Supratentorial volumn and pressure increasing factors | 1) Swelling gyrus and basal ganglia caused by IAE 2) Intermittent chronic occlusion of the aqueduct resulting in gradual increase in ventricular pressure 3) Edema caused by vascular compression of the central herniation |
Infratentorial volumn and pressure decreasing factors | Decreased volumn of the posterior fossa cystic space of PCH created the space and negative pressure gradient |
Other | Idiopathic |