Verbal and Visual Selective Reminding Procedures in Patients with Temporal Lobe Epilepsy

Purpose: The verbal and visual Selective Reminding Procedures (SRP) of Buschke (1974) were performed in patients with temporal lobe epilepsy (TLE) to examine their usefulness for determining the laterality of the seizure focus. Methods: The subjects were 59 (33 male and 26 female) patients with TLE. Their mean age at testing was 28.2 years (range, 15–55 years); their age at seizure onset was 11.3 years (range, 1–34 years); and their full-scale IQ with the WAIS-R was 79.3 (range, 52–119). The laterality of the seizure focus was determined by a preoperative workup and verified by the postoperative course for >1 year (seizure reduction to <10%). The focus was on the left side in 33 patients (group L) and on the right in 26 patients (group R). Demographic features were similar between groups L and R. All patients had left hemisphere language dominance as determined by the Wada test. Verbal SRP and visual SRP were performed preoperatively. The verbal SRP consisted of 12 unrelated nouns with three to four syllables, and the visual SRP consisted of 12 figures collected from the Rey Visual Learning Test. Performances on the verbal SRP and visual SRP were compared between groups L and R. Fisher's test, the Mann-Whitney U test, and an unpaired t test were used for statistical analyses. Results: Most patients of groups L and R immediately recalled five to seven stimuli on the first trial of both SRPs. On the verbal SRP, significantly more patients in group R (25 patients, 96%) recalled the 12 stimuli on two consecutive trials than those in group L (23 patients, 70%; p < 0.01), whereas the results for both groups on the visual SRP were similar (group L: 16 patients, 61%; group R: 20 patients, 62%). The number of trials before recalling the 12 stimuli without intervening reminding was similar in both groups (6.9 ± 2.24 trials in group L; 5.9 ± 2.31 in group R) on the verbal SRP, but group R needed significantly more trials (8.0 ± 2.28 trials) than group L (5.7 ± 1.89 trials) on the visual SRP (p < 0.01). On three consecutive trials, the 12 stimuli were recalled by 10 (30%) patients of group L and by 11 (42%) patients of group R on the verbal SRP, but on the visual SRP by 14 (42%) patients of Group L and by only four (15%) patients of group R (p < 0.05). The number of intrusion errors were 2.4 ± 3.60 in group L and 1.4 ± 3.80 in group R on the verbal SRP, but 16.2 ± 17.6 in group L and as much as 25.9 ± 15.8 in group R on the visual SRP (p < 0.05). Conclusions: Group L showed difficulty in storing verbal stimuli compared with group R. On the other hand, group R was more impaired in the effective storage and retrieval of visual stimuli than was group L. Verbal and visual SRPs may help to determine the laterality of the seizure focus in patients with TLE.