2.6: Papilloedema

Question 1

Describe swollen discs?

Answer 1

This is swelling of the optic disc

ANY CAUSE

Question 2

Describe papilloedema?

Answer 2

This is swelling of the optic disc caused SPECIFICALLY by raised intracranial pressure

Question 3

What does ICP mean? What does IOP mean?

Answer 3

ICP = Intracranial pressure. The pressure within the skull , where the brain is
IOP = Intraocular pressure. The pressure within the eye

Question 4

All patients with bilateral disc swelling should be suspected of having what?

Answer 4

Raised intracranial pressure caused by a space occupying lesion
Raised ICP caused by a SOL

Question 5

Raised ICP is a medical emergency

True or False?

Answer 5

True

Raised intracranial pressure is a medical emergency

Question 6

69 Year old male presents with headaches and blurred vision
Visual Acuity: 6/6 On both left and right
Fundoscopy: Bilateral disc swelling

Diagnosis?
What is causing the disc swelling?

Answer 6

Diagnosis: Space Occupying Lesion (Brain Tumour)
Disc swelling is caused by raised ICP
This is a TRUE PAPILLOEDEMA

Question 7

Describe how raised ICP leads to a swollen disc?

Answer 7

The subarachnoid space surrounds the brain and is continuous with the subarachnoid space surrounding the optic nerve.
When intracranial pressure is raised, this pressure is transferred first to the subarachnoid space and then onto the optic nerve
Compression of the optic nerve leads to disruption of the ‘axoplasmic flow’ (nerve impulse conduction) and venous congestion
Results in disc swelling

1. Raised ICP
2. Transferred to subarachnoid space
3. Transferred to Optic Nerve
4. Disruption of axoplasmic flow (nerve conduction)
5. Disc Swelling

Question 8

Describe the components of intracranial pressure?

Answer 8

The sum of:
Blood
Brain
CSF

Question 9

Describe the Monro-Kelli hypothesis?

Answer 9

If one component is increased, the other components will decrease to maintain the intracranial pressure at a constant level

Question 10

Describe how the intracranial pressure is kept equal?

Answer 10

If one component is increased, the other components will decrease to maintain to in cranial pressure at a constant level and vice versa

Question 11

Describe the effect increasing intracranial mass has on intracranial pressure?

Answer 11

At first, compensatory mechanisms prevent the pressure from rising
However, these can only work for so long
After the compensatory mechanisms fail, a small change in intracranial mass causes a large change in intracranial pressure (exponential)

Question 12

Describe the link between the blood and the brain?

Answer 12

The brain requires a constant supply of blood
It is very intolerant to hypo/hyperperfusion
Blood undergoes auto-regulation to prevent this

Question 13

Describe malignant hypertension?

Relevance to ophthalamology?

Answer 13

High blood pressure that develops rapidly and causes some type of organ damage
180/120
Can cause bilateral disc swelling
This is a differential for bilateral disc swelling (Not all patients with raised ICP have an SOL)

Question 14

In patients with bilateral disc swelling and very high blood pressure:

• What are you less concerned about?
• What are you more concerned about?

Answer 14

Less likely to be a space occupying lesion and more likely to be malignant hypertension

More concerned about malignant hypertension as this can cause damage and is a serious problem

Question 15

What simple, easy, clinical test should always be done in bilateral disc swelling?
Hint: Learned this in 1st year
Done all the time

Answer 15

Blood Pressure

Question 16

What are the functions of the CSF?

Answer 16

Protection for the brain
Buoyancy
Nutrient supply
Removes waste products
Stable extracellular environment for the brain

Question 17

Where is CSF produced?

Answer 17

Produced in the choroid plexus of the lateral ventricles

Question 18

What is the choroid plexus?

Answer 18

Network of blood capillaries

These filter produce to produce CSF

Question 19

Briefly describe CSF circulation?

Answer 19

Lateral Ventricles
3rd Ventricle
4th Ventricles
Subarachnoid Space
Reabsorbed

Question 20

How can the CSF cause raised ICP?

Answer 20

CSF Obstruction
Lack of CSF Absorption
Excess CSF

Question 21

25 year old female
Presents with headaches
BMI of 40

Visual Acuity: 6/6 on both left and right
Fundoscopy: Bilateral Disc Swelling
MRI: Normal
Lumbar Puncture: Raised CSF opening pressure

Diagnosis?

Answer 21

Idiopathic Intracranial Hypertension

Question 22

Describe idiopathic intracranial hypertension briefly?

Answer 22

Not fully understood
Could be caused by obstructing CSF or impairing CSF absorption
Leads to swollen discs

Question 23

What would happen if disc swelling was left untreated?

Answer 23

Disc swelling would eventually subside
Discs become pale and atrophied
Loss of visual function and blindness may occur