neurologic disorders
Brain Herniation
Upward transtentorial herniation
Upward transtentorial herniation can occur when an infratentorial mass (eg, tumor in the posterior fossa, cerebellar hemorrhage) compresses the brain stem, kinking it and causing patchy brain stem ischemia. The posterior 3rd ventricle becomes compressed. Upward herniation also distorts the mesencephalon vasculature, compresses the veins of Galen and Rosenthal, and causes superior cerebellar infarction due to occlusion of the superior cerebellar arteries. 