anaesthesia in brain tumour

patients with brain tumour may come to the surgical theatre with normal or raised intracranial tension, with or without alteration or the vital functions.the anaesthetist finds himself facing some problems of anaesthesia for these patients, these problems are regulation of brain volume and tension, control of haemorrhage during surgical manibulation, also protection of nervous tissue from ischaemia and surgical injury and some other problems as the position and its complications.