Skull changes with intrasellar cisternal herniation (empty sella).

Forty-seven cases with intrasellar cisternal herniation (empty sella) examined by plain X-ray of the skull and pneumoencephalography have been reviewed. Although the diagnosis may frequently be anticipated from the plain X-ray findings, further studies are necessary to establish the diagnosis. Also the type of herniation, whether horizontal, anterior or complete, may be anticipated from the appearance of the sella. Signs attributable to increased intracranial pressure, mainly erosion of the dorsum sellae, were found in about half of the cases.

Pneumoencephalographic changes with intrasellar cisternal herniation (primary empty sella).

In a selected material of 47 cases of primary intrasellar cisternal herniation, analysis of pneumoencephalographic changes demonstrated the long axis of the anterior part of the third ventricle to point towards the center of the herniation. Transmitted CSF pulsations from the third ventricle probably determine the formation and location of intrasellar herniations. The distribution of air in the subarachnoid space indicated a disturbed CSF circulation in the majority of patients. Visual field defects were unrelated to the slight deformity of the optic nerves observed but rather to a high position of the third ventricle.

Diagnosis of intrasellar cisternal herniation (empty sella) by computer assisted tomography.

Twenty-six cases of empty sella were studied using computer assisted tomography (CAT). Emphasis was placed on the technical factors controlling the pictures. The diagnosis seems to be feasible in a large number of cases provided movement artifacts are reduced and the angulation, thickness, and level of the cut are carefully chosen.