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Flashcards in Raised intracranial pressure Deck (15)
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1
Q

Name five potential causes of raised ICP.

A
space occupying lesion
increased CSF volume
stroke
meningitis
head injury/trauma
2
Q

Why can’t the cranial cavity cope with increased pressure?

A

cavity is an enclosed space, not flexible or elastic.

3
Q

What is the Monroe-Kellie hypothesis?

A

the cranial cavity is incompressible- an increase in the volume of one of its constituents (i.e. brain tissue, blood, CSF) must be compensated for by a decrease in one of the others

4
Q

What visual symptoms may be seen in raised ICP?

A
blurred vision
double vision
loss of vision
papilloedema
pupillary changes
5
Q

What are the three layers of the meninges?

A
From exterior to interior:
dura mater
arachnoid mater
(subarachnoid space)
pia mater
6
Q

Where is CSF produced?

A

Choroid plexus of the ventricles

7
Q

Describe the ventricular system of the brain.

A

The right and left lateral ventricles within the right and left cerebral hemispheres; the 3rd ventricle in the midline within the diencephalon; the 4th ventricle between the cerebellum and pons

8
Q

What connects the 3rd and 4th ventricles?

A

the cerebral aqueduct

9
Q

Where is CSF reabsorbed?

A

Via arachnoid granulations protruding into the dural venous sinuses

10
Q

Why is raised ICP transmitted along the optic nerve sheath?

A

optic nerve is a CNS tract covered by meninges, and has a sub-arachnoid space, hence raised ICP is transmitted along the optic nerve sheath

11
Q

Which structures will be compressed within the optic nerve sheath in raised ICP?

A

the optic nerve, the central artery and vein of the retina

12
Q

What effect can raised ICP have on the optic disk?

A

bulging or swollen (papilloedema)

13
Q

What consequences can compression of the oculomotor nerve have?

A

paralysis of somatic muscle innervation- ptosis, eye turned inferolaterally

paralysis of parasympathetic innervation of the pupil- loss of pupillary light reflex, dilated pupil

14
Q

What consequence does compression of the oculomotor nerve have?

A

paralysis of superior oblique muscle- eye cannot move inferomedially

15
Q

What consequence does stretching of the abducent nerve have?

A

Paralysis of lateral rectus- medial deviation of the eye