Abstract

The Wechsler Memory Scale-Revised(WMS-R) is used routinely as a presurgical assessment of memory for patients considering elective resection of the temporal lobe and /or hippocampus for the relief of intractable temporal lobe epilepsy. This research investigated the psychometric properties of the WMS-R in a population of patients with intractable epilepsy. The sample consisted of 162 patients with a diagnosis of epilepsy who underwent a comprehensive neuropsychological examination as a routine part of their investigation. To identify the psychometric properties of WMS-R was conducted the factor analyses. At first, the factor analysis was conducted on the 8 immediate recall subtests to avoid the effect of the correlation between immediate and delayed recall trials of the same material. Second, the factor analysis was conducted on 8 immediate and 4 delayed subtests. Additional analyses included VIQ and PIQ from KWIS to examine the relation between memory and intelligence. And then the factor analysis conducted to 80 patients with a clear temporal lobe epilepsy to examine if the WMS-R lateralizes the visual memory and verbal memory. Initial analyses of immediate recall subtests indicated two-factor solution -general memory factor, attention/concentration factor- similar with previous results. Inclusion in the analysis of delayed recall subtests revealed three-factor solution with factors interpreted as cuedrecall and learning, attention/concentration, verbal memory. The result of factor analysis conducted to temporal lobe epilepsy supported the interpretation of three factors-visual memory, attention/concentration, verbal memory. However, the subtests consisting of visual memory factor are not pure measure of visual memory. Therefore, it is problematic to be interpreted as visual memory factor like previous research. It is concluded that the WMS-R provides a useful estimate of overall memory functioning, but is not effective to describe the nature of the pattern of memory deficits.