A 18-year-old man crashed on a motorbike and suffered a severe traumatic deformity of the right half of the head with multiple splintered dislocated fractures of the cranial vault and base, massive contusion of the right cerebral hemisphere, diffuse cerebral oedema and marked compression of the left cerebral hemisphere. He died after 74 hours in hospital. Since the injury he was in deep coma with photoareactive pupils, GCS 3. During hospitalization he had for 72 hours arterial h ypertension within the range of 160–240/80–180 mm Hg, tachycardia 100–196/min. and hyperthermia 38.3–42.5 °C. With regard to the planned collection of the kidney, after 51 hours of hospitalization angiography of the aortic arch was performed which was repeated after 30 minutes. During both angiographies both aa. carotis comm. and aa. vertebrales were visualized up to the vertebra C6, the contrast material did not penetrate into the skull. Eight hours after the angiographies residual spontaneous respiratory activity developed and the oblongata reflexes could be produced – oculocardial, coughing, vomiting and gag reflex. The collection of kidneys was abolished. Survival of the medulla oblongata in arrest of the circulation in the carotid and vertebrobasilar area can be explained by the mechanism of spinal collateral circulation – retrograde blood stream to the level of the medulla oblongata in the a. spinalis ant. and in the aa. spinales post., supplied by radiculomedullary arterioles from the branches of the subclavian arteries – a. cervicalis asc., a. cervicalis prof. and a. intercostalis suprema. The arrest of the circulation in the area of the aa. carotis ext. can be explained by excessive local arterial spasms associated with the severe traumatic deformity of the head. Conventional angiographic evidence of arrest of the cerebral circulation is absolute evidence only during concurrent clinically proved afunction of the medulla oblongata which occurred only two hours before death as a result of collapse of the circulation.

        Key words: diagnosis of cerebral death, arrest of cerebral circulation, afunction of the medulla