Delayed epidural hematoma. A review.

Since the CT has become the main diagnostic tool in head trauma, more cases of DEDH have become confirmed and published although some have been classified among other entities and under different criteria. This review tries to describe the characteristics of DEDH based on the cases previously published, as well as on three of our own cases. The entity is mainly radiological i.e. appearance of an epidural hematoma in a CT scan following up a previous one which has not shown this pathology. Although not specific, we have found some common features among the cases published. The patients are usually young people. The cause of many injuries is either a fall injury or involvement of a pedestrian in a road accident. Skull fracture under which the DEDH develops is the rule. DEDH is not found in the usual location of the classic epidural hematoma (the temporal fossa). Some of the patients developed DEDH after an earlier neurosurgical operation for evacuation of another traumatic mass lesion for urgent decompression. Others developed DEDH after medical treatment aimed at restoring normal blood pressure or reducing increased ICP. This main group of patients had other associated lesions, mainly intracranial. The others (including our case no. 1) were considered to have a skull fracture associated only with concussion of the brain, as the clinical picture changed or persistent headache developed, another CT scan was indicated and DEDH was then found. This group constitutes those patients in whom the prognosis is expected to be good or excellent. Keeping in mind the necessity for repeated CT scans in this group (we think the number will increase in the future), other patients will benefit from the awareness of the clinician of the importance of this diagnostic tool. CT scan is efficient, accurate and can be repeated at short intervals. It enables a correct diagnosis to be made in nearly 100% of cases of head trauma. Although this liberal use of CT may increase the number of negative scans, it will also increase the number of DEDH's diagnosable at an earlier stage.