INFLUENCE OF SIZE AND SITE OF CEREBRAL-LESIONS ON SPONTANEOUS-RECOVERY OF APHASIA AND ON SUCCESS OF LANGUAGE THERAPY

Changes in linguistic competence were assessed with the Aachen Aphasia Test in 18 aphasic patients across 8 weeks of spontaneous recovery, 8 weeks of intensive language therapy, and after a follow-up period of 8 weeks without therapy. CT scans were obtained from all patients and were evaluated for size of lesion and for affection of Wernicke's area , adjacent regions of superior and middle temporal gyrus, inferior par ietal lesions, and temporobasal lesions. Size of lesion had a negative influence on recovery in all phases. Patients with lesions to temporo basal regions showed less improvement during therapy and less total re covery, but a similar amount of spontaneous recovery than patients wit hout such lesions. Lesions that affected the temporobasal regions were on average larger than those which spared them, but the dissociation between reduced therapy success and unaffected spontaneous recovery be came even more conspicuous when the concurrent effect of lesion size w as minimized by appropriate selection of patients. Possibly, temporoba sal lesions cause a disconnection between the hippocampal formation an d perisylvian language areas and hinder explicit learning of linguisti c knowledge and compensatory strategies. (C) 1994 Academic Press, Inc.