Reliability and clinical usefulness of the short-forms of the Wechsler memory scale (revised) in patients with epilepsy

Purpose: The Wechsler Memory Scale-R (WMS-R) is often used for the evaluati on of patients with epilepsy, but is time consuming. Two shortened forms of the WMS-R have been published in an effort to reduce the time involved in the lest. The purpose of this study is to cross-validate these abbreviated forms in patients with epilepsy. Methods: We assessed 103 consecutive patie nts with drug-resistant partial epilepsy being treated in our epilepsy unit . The WMS-R was administered to all patients. The reliability of two shorte ned Versions of the WMS-R were evaluated. The appraisal was performed takin g into account the side of the epileptogenic region. The statistical analys es were carried out with the Pearson's correlation and with the intraclass correlation coefficient. Results: Both shortened formulas showed good relia bility coefficients for predicting the General Memory and Delayed Recall In dices. In the overall accuracy of the predictions by both short forms no si gnificant differences were found among the three study, groups (right, left or bilateral). However, when considering the predictive error only the thr ee-subtest formulas comprising logical memory. verbal paired associates and visual reproduction efficiently predicted performance, regardless of the s ide of the epileptogenic region. Of the predicted scores in the overall sam ple, 92 and 97% fell below the standard error of measurement for general an d delayed memory index, respectively. Both short forms correctly classified 89-94% of the performances at the average or impaired level. Conclusions: The short form of the M-MS-R using three subtests (logical memory, verbal p aired associates and visual reproduction) is reliable and time-efficient fo r estimating the General and Delayed Recall Memory indexes in patients with drug-resistant partial epilepsy. (C) 2000 Elsevier Science B.V. All rights reserved.