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.