There are relatively few innovations in neurological surgery that equal the impact and durability of the Wada test. First described in 1960 by Wada and Rasmussen in the following historical Journal of Neurosurgery article, the method continues to be used today, virtually unaltered, almost one-half century later.
Unilateral intracarotid sodium amobarbital (Amytal) or sodium methohexital (Brevital) injection remains the diagnostic mainstay for localization of the language-dominant hemisphere. Speech arrest concurrent with contralateral transient hemiparesis is a clear end point and, ultimately, the most useful finding of the test. Localization of the language-dominant hemisphere has obvious and strong implications