Use of preoperative functional MRI to predict verbal memory decline after temporal lobe epilepsy surgery.
OBJECTIVE
Verbal memory decline is a frequent complication of left anterior temporal lobectomy (L-ATL). The goal of this study was to determine whether preoperative language mapping using functional magnetic resonance imaging (fMRI) is useful for predicting which patients are likely to experience verbal memory decline after L-ATL.


METHODS
Sixty L-ATL patients underwent preoperative language mapping with fMRI, preoperative intracarotid amobarbital (Wada) testing for language and memory lateralization, and pre- and postoperative neuropsychological testing. Demographic, historical, neuropsychological, and imaging variables were examined for their ability to predict pre- to postoperative memory change.


RESULTS
Verbal memory decline occurred in over 30% of patients. Good preoperative performance, late age at onset of epilepsy, left dominance on fMRI, and left dominance on the Wada test were each predictive of memory decline. Preoperative performance and age at onset together accounted for roughly 50% of the variance in memory outcome (p < 0.001), and fMRI explained an additional 10% of this variance (p <or= 0.003). Neither Wada memory asymmetry nor Wada language asymmetry added additional predictive power beyond these noninvasive measures.


CONCLUSIONS
Preoperative fMRI is useful for identifying patients at high risk for verbal memory decline prior to L-ATL surgery. Lateralization of language is correlated with lateralization of verbal memory, whereas Wada memory testing is either insufficiently reliable or insufficiently material-specific to accurately localize verbal memory processes.
Binder
Jeffrey R
JR
Department of Neurology, Compreshensive Epilepsy Center, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA. jbinder@mcw.edu
Sabsevitz
David S
DS
Swanson
Sara J
SJ
Hammeke
Thomas A
TA
Raghavan
Manoj
M
Mueller
Wade M
WM
D000328:Adult; D038481:Anterior Temporal Lobectomy / Q000379:methods*; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis / Q000453:epidemiology*; D011939:Mental Recall; D009483:Neuropsychological Tests; D019635:Neurosurgical Procedures; D011237:Predictive Value of Tests; D011300:Preoperative Care; D012720:Severity of Illness Index; D014705:Verbal Behavior