Raised Intracranial Pressure Flashcards

1
Q

What are the causes of raised intracranial pressure?

A

Head injury

Space occupying lesion, abscess or haemorrhage

Hydrocephalus

Meningitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the sunset sign

A

Whites of eyes showing above iris- pressure on nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the three layers surrounding the brain?

A

Dura Mater
Arachnoid mater
Pia Mater

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the layers of dura mater?

A

1) endosteal

2) meningeal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is found in between the layers of dura mater?

A

Venous blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where do the two layers of dura mater separate?

A

1) longitudinal fissure between the two hemispheres

2) tentorial notch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the tentorial notch?

A

Brainstem passes through it, any raised ICP pushes the brainstem through it and raises the chances of hypothalamus compromised

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What runs along the tentorial notch?

A

Cranial nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe arachnoid mater?

A

Spidery thin layer with CSF deep to it

Pool of CSF can be larger areas or smaller areas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe pia mater

A

Soft mother

Single layer that surrounds the brain tissue; not visible to naked eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the ‘veins’ of the dura?

A

Sinuses; have no walls but are surrounded by two layers of dura

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What carries CSF from arachnoid to dural venous sinuses?

A

Arachnoid Villi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does CSF pass though the ventricular system?

A

Passes through channels from lateral to third then fourth ventricles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What surrounds the brain and spinal cord?

A

Subarachnoid space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where do veins of the brain pass into?

A

Dural venous sinuses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What visual problems are reported as a result of raised ICP

A

Transient blurred vision
Double vision
Loss of vision
Papilloedema

17
Q

Describe the monro-kellie hypothesis

A

Cranium is an incompressible space, any increase in one component (CSF, brain, blood) must be compensated by a change in another

18
Q

Why is the optic nerve considered an extension of the brain?

A

CNS tract covered by meninges

19
Q

What is the subarachnoid space?

A

Space between pia and arachnoid

20
Q

Why does raised ICP cause direct globe manifestations?

A

The subaracnoid space extends to the back of the globe

21
Q

What leads to bulging/swollen optic discs?

A

raised ICP will compress the central artery and vein of the retina as well as the optic nerve

22
Q

What are the visual symptoms of papilloedema?

A
Transient visual obscurations (grading out of vision)
Transient flickering 
Blurring of vision 
Constriction of the visual field 
Decreased colour perception
23
Q

Describe the grading of papilloedema

A

Grade 1: blurry C shaped halo

Grade 2: halo becomes circular, more blurry, larger

Grade 3: you cant see some of the surrounding vessels

Grade 4: central vessels start to disappear

Grade 5: vessels disappear completely

24
Q

Why is the oculomotor nerve susceptible to damage?

A

Compression

Tentorial herniation (ICP)

25
What does the oculomotor nerve contain?
Motor nerve that contains parasympathetics
26
Which cranial nerves contain parasympathetics?
CN 3, 7, 8, 10
27
What is the first thing to be damaged in a nerve due to Raised ICP?
Parasympathetics (outside of nerve)
28
What happens if the oculomotor nerve is damaged?
-paralysis of somatic motor innervation (extra ocular eye muscles) -paralysis of parasympathetic innervation (constrictor pupillae)
29
What may someone with raised ice SHOW?
NO/slow pupillary light reflex Dilated pupil Ptosis Position of eye; down and out
30
Why is the trochlear nerve susceptible to damage?
Long intracranial course - stretching - compression - only nerve that comes from posterior brainstem
31
Describe the function of the eye when the trochlear nerve has been damaged?
Inferior oblique is unopposed Eye cannot move inferomedially Diplopla
32
How is the abducens nerve susceptible to damage?
By stretch
33
What happens to the function of the eye when the abducens nerve is damaged?
Paralysis of lateral rectus Medial deviation of the eye