What to Expect During the Wada Test
The first part of the procedure requires that you have an angiogram. An angiogram looks at the arteries that supply the brain with blood. After you are positioned comfortably on the angiogram table:
- The groin area, where the catheter will be inserted, will be cleaned and injected with a numbing medication such as lidocaine (similar to medicine like novocaine that you get at the dentist office).
- The surgeon will make a small incision in the skin (no stitches will be needed) and insert a special needle into the vessel in the groin area. After the needle is inserted, the catheter is gently guided to its destination. Most patients do not feel the movement of the catheter through the blood vessel.
- Some contrast medium will be given through the catheter so that X-ray pictures of the blood vessels may be taken.
- When the contrast medium enters the bloodstream you may experience a feeling of heat, pressure and possibly some discomfort. Some patients report a metallic taste in their mouth that will be short-lived.
- After the X-ray pictures, the neurologist and neuropsychologist will enter the room and sodium amytal will be injected into the catheter. Sodium amytal is a short acting sedative that will put one half of the brain “to sleep” for 4-5 minutes while the other side continues to function as usual. This will allow the doctor and neuropsychologist to test each side of the brain for memory and language, separately.
What Happens When the Brain is “Asleep”?
- During the first several minutes, the neuropsychologist will ask you to follow some simple commands such as “squeeze my hand” or raise your arm. Additionally, you will be asked to identify some pictures, words, shapes and objects that are being shown to you.
- You will not be able to move one side of your body and may not be able to speak immediately after the injection of amytal. You may feel happy or elated or you may be fearful. Please know our team is here to support you through this procedure.
- The weakness and inability to speak will subside in several minutes and the amytal effects will wear off so that you feel back to normal in about 5-10 minutes.
- You will then be asked to remember the items you were shown previously. It is important for you to try to remember to the best of your ability what the objects, words and pictures were. If you are uncertain of the answers you may be asked to make your best guess.
- The surgeon will then move the catheter to test the other side of the brain. The same catheter is guided to the next area and the contrast medium will be injected again to check the blood vessels on that side.
- 30 minutes after the first injection, the second injection of amytal will be given. Again, you will be weak on one side of your body and may not be able to speak for several minutes. The neuropsychologist will again show you some pictures, words, shapes and objects. Ten minutes later you will be asked to remember what you were shown.
- After the testing is complete, the catheter will be removed and a pressure device will be placed over the area to prevent bleeding. You will be taken back to the recovery area prior to discharge.