The Wada test, also known as the “intracarotidsodiumamobarbital procedure” (ISAP), is used to establish cerebral language and memory representation of each hemisphere. Abarbiturate (which is usually sodium amobarbital) is introduced into one of the internal carotid arteries via an intra-arterial catheter. The drug is injected into one hemisphere at a time. The effect is to shut down any language and/or memory function in that hemisphere in order to evaluate the other hemisphere (“half of the brain”). Then a neuropsychologist will perform a series of memory and language related tests on that side of the brain. After a few minutes the medicine wears off, and that side of the brain wakes up. The procedure is then performed on the other side, and the neuropsychologic tests are repeated. An epileptologist interprets the test results.
