Let's simply learn about the Wada Test performed before brain surgery (Wada Test)

Imagine that your doctor has recommended surgery for you or someone you know, whether it's for a condition like epilepsy or a brain tumor. Then, one of your biggest fears is, 'Will I not be able to talk after the surgery? Will I lose my memory?' There is a special test that helps doctors find answers to such important questions and perform the surgery safely. That's what we call the Wada Test.

What exactly does the Wada Test look for?

Simply put, with this test, doctors are looking for answers to two main questions.

• The ability to speak, that is, whether the left or right side of your brain controls linguistic functions.
• How important each side of the brain is to your memory.

With this information, your neurosurgeon can assess in advance how your speech and memory may be affected after surgery, and plan the surgery accordingly.

This test was first performed in 1949 by a doctor named Dr. Juhn Wada. That is why it got its name. It is also called `(Intracarotid amobarbital test)`.

Which side of the brain controls language and memory?

Most of us usually have speech control on the left side of our brain. But this is not common to everyone. This can vary, especially for left-handed people. That's why it's important to confirm this accurately by taking the Wada test.

When it comes to memory, it can be controlled by both sides of the brain. Typically, in people who are left-brain dominant, verbal memory is controlled by the left side, and visual memory, which is the ability to remember images, is controlled by the right side. The Wada test can help your doctor determine which side of the brain is better at memory.

Who can do this test?

This test can be done by adults as well as children. However, if it is a young child, they must be old enough and mentally mature enough to understand the instructions given during the test, speak, and cooperate. Imagine, even if you show a card to a small baby, he or she will not be able to understand it. Therefore, only children above a certain age can successfully do this.

Who performs the Wada Test?

This is not a test performed by a single person. It is performed by a team of specialist doctors.

How do you prepare before the test?

Your doctor may ask you to stop taking certain medications about two weeks before the test, such as aspirin, NSAIDs, and blood thinners.

What happens on the day of the test?

You will be fully conscious during this test. The entire test can take about three to four hours.

Before the test begins

First, you will be given a hospital gown to wear. Then, the hair in your groin area will be removed to allow access to the blood vessels needed for the test. Next, several electrodes will be attached to your scalp for an ``EEG - electroencephalogram`` test to measure your brain activity.

Then, doctors numb your groin area. Through it, a thin tube (catheter) is inserted into a blood vessel in your leg and guided to the main artery in your neck (carotid artery). During this time, you may feel a metallic taste and a warm sensation. It is not painful.

How to do the Wada Test

Now the main part of the investigation begins.

1. Temporary sleep paralysis of one side of the brain: Through a thin tube called a ``catheter'', an anesthetic is injected into a blood vessel that runs to one side of your brain. Imagine that the drug is given to the right side. Then the right side of the brain temporarily goes to sleep. At the same time, the left side of your body becomes numb. You may feel like you are seeing stars in front of your eyes, feel pressure behind your eyes, and feel a warmth in your face. These are normal things.

2. Memory and speech testing: While you are sleeping on one side of your brain, the neuropsychologist will show you cards with words and pictures. They will also test your ability to speak. You will be asked to remember these things. During this time, you may have difficulty speaking and may feel slurred speech. This is normal.

3. Brain reawakening: The effects of the anesthetic wear off within a few minutes. Then the side of the brain that was asleep wakes up again. Then you are asked what was on the cards that were shown to you. You may not remember them. That's okay.

4. Testing the other side: After a while, the tube is directed to the other side's carotid artery, that side is also anesthetized in the same way, and the test is repeated with a new set of cards.

What happens after the test?

After the test is over, you will be taken to a recovery room. There, the medical staff will regularly check your leg, where the tube was inserted, to see if there is a pulse, and if the bandage is in place. You will be able to go home the same day. However, you will be advised to avoid strenuous activities for a day or two.

Is this a dangerous test? Are there any risks?

The Wada Test is a very safe, low-risk test. The most common side effect is mild pain once the numbness wears off at the site of insertion. However, there are some very rare complications that can occur.

What do the test results say?

By combining the data from this test, your medical team will determine which side of your brain is primarily responsible for your speech and memory.

This information is compared with other test results, such as where the seizures are located in your brain. By combining all this information, your surgeon can plan the surgery to minimize the risk of damage to your speech and memory.

Epilepsy can be a scary disease. And the thought of brain surgery can be even more frightening. But fortunately, your doctors have the knowledge and tools to help prevent these complications. The Wada Test is one such important tool. If you have any questions about this test, don't hesitate to talk to your doctor.

Wada Test, brain surgery, epilepsy, memory and speech