Benefits and Risks – Shunt Therapy Shunt for Hydrocephalus


Although there is currently no cure for hydrocephalus, a shunt, like those from Medtronic, can help relieve some of the symptoms of the condition.


A shunt redirects cerebrospinal fluid from the nervous system to another area of the body. This technique allows the brain’s enlarged ventricles to return to a more normal size in an effort to relieve the symptoms of hydrocephalus.

A shunt is designed to:

  • Regulate the amount, flow direction, and pressure of cerebrospinal fluid out of the brain’s ventricles
  • Provide an easy way for your healthcare team to get cerebrospinal fluid samples (with a valve reservoir)


Unlike most surgical procedures, in which the risks are highest during the operation itself, most of the common problems associated with shunting can and do occur at a later time.

The most common complications with shunting are obstruction, infection, and overdrainage of cerebrospinal fluid.

Magnetic interference

Traditional adjustable valves used to treat hydrocephalus or other cerebrospinal fluid (CSF) disorders contain a magnet that allows a neurosurgeon to change the performance level setting. 

Patients with traditional adjustable pressure valves need to take certain precautions when encountering MRI and magnet-containing consumer devices to avoid unintended changes to valve performance settings.*

Medtronic offers both traditional adjustable valves as well as valves with magnetic resistant walls that prevent the valve from moving out of the prescribed performance level. 

Learn more about why magnets matter and your options.

Shunt Obstruction

Obstruction is the most common complication of shunting. The blockage may occur at any point along the shunt, and will produce signs and symptoms of increased pressure in the head. These symptoms will vary depending upon the degree of obstruction and person’s age.

Symptoms of obstruction may include:

  • Periodic headache
  • Nausea and vomiting
  • Drowsiness, listlessness, and decreased mental function

Emergency hospitalization may be required if the person becomes confused and slow to react or comatose. A neurosurgeon will run tests to determine the nature of the obstruction. He or she may remove or replace the obstructed part of the shunt.


Infection is a risk of all surgical operations, especially when a foreign body like a shunt is implanted. If left untreated, infection can cause the wound to open up or cause systemic infection with chills and high fever.

Infection usually requires removal of the shunt. In some cases, the infection can be controlled with intensive antibiotic therapy without removing the shunt.

Symptoms of infection may include unusual redness or swelling of the wounds or along the length of the shunt.


Overdrainage generally happens when gravity drains too much fluid from the person’s ventricles while the individual is upright.

Symptoms of overdrainage may include:

  • A headache that gets worse when standing and improves when lying down
  • Nausea
  • Vomiting
  • Drowsiness
  • Changes in vision, particularly double vision
  • Declining performance in school

The strength of a magnet weakens significantly with distance, and most ordinary household magnets will not affect the setting of an adjustable valve.  


Information on this site should not be used as a substitute for talking with your doctor. Always talk with your doctor about diagnosis and treatment information.