Hydrocephalus and VP Shunts

In hydrocephalus excess cerebrospinal fluid (CSF) accumulates in and around the brain and spinal cord causing potentially harmful pressure on those tissues. This results from an imbalance between production and absorption of CSF, usually through an obstruction in the typical pattern of flow, sometimes due to decreased absorption, and very rarely due to increased production. Hydrocephalus may be congenital or acquired. Causes of hydrocephalus include:
  • damage to the developing brain (e.g., associated with spina bifida and Dandy-Walker malformation);
  • genetic defects (e.g., aqueductal stenosis); and
  • injury (e.g., accumulation of blood clots after intraventricular hemorrhage).
Hydrocephalus ex vacuo results from injury, often to the blood vessels supplying the brain resulting in poor brain growth and/or atrophy of the brain. The CSF then increases in volume to fill the empty space. Hydrocephalus may be a primary cause of CP and/or developmental delay or an associated condition. Many causes of CP may result in hydrocephalus, including intrauterine infection, intracranial bleed, and brain malformations.
Hydrocephalus may affect up to 1 in 500 children. See Hydrocephalus information from the NIH.
Signs and Symptoms
Initial signs of hydrocephalus in infants, which may be subtle, include sleepiness, irritability, vomiting, sunsetting eyes, a bulging or full fontanelle, splayed sutures, and seizures, as well as a large and/or rapidly increasing head circumference. In children whose skull bones have already fused, nausea, headache, sunsetting eyes, balance problems, irritability, seizures, and visual disturbances, such as diplopia and blurred vision, may develop. Hydrocephalus that is slowly developing may cause more subtle changes, and may be more difficult to recognize as changes occur slowly, such as a plateau or regression in developmental milestones, new learning problems, such as memory loss and difficulty concentrating, and personality changes. Hydrocephalus that is slowly developing may cause more subtle changes, such as a plateau or regression in developmental milestones, new learning problems, such as memory loss and difficulty concentrating, and personality changes. In a child with CP, these complaints should lead to imaging for possible hydrocephalus.
If hydrocephalus is present, the child will require either a shunt placed by a neurosurgeon or in some cases, a third ventriculostomy with choroid plexus cauterization (ETV+CPC). A third ventriculostomy is a procedure in which a small hole is made in the floor of the third ventricle to allow the CSF to escape the ventricular system to the space surrounding the brain, thus bypassing the obstruction. The choroid plexus is the structure within the ventricles which make 80% of our cerebro-spinal fluid (CSF). Coagulation of the choroid plexus is done through a single burrhole in the skull from which the neurosurgeon can coagulate both sides of the brain. The decision on which operation to do will ultimately be made at the time the surgery is being performed, although a pre-surgery MRI is helpful in making the decision of which surgery to do as well. The decision on timing of the first shunt placement or ETV+CPC must balance the risks of surgery and related complications with potential brain damage from hydrocephalus. Nobody knows if a child with small ventricles and a shunt will do better than a child with stable, large ventricles. The most typical arrangement for a shunt is a ventriculo-peritoneal shunt.
If a VP shunt is inserted, risks of the shunt include shunt malfunction, obstruction, or overdrainage, abdominal complications, and infection. Infection is more common in the first few months after shunt placement and is most often due to Staphylococcus species. Families and providers for children with VP shunts should be alert to the primary signs of shunt obstruction and infection, including headaches, vomiting, and drowsiness. Slowly progressing shunt malfunctions may present with progressively worsening headaches, loss of developmental milestones, falling asleep in school, personality changes, and new learning problems. These signs should prompt evaluation by the neurosurgeon or local emergency room. X-rays of the shunt (commonly called a "shunt series") and a CT scan or FAST MRI of the head may be indicated, along with, if infection is a concern, a shunt tap to examine the CSF.
Risks of an ETV+CPC include procedure abandonment due to hemorrhage or dangerous anatomy, meningitis, seizures, CSF leak, or, rarely, major arterial injury. Signs and symptoms of ETV+CPC failure are identical to those of shunt failure described above. Although a shunt series is not necessary, repeat CT or MRI of the brain is required to assess for failure and whether a repeat ETV or a shunt is required.
The prognosis for hydrocephalus is related to its underlying causes and associated conditions. Many children with hydrocephalus will benefit from early intervention, rehabilitation, and educational interventions.


Information & Support

For Professionals

Hydrocephalus information from the NIH
Hydrocephalus related information from the NIH.

Hydrocephalus (MedlinePlus)
Hydrocephalus information with links to other sites in English and Spanish; from the National Library of Medicine

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Authors & Reviewers

Initial publication: October 2009; last update/revision: September 2013
Current Authors and Reviewers:
Authors: Lynne M. Kerr, MD, PhD
Jay Riva-Cambrin, MD