title: Grammar tests increase the ability to lateralize language function in the Wada test.
abstract: BACKGROUND
  Grammar is a core component of the language system, yet it is rarely assessed during the Wada (intracarotid amobarbital) test. It is hypothesized that adding grammar tests to the recovery phase of the Wada test will increase our ability to lateralize language function.
  
  
  METHODS
  Sixteen individuals (nine females, fifteen right-handed, mean age 38.4 years, SD=10.7) with medically refractory temporal lobe epilepsy participated in the study. On EEG ten patients had seizures originating in the left hemisphere (LH), five in the right hemisphere (RH), and one was insufficiently lateralized. We included only patients who were LH-dominant on the standard test in the encoding phase of the Wada test. In the recovery phase of Wada testing the participants underwent evaluation with a standard language and a new test of grammar, the CYCLE-N. Ten patients underwent bilateral injections, six unilateral (one RH, five LH).
  
  
  RESULTS
  As expected, injection in the LH decreased language performance to a greater extent than injection to the RH on both tests. However, the CYCLE-N produced more profound language deficits in the injected LH compared to the RH (p=0.01), whereas the standard tests did not cause such pronounced differences (p=0.2).
  
  
  CONCLUSIONS
  The results suggest that the standard tests did not significantly differentiate the effects of the injections and the CYCLE-N, for the most part, did. Our results are of particular relevance to patients who are too obtunded to speak in the encoding phase. In sum, the CYCLE-N may be helpful in assessing hemispheric dominance for language.
authors.affiliation: UCLA Department of Psychiatry and Biobehavioral Sciences, Los Angeles, CA, USA; Faculty of English, Adam Mickiewicz University, Poznań, Poland. Electronic address: plmonik@wa.amu.edu.pl.
authors.forename: Monika
authors.initials: M
authors.lastname: Połczyńska
authors.affiliation: UCLA Department of Linguistics, Los Angeles, CA, USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Curtiss
authors.affiliation: UCLA Department of Psychiatry and Biobehavioral Sciences, Los Angeles, CA, USA.
authors.forename: Particia
authors.initials: P
authors.lastname: Walshaw
authors.affiliation: UCLA Department of Psychiatry and Biobehavioral Sciences, Los Angeles, CA, USA.
authors.forename: Prabha
authors.initials: P
authors.lastname: Siddarth
authors.affiliation: UCLA Department of Psychiatry and Biobehavioral Sciences, Los Angeles, CA, USA.
authors.forename: Chris
authors.initials: C
authors.lastname: Benjamin
authors.affiliation: University of Cincinnati Department of Neurology, Cincinnati, OH, USA.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Moseley
authors.affiliation: UCLA Department of Psychiatry and Biobehavioral Sciences, Los Angeles, CA, USA.
authors.forename: Celia
authors.initials: C
authors.lastname: Vigil
authors.affiliation: UCLA Department of Psychiatry and Biobehavioral Sciences, Los Angeles, CA, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Jones
authors.affiliation: UCLA Department of Neurology, Los Angeles, CA, USA.
authors.forename: Dawn
authors.initials: D
authors.lastname: Eliashiv
authors.affiliation: UCLA Department of Psychiatry and Biobehavioral Sciences, Los Angeles, CA, USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Bookheimer
mesh_terms: D000328:Adult; D000654:Amobarbital; D001921:Brain / Q000187:drug effects / Q000503:physiopathology*; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis* / Q000503:physiopathology*; D005260:Female; D007839:Functional Laterality; D018757:GABA Modulators; D006801:Humans; D007802:Language; D007807:Language Tests; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D018757:GABA Modulators; D000654:Amobarbital
keywords: Epilepsy; Grammar; Intracarotid amobarbital procedure; Language; Wada test