Neurology: Hydrocephalus

Question 1

What is hydrocephalus?

Answer 1

An accumulation of CSF in brain

Question 2

What are the 2 types?

Answer 2

Obstructive - non communicating

Communicating - problem with absorption of CSF

Question 3

What causes of non communicating hydrocephalus are there?

Answer 3

Congenital malformations:
Aqueduct stenosis
Atresia of the outflow foramina of the fourth ventricle
Chiari malformation

Posterior fossa neoplasm or vascular malformation
Intraventricular haemorrhage in preterm infants

Question 4

What communicating causes are there?

Answer 4

SAH

Meningitis

Question 5

In infants with hydrocephalus, why will the head circumference be disproportionally large?

Answer 5

Their skull sutures have not fused

Question 6

What clinical features are associated?

Answer 6

Enlarged head circumference 
Anterior fontanelle bulging 
Scalp veins prominent 
Sun setting of eyes - fixed downwards gaze (an advanced sign) 
Older children - signs of raised ICP

Question 7

How is it diagnosed?

Answer 7

Antenatal US screening

In preterm infants - routine cranial US scanning

Question 8

What is the initial assessment in suspected hydrocephalus?

Answer 8

Cranial US in infants or CT or MRI head scans

Question 9

How is it treated?

Answer 9

Insertion of a ventriculoperitoneal shunt

Question 10

Why can low pressure headaches occur with a shunt?

Answer 10

Over drainage of fluid - programmable valve insertion can help prevent this

Question 11

How can shunts malfunction?

Answer 11

Blockage or infection