We present two patients who became unrousable within 48 h after genera
l anaesthesia for non-neurosurgical operations; both were found to hav
e frontal meningiomas. Analysis of these and previous reports suggest
that several anaesthetic and perioperative factors probably combine to
contribute to the accelerated presentation of these previously ''sile
nt'' tumours, and we recommend that dexamethasone should be administer
ed early in the course of unexplained neurological deterioration after
operation.