Language assessment in Wada test: comparison of methohexital and amobarbital.
BACKGROUND
Methohexital has replaced amobarbital during Wada testing at many centers. The objective of our study was to compare the use of methohexital and amobarbital during Wada testing regarding language and memory lateralization quotients as well as speech arrest times.


METHODS
A chart review of 582 consecutive patients undergoing 1041 Wada-procedures was performed (left=60, right=63, bilateral=459). Language lateralization was calculated based on duration of speech arrest using a laterality index, defined as (L-R)/(L+R). Memory lateralization was expressed as percentage of retained objects and laterality quotient.


RESULTS
Language and memory lateralization revealed a similar distribution with amobarbital and methohexital. Speech arrest after left and right-sided injection was significantly longer in the amobarbital group as compared to the methohexital group. Language lateralization did not differ in the two groups. Percentage of retained memory items was higher in the methohexital group and there were fewer presented test items in the methohexital group.


CONCLUSIONS
Language and memory testing during the Wada test can successfully be performed with methohexital instead of amobarbital. The shorter half-life of methohexital allows repeated injections and shorter interhemispheric testing intervals, but also shortens the testing window.
Neurological Institute, Cleveland Clinic, Cleveland, OH, United States. tobias.loddenkemper@childrens.harvard.edu
Tobias
T
Loddenkemper
Gabriel
G
Möddel
Dudley S
DS
Dinner
Hyunmi
H
Kim
Stephan U
SU
Schuele
Andreas V
AV
Alexopoulos
Prakash
P
Kotagal
Hans O
HO
Lüders
D000293:Adolescent; D000328:Adult; D000368:Aged; D000654:Amobarbital / Q000494:pharmacology*; D018686:Anesthetics, Intravenous / Q000494:pharmacology*; D001921:Brain / Q000187:drug effects*; D002648:Child; D007839:Functional Laterality / Q000187:drug effects; D006801:Humans; D006993:Hypnotics and Sedatives / Q000494:pharmacology*; D007802:Language; D007807:Language Tests; D008568:Memory / Q000187:drug effects; D008723:Methohexital / Q000494:pharmacology*; D008875:Middle Aged; D055815:Young Adult
D018686:Anesthetics, Intravenous; D006993:Hypnotics and Sedatives; D008723:Methohexital; D000654:Amobarbital