Your doctor may ask you to have a Wada test if you are a candidate for epilepsy surgery. The Wada test checks to see which side of your brain is responsible for language and memory. Just before a Wada test, a cerebral angiogram is performed. A neuroradiologist places a catether into an artery in your leg and directs the catheter to the right or left carotid artery. Then the neuroradiologist injects a dye into the carotid artery and a special x-ray machine takes pictures of your brain’s blood vessels. Electroencephalogram (EEG) electrodes are placed on your scalp.
At the start of the Wada test, the neuroradiologist will inject sodium amytal into the catheter that is in the carotid artery. This drug will put half your brain to sleep. Then the neuropsychologist or neurologist will show you flashcards and ask you to name and remember objects or pictures. After a few minutes, the side that was asleep wakes up. You will be asked to recall what pictures or objects were shown. The same procedure is repeated on the other side.
The Wada test is an outpatient procedure and is performed in the hospital cath lab. Because of the angiogram, you will need to lay flat with your leg straight for a couple of hours.