Gas bubbles within acute intracranial epidural haematomas.

In order to assess the actual incidence of gas bubbles trapped within acute intracranial epidural haematomas, as revealed by computed tomography (CT) of the skull, a series of 204 patients with surgically verified epidural haematomas was retrospectively reviewed. Gas bubbles were observed on CT scan in 22.5% of the cases, with the incidence rising to 37% when CT scanners of the last generation were employed. The available data failed to demonstrate the actual source of intracranial gas. No correlation was found between the presence of gas bubbles and outcome. No patient in the whole series showed any sign of intracranial infection.