Raised Intracranial Pressure

Question 1

What is meningitis?

Answer 1

Inflammation of the meninges, most commonly viral

Question 2

What are the clinical features of meningitis?

Answer 2

Photophobia
Nuchal rigidity
Brudzinski’s sign (bending head forward causes hip flexion)
Kernig’s sign (pain on extending knee during hip flexion)

Question 3

What investigations can be done in suspected meningitis?

Answer 3

CT
Lumbar puncture
FBC, CRP, PGLU, COAG, EUC, Blood culture
Chest x-ray to rule out pneumonia
STIX to rule out UTI

Question 4

How is meningitis managed?

Answer 4

In suspected meningitis give benzylpenicillin 1.2mg IM/IV immediately
ABC, protect airway, high flow O2, fluids
Antibiotics: cefotaxime (+ampicillin in over 55s)
Aciclovir if viral encephalitis is suspected

Question 5

How would normal pressure hydrocephalus present?

Answer 5

Wet
Wobbly
Wacky

Question 6

What would be found on CT/MRI in a patient with normal pressure hydrocephalus?

Answer 6

Communicating hydrocephalus

Question 7

How are symptoms relieved in normal pressure hydrocephalus?

Answer 7

Symptoms improve with removal of CSF, gait first then incontinence and finally memory improvements

Question 8

Describe the production, flow and reabsorption of CSF

Answer 8

Choroid plexus in the lateral ventricles, through foramen of Monro into 3rd ventricle, through aqueduct into 4th, out through Luschka and Magendie, around brain and spinal cord, reabsorbed by arachnoid villi in venous sinuses by pressure gradient

Question 9

What usually results in communicating hydrocephalus (CoH)?

Answer 9

A problem with CSF resorption. Production>resorption

Question 10

How does CoH usually present in young children?

Answer 10

Before sutures fuse, presents with disproportional increase in head circumference

Question 11

How does CoH usually present in adults?

Answer 11

With symptoms of raised intracranial pressure

Question 12

What are common symptoms of raised intracranial pressure?

Answer 12

Headache
Nausea/vomiting
Papilledema
Gait disturbance
6th cranial nerve palsy
Up gaze difficulty

Question 13

What are possible causes of CoH?

Answer 13

Infection
Subarachnoid haemorrhage
Postoperative
Head trauma

Question 14

What causes a non-communicating hydrocephalus (NCH)?

Answer 14

Any physical obstruction to normal flow of CSF

Question 15

Give some example causes of a non communicating hydrocephalus ?

Answer 15

Aqueductal stenosis
Tumour, masses, cancers
Cysts
Infection
Haemorrhage
Congenital

Question 16

What is the earliest finding in hydrocephalus on a radiological scan?

Answer 16

Dilation of the temporal horns of the lateral ventricles. (They should be almost invisible in a normal brain scan)

Question 17

What is the Evans ratio?

Answer 17

The ratio between the anterior horn width vs the width of the calvarium at the level of the foramen of Munro

Question 18

How are cases of hydrocephalus treated?

Answer 18

Surgically

Question 19

What is used as an emergency treatment for acute hydrocephalus?

Answer 19

External ventricular drain (EVD). A catheter through the scalp and skull into the lateral ventricle

Question 20

What shunts can be used in hydrocephalus?

Answer 20

Ventriculo-peritoneal
Lumbar-peritoneal
Ventriculo-atrial

Question 21

Why might a lumbar-peritoneal shunt be avoided?

Answer 21

Can cause overdrainage

Question 22

Why might a ventriculo-atrial shunt be considered?

Answer 22

If a ventriculo-peritoneal shunt fails

Question 23

What two methods can be used in NCH?

Answer 23

Removing the blockage

Third ventriculostomy

Question 24

What is done in a third ventriculostomy?

Answer 24

Surgically open a hole in the floor of the thrid ventricle to allow CSF to flow straight into the interpeduncular cistern and pre-pontine space, bypassing the aqueduct