The value of computerized tomography in the management of 1000 consecutive head injuries.

One thousand consecutive head injuries were evaluated in a 14-month period. Computerized tomography (CT) was performed in 316 patients and 200 (63%) were scanned within 72 hours of injury. Fifty-one percent of patients had abnormal scans. The yield of abnormal scans varied with the neurological state at the time of the scan: alert and normal neurologically, 13%; alert and focal deficit, 50%; impaired consciousness and no lateralizing findings, 35%; impaired consciousness and lateralizing findings, 85%; deep coma or posturing, 56%. Thirty-eight percent of patients had multiple lesions. Repeat scans were done in 103 patients, 52% developed new lesions or deterioration in known lesions, and 31% required subsequent surgery. Ten patients developed delayed onset subdural hygromas noted six to 46 days after injury. Two of eight operated patients improved markedly. The CT scan appearance of subdural lesions may be independent of the time from injury depending upon initial composition and rebleeding episodes. Thus, subdural lesions should not be labeled "acute," "subacute," or "chronic" on the basis of CT morphology alone. Seven patients had subdural lesions with the same density as brain (isodense). Arteriography aided diagnosis in six patients. The CT scan readily shows what proportion of a parenchymal lesion is intracerebral hematoma, contusion, or edema, rather than nonspecific arteriographic mass effect, and allows precise surgical decisions. Eighteen of 40 patients (45%) with "brain stem contusion" harbored surgical lesions, including five cases of delayed subdural hygroma.