Intracranial Pressure

Question 1

What causes raised ICP

Answer 1

increased pressure in the fluid surrounding the brain

increase in pressure in the brain itself

Question 2

Give some examples of pathologis which result in raised intracranial pressure

Answer 2

brain tumour
head injury
hydrocephalus 
meningitis
stroke

Question 3

how does the intracranial volume remain constatn

Answer 3

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

Question 4

What visual problems occur with raised intracranial pressure

Answer 4

transient blurred vision
double vision
loss of vision
papilloedmea
pupillary changes

Question 5

What is the outermost layer of the meniges

Answer 5

the dura mater

Question 6

what is the sensory nerve supply to the dura mater

Answer 6

CNV

Question 7

What is enclosed in the dural mater

Answer 7

dural venous sinuses

Question 8

What is the menige that adheres to the brain

Answer 8

pia

Question 9

Where is CSF and blood vessels contained

Answer 9

the subarachnoid space

Question 10

where is csf produced

Answer 10

the choroid plexus of the ventricles

Question 11

where is csf reabsorbed

Answer 11

the dural venous sinuses via the arachnoid granulations

Question 12

How can csf be accessed

Answer 12

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

Question 13

Where does the subarachnoid space end

Answer 13

inferiorly att the level of S2 of the sacrum

Question 14

where is the choroid plexus situites

Answer 14

the lateral and third ventricles

Question 15

Decribe the circulation of CSF

Answer 15

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

Question 16

What are the symptoms of papilloedema

Answer 16

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

Question 17

What will result if the oculomotor nerve is damaged

Answer 17

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

Question 18

What will result from damage to the trochlear nervw

Answer 18

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

Question 19

what will result for damage to abducent nerve

Answer 19

paralysis of lateral rectus

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

Question 20

What is papilloedema

Answer 20

swollen optic discs secondary to raised ICP

Question 21

what do all patients with a bilateral optic disc swelling have

Answer 21

raised ICP due to a space occupying lesion until proven otherwise

Question 22

what happens if disc swelling due to any cause becomes chronic

Answer 22

disc swelling subsides but discs become atrophic and pale

loss of vision and blindness may occur

Question 23

Name the parts of cranial nerve II examination

Answer 23

opthalmoscopy

visual acuity
pupil exam
visual field

Question 24

Why is it important to check blood pressure

Answer 24

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

Question 25

What usually causes a sixth nerve palsy

Answer 25

raised intracranial pressur

Question 26

What usually causes a fourth nerve palsy

Answer 26

trauma

or congenital

Question 27

What usually caused a third nerve palsy

Answer 27

aneurysm

MS also important

Question 28

What usually caused a third nerve palsy

Answer 28

aneurysm

MS also important

Question 29

What is the causes internuclear opthalmoplegia

Answer 29

MS

vascular