Risks of CSF Shunts
CSF shunt systems typically require monitoring and regular medical follow up. When there is reason to suspect that a CSF shunt system is not functioning properly (for example, if the symptoms of hydrocephalus return), medical attention should be sought immediately.
Some of the most common risks of CSF shunts include infection, shunt malfunction, and improper drainage.
Infection from a shunt may produce symptoms such as a low-grade fever, soreness of the neck or shoulder muscles, and redness or tenderness along the shunt tract.
Shunt malfunction is most commonly due to a blockage or some obstruction within the shunt system. If the blockage is not corrected, symptoms of hydrocephalus will return. In some cases, shunt blockage may require surgery to replace the affected component or components.
Overdrainage occurs when the shunt allows CSF to drain from the ventricles more quickly than it is produced. Overdraining can cause the ventricles to collapse, tearing blood vessels and causing headaches, hemorrhages (subdural hematomas), or a condition where the ventricles decrease in size until they are too small (slit ventricle syndrome). Symptoms of overdrainage often include headache and are similar to the symptoms of underdrainage (hydrocephalus).
Underdrainage occurs when CSF is not removed quickly, fluid builds up in the ventricles and the symptoms of hydrocephalus recur.
Overdrainage and underdrainage of CSF can be addressed by adjusting the drainage pressure of the shunt valve; if the shunt has a magnetically adjustable pressure valve, these changes can be made noninvasively.
Other problems that can occur with these devices are:
- Catheters harden (calcify) or break
- Catheters may disconnect from the valve and reservoir unit
- Valves may break or stick
- Fixed pressure valves may be set to the wrong pressure
- Catheters may be too short and need to be lengthened
MRI and CSF Shunts
Magnetic Resonance Imaging (MRI) is an important screening and diagnostic device that relies on powerful magnetic fields, which could potentially adjust a patient’s CSF valve. Patients with CSF shunts should inform their health care providers prior to receiving MRI due to the potential of the MRI magnetic field to change their implanted device.
Symptoms of hydrocephalus
Patients and caregivers should be aware of the symptoms of hydrocephalus because they are similar to symptoms of underdrainage of a CSF shunt system. Symptoms of hydrocephalus may be expressed differently in patients of different ages. In patients with CSF shunt systems, these symptoms can indicate problems with the shunt system that need to be evaluated by a physician.
Symptoms commonly found in infants and younger children:
- Distended scalp veins
- Downward gaze (sometimes called “sunset eyes”)
- Enlargement of the head
- Enlarged and bulging fontanel
- Feeds poorly/Decrease in appetite
- High-pitched cry
- Recurrent vomiting
Symptoms commonly found in older children, teens, and adults:
- Decrease in appetite
- Deteriorating mental capabilities
- Difficulty in walking
- Double vision
- Increased intracranial pressure
- Personality changes
- Hydrocephalus Association
- Pediatric Hydrocephalus Foundation
- NIH-NINDS Hydrocephalus Information Page