Hydrocephalus and Management of VP shunts

Causes of hydrocephalus

Non-communicating:

• Congenital malformation (especially aqueduct stenosis), may be associated with spina bifida (Arnold Chiari malformation); vascular malformations.
• Neoplasm or tumour

Communicating:

• Infection: Secondary to meningitis, intrauterine infection.
• Post haemorrhagic: Premature infants with intraventricular haemorrhage, post subdural/subarachnoid haemorrhage.
• Dural venous sinus thrombosis

Signs and Symptoms

• Rapidly increasing head circumference. Measure at least weekly. Paediatric Surgical Ward provides "hydrocephalus passports" with percentiles for the measurements.
• Bulging fontanelle
• Widening suture lines (if not closed yet)
• Distended scalp veins
• Setting sun eye sign
• Signs of raised intracranial pressure (headache, vomiting, blurred vision, high BP, low PR, reduced conscious level)
• Developmental delay, ataxia

Investigation

• Cranial USS
• Consider lumbar puncture and/or ventricular tap if signs of infection/ raised intracranial pressure (ICP)

Management

• Treat infection if any (ventriculitis may require longer term parenteral treatment than meningitis)
• Therapeutic ventricular tap if signs acute raised ICP
• Surgical referral for ventriculo-peritoneal (VP) shunt or endoscopic third ventriculostomy (ETV)

Complications of VP shunts

Shunts can become infected or blocked and need to be treated urgently. Suspect in a child with VP shunt if any of the following:

• Vomiting
• Headache
• Reduced level of consciousness
• Ataxia
• Cranial nerve palsy
• Visual disturbance
• Fever

Investigations of possibly blocked shunts:

• Blood culture if febrile
• Xray shunt series.
• USS brain/ CT if possible
• Avoid LP as can result in coning if shunt blocked. Consider ventricular tap.

Treatment of blocked shunts:

• Start iv antibiotics as for meningitis
• Refer to surgeons for possible urgent shunt removal if blocked or infected and subsequent revision/replacement at a later date