A comparison of the localization of higher cortical functions in crossed dextral aphasia and sinistral aphasia

We have compared the aphasia, apraxia, and agnosia in nine cases of crossed dextral aphasia ( CDA) and six cases of sinistral aphasia(SA). The control group was twenty-two cases of dextral aphasia with mirror image lesion (CT scan) of respective CDA. The common prominent aphasic syndromes in CDA and SA were agrammatism and good naming ability. According to Hécaen and Brown(1976), CDA differs from SA in the frequency of agrammatism, anomia, and phonemic paraphasia. However, with regard to these syndromes, Our cases did not exhibit such a difference. For three cases of CA, the relation between the caudality of lesional localization (CT scan) and the types of aphasia diverged from that of DA, i. e., they displayed Wernicke's aphasia by anterior lesion or Broca's aphasia by posterior lesion. Therefore, localization of language function in CDA did not seemed to be the mirror image of DA. As to apraxia and agnosia, both dominant and non-dominant hemisphere syndromes were seen in aphasics of right hemisphere lesion. This could be interpreted that in these patints., functions of the left hemisphere overlapped, never reversed, with those of the right hemisphere.