Subacute and chronic extradural hematomas: a study of 30 cases.

The authors report 30 cases of extradural hematomas with prolonged course: the interval between injury and development of clinical signs was more than 48 hours. Twenty-nine were operated upon. These delayed cases have a mild clinical course and a better prognosis than the acute. Contrary to the reports that many subacute and chronic epidural hematomas are located other than temporally, the present series shows the high incidence (83%) of temporal lesions. Of the patients 74% recovered and returned to their previous occupations: the two deaths were from causes not directly related to the injury and hematoma. We conclude that most subacute hematomas arise from various, often combined, low-tension sources of bleeding. The importance of recognizing gradual neurologic deterioration and performing craniotomy in these patients is emphasized.