Papilloedema Flashcards
Define papilloedema
What are the clinical features?
Swollen optic disc secondary to raised intracranial pressure
What are the clinical features of papilloedema?
Enlarged blind spot Blurring of vision Visual obscurations Visual loss Blindness
What must be ruled out in patients with bilateral swollen optic discs?
Raised intracranial pressure due to space-occupying lesion
What does an examination of cranial nerve II comprise of?
Ophthalmoscopy Visual acuity Visual field assessment Pupillary response Colour vision
What is the pathophysiology behind true papilloedema?
Subarachnoid space surrounding brain is continuous with subarachnoid space surrounding optic nerve
When ICP increases, this is transmitted to the nerve, causing swollen discs
What 3 components contribute to intracranial pressure?
Brain
CSF
Blood
How does a patient die from raised ICP as a result of increased brain size?
Brain squeezes through foramen magnum and compresses brainstem, inhibiting respiratory centre - patient can’t breathe and dies
The brain is very tolerant of hypo/hyper -perfusion. True/False?
False
Needs constant blood supply over range of pressures
What factors relating to CSF contribute to raised ICP?
Obstruction to CSF circulation
Overproduction of CSF
Inadequate absorption of CSF
If a CT is normal following suspected raised ICP, what is done?
Lumbar puncture to assess CSF
What is the term used to describe increased CSF in the ventricular system?
Hydrocephalus
What are the features of idiopathic intracranial hypertension?
Hypertension
Headaches
Visual disturbances
Typically, obesity
How is idiopathic intracranial hypertension managed?
Weight loss
Acetazolamide
Lumbar puncture
What is glaucoma? How is it treated?
Increased introcular pressure due to imbalance between secretion and removal of aqueous humour
Carbonic anhydrase inhibitors e.g. dorzolamide, acetazolamide.
List the meninges in order from the immediate covering of the optic nerve
- Pia
(Subarachnoid space) - Arachnoid matter
- Dura
What is papilloedema commonly mistaken for?
Cupping - progressive thinning of the neuroretinal rim causing an increase in cup size
What clinical features would you expect from paralysis of the oculomotor nerve?
Slowing of pupillary light reflex
DIlated pupil
Ptosis
‘Down and out’ pupil
What clinical features would you expect from paralysis of the trochlear nerve?
Diplopia when looking down
Can’t intort causing inopposed extorsion and head tilt to affected side
What clinical features would you expect from paralysis of the abducent nerve?
Medial deviation of the eye (eye cant ABD)
Describe the tentorial herniation causing compression of CNIII
Medial temporal lobe herniates through tentorial notch
