Clinical features of cerebral embolism

Analysis of 48 cases in the acute stage

Abstract

In order to reestablish the precise clinical image of cerebral embolism by comparing with those of nonembolic cerebral infarction, 48 cases of cerebral embolism were selected from 274 consecutive cases of cerebral infarction who were admitted within one week after the onset. The diagnosis of cerebral embolism was made by the following criteria; 1) abrupt onset and completion of focal cerebral symptoms and signs, 2) presence of embolic sources, and 3) evidence of systemic embolism.
Patients with cerebral embolism showed more severe symptoms than those of nonembolic cerebral infarction. Disturbances of consciousness of various degrees were seen in more than one half of the cases with cerebral embolism. Eleven patients died during admission, and 15 were disabled at the time of discharge.
Forty-six cases had cerebral lesions in the territory of the internal carotid artery, while only one case in regions supplied by the vertebro-basilar artery system and one in both systems. There was no difference in the incidence of involved sides.
Among 42 patients in whom cerebral angiography was performed, 38 cases had arterial occlusions, and four cases showed normal angiograms. Eleven lesions were found in the internal carotid artery (ICA), eight in the stem of the middle cerebral artery (MCA), 18 in the branches of MCA, four in the anterior cerebral and one in the vertebral artery (VA). Radiolucent shadows which were thought to be emboli were frequently seen in large cerebral arteries, in eight of 11 cases with ICA occlusion, in four of eight MCA stem occlusion and in one VA occlusion. Only four out of 18 MCA branch occlusion showed emboli on cerebral angiogram.
Follow-up angiography was performed in 21 cases, and 18 of them showed the reopening of previously occluded arteries.
Hemorrhagic infarction occured in 12 of 36 cases in which CT and/or cerebrospinal fluid examination were done at the appropriate time. Deterioration of consciousness was observed in only four cases of 12 hemorrhagic infarction. It seems that hemorrhagic infarction does not necessarily worsen the symptoms in the majority of cases.
Twenty-one recurrent embolic events occurred in 16 cases during admission not only in the brain but in various parts of the body. They tended to occur frequently within two weeks after the onset of cerebral embolism. When embolic episodes which occured before the admission were included, 88 events occured in 48 patients in total; 66 events occured in the brain, nine in the extremities, seven in the abdominal organs and one in the ophthalmic artery.
In summary, clinical manifestation of cerebral embolism were variable and much more severe than those of cerebral thrombosis. The incidence of reopening of the occluded arteries was extremely high as it is mentioned in the literatures, although that of hemorrhagic infarction was somewhat lower than that reported in the pathological studies. It seems necessary to differentiate the cases of cerebral embolism from those of nonembolic infarction and to treat them differently, since cerebral embolism has such specific features in its clinical manifestation.