Diagnostic Tests

In order to determine whether a shunt is right for you or your family member, your neurosurgeon will use one or more of a variety of possible diagnostic tests. They will also consider any other conditions present.

Diagnostic Procedures

There are several diagnostic tests that can help in diagnosing hydrocephalus. These same studies can also help evaluate the shunt in case of malfunction or infection.

Ultrasound

A sophisticated method of outlining structures within the head using high frequency sound waves, ultrasound can be used only in infants whose fontanels are open, since the skull otherwise blocks sound waves.

Computerised Tomography 

Computerised tomography (CT) scans use tiny beams of x-ray to outline the skull, brain, and ventricles. In addition to visualising the size and shape of the ventricles, abnormalities such as tumours, cysts, and other pathology can also be seen.

Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) is a non-invasive diagnostic tool that uses radio signals and a magnet to form computer images of the brain and the ventricles.

Cisternography

Cisternography is a test requiring injection of a small amount of radioactive material into the cerebrospinal fluid. Cisternography differentiates communicating from obstructive hydrocephalus, and determines cerebrospinal fluid flow.

Angiography

Angiography is a specialised technique in which “contrast material” is injected into the arteries supplying the brain. Abnormal blood vessel problems or pathological lesions can be detected with this technique.

Neuropsychological Tests

This series of questions and answers helps the healthcare team determine if hydrocephalus is causing a decrease in brain functioning.

Lumbar Infusion Test

With this specialised technique, fluid is injected into the lumbar area of the spine. This procedure is used for individuals with normal pressure hydrocephalus to determine their cerebrospinal fluid absorptive capacity.

External Lumbar Drainage

A technique used to externally drain cerebrospinal fluid. The test is used to determine if an individual with normal pressure hydrocephalus will improve if a shunt is implanted.

Next: Surgery: What to Expect

Surgery: What to Expect – Implanting a Ventriculoperitoneal (VP) Shunt

Your neurosurgeon will walk you through the surgical process for shunt implantation, which includes important steps before, during, and after the procedure.

During the Procedure

The neurosurgery team performs the surgery in sterile conditions in theatre under general anaesthesia. The operation usually takes less than an hour. It generally involves the following steps:

1. A small incision will be made in the scalp. A small hole will then be made in the skull.
2. A tiny opening will be made in the protective coverings of the brain. These openings accommodate the catheter placement in the lateral ventricle.
3. The neurosurgeon will make two or three small incisions to place the shunt valve (usually above or behind the ear).
4. The catheter will be tunneled under the skin.
5. The end of the catheter will be carefully placed in the appropriate receiving cavity (usually the abdomen).
6. Following the operation, small sterile bandages will be applied to each incision.

After the Procedure

Immediately after surgery, you will be taken to the recovery room. You will stay there for close observation for an hour or so and then be taken to their ward. Most patients leave the hospital within 2 to 7 days, depending on their progress.

Although this is the usual procedure when a shunt is placed, each individual may have a slightly different experience based upon their neurosurgeon, hospital, and their particular medical needs.

Next: Living With a Shunt