Neurology - Hydrocephalus

Question 1

What are the general causes of hydrocephalus?

Answer 1

Too much production of CSF

Insufficient drainage of CSF

Question 2

What are the congenital causes of hydrocephalus?

Answer 2

Aqueductal stenosis - most common
Cerebral aqueduct connecting third and fourth ventricle is stenosed, CSF build up in 3rd and 4th ventricle

• Arachnoid cysts - can block outflow of CSF
• Arnold-Chiari malformation - cerebellum herniates down through foramen magnum blocking CSF outflow
• Chromosomal abnormalities and congenital malformations obstructing CSF drainage

Question 3

Why do babies with hydrocephalus have an enlarged and rapidly increasing occipito-frontal circumference?

Answer 3

Cranial bones not fused at sutures until 2

Skull able to expand

Outward pressure on cranial bones

Question 4

How does hydrocephalus present?

Answer 4

• Enlarged occipito-frontal circumference
• Bulging anterior fontanelle
• Poor feeding and vomiting
• Poor tone
• Sleepiness

Question 5

How can hydrocephalus be treated?

Answer 5

Ventriculoperitoneal shunt

Drains CSF from ventricles into peritoneal cavity

Question 6

What are the complications of a ventriculoperitoneal shunt?

Answer 6

Infection
Blockage
Excessive drainage
Intraventricular haemorrhage (during surgery)
Outgrowing them (need replacing every 2 years as they grow)