This night a 23 y.o. man arrived in the emergency room for brain and some minor abdominal trauma, having not a regular respiration he get intubation on the street. A CT scan disclose a 5 cm. hematoma on the left frontal lobe and air in the brain arteries from both carotid to the smallest on the cortex, and no fractures at all. Now the patient is gong in the OR for drainage of the hematoma. Has anyone idea where the air may come from?