The empty sella syndrome-intrasellar cisternal herniation-in 'normal' patients and in patients with communicating hydrocephalus and intracranial tumors.

The occurrence of empty sella was studied on 450 pneumoencephalograms. It was not sex dependent, and seemed to be an acquired condition increasing in frequency with age. Empty sella was found in 10% of subjects with otherwise normal encephalograms. The frequency was higher in persons with communicating hydrocephalus (32%), hormoneproducing pituitary tumors (33%) and increased intracranial pressure due to cerebral tumors (18%). In all these subjects empty sella was often accompanied by demineralization and erosion of the sella turcica. Independent of the lumbar pressure, empty sella was most often found in patients with communicating hydrocephalus with only moderately high ventricle index and comparatively increased volume of the third ventricle. Empty sella was also frequent among patients with temporal tumors (32%) causing deformation and displacement of the third ventricle but in whom signs of increased intracranial pressure were lacking. The disturbed anatomy of the third ventricle possibly explains the higher frequency of empty sella in association with these tumors compared to other supratentorial tumors. altogether, these findings indicate that disturbance of the cerebrospinal fluid (CSF) circulation, especially in the third ventricle, with or without established increase of the intracranial pressure, plays an important role in the etiology of empty sella. This is further substantiated by the demonstration that the type of intrasellar herniation could be related to the position of the third ventricle. Neither the type of herniation nor the form of the sella could be related to the presence or absence of a co-existing intracranial tumor or to the location of the tumor. [ABSTRACT FROM AUTHOR]