[Contribution of the right hemisphere to language in aphasic patients. Disappearance of this language after a right-sided lesion].

Assessments vary as to the contribution of the right hemisphere to language in aphasic patients. Results of a clinicopathologic study in two right-handed subjects with aphasia are reported. The lesions involved the territories of the left middle and anterior cerebral arteries. Oral productions in one case, studied during the three weeks of survival, were limited to automatic series, recitation of a fable, and completion of sentences. Follow-up in the other case was possible during 2 years of language rehabilitation. At the end of this period, repetition of an echolalic type was possible; a propositional expression had appeared, reduced to substantives and verb infinitives; denomination was possible but rich in semantic paraphasias. A second infarction in the right sylvian region caused the recovered language to disappear and to be replaced by an abolition of all communication. Proof was thus obtained that the progress accomplished was dependent on the right hemisphere. These findings are discussed in the light of observations of patients following left hemispherectomy and of the capacity of the right hemisphere to generate language as demonstrated in patients after commissurotomy. A dynamic interpretation of the taking over of expression by the right hemisphere during some aphasias is proposed.