Neurology & Pain Management Coding Alert

Question: What CPT code do I use for EEG performed in Wada testing? What is a Wada test?

Florida Subscriber

Answer: The CPT code for this is:

• 95958 -- Wada activation test for hemispheric function, including electroencephalographic (EEG) monitoring.

The Wada test is one of several neuropsychological tests to determine focal cognitive dysfunction; for example, language and memory functions. Basically, these tests will determine which part of the brain controls which functions. This test is particularly important when surgery is being contemplated to treat seizures and epileptic conditions as the test will help determine how much brain tissue can be removed safely.

During the Wada test, one side of the brain is put to sleep by injecting sodium amobarbital, an anesthetic medication into the right or left carotid artery. Hence, it is also called the intracarotid amobarbital procedure (ISAP). If the right carotid is injected,the right side of the brain goes to sleep and cannot communicate with the left side. In order to confirm that the injected side of the brain is asleep, EEG (brain wave) recordings are done at the same time with a neurological examination. The neurologist then will evaluate the patient's ability to speak and will also show the patient individual cards of pictures and words. The "awake" side of the brain tries to recognize and remember what it sees.

After just a few minutes, the anesthetic wears off and the half of the brain that was asleep starts to wake up. Once both sides of the brain are fully awake, the neurologist asks the patient what he was shown. If the  patient doesn't remember what he saw, items are shown one at a time, and the patient is asked whether he saw each one before. After a brief recovery time, the Wada test will be repeated on the contralateral side of the brain.