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Opthalmology > Intracranial Pressure > Flashcards

Flashcards in Intracranial Pressure Deck (29)
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1
Q

What causes raised ICP

A

increased pressure in the fluid surrounding the brain

increase in pressure in the brain itself

2
Q

Give some examples of pathologis which result in raised intracranial pressure

A
brain tumour
head injury
hydrocephalus 
meningitis
stroke
3
Q

how does the intracranial volume remain constatn

A

monro kellie hypothosis
ie and increase in one of the cranial cavity compontens (brain, blood and CSF) will result in a decrease in the other components to try and maintain a stable intracranial volume

4
Q

What visual problems occur with raised intracranial pressure

A
transient blurred vision
double vision
loss of vision
papilloedmea
pupillary changes
5
Q

What is the outermost layer of the meniges

A

the dura mater

6
Q

what is the sensory nerve supply to the dura mater

A

CNV

7
Q

What is enclosed in the dural mater

A

dural venous sinuses

8
Q

What is the menige that adheres to the brain

A

pia

9
Q

Where is CSF and blood vessels contained

A

the subarachnoid space

10
Q

where is csf produced

A

the choroid plexus of the ventricles

11
Q

where is csf reabsorbed

A

the dural venous sinuses via the arachnoid granulations

12
Q

How can csf be accessed

A

lumbar puncture at L3/4 or L4/5 IV discs

13
Q

Where does the subarachnoid space end

A

inferiorly att the level of S2 of the sacrum

14
Q

where is the choroid plexus situites

A

the lateral and third ventricles

15
Q

Decribe the circulation of CSF

A

Choroid plexus - lateral venticles- third ventricle- via the cerebral aqueduct to 4th ventricle- subarachnoid space- reabsorbed into the dural venous sinus

16
Q

What are the symptoms of papilloedema

A
transient visual obscurations
transietn flickering
blurring vision
constriction of the visual fiels
decreased colour perception
17
Q

What will result if the oculomotor nerve is damaged

A

loss of pupillary light reflex (due to loss of parasympathetic innervation to the eye)
dilated pupil
ptosis
eye will turn inferiolaterally

18
Q

What will result from damage to the trochlear nervw

A

superior oblique paralysis
eye will move inferomedially due to inferior oblique being unopposed
diplopia when looking down

19
Q

what will result for damage to abducent nerve

A

paralysis of lateral rectus

eye cannot move laterall in horizontal plane – results in medial deviation of the eye

20
Q

What is papilloedema

A

swollen optic discs secondary to raised ICP

21
Q

what do all patients with a bilateral optic disc swelling have

A

raised ICP due to a space occupying lesion until proven otherwise

22
Q

what happens if disc swelling due to any cause becomes chronic

A

disc swelling subsides but discs become atrophic and pale

loss of vision and blindness may occur

23
Q

Name the parts of cranial nerve II examination

A

opthalmoscopy

visual acuity
pupil exam
visual field

24
Q

Why is it important to check blood pressure

A

malignant hypertension or idiopathic intracranial hypertension are both causes of raised ICP and thus papilloedema

25
Q

What usually causes a sixth nerve palsy

A

raised intracranial pressur

26
Q

What usually causes a fourth nerve palsy

A

trauma

or congenital

27
Q

What usually caused a third nerve palsy

A

aneurysm

MS also important

28
Q

What usually caused a third nerve palsy

A

aneurysm

MS also important

29
Q

What is the causes internuclear opthalmoplegia

A

MS

vascular