tentorial herniation
Last reviewed 01/2018
The clinical features of tentorial herniation include:
- pupils dilated and unreactive to light:
- due to compression of the III nerve and oculomotor nucleus
- the palsy is unilateral at first - on the side of the lesion - but later becomes bilateral
- ptosis or impaired eye movements:
- may be difficult to discern if conscious level depressed
- upward gaze is usually lost first because of pressure on the pretectum and superior colliculi
- homonympus hemianopia - due to occlusion of posterior cerebral artery
- limb weakness on same side of lesion:
- a false localising sign - due to pressure from the edge of the tentorium on the opposite cerebral peduncle - Kernohan's notch
- diabetes insipidus - from downward action on pituitary stalk and hypothalamus
- may progress to tonsillar herniation