[Computed tomography in crossed aphasia (author's transl)].

Crossed aphasia, first described by Bramwell, is aphasia due to the hemispheric damage on the side of handedness. Crossed aphasia in a dextral is rare, and in Japan, there have not been more than ten cases in which the lesion is localized clearly. The cases reported till now have been verified mainly by necropsy. However, the time lag between the appearance of aphasia and the necropsy may affect the conclusion subtly. We consider that computed tomography (CT) can obtain almost the same findings as that by necropsy. However, at present there have been few cases diagnosed by CT except two cases reported by April et al. and Wechsler. We have reported a 47-year-old man in a dextral, who shows left hemiparesis and Broca's aphasia. His lesion is diagnosed by cerebral angiography and CT as the right hemisphere infarction due to right middle cerebral artery occlusion. CT localizes the lesion on the right hemisphere mainly sited deep region and sited wedge shaped cortical area of the fronto-parietal region. On the other hand, it localizes no lesion on the left hemisphere. CT in aphasia has been already reported by Hayward et al. In their report they concluded that correlation of lesion located by CT with aphasia type supported Geschwind's concept of aphasia. In this report we have discussed CT in crossed aphasia analysing our case and the two cases by April et al. and Wechsler. Three cases including our case are all Broca's aphasia, and we compare the lesion location of these three cases with Hayward's lesion located on Broca's aphasia. As the result of this, we can draw the conclusion that the lesion location by CT of these three cases and that of Hayward's report are almost symmetric.