Predictors of postoperative memory function after left anterior temporal lobectomy

Patients who undergo left anterior temporal lobectomy (ATL) for intractable epilepsy are at risk of postoperative memory decline. This study attempts to identify the best predictors of memory after ATL using preoperative tests. Thirty-two consecutive patients who underwent left ATL with preoperative and postoperative neuropsychological testing were retrospectively identified. The following independent variables were analyzed by multiple regression: age of onset of seizures, age of temporal lobe damage, gender, MRI results, preoperative memory testing, and intracarotid amytal procedure (IAP) results. Neuropsychological measures of verbal and nonverbal memory served as dependent variables. Male gender (P<0.005), failing the IAP with both left and right hemispheres (P<0.001), and higher logical memory (LM) scores preoperatively (P<0.001) were associated with greater declines in LM after surgery. Our data demonstrate that the IAP predicts postoperative memory independent of other factors known to affect memory after left ATL.