Indications for brain CT scan in patients with minor head injury.

OBJECTIVES Minor head injury is the most common type of head injury. Despite of high incidence and numerous studies performed, there is much controversy about correct evaluation of these patients. The aim of this study was to find clinical signs and symptoms which help to predict the indications for brain CT scan following minor head injury. METHODS A series of 682 consecutive patients who had been attended at two university hospitals (Alzahra and Kashani) with minor head injury (GCS=15) were prospectively enrolled in this cohort study. In all cases clinical signs and symptoms were collected and a cranial computerized tomography (CT) scan was obtained. The relationship between the occurrence of clinical findings and appearance of intracranial posttraumatic lesions on cranial CT was analyzed by chi-square tests and statistic logistic regression methods, with 95% confidence intervals. RESULTS Of 682 patients, 46 (6.7%) presented brain injuries on CT scan. All patients with abnormal CT scans had at least one of the following factors (risk factors): posttraumatic amnesia, loss of consciousness, posttraumatic seizure, headache, vomiting, focal neurological deficit, skull fracture, coagulopathy or antecedent of treatment with anticoagulants and patient age older than 60 years. No abnormal CT scans were found among patients without any of those risk factors on admission. Vomiting, skull fracture and age greater than 60 years were risk factors significantly correlated to an abnormal cranial CT after head injury. The presence of several risk factors in a patient increased the probability of posttraumatic lesion on CT scan. CONCLUSION Some clinical risk factors can be used as a guide to predict the probability of abnormal CT following minor head injury.