Two types of delayed post-traumatic intracerebral hematoma.

Abstract

The findings of repeated CT scans, clinical courses and pathological studies in 28 cases of delayed post-traumatic intracerebral hematoma were studied retrospectively to elucidate the mechanism of bleeding and to establish adequate treatment. Based on the results obtained, it became clear that there are two types of delayed hematoma. In 10 of the 28 cases, initial CT findings within 6 hours after head injury revealed cerebral contusion or hemorrhagic contusion, and spots of high density scattered in the low density zone gradually became confluent to form an irregularly shaped hematoma according to follow-up CT findings. This was termed “hematoma within a contusional area.” In 15 of the 28 cases, initial CT findings within 6 hours after head injury revealed no abnormal density within the brain and the hematoma appeared suddenly 3 ?? 6 days after the injury. In eight of the 15 cases, emergency surgery was performed for the removal of epidural or subdural hematoma. This type of hematoma is termed “contusional hematoma” and constitutes the second group. In three of the 28 cases, both types of hematoma were observed. Based on histological findings for the two types of delayed hematoma. The first group may be induced by an anoxic vasodilation mechanism (Evans et al.9)), while the second group may be derived from a different mechanism related to ishemic changes and the free radical reaction caused by the reflow phenomenon (Tsubokawa et al.14-16)) It is important to establish correct diagnoses 1 for delayed hematomas based on differences between follow-up findings of repeated CT and an initial CT performed within 6 hours after head injury since the operative indications and operative results for the two groups are different as indicated by our 28 cases.