Raised ICP and Hydrocephalus

Question 1

What are the 3 components of the skull?

Answer 1

Brain
Blood
CSF

Question 2

Where is CSF produced?

Answer 2

Choroid plexus - found in the lateral ventricles.

Question 3

What does obstruction to the flow of CSF result in?

Answer 3

Raised ICP

Hydrocephalus

Question 4

What is autoregulation?

Answer 4

The action taken by the body to keep cerebral blood flow constant, despite fluctuating BP.

Question 5

What is an obstructive hydrocephalus?

Answer 5

Hydrocephalus resulting from a mass preventing the flow of CSF around the ventricles.

Question 6

What is a communicating hydrocephalus?

Answer 6

Hydrocephalus resulting when CSF cannot be absorbed into the arachnoid granulations. These are blocked - can be due to subarachnoid haemorrhage or meningitis.

Question 7

What are early symptoms of raised ICP?

Answer 7

Decreased LOC
Headache
Pupillary dysfunction and/or papilloedema 
Change in vision
Nausea and vomiting

Question 8

What are late symptoms of raised ICP?

Answer 8

Coma
Fixed, dilated pupils
Hemiplegia
Bradycardia
Hypotension
Hyperthermia
Increased urinary output

Question 9

Which medications can be used to treat raised ICP?

Answer 9

Diuretics (usually hypertonic saline)
Barbiturate coma
Antiepileptics (prophylactically)
Surgery (final stage - a VP shunt)

Question 10

What is the most common cause of obstructive hydrocephalus?

Answer 10

Aqueductal stenosis

Question 11

What appears enlarged in a communicating hydrocephalus?

Answer 11

Lateral ventricles
3rd ventricle
4th ventricle

Question 12

How is raised ICP treated?

Answer 12

Maintain head at midline at 30-45 degrees elevation
Loosen collars to encourage blood flow
Maintain fluids and treat hyperthermia
Manage normocarbia

Question 13

in which group of individuals will hydrocephalus develop in, at normal ICP levels?

Answer 13

Elderly

Question 14

What is hydrocephalus?

Answer 14

Accumulation of fluid due to excess in the ventricular system.

Question 15

What changes are seen on CT in those with normal pressure hydrocephalus?

Answer 15

The size of the ventricles will be disproportionate to the sylvanian fissures.

Question 16

How is normal pressure hydrocephalus treated?

Answer 16

VP shunt

Question 17

What is idiopathic intercranial hypertension?

Answer 17

Raised ICP of an unknown cause. There will be no ventricular dilatation.

Most common in young woman who are overweight.

Question 18

What is a complication of IIH?

Answer 18

Blindness

Question 19

How is IIH treated?

Answer 19

Rapid weight loss
Diuretics
Carbo-anhydrase inhibitors

Can also fit a VP shunt.

Question 20

Why does the head not enlarge in adults with hydrocephalus (but does in children)?

Answer 20

As the skull is rigid. In children the skull is more flexible and can therefore move to compensate for rises in ICP.

Question 21

What are the causes of raised ICP?

Answer 21

SOL
Diffuse oedema
Raised CSF
Increased venous volume
Physiological

Question 22

What is cerebral perfusion pressure dependent on?

Answer 22

Mean arterial pressure

Intracranial pressure

Question 23

What is hydrocephalus ex vacuo?

Answer 23

When the ventricular system dilates due to a loss of brain parenchyma.

Can be due to AD or an infarct.