesions. In Study 1, all patients whose CT scan, carried out within a given period, showed subcortical lesions in both hemispheres, were evaluated for presence and type of aphasia; conversely, in Study 2 the records of all patients referred to our Aphasia Unit for language evaluation within a given period, were examined for presence of subcortical lesions on the CT scan. In Study 1 aphasia was found in two out of six patients. In Study 2 stabilized, strictly subcortical lesions of the left hemisphere were found in six out of 250 patients referred to the Aphasia Unit; 4 out of 6 were aphasics. Closer scrutiny of the type of language disorder in the aphasics from both studies (N = 6) suggests the possibility of differentiating two types of defect: an atypical non fluent aphasia, sometimes associated with anterior capsular-putaminal lesions, and a mild fluent aphasia, sometimes associated with posterior capsular-putaminal lesions.