2.6: Papilloedema Flashcards Preview

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Flashcards in 2.6: Papilloedema Deck (23)
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1

Describe swollen discs?

This is swelling of the optic disc
ANY CAUSE

2

Describe papilloedema?

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

3

What does ICP mean? What does IOP mean?

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

4

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

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

5

Raised ICP is a medical emergency
True or False?

True
Raised intracranial pressure is a medical emergency

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?

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

7

Describe how raised ICP leads to a swollen disc?

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

8

Describe the components of intracranial pressure?

The sum of:
Blood
Brain
CSF

9

Describe the Monro-Kelli hypothesis?

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

10

Describe how the intracranial pressure is kept equal?

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

11

Describe the effect increasing intracranial mass has on intracranial pressure?

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)

12

Describe the link between the blood and the brain?

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

13

Describe malignant hypertension?
Relevance to ophthalamology?

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)

14

In patients with bilateral disc swelling and very high blood pressure:
- What are you less concerned about?
- What are you more concerned about?

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

15

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

Blood Pressure

16

What are the functions of the CSF?

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

17

Where is CSF produced?

Produced in the choroid plexus of the lateral ventricles

18

What is the choroid plexus?

Network of blood capillaries
These filter produce to produce CSF

19

Briefly describe CSF circulation?

Lateral Ventricles
3rd Ventricle
4th Ventricles
Subarachnoid Space
Reabsorbed

20

How can the CSF cause raised ICP?

CSF Obstruction
Lack of CSF Absorption
Excess CSF

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?

Idiopathic Intracranial Hypertension

22

Describe idiopathic intracranial hypertension briefly?

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

23

What would happen if disc swelling was left untreated?

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