[Delayed onset of postoperative deterioration in clivus chordoma and clivus meningioma].

The starting-point of the presented retrospective, clinical study is the observation, that in some cases a delayed postoperative neurological deterioration develops after removal of great, extraparenchymal, infratentorial brain tumors. Therefore, we evaluated the postoperative clinical course of 50 clivuschordomas and clivusmeningiomas of the Neurosurgical University Clinic in Mainz (Germany). The results obtained show, that 1 of 3 patients develops a delayed, postoperative deterioration. Important factors, which cause that deterioration, are the age of patients and the size of tumors. Mostly, we found a perifocal edema concomitant to the delayed deterioration within the decompressed brain tissue. We call that phenomenon "decompression edema" as a "hypothesis a posteriori", which has to be proven experimentally.