Brief Communication The intracarotid etomidate Wada test: A 54-patient series Valmir Passarelli ⁎, Lecio F. Pinto, Carmen L. Jorge, Paulo Puglia, Carla C. Adda, Hung-Tzu Wen, Luiz H. Castro Department of Neurology, Hospital das Clinicas, Universidade de São Paulo, Sao Paulo, Brazil abstract article info Article history: Received 3 June 2014 Revised 12 August 2014 Accepted 13 August 2014 Available online xxxx Keywords: Wada test Etomidate Epilepsy surgery Hemispheric language dominance and isolated hemispheric memory function evaluation can be undertaken with the intracarotid injection of a general anesthetic agent (Wada test). Amobarbital has been traditionally used as the anesthetic agent, but legal and commercial constraints limit its use. We evaluated the use of etomidate as an alternative agent for the Wada test in a series of 54 consecutive adult patients with mesial tem- poral sclerosis undergoing presurgical evaluation for epilepsy surgery. Language lateralization and hemispheric memory function evaluation were successfully achieved in all cases. Side effects (somnolence, tremor, and dys- tonia) were infrequent, minor, and transient and did not require interruption of the procedure. Etomidate ap- pears to be a safe and effective alternative agent to amobarbital in the Wada test. Similarly to the amobarbital Wada test, the ability of the etomidate Wada test to predict postoperative memory decline remains unclear. © 2014 Elsevier Inc. All rights reserved. 1. Introduction In 1949, Juhn Wada described the use of intracarotid amobarbital in- jection to assess language laterality in candidates for epilepsy surgery [1]. Indications for the Wada test were later expanded to include evalu- ation of hemispheric memory function in candidates for temporal lobe resection and epileptogenic zone lateralization. Improved neuroimag- ing methods, widespread use of video-EEG monitoring, and, more re- cently, use of functional MRI resulted in more restricted indications for the procedure [2,3]. The Wada test remains useful to determine memory reserve in se- lected candidates for temporal lobectomy and to evaluate language laterality when fMRI is inconclusive, not available, or not achievable [4]. Sodium amobarbital is the standard drug for the Wada test because of its short action and low toxicity as well as clinicians' extensive expe- rience with its effects. However, amobarbital availability has been a problem, with frequent shortages worldwide and legal restrictions to amobarbital use in some countries. Uncertainty about amobarbital availability has led to the evaluation of alternative anesthetic agents, such as methohexital, pentobarbital, propofol, and etomidate [5]. Etomidate is an extremely safe short-acting intravenous anesthetic agent used for general anesthesia induction and for sedation in short procedures [6,7]. We report our experience with etomidate use in the Wada test in a consecutive case series of adult patients with temporal lobe epilepsy associated with mesial temporal sclerosis who were being evaluated for epilepsy surgery. 2. Patients and methods 2.1. Patients Fifty-four adult patients with medically refractory temporal lobe ep- ilepsy (TLE) secondary to unilateral mesial temporal sclerosis (MTS) underwent the intracarotid etomidate Wada test as part of a presurgical evaluation protocol. Two patients underwent repeat tests, totaling 56 procedures. All patients signed an informed consent form prior to the procedure. 2.2. Study design This was a prospective case series from a large tertiary epilepsy cen- ter in Sao Paulo, Brazil as part of a larger project that is evaluating pre- and postoperative neuroimaging and cognitive aspects of temporal lobe epilepsy (Cinapce Project). 2.3. Procedure 2.3.1. Anesthetic agent Etomidate was used in all cases. 2.3.2. Baseline evaluation Language and strength were assessed before anesthetic injection. The procedure was explained, and questions were answered. Epilepsy & Behavior 39 (2014) 73–77 ⁎ Corresponding author at: Rua Oscar Freire, 1380 apto: 51, CEP: 05409-010, Brazil. Tel.: +55 11 9633 8439 (cell number). E-mail address: valmirpas@ig.com.br (V. Passarelli). http://dx.doi.org/10.1016/j.yebeh.2014.08.028 1525-5050/© 2014 Elsevier Inc. All rights reserved. Contents lists available at ScienceDirect Epilepsy & Behavior journal homepage: www.elsevier.com/locate/yebeh