[External ventricular drainage--a new aspect in the operative treatment of head injury (author's transl)].

It is not only for CSF-removal in conservative treatment of oedema and control of the effectiveness of osmo-onco-therapy, contricosteroids, anticholinergics and aldosterone-antagonists, that external CSF drainage in severe cerebral trauma has proved of value. It has also made it possible to assess objectively the indications for bitemporal craniotomy in raised intracrainial pressure with an acute midbrain syndrome caused by tentorial herniation. Continuous monitoring of ICP permits an intervention at the right time and prevents one from operating too late, namely at a moment, when manifest neurological signs already indicate cerebral decompensaervative steps failing, a bitemporal craniectomy is indicated: in this way we lower intracranial pressure, liberate the rostral brain stem out of its strangulation and improve cerebral perfusion and metabolism.