<unk>  are<unk>  secondary to raised intracranial pressure with formation of a transtentorial pressure cone involving the front part of the cerebral peduncles, the cerebral crura. Increased pressure above the tentorium may also involve other midbrain structures. Kernohan's notch is a groove in the cerebral peduncle which may be caused by this displacement of the brainstem against the tentorial incisure. The resulting ipsilateral hemiparesis is a false localising sign, known as the Kernohan-Woltman syndrome. This may succeed or accompany temporal lobe (uncal) herniation and subfalcian herniation secondary to a supratentorial mass. The pathophysiological mechanism is uncertain but is probably caused by the displacement of the brainstem stretching and tearing perforating branches of the basilar artery to the pons; venous infarction may play a role.
Duret haemorrhages
Splinter hemorrhage
Cavernous sinus thrombosis
Pseudoaneurysm
Cerebral venous sinus thrombosis
Pseudosubarachnoid hemorrhage
Vitreous hemorrhage
Cirsoid aneurysm