Abstract
The CT and MRI findings of the patients with frontal lobe infarction were discussed. In this paper, aphasia was chosen as the left frontal lobe sign. The patient with motor aphasia showed the infarction of the lesion including both the Broca's area and the precentral gyrus. Pure word dumbness occurred in the infarction of the precentral gyrus. The patients who have a lesion of the Broca's area presented transcortical sensory aphasia. Transcortical motor aphasia was observed next to the lesions surrounding Broca's area which was produced by the borderzone infarction, or medial portion of the frontal lobe which was perfused by the anterior cerebral artery. Superficial borderzone infarctions may cause transcortical aphasia. Anterior type borderzone infarct will produce transcortical motor aphasia. Deep borderzone infarct due to carotid or middle cerebral occlusion of its main trunk may also produce transcortical motor aphasia. The marked reduction of cerebral blood flow in the frontal lobe including the Broca's area and the precentral gyrus will be observed in these cases with borderzone infarctions when measuring the cerebral blood flow using SPECT or PET.
