Eye and ICP Flashcards
What can cause a raised intracranial pressure?
Head injury
Space occupying lesion, tumour, abscess or haemorrhage
Hydrocephalus - blockage of circulation of CSF
Meningitis
What are the 3 layers of the brain?
Dura mater
Arachnoid mater
Pia mater
What passes through the tentorial notch?
Brain stem, hypothalamus
Where will the CSF pass from the subarachnoid space to the superior sagittal sinus?
Arachnoid villi (granulations)
What visual problems can occur with a raised ICP?
Transient blurred vision Double vision Loss of vision Papilloedema (swelling of optic disc due to increased ICP) Pupillary changes
What covers the optic nerve?
Meninges (dura mater, arachnoid and pia mater)
What effect will a raised ICP have on the optic nerve?
Compress optic nerve along with the central artery and vein of the retina
Symptoms of papiloedema?
Transient visual obscurations Transient flickering Blurring Constriction of visual field Decreased colour perception
How can the oculomotor nerve be damaged?
Compression Tentorial herniation (raised ICP)
What will occur with injury to oculomotor nerve?
No/slow pupillary light reflex
Dilated pupil
Ptosis
Position of eye: looking down and out as there is no opposition to lateral rectus and superior oblique
How can the trochlear nerve be damaged?
Stretching
Compression
Very rare to have an isolated trochlear nerve injury
What will happen to the eye with an oculomotor injury?
Inferior oblique unopposed - eye cannot move inferomedially
Diplopia when looking down
What will occur with an injury to the abducens nerve?
Paralysis of lateral rectus and therefore medial deviation of eye
