“…20,22 Pathophysiological Theories Before the identification of the anatomical structure responsible for vertical gaze, 7,48 some authors proposed that cystic dilation of the suprapineal recess with herniation in the quadrigeminal cistern, frequently observed in obstructive hydrocephalus 32,37,43 and dilation of the upper portion of the aqueduct rostral to the obstruction, 29 could distort and compress the tectal plate where the center for vertical gaze was thought to be located. 9,18,38,39,49,54,61 Other theories included axial enlargement of the third ventricle leading to stretching of the posterior commissure, 12 axial enlargement of the third ventricle associated with distortion and caudal displacement of the mesencephalon, 3 dilation of the rostral portion of the aqueduct with distortion and stretching of the periaqueductal gray matter, 37 and gliosis of the periaqueductal gray matter. 37 Upward gaze palsy can also be observed in cases in which supratentorial space-occupying lesions induce posterior herniation of the temporooccipital lobes.…”