The NAB shape learning subtest as a predictor of lateralized seizure onset

This study presents the first empirical evaluation of the predictive value of the Neuropsychological Assessment Battery Shape Learning (NAB-SL) subtest in a sample of patients with unilateral temporal lobe epilepsy. Stimulus characteristics of the NAB-SL may improve predictive ability over other commonly used visual memory tests. Forty-nine patients with unilateral temporal lobe epilepsy were compared on measures of non-verbal and verbal memory (NAB-SL and Wechsler Memory Scale-III subtests). Univariate and forward conditional logistic regressions identified predictive values for each memory test individually and in combination. The NAB-SL delayed memory demonstrated consistently stronger predictive power over visual reproduction at the univariate and multivariate levels. The NAB-SL was a good predictor (80% range) of lateralized seizure onset when combined with a verbal memory measure. These preliminary results provide support for the use of the NAB-SL in preoperative epilepsy evaluations as a predictor of non-dominant temporal lobe dysfunction. Potential benefits of this test are discussed.

► A new test of visual memory (NAB-SL) was used as a predictor of seizure onset side. ► The NAB-SL and WMS-III subtests were compared. ► The NAB-SL was the best univariate predictor and had the highest AUC value. ► The NAB-SL and a verbal memory test had predictive values in the 80% range. ► Results indicate the NAB-SL may be a useful test to predict side of seizure onset.