The Eye and Raised ICP Flashcards
What is the Monro-Kellie hypothesis?
That ICP cannot be changed without changing the brain, blood or CSF
Give some ophthalmic pathologies due to raised ICP
Blurred vision Double vision Loss of vision Papilloedema Pupillary changes
What is papilloedema?
Swelling of the optic disc due to increased ICP
What are the three components of the meninges?
Dura mater
Arachnoid mater
Pia mater
Which space filled with CSF does the optic nerve pass through?
Sub-arachnoid space
What can happen if there is an increase in CSF volume?
Optic nerve compression and injury
Where is the subarachnoid space?
Between arachnoid mater and pia mater
Where can the subarachnoid space be accessed?
L3-5 via lumbar puncture
Where is CSF produced?
Choroid plexus of ventricles
Where is CSF reabsorbed?
Dural venous sinuses via arachnoid granulations
What are some visual symptoms of optic nerve compression?
Transient visual obscurations Transient flickering Blurring Visual field constriction Decreased colour perception
If there is oculomotor nerve injury, what direction does the eye look?
‘Down and out’
Infero-temporally
When does an increase in ICP affect CN III?
If the medial temporal lobe herniates through tentorial notch
CN IV comes off the front/back of the brainstem?
Back
A trochlear nerve palsy causes the eyes to gaze right/left?
Right
