Use of fMRI language lateralization for quantitative prediction of naming and verbal memory outcome in left temporal lobe epilepsy surgery

Partial removal of the anterior temporal lobe (ATL) is a highly effective surgical treatment for intractable epilepsy, yet roughly half of patients who undergo left ATL resection show decline in language or verbal memory function postoperatively. Preoperative fMRI has been shown in several studies to predict postoperative naming and verbal memory outcome in such patients. Most importantly, fMRI significantly improves the accuracy of prediction relative to other noninvasive measures used alone. Addition of language and memory lateralization data from the intracarotid amobarbital (Wada) test did not improve prediction accuracy in these studies. Thus, fMRI provides patients and practitioners with a safe, noninvasive, and well-validated tool for making better-informed decisions regarding elective surgery based on a quantitative assessment of cognitive risk.