Positive predictive values of selected clinical signs associated with skull base fractures

The goal of this study was to determinate the positive predictive values of selected clinical signs for skull base fractures and associated intracranial lesions.

Clinical and radiological data were collected prospectively for all patients with selected clinical signs of skull base fractures, and their admission criteria were: 1) recent head injury story; 2) presence of one or more of following clinical signs: unilateral or bilateral blepharohaematoma, bloody otorrhea, and Battle's sign.

Emergency service of a institutional hospital.

One hundred forty two patients with the selected clinical signs for skull base fracture.

Frontal bone fractures were the most frequent in patients with selected clinical signs. Battle's sign (100%) and unilateral blepharohaematoma (90%) were the signs with higher positive predictive values for skull base fractures; bilateral blepharohaematoma (70%) and bloody otorrhea (70%) were those with less values. The positive predictive values of the selected signs for intracranial lesions (acute extradural haematoma, pneumocephalus, brain contusion, brain sweLling, and acute subdural haematoma) were: unilateral and bilateral blepharohaematoma with positive predictive values of 85% and 68%, respectively; Battle's sign was 66%; and bloody otorrhea was 46%. For patients at admission on the 13-15 Glasgow Coma Scale only, the positive predictive values for that intracranial lesions were: blepharohaematoma=78%; Battle's sign=66%; and bloody otorrhea=41%.

Our data demonstrated that the selected signs of skull base fractures have high positive predictive values for the presence of skull fracture and intracranial lesions, even in those patients classified in the Glasgow Coma Scale between 13 and 15. This indicates that all patients with the selected clinical signs should be submitted to computerized tomography of skull and with bone window, with the aim to detect associated lesions.