Abstracts

Drawing from memory (DfM) may implicate a number of cognitive processes and brain areas. This study evaluated temporal (TLE) and frontal lobe epilepsy (FLE) patients and healthy subjects aiming to assess DfM in patients with different sites of cortical dysfunction and to explore the relation of DfM to semantic, perceptual, and praxis abilities., Sixty-six patients with left or right TLE were compared with 30 patients with left or right FLE and 30 healthy subjects. The DfM test required the production of drawings of eight living and eight non-living items; the total score was the sum of all correct drawings. The verbal and visual Pyramid and Palm trees tests (PPTT), Raven[apos]s Coloured Progressive Matrices (RCPM), and Rey Complex Figure copying (RCFC) assessed semantic memory, visuospatial reasoning, and constructive praxis. Non-parametric Kruskall-Wallis one-way ANOVA and Mann-Whitney tests were used to compare patient and controls, with significance level of p[underline][lt][/underline] 0.01., Between-group comparisons showed significant differences in DfM, RCPM, and RCFC; difference in PPTT approached significance (p=0.03).
Post-hoc tests indicated that both TLE groups and left FLE patients were impaired in DfM compared to controls. In addition, right TLE patients were impaired in RCPM, RCFC, and visual PPTT; left TLE patients were impaired in RCPM, RCFC and at both versions of the PPTT; left FLE patients were impaired in RCPM, RCFC, and verbal PPTT; and right FLE patients were only impaired in RCFC.
Correlation and regression analyses showed different patterns in the four epilepsy groups. In the right TLE patients, the DfM scores were significantly associated with visual PPTT scores; in the left TLE patients with verbal PPTT scores; in the left FLE patients with RCFC scores; and in all patient groups with RCPM scores., The present findings indicate that DfM is impaired in both right and left TLE and left FLE. The results of correlation and regression analyses suggest that different cognitive mechanisms may be responsible for such impairment in each group. The relation between DfM and PPTT in TLE patients supports the view that impaired performance may reflect altered semantic memory, while the relation of DfM with RCFC in left FLE patients indicates a role for constructive skills. On the other hand, the association of DfM with RCPM in all patient groups is compatible with a main role of visuospatial abilities. The present findings indicate that DfM implies an interaction of both hemispheres supporting different visual and verbal cognitive abilities. Thus, focal cortical dysfunction in the temporal and frontal lobes, as determined by epilepsy, may cause impairment in DfM depending on the involvement of different cognitive mechanisms.,